View Full Version : Longfellow – a Viking / LodeRunner hybrid

07-13-2013, 01:05 AM
Originally I planned to build a Viking tandem and skin it as a velomobile. I began collecting parts, then Brad started his velomobile (http://forum.atomiczombie.com/showthread.php/7227-Atomic-Zombie-s-velomobile). Cargo space was a priority for him, and the more I thought about this the more important it seemed.

So I considered the LodeRunner tandem. The higher seating would need a very tall velomobile shell, but the Viking centre section would fit between the LodeRunner ends and also lower the centre of gravity. This idea became the “LodeRunner Sport”.

Just before construction started (June 2013), a winter storm encounter in my current velomobile caused me to reconsider cross-wind stability – especially for a tandem-length velomobile. The obvious answer is two front wheels – effectively the Viking front end but with limited lateral pivoting to keep four wheels on the ground on uneven surfaces.

Eliminating the single wheel out the front also shortens the machine by about 60cm – so it will be “only” four metres long. The frame weight remains about the same (add front axle cross member but eliminate forks and front tube) and the weight of the extra wheel will be offset by the shorter body shell.

Overall the design becomes about a 50/50 split between the AZ plans: LodeRunner rear end and drivetrain grafted onto Viking centre section and front end. It could be a “LodeRunner Sport” or a “Viking Cargo” … but it really needed a name all of its own. Ticktock suggested “Longfellow” (i.e. long velo) which sounds good to me – thank you TT.

07-13-2013, 01:06 AM
With two rear wheels I can use a narrower front track than the standard Viking for a sleeker shape. I will use the same track as the AZ Warrior - leaving room for legs between the front wheels, even when fully turned.

I will keep the standard LodeRunner rear track - about 10cm narrower. Then the shell can taper front-to-rear (better aerodynamics), and also enclose the rear wheels with no openings.

I don’t know yet if the front wheels can also be enclosed, or will need to be open for steering. I’ll determine the required steering lock during open-bike testing before shell construction starts, then consider how wide the shell would need to be to enclose the front wheels.

07-13-2013, 01:07 AM
The frame steel available from the local supplier has a 2mm wall (about 14 gauge). It’s fractionally thicker than the 16 gauge specified in the AZ plans, but less than 800 grams extra weight. This shouldn’t be noticeable in an aerodynamic tandem and the extra thickness will help with load capacity.

I can’t use power tools in the evenings because of workshop proximity to the neighbours and our sleeping princess. Welding outdoors will also need to wait for daylight at the weekend (it’s mid-winter here).

Over the first week of evenings I used a hacksaw to cut the rear deck frame, main boom and front axle cross member. The cross member uses the same larger size steel as the main boom rather than 1½ inch as shown in the plans – I don’t want to buy a whole length of 1½ inch just for this part. As a quad this bike needs lateral axle articulation between the cross member and the main boom … the extra depth will allow the pivot to be partially recessed into the cross member and still leave more metal uncut (pictures later).

The ends of the cross member are too wide to simply fish-mouth onto the steering heads. To taper them I cut out narrow wedges then pressed the gaps closed, welded them and filed the joints smooth:

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Cross_member_ends_zpsefca0a65.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Cross_member_ends_zpsefca0a65.jpg.html)

If you use this method, it’s best to cut, bend and weld one side at a time … so the uncut side holds everything in alignment.

07-13-2013, 01:08 AM
Saturday morning. It’s due to rain this afternoon but there’s time for welding before the bad weather arrives. Here are all the bits laid out … this bike is going to be huge – around 4 metres.

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Parts_laid_out_zpsc7e7d153.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Parts_laid_out_zpsc7e7d153.jpg.html)

We got the two booms welded together, and the frame for the load deck partly welded … then the rain set in. So here’s sum total of the progress for the day:

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Booms_and_load_deck_zps2e4b96b9.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Booms_and_load_deck_zps2e4b96b9.jpg.html)

Work will continue when weather and other commitments permit...

07-13-2013, 07:11 AM
Sounds like something I plan to start building.
Couple questions, you mention crossmember. I assume your refering to the front arms (warrior front arms?) Then you showed a pic of fish-mouthing the ends. I'm los
Then you mention limited lateral pivoting. Where is this pivoting going to take place and how?The Viking plans show no pivot point??
The rear frame section, you show the frame assembled with short sections of tubing on top of the frame. Is this for mounting the pillow blocks?
Last night I got to wondering if valve springs from a car engine would be useful to add some suspension to a pillow block?

07-13-2013, 08:22 AM
Sounds like something I plan to start building.

Couple questions, you mention crossmember. I assume you're referring to the front arms (Warrior front arms?) Then you showed a pic of fish-mouthing the ends. I'm lost.

Then you mention limited lateral pivoting. Where is this pivoting going to take place and how? The Viking plans show no pivot point?

The rear frame section, you show the frame assembled with short sections of tubing on top of the frame. Is this for mounting the pillow blocks?

Last night I got to wondering if valve springs from a car engine would be useful to add some suspension to a pillow block?

Yes - cross member is the lateral arm unit that the front wheels attach to. Because this is a quad, there needs to be articulation between the front and rear axles so all four wheels stay on the ground even when the ground isn't even. The original Viking is a trike so it doesn't need articulation because three wheels will always touch the ground anyway.

