View Full Version : Easy Front Runner Build ?

09-28-2012, 01:52 PM
Is there such a thing as an easy build, or easier build.
I have now built 7 bikes/quads/trikes, some have worked, some have not.
Really keen to build a front runner as my first ever build was based on a staiger airbike - the result too scary to ride.

Anyway i have by default built a bike to plan, then a more off the wall heavily adapted from plan bike, then a bike from plans etc. etc.

Now to follow this pattern, i am going to build a Front Runner and have been buying all the parts i need before i start.
Wheels 26" with smooth tyres and mechanical disc brakes.
Gearing 8 speed 32/11 cassette
Front chain ring 28/38/48 (for speed hopefully)
Donor Bike - girls frame mountain bike.
Seat - fibre glass one with seat cover.

Looking at my pile of other donor bikes, i realised i had a cheap full suspension framed bike, the rear triangle part for the back wheel even includes a disc brake mount - incredible bonus.

So here is what i am thinking, use all of this rear triangle part.
Add piece "A" which bolts into the suspension mount just like the top truss mount on the original plans. The rear triangle will be welded to the lower end of the bikes original forks.
Then add two pieces "B" to replace the crank boom in the original plans.

At the rear end, i have found by a bit of careful force, a front wheel can be fitted into the rear forks.
The seat post tube, can then be used to support my fibreglass seat, and later on a bike rack can be easily fitted.

I am keeping the middle section idea of the extendable section, although i do have a folding shopper bike hinge i could use - mmmm more thinking to do.

Will post some more mock up pictures, but in the meatime
Please let me know the collective AZ wisdom if you think this front end arrangement will work.

09-28-2012, 09:00 PM
I have not built or ridden one of these, so I won't comment on how it will work, although I see no reason why not.
But just be careful that when you add piece B that it does not fight for space with the front brakes!
Looks interesting.
Steve G
PS--Would love to know how the half smooth /half knobby tire works out!!!

09-29-2012, 01:52 AM
Hi Steve
Thanks for replying, the beauty of this idea is I will be using disc brake, so no interference with piece B

09-29-2012, 05:12 AM
Have you looked to see how I did mine? There is no reason the way that I did my front end couldn't be mated to the way the rear end is on the ones in the plans

09-29-2012, 09:58 AM
I was really worried about piece B, somthats OK now, but you did not tell me how the half an half tire worked out!!!
Steve G

09-30-2012, 03:23 PM
IMO, you need to keep the total weight of the front portion of an MBB bike as low as possible.

10-01-2012, 02:32 AM
Thanks for the advice.
Looking again last night at the photo I had posted, and although it could be easier, it could also be more ugly.
Also it puts the crank further away from the centre of the wheel, and I don't know whether this is a good thing or not.

Decision made, follow the plans, just changing the seat. If time permits I will start saturday.

10-01-2012, 09:42 AM
Better to move the cranks further from the wheel center , rather than closer, as this leads to gear change problems.
Steve G

10-01-2012, 11:09 AM
Just a couple of thoughts from my studies. You can pick up the building experiences of others on MBB's by searching the European Forums. They have been doing this for some time.
Although you will never eliminate PIS on a FWD MBB there are ways to minimize the effects.
The seat should be as close to the head tube as practical. The least amount of PIS will be with the BB at 12 or 6 o'clock. 3 o'clock being the worse option. Obviously this would have the most leverage against the handle bars.
There is a limited amount of distance you can move the BB from the hub. To far and you could not reach the pedals and to close and the BB would rub the tire. I have seen others using 4 inch extensions between the chain stays and the BB to raise the BB and place the rider in a better racing position on one of the commercial bikes.
Learning is said to be easier with the seat in an upright position easing the seat back with experience.
Regardless of the design, persistence seems to be the common factor to riding a FWD MBB successfully. I saw my son riding his at 25 or 30 mph in a residential area days after building his. The accounts of others have been giving up within hours. The advise of all have been practice in an empty parking lot before taking to the streets.