I will articulate by adding a bottom bracket lying longitudinally along the centre line of the bike. The shell of the BB will be fishmouthed into the cross member, and the axle will attach to brackets which are attached to the main longitudinal boom. It's important that this pivot can handle substantial weight and can be adjusted to remove any free-play - hence using a bottom bracket. There will also be rubber compression blocks to limit articulation to around three inches either way at the wheel. That will allow the frame to cope with ground variations of up to six inches (because when one front wheel goes up by three inches then the other one goes down by the same amount).

Other question - the short sections of tubing are mounts for the pillow block bearings - the frame is upside down in the photo. The rear load deck can be lower than on the original LodeRunner and still have enough clearance for 160mm disc brakes. I am minimising the height to fit into a velomobile shell.

Your idea about using valve springs for suspension could work, but I'm not sure if the pillow blocks would slide up and down freely on the threaded bolts - or if a cast iron housing will cope well when not supported along its entire face. The bearing casting might need to be bolted to another piece of steel which is spring-mounted to the main chassis.

07-13-2013, 08:58 AM
Hi Petone,
Re bouncing pillow blocks--they would not like sliding around a bolt for the rest of their lives! But the valve spring concept is a good one, and is used here in China (they look like valve springs, so they must be valve springs, except in China !) But they do not slide on anything . I will have to have a closer look, as I don't know how they do this. I suspect their way would be a bit rough for what we want, but the springs are a good idea.
Tell you more when I've had a look!
Steve g

07-13-2013, 09:14 AM
The limited lateral pivoting idea sounds good but perhaps a drawing of your concept?
I though about the cast iron not liking the sliping n sliding so perhaps a plate of steel to mount the pillow block and sleves to allow the pillow block assembly to slide without too much side-way play

07-13-2013, 09:17 AM
Guys realize that a valve spring is not linear in movement. A bicycle spring and shock is linear. The movement has to be linear to keep the chain aligned to the drive sprockets. Also the Shock prevent the movement from exceeding the chain stretch. So I would say no to the Valve spring idea unless you can capture it in to a linear movement that would keep the sprocket and chain aligned.

This is a very neat project and considering the Dutchman build I am assuming the Cargo is Princess Bee with escorts Mom and Dad. Or is Pricess Bee growing so fast that she wants to pedal already?

07-13-2013, 10:10 AM
Easier to deign real suspension, or just keep it simple. I have three bents here, (two trikes, one LWB) all no suspension, and I would consider it a luxury, not a necessity, even in Beijing .
If you cant do it properly, keep it simple. I'm glad I did not try for suspension of on my first build, and perhaps the fact that all three bikes have been re built at some time should shown that I do not considerate important--even after posting designs for a suspension rear end.
There has to be a point at which you stop adding complications , on bikes and on clocks!
Steve G

Radical Brad
07-13-2013, 10:31 AM
This build is coming along nicely, and will certainly result in an interesting vehicle.
Keep 'em coming!


07-13-2013, 04:15 PM
This is a very neat project and considering the Dutchman build I am assuming the Cargo is Princess Bee with escorts Mom and Dad. Or is Princess Bee growing so fast that she wants to pedal already?

Princess Bee is now four and a half. She still fits in the box bike with the hood closed, but the day is coming when she won't. She is also very independent and likes to ride a bike (any bike) for herself ... I'm not sure where this comes from :). If the theory about adult height being double two year old height is correct then she will grow to 163cm (5' 4"). My dear wife (Princess Bee's Grandmother) is also about that height.

Bee and I were both disappointed when she'd no longer fit with me in the single seater velobobile, so clearly we NEED a tandem velo. Her primary criteria for good bike design is "I fit, you fit".

This new bike will take two people my size, and I'm 190cm (6' 3"). I need to fit in either seat, so I can share it with anyone and others aren't restricted to riding only at the back. But that makes it 30cm (12") longer than it could otherwise be.

After seeing it laid out on the driveway I've thought about how it could be shortened:
- Give up freight space (don't want to)
- Make seat backs more upright (won't save much length and probably too much height for a velomobile)
- Stack pilot seat above stoker pedals (too much height for a velomobile)
- Shorten stoker leg space (don't want to as above)

So I shall build it as laid out and just accept that it's as long as a medium car. The extra space at the back won't be wasted because for smaller riders the seat will slide forward leaving more freight space.

It looks like the bare frame will weigh around 23 kg. My current velo is 40kg in road-ready trim ... if this one comes in under 60-70 kg including shell then I will be happy. For comparison Brad quoted the Viking at 80lb (36kg) and the LodeRunner 2 at 150lb (68kg) - both without a shell but I think the LodeRunner included electric assist and batteries.

07-13-2013, 05:25 PM
Am curious on how your going to configure the tie rods if the cross arms w/ hubs & wheels on ends are able to swing independtly with the boom as the pivot point. Unless I am lost on the description?

07-13-2013, 05:38 PM
Here is what I am picturing from description.
How are the tie rods / steering going to connect?
I have the crossmember arms below the BB for clarity.http://i992.photobucket.com/albums/af44/MrDEB/axles_zps81f135ee.png (http://s992.photobucket.com/user/MrDEB/media/axles_zps81f135ee.png.html)

07-13-2013, 10:06 PM
Hi Petone,
That sounds exactly like the excercse I went thru when drawing out the Two Spirit Tandem. Luckily, then, height was not such a problem, so I was able to tuck the wheels under the mechanics and two motors,. Fitting two people in/on a bike means a battle with length, height or width, and if you start talking velo, even more so.
Good point is that the length has very little effect on drag at our speeds, but it may cause a few parking problems!
As it is a quad, the stoker can move back between the wheels, to the point of almost sitting on the axle, but this may give a seat higher than you want, .
Remember that chains and bodies don't mix too well, so leave a space for the chains!
Should be a really useful vehicle when finished.

07-14-2013, 12:59 AM
Am curious on how your going to configure the tie rods if the cross arms w/ hubs & wheels on ends are able to swing independtly with the boom as the pivot point. Unless I am lost on the description?

Here's how I plan the front articulation and steering. I have no CAD program (nor inclination to instal and learn one) so this is from a simple vector drawing program.

http://i1260.photobucket.com/albums/ii576/nwmar2012/Articulation_zps492dd1de.gif (http://s1260.photobucket.com/user/nwmar2012/media/Articulation_zps492dd1de.gif.html)


1. The bottom bracket shell is welded to the cross member, and the bottom bracket axle is joined to the main boom (via brackets which aren't shown) - so articulation occurs when the BB shell rotates around the axle.

2. The connecting rod between the two axle stubs is mounted only to the axle stubs - as in the Viking plans. When articulation occurs this rod articulates with the cross member (and remains parallel to it), so Ackerman steering angles are unaffected. The axle stubs (not shown in pictures) are built as in the Viking plan.

3. Steering is via a steering head which passes through the main boom. Articulation will cause a fractional change of distance between the steering head and the axle stub where the shorter connecting rod connects, but sudden articulation should occur only at low speeds so the effect will be minor.

The drawing shows the short connecting rod joining the right axle stub (as viewed from the bottom). Of course it should go to the left axle stub to avoid the chain, but the principle is the same.

07-14-2013, 01:07 AM
Fitting two people in/on a bike means a battle with length, height or width.

Very true - especially when they're both grown-ups. (Non-pedalling kids are easy!)

Remember that chains and bodies don't mix too well, so leave a space for the chains!

Indeed! All chains will be in tubes or otherwise covered, so I know that small fingers (which are out of my sight) won't get into any trouble.

One other technical problem I have to resolve: here's a shot of my workshop where the finished bike will live. You can probably see why I work outside most of the time, and I shall need to undertake some Spatial Reprioritisation Initiatives very soon...

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Workshop_zps9bec40e2.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Workshop_zps9bec40e2.jpg.html)

07-14-2013, 03:02 AM
You may have a small problem getting a long tandem velo in there right now!

07-14-2013, 08:01 AM
Looking at your drawings is exactly what I interpreted. Several issues I think should be addressed such as limiting the amount of swing, To much and the tie rod from steering head to one wheel would need a swivel more that a heim joint could provide.
Also some sort of damping so its swinging is somewhat controlled. Without damping you could get sea sick--lol
My planed build is basically the same but going w/ 26inch tires in rear so I can get the COG lower than the axle center-line. Using 20" wheels the seat is basically even with axle center-line (10" ground clearance as per Viking plans). With 26 inch tires the seat is still 10" off the ground BUT 3inches below the axle center-line.

07-14-2013, 08:08 AM
Looks as bad as my shop/garage. Also why I work outside.

07-14-2013, 08:23 AM
Suggested method to dampen the axle arms. The springs might be just about right but ??
To secure to plates, use washers and bolts or maybe just pockets drilled into the two plates but secure with bolts as well.
This was first idea I had but must be refined.http://i992.photobucket.com/albums/af44/MrDEB/frtsuspension_zps01b99fe3.png (http://s992.photobucket.com/user/MrDEB/media/frtsuspension_zps01b99fe3.png.html)

07-14-2013, 08:58 AM
I don't think valve springs are going to be much help with such a short lever-given a a lever with about 6:1 leverage they can be compressed easily by hand. Working relatively close to the frame they hardly count for suspension, let alone any damping--which they won't do any way--they may cushion the bump, but there's nothing to stop an even quicker rebound.
Its a proper shock absorber, or nothing except limit stops, with only a small movement needed on the axle. This is only to even out diagonal loads on the wheels, and get better traction at both ends.
DIY can only go so far--unless you want to use levers and leather washers!
Steve G

07-14-2013, 09:52 AM
Also consider there will be no sea sawing as the back is 2 wheels. It will be as stable as any delta on 3 wheels. As to stops it will be self limiting once the velo shell is mounted. I'd keep the valve springs in the engine and discontinue attempting to use them on a bike.

Petone this looks to be a very slick design. Not sure how you thought up how to build this but it sure follows the KISS engineering principles used by Brad in building these cycles. Looking forward to the ride report.

07-15-2013, 05:33 AM
As Darnthedog mentioned, there's no need for damping on the articulation because the fixed rear end will stabilise it.

There is a need to limit the maximum articulation - otherwise (even though there are four wheels) stability would be no better than a delta trike. Here's how the limit stops will be done:

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Articulation_stops_zpsf7973050.gif (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Articulation_stops_zpsf7973050.gif.html)

Result: the front cross member will articulate freely up to 3 inches in either direction, then encounter the rubber stopper. A that point the bike behaves like a rigid quad in terms of resisting lateral rollover.

At full articlation there's 6 inches of height difference between the front wheels, which should be enough for a bike that isn't intended to go off-road. I will test this thoroughly before building the shell ... because if there isn't enough articulation then significant twisting force will be imposed on the main boom, which would be quite bad for a velomobile shell that's mounted off the entire length of the boom.

DTD - I expect it'll be some months before the first ride report. Before then I have to clear a space in the workshop (see previous picture), which means completing some other projects to rehome them. Also, during southern hemisphere winter most construction is limited to non-rainy weekends outdoors. But I'll get there...

07-15-2013, 05:41 AM
Hi Petone,
Safe solution is to use a three point mounting for the body , where one can swivel to allow for chassis twist. No stress on the body.
Steve G

07-15-2013, 03:32 PM
Hi Petone,
Safe solution is to use a three point mounting for the body , where one can swivel to allow for chassis twist. No stress on the body.
Steve G

Thank you, Sir! Now why didn't I think of that? Two fixed mounts off the load deck frame and one (possibly more) swivelling mounts along the main boom - as long as they all line up.

This morning it occurred to me that there will be a weight of - say max 150kg - applied to a lever that's 40cm long trying to twist a 50mm steel box section with a 2mm wall and 3 metre length. Hopefully there won't be a huge amount of twist...

07-21-2013, 01:01 PM
I got to thinking about this idea of a swivel for the front wheels and ten I realized this concept may present more issues than solutions.
Ford has the twin I beam suspension for a reason - one wheel goes down in a hole while the other stays straight.
Using one pivoting beam with wheel at each end then one wheel goes into a hole, what will the other wheel do? It will tilt and possibly cause extream stress on hub ot ?. Maybe something to think about.
I am collecting all the parts to build a Viking w/ two front wheels and two rear (a narrower track in rear) and contemplating this pivioting idea until I realized it may induce more issues and problems using one pivot than solutions??
Thinking of doing two pivot points?

07-21-2013, 04:08 PM
I got to thinking about this idea of a swivel for the front wheels and ten I realized this concept may present more issues than solutions.
Ford has the twin I beam suspension for a reason - one wheel goes down in a hole while the other stays straight.
Using one pivoting beam with wheel at each end then one wheel goes into a hole, what will the other wheel do? It will tilt and possibly cause extream stress on hub ot ?. Maybe something to think about.
I am collecting all the parts to build a Viking w/ two front wheels and two rear (a narrower track in rear) and contemplating this pivioting idea until I realized it may induce more issues and problems using one pivot than solutions??
Thinking of doing two pivot points?

If I were building an off-roader then holes in the ground could indeed be a problem. But this machine is intended as a road-going bike, so it needs only enough articulation to deal with normal road undulations.

Imagine how the single front wheel of a standard LodeRunner would deal with a hole such as you describe - i.e. not at all well. With a LodeRunner I'd have to see and avoid large holes, and the same will apply with the Longfellow.

Not much progress this weekend because I was out of town for most of it, but I finished welding a couple of half-complete joints.

07-21-2013, 09:18 PM
Because we are talking of a quad,the rules change a bit! Any frame stiffness will fight the urge for the wheel to down into the pothole. With a 100%stiff frame and weight at the rear it would just ride straight over it. But move the weight to the front, and it will then descend to the bottom of the hole easily, lifting rear wheel in the process. When this happens, it must hit the other side of the pothole eventually. It then has to lift the front end , and twist the frame at the same time, so as to get out of the hole. this applies to whichever end has the most weight. If you have different wheel tracks, it complicates the theory a bit, but the principle is the same.
If you have articulation at ,say, weight at the front, things are a little different. The wheel still falls into the hole, the body does not twist (less twist --smoother ride) As the wheels do not have to twist the body to get out of the hole, there is less load on them and tyres, and the whole bike .
Sounds , good, and it is, until you get to the point that you run out of articulation. Then , when the front wheel goes into a deep hole, it goes down as far as it can, and then all the front end load is transferred to the high side wheel---the quad becomes a trike with an offset front wheel! Now with the weight on the front end, the low wheel keeps going down, but now twists the body, and lifts the rear wheel on the high side--yes we are back where we started with a rigid front end. If some form of springing is incorporated into the articulation stops, rubber blocks, this becomes a more gradual process, and over all, a better ride is achieved, even over the bigger pot holes.
When it comes to hitting bumps, the story is similar, Here , with 100% rigid frame , the heavey end gets to keep two wheels on the ground, and the light end has one wheel in the air. A rider sitting in the center is lifted by half the height of the bump! And the body gets twisted. Add articulation, and things get smoothed out, as before.
Is there a problem with articulation? In "normal" use, I would say no. But off road and on steep banks there is a real problem!
If riding on a bank with say right side high, the front drops into a hole--no real problem until the limit of articulation is reached. Up to that point , the front has been sharing weight. So its like a trike.
The moment it hits the stops, all the weight is now on the right side, high, wheel, and the COG has not changed--but the wheel base triangle has changed. if the hole is deep enough, its instant roll over!
And the hole does not have to be that deep in these cases----trust me--years on a tractor have proved this point very well.
So off road it can be a bigger problem than on road, and as Petone plans, only a small amount of articulation is needed . But a freewheel diff is needed for the times you run out of articulation.
So the point of al this, articulation does reduce wheel loadings, within limits.
Steve G

07-21-2013, 10:36 PM
GREAT explaniation Steve. I might put some sort of articulation on the front?

As for a differential, YES.
Wondering if I really need the 48 spoke rims all around if going with a Viking Quad?
Locating 24spoke rims might be an issue (have two and plan to drill out additional spoke holes). also have a 36 spoke rim. All of these will need new spokes as I am needing to fashion hubs.

07-22-2013, 05:57 AM
Longfellow has 48 spoke rear wheels and will have 36 spoke front wheels - once the hubs arrive. Ideally I'd like 48 spokes at the front too, but I'm not aware of any 48 spoke front hubs that take a disc brake and 20mm axle. The original Viking uses 36 spoke front wheels so I guess they'll be sufficient here too.

I had some unexpected free time today so I welded the two booms together:

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Booms_welded_zps5788ed6b.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Booms_welded_zps5788ed6b.jpg.html)

and capped the ends of the rear bearing supports:

http://i1260.photobucket.com/albums/ii576/nwmar2012/longfellow/Bearing_blocks_zps64e7b7ae.jpg (http://s1260.photobucket.com/user/nwmar2012/media/longfellow/Bearing_blocks_zps64e7b7ae.jpg.html)

The next major steps (which must occur in this order) are:

1. Fit rear axle bearings and build back wheels to determine rear deck height.
2. Build front wheels - once hubs arrive and spokes bought.
3. Build front cross member with centre pivot - requires completed wheels to determine centre point angles.
4. Mount main boom onto front cross member, via centre pivot.
5. Level main boom (now joined to cross member) and determine height on stoker seat back tube where rear load deck meets it.
6. Add short horizontal section to rear of stoker seat back tube so stoker seat doesn't excessively overlap load deck.
7. Stoker seat will slide fore/aft and have self supporting back, so cut top of stoker seat back tube flush with load deck.

Measuring the parts as in the picture above confirms that the finished bike will be 4.1 - 4.3 metres long (approx 14 feet) ... depending on acceptable overlap between stoker's seat and load deck.

07-22-2013, 08:49 AM
I can only get 36 spoke 20 inch wheels here, and that's on request 32 is normal. You wont break them unless you are thinking of racing or trick riding, , or you use a narrow hub.
Articulation should be limited--say 2inch each wheel free then a firm rubber stop. More than 3 inches on full load is more than you should need on the road, provided you have a freewheel diff to get off the odd diagonal driveway.
Any 24 spoke rim is suspect--unless it is the same as 32 or 48 spoke rim, when may be ok, but it sounds like you have a steel rim, as most alloy rims have eyelets for the spokes.
Not sure I want to go down that track, even for advice. If asked I would say no, to play safe, others may be able to give an OK on steel rims. My reason is ypou know nothing about them,and a 24 spoke rim is off a cheap bike--chances are that rim is only just strong enough for what it was made for--a kids bike.
I just pulled a spoke though the rear,26 inch, rim on my LWB, meaning a new rim and a re-spoke Discovered 6pm last night, and back on the road this morning! Still don't know what time the LBS closes.
Spent a fun evening counting 1-2-3-4 over and over , and got the truest wheel I have ever done--really pleased with that one.
Reason for mentioning is that even with sstonger rims, things do happen. So start with a weaker rim, and they happen more often .
Steve G

04-11-2014, 04:02 PM
A quick check-in report. Since we moved out to the country I've had other budget and time priorities so there's been little progress on the Longfellow. But since Christmas I have:

- Bought the first two brake discs - 203mm diameter
- Bought two AZ axle freewheel adaptors before they went out of stock
- Bought the front hubs - 36 spoke, 20mm bearings, disc compatible
- Cut and re-welded some of out-of-square joints (so now they are less out of square).

Currently saving my pocket money for front spokes - once I have these then the front wheels will be assembled and the front cross-member can be finished.

I have decided to go with hydraulic disc brakes. All up velo weight will be around 60-70kg + 2 people + whatever a LodeRunner can carry and we live near the top of a big hill, so I want the best brakes I can manage. Also the back brake connection will be about 4 metres long, which would give horrendous stretch in cables. I've read the comments elsewhere about hydraulics not being repairable on the side of the road. But this velo will have four wheel discs with front and rear on separate circuits, so total failure is unlikely.

Equally importantly, after six months of motorcycling to work I lost all cycling fitness. It's a 45km commute each way with a 3km hill at the end of the homeward trip. I am now riding the existing velomobile to work two days a week, and the power-plant (puff puff) has returned to a reasonable state of tune. The homeward trip has reduced from three hours to 2:10 ... and of course the power-plant is far more ready for the eventual launching of Longfellow.

04-12-2014, 07:52 AM
I have restarted my work on my 2 x 4 Viking when I get time. LOML wants to move closer to the grand-kids so been cleaning up and sprucing up yard / house / shop.
Now on the brakes since it was mentioned, I am seriously considering goinf with large rotor disc brakes in the rear and go with hydraulic in rear and cable in front. More of a cost saving than anything. My take on hydraullic brakes- they work vvery reliably on a motorized vehicle so why not on a HPV. BUT ONLY if precautions are taken such as using steel lines instead of plastic and procure a braded flex hose for connection to calipers. LOOK at the method a full sized vehicle uses. no plastic hoses or lines.
In process of assembling the front arms / king pins etc but using 1/2" grade 8 bolts in conjunction with flanged bearings. Have a mis mash of head tubes and a few forks but no matching pairs.

04-12-2014, 09:35 AM
Large motorized vehicles are using tons of stopping power to stop tons of weight. HPV do not weigh tons. Nor do they go very fast in comparison to motorized vehicles. IT is a factor or weight verse speed verse power. The plastic used on Bicycle brakes is more than capable of handling the power you can generate squeezing the handle bar.
Also if you consider the liabilty aka law suits- bicycle manufactures would would not use plastic if there was any issues with it.

Secondly I would reverse the thinking- hydralic brakes create far more power than the cables for stopping. As your braking is primarily on the front wheels I'd put hydralics to the front and run your cables to the rear wheels. The cost of hose to the rear verse just using it on front would also be a good reason to put hydralic on front verse rear.
Distance is not your frind with hydralic brakes. The hose cost money. And it takes a bit of fluid to bleed the lines and insure no air in line to compromise the stopping ability.

04-12-2014, 04:13 PM
You made a good point on weight but a system could be fabricated where the front are applied with more force than the rear. Just thinking the hydraulic would be more efficient than cables for braking force and amount of power applied to the brake lever. I think you might find 1/8" steel or copper or maybe aluminium tubing might weigh as much or less than a steel cable w/ steel outer sleeve?

04-12-2014, 05:31 PM
Becareful in using anything but steel tubing or rubber. The Hydralic fluid may have adverse reactions to Copper or Aluminum due to the inhibitors/additives in fluid.

You stated you planed to use cables to the front and hydralic to the back. I was stating reverse the order. Hydralic to the front and cables to the back. If your going front and back hydralic your going to want 2 levers anyway. One for front hydralic and one for the rear. That is how motorcycles and bicycles do it anyways. No need for a complex pressure distribution system. Actually I won't suggest you home brew brakes at all. Use good commercial brakes and use them as built. Add cable length or hose length but do not create your own. None of Brads plans suggest this nor any other site I have visited. So please don't think is it wise to do.

This conversation is getting beyond Petone_NZ conversation. Sorry Petone.

08-09-2014, 03:01 AM
Progress is slow - combination of budget and time scarcity. Both my power drill and grinder died last week, but a determined garage hacker can get by with an Armstrong drill. Here are the back wheel spoke flanges in progress:


Why the bike budget is so tight? Three months ago the bicycle faeries smiled kindly upon me ... a 14 speed internal gear hub showed up second hand at the one time I could afford it. This will mount to the frame just behind the stoker's seat and have an output chainwheel bolted to each spoke flange. Effectively it combines the gears and freewheel differential into a single unit, and means I can shorten the main frame because the standard LodeRunner II crossover drive is no longer required.


At the end of September I should be able to get my welder gas bottles refilled so progress will pick up then.

10-18-2014, 01:57 AM
After a year with no welder, I’ve started building again. During the break I looked for ways to reduce weight without compromising durability or utility.

Longfellow’s rear axle blocks were formerly solid lengths of 2 inch box section. There’s no need for the double skin between the axle blocks and the load deck so I removed it. (Deck is upside down in these pictures.)



10-18-2014, 02:00 AM
Still on the load deck, 2 inch box section is heavier than I need aft of the axle. So I cut it diagonally to leave L section, and added diagonal faces of thinner panel steel. (Deck is upside down in these pictures.)






10-18-2014, 02:02 AM
Here’s the original Viking frame I built last year, and planned changes:


Longfellow needs to fit riders from around 160cm to 190cm (5 ft 4 in to 6 ft 3 in). A tandem drivetrain won’t allow large adjustments to the bottom bracket positions, so the seats will slide instead. This means the seat backs must be self-supporting independently of the main bike frame ... but the frame can be simplified compared to the Viking.

These changes removed 2.6kg from the frame. The stoker seat tube will be shortened later, once the intersection point with the mid drive tube (between seat tube and load deck) is known.


For an open frame bike I would add the truss rod now to prevent frame flex. But Longfellow will eventually have a velomobile shell, and the floorpan will serve the same purpose. There will be “droppers” below the frame to mount the floorpan, but the drivetrain needs to be installed first to determine the floorpan height.

10-18-2014, 02:03 AM
I made the front axle cross-member as per the Viking instructions, but with track narrowed to 710mm (28 in) – similar to the back track width. Wide front track is not needed for stability because Longfellow is a quad rather than a trike, and keeping the track narrow will allow a slimmer velomobile shell – hopefully with fully faired front wheels.

I left the tyres off when setting up the front end alignment so I could bolt the rims to a board through the valve holes. This allowed steering position adjustments but kept the wheels positively located on the correct points:


Tape on the rims prevents scratching when the top nuts are tightened:


10-18-2014, 02:07 AM
The front axle cross member has a longitudinal pivot for axle articulation required by a quad. It’s a one piece bottom bracket with the pedal crank shortened to an axle:




The rounded notch is deeper at the front than the back to set the required caster angle (from Viking plans).


Yet another serial number here. The completed bike will have three bottom brackets and four steering heads. So far it has inherited three serial numbers from donor bikes – a rolling identity crisis!


Pivot mount wedges tack welded to frame and cross member hanging loosely. The mounting studs go through the wedge and touch the bottom layer of the main frame for additional support.

It’s not clear yet if the pivot alone will be sufficient to locate the front cross member. The leverage when one front wheel hits a bump may require additional arms to take some of the strain. Any such arms will need to avoid the chain and steering so I’ll consider them later.

10-18-2014, 02:08 AM
After mounting the front cross member to the main frame, I levelled the main frame and the load deck frame to determine the height at which they meet:



Then I marked the joint lines, cut them and joined the two halves. So here is Longfellow’s basic frame completed – a happy merger of Atomic Zombie’s two big inline tandems. As shown here the frame is 3.6 metres (11 ft 10 in) long and weighs 21kg.


10-18-2014, 02:09 AM
The frames for the sliding seats are made from steel shelving – 2mm thick with holes which reduce the weight and will simplify adjustable mounts. There will be a series of horizontal holes through the main frame with anti-crush tubes welded inside.


10-18-2014, 02:10 AM
The chainwheels are Shimano’s “Front Freewheeling System” from the 1980s, with a freewheel between the pedal axle and the chainwheel. The captain’s and stoker’s chainwheels will be hard-coupled by the index chain but either rider can stop pedalling independently of the other.


Both sets of teeth are worn out and the wrong size for Longfellow’s gearing anyway. Later I will cut off the existing chainwheels and make aluminium adaptor rings to fit the new ones.

10-18-2014, 02:11 AM
The main gearing is via a Rohloff 14 speed hub which I was fortunate to obtain second hand. (A new one would have been beyond the budget for Longfellow.) It’s mounted as a mid drive under the main boom behind the stoker’s seat. A chainwheel will mount to each spoke flange and drive a freewheel on each rear axle. This achieves the same “freewheel differential” effect described on another thread, with no need for a separate jackshaft.

Both riders will share the full range of gears through a common gear system – more flexible than Viking but less flexible than the independent drivetrains of LodeRunner 2.

The mid drive mount is mostly welded in place. I curved the tubes by cutting slots, bending, then welding the slots closed – similar to Brad’s velomibile shell frame construction method.


At this point I ran out of acetylene and oxygen, so after a busy fortnight there will be another pause until the bicycle budget can cover the refills.


As you can see I am not in the dogbox in the background ... but apparently I could be very soon unless I attend to some other jobs around the property. So on that note I’ll end the current burst of progress.

10-18-2014, 08:57 AM
Wow--that is Loooooong!
You need a good two way intercom on that one!
Steve G

10-18-2014, 09:48 AM
A burst of creation there Petone. Looking good. As it has been a year- has Prince Bee grown 1.5 times her size as predicted? And Racing Dad now? Should be close to 5 1/2 years now and nearly ready for school.

Hope you get the Gas to finish this soon. This is getting to be quite a neat project despite the length. I can hardly wait to see the Velo shell. I like how you reduced the weight.
You may want to place Anti-crush tubing inside the rear wheels support. But other than that it is really coming along.

10-19-2014, 07:10 AM
Looks really good! You've got some great workable ideas there, I may have to borrow some of them when I get to my next build.

10-19-2014, 09:26 PM
Just a thought--any need, or plans for, extra bracing on the looong boom?
Or is it OK on its own?
Steve G

10-20-2014, 05:01 AM
As it has been a year - has Princess Bee grown 1.5 times her size as predicted? And Racing Dad now? Should be close to 5½ years now and nearly ready for school.

Yes, Princess Bee is 5½ now and eagerly awaiting the completion of "our new velomobile". She tells me she will drive and I can ride in the back.


Currently we ride about a mile to the school bus each morning using our other freight bikes (bakfiets (http://forum.atomiczombie.com/showthread.php/6377) or longtail (http://forum.atomiczombie.com/showthread.php/7542)) or a tag-along trailer bike. Originally we re-homed the two freight bikes when we moved to the country but the new guardians changed their minds and returned them.

Conveniently I have a spare BMX frame/forks with VERY strong dropouts and bottom bracket, some leftover round tubing and two spare 48 spoke BMX wheels ... so I am vaguely planning a third freight bike inspired by Clever Cycles' Xtravois 2.0 (http://clevercycles.com/blog/2011/09/22/xtravois-2-0-our-oregon-manifest-bike/). I have to build another garage/shed anyway so we might as well fill it...

Looks really good! You've got some great workable ideas there, I may have to borrow some of them when I get to my next build.

Charlie - please take and use whichever ideas you like. I am grateful for many fine ideas posted by other AZ crew, and happy to contribute something in return. I'm fortunate about the 12 month enforced break - it gave me plenty of time to consider every part of the plan rather than rushing in like a bull at a gate. In general my approach to weight saving was:

1. Why is this part here?
2. Does it need to be this big and heavy?

On the load deck frame, gas-welding the side diagonal plates introduced about 4mm of front-to-back warp on the outer edge only of the top surface - but the inner edge stayed straight. I tack-welded all around before seam welding, but even that didn't stop it. For me it won't matter because the load deck will end up inside the velomobile shell and I can simply add 4mm packers, but you may need to allow for the same result.

Another possible weight saving: The load deck surface will likely be 3/4 inch plywood. But using a woodwork router I can thin most of it to 3/8 inch thickness, leaving full thickness ribs around the edge and spaced across the middle for strength. Or maybe start with 3/8 inch plywood and glue on separate ribs, so the grain in each rib runs longitudinally to the rib.

Just a thought--any need, or plans for, extra bracing on the looong boom? Or is it OK on its own? Steve G

Hi Steve. The boom will need bracing, in the middle, probably at the front and probably between the boom and the load deck. Both Viking and LodeRunner 2 have a truss rod to minimise vertical flex but no lateral bracing.

Once the drivetrain is in place (so I know how deep it is) I will add a series of vertical "droppers" (40mm box section?) hanging below the main boom. Each dropper will have a lateral "floor former" at its bottom end like an upside down "T", made from the same steel shelving as the seat frames. These formers will curve upward slightly at their outer ends. A 3mm plywood floor will bolt to the underside of the formers. This plywood floorpan will hold tension front-to-rear - serving the same purpose as the Viking/Loderunner truss rod. The curve up at the floorpan edges will prevent any front-to-rear flex, and the width of the floorpan (combined with the floor formers and droppers) should resist any lateral flex in the main boom.

I realised I have made one significant mistake so far - the seats are too far off the ground; they should be at approximatly Viking height. This is caused by the narrower front track (= less dip in middle of front cross member) and the depth of the cross member pivot. Rather than remodelling the front cross member I will probably put a "step up" in the front boom, or even remount the cross member above the boom if that much adjustment is required. The load deck height will remain the same but the small step-up in the boom just behind the stoker's seat will also need to be lengthened.

10-20-2014, 05:48 AM
Sounds al thought out proper!!! Just watch that the cross member does not hit the back of your legs! That should be--watch that the back of your legs don't hit the cross member when peddling!
Not to sure on the "stressed floor" concept, as it means that you are relying on the fixings (screws, bolts, glue, magic, etc) of the ply to the frame for strength, and I'm not sure that you will get away with this one! There is a fair bit of stress on these braces, and I think it may be a bit more than you handle with ply fixings. If I read the post wrong, ignore all this!
Steve G

PS If you are only talking about 3 to 4 inches in seat height change, why worry? Unless you plan on racing, I doubt it will worry you, and the improved visability could be an advantage (but I admit I'm not sitting in your seat seeing what you see)

10-20-2014, 08:10 AM
Another thought here about the height. With your project being so long a little extra height may help prevent high centering. Maybe you don't have rolling hills or dips where you plan to ride. But I could imagine it as I just had the issue with a piece of equipment recently. You don't want the cycle to bottom out in the middle when going over a hump in the road.

10-21-2014, 05:03 AM
Right - I've just been out to the garage with measuring stick and kitchen scales, and established:

• The seat height is only 35mm (about 1 3/8 inches) higher than a standard Viking.
• Adding a truss rod of steel shelving (as used for the seat frames - I love that stuff) would add 2.5kg ... or 1.25 kg if cut down from L section to flat bar.

So ... I will leave the ride height as it is. The wheelbase is a little longer than standard Viking because of the LodeRunner load deck, long leg length for both riders and the front axle cross member is further forward than a standard Viking. But the finished ground clearance will probably be similar to Viking, taking into account the underslung floorpan.

I will also add a truss rod of steel shelving. I could save 1.25 kg by cutting it down to flat bar - it would still resist tension "pull" (the main force) but the plywood floorpan would have to resist any compression "push" (e.g. if the floorpan is grounded or the bike is somehow lifted in the centre). Any thoughts either way about this, Ticktock and DTD (and any others)?

Rather than using 40mm box section for the droppers I could use two pieces of shelving in a V - welded below the frame approx 15cm apart and meeting at the truss rod. This would be lighter and about as resistant to fore-and-aft flexing.

10-21-2014, 10:08 PM
Remember that the truss bar will be the thing that takes the weight if the bike does get bottomed out mid length. So if it does not have some rigidity of its own, its going to deflect, and add to the "reverse" bending you are trying to avoid! And plywood is not the most stable of materials compared to good old steel! So, no, I don't think the ply floor counts for much here--only for weatherproofing, streamlining and standing on.
when it comes to something as important as that truss bar, 1.5 kg is nothing. Its hard to peddle with the middle of the boom dragging on the ground.
Personally, I would be looking at using a 1inch square tube for the truss, supported at about 12 inch centers. This would (applied as on Viking and Loadrunner 2) be enough to stiffen the frame for riding, and then, when needed, be able to support the bike if it did get grounded.
You would need at least 1/2 inch ply just to stand any chance of withstanding the impact loads from bottoming, and a I bet this weighs far more than the steel tube! Stick with a steel frame, and a wood shell two different jobs--much safer and more predictable.
Steve G