It's a wonderful day in the neighborhood, think I'll go ride my bike.

10-02-2012, 07:06 AM
Thanks for all the advice, really useful to have this help available.
Rather than a protacted build, I am going for a follow the plan build.
Whilst it will not be a race, I think I am going to log the time spent building this one and post pictures of progress.
The only changes to plan is to use a seat I already have and use disc brakes.
Hope to get started tonight.
Hour one approaches, yippee can't wait.

10-06-2012, 01:49 PM
5416Hi folks,
Got 3 hours clocked up today, tyres and discs on wheels, rear fork taken off donor and cleaned up.
Took apart a ladies mountain bike for build:builder2: parts, cleaned up head tube, front bottom bracket and kept the boom tube long, hoping to cut and weld some bends into it.
Front fork cut for bending to accept a rear wheel - clearance problem disc to fork and not enough room for the chain when on smallest sprocket. Realised that if I spread the fork wider then weld rear drop outs both clearance issues would be solved.
Loads done in 3 hours, very pleased with progress.

10-08-2012, 04:39 PM
Got 1.5 hours in tonight.
Using the rear section from a donor bike, added this to the front forks to allow disc brake mount and derailer hanger to be fitted as one.
Doing it this way was like having it all self jigged so quite easy to do.
Once forks tacked in place by aligning all the dropouts together using a scrap wheel, I the cut off the original dropouts off, cut a slot in the forks to fit a 5mm wide small web.
Once all welded up I cut off the donor section.
Got to shape the spare metal of the new dropouts, should look good when painted. Need some more filling weld and grinding to smooth finish.
Really pleased with the clearances for the disc and highest gear (River pointed out this potential issue in his build thread).

10-09-2012, 04:55 PM
Amazing, got another garage pass tonight (although cooking evening meal probably got the pass awarded).
So total hours to date 6.5 hours, having done 2 hours tonight.

Finished filling with weld and smoothing front fork dropouts.

Connected rear fork to boom and cut the other two frame pieces.
Front bottom bracket boom yet to be bent.

You will see all donor parts are bare metal, decided at the start to remove all paint, rather than having to keep stopping to swap discs to remove paint, I used a finishing pad on the grinder and it gave a good finish, without removing metal.

I will be amazed if I get a pass tomorrow night also, but you never know.

10-09-2012, 05:48 PM
I don't think the rear drop outs are to be pointing up. As the support the rear wheel gravity will forever attempt to drop the frame from the axle. Otherwise nice looking build so far. This is just an observation and opinion. Feel free to ignore my advice- But all the plans I have show the drop out for both front and rear wheels pointing downward.

10-12-2012, 05:52 PM
Hi darnthedog,
Gravity will win every time, however at this stage just following the plans, your comment has got me thinking of an easy way to correct this.
The plans suggest that you can cut off the dropouts and remount them, which is fine, but means getting everything lined up again with respect to the wheel relative to the forks. Anyway not had a garage pass since earlier in the week, so been thinking about this little issue and come up with the following easy fix.
By cutting the dropout where the (wobbly) black line is I can maintain the relative position of the wheel. Each cut off piece of dropout can be switched the left piece to the right and right piece to left. Then I can easily weld these back in place and get the slot in the dropouts facing downwards.
Should be an easy fix to this little problem, what do you think?

Radical Brad
10-12-2012, 06:59 PM
Nice build so far.

Your rear dropouts are slightly upward because the forks are also slightly upward rather than following the parallel line of the square tube (Figure 27). This won't be a problem, and remember that the angle of the frame is also tilted upward, so the dropouts may actually end up parallel to the ground.

If you do end up with upward pointing rear dropout slots, then yes, you could just cut and reweld them (do this 1/4 inch up into the fork leg tips), or use a tabbed washer as a safe guard.

If you intend to add a read disc brake as well, then you definitely want to reverse the dropouts.


10-13-2012, 03:08 AM
Hi Brad
Thanks for the reply, wow I thought I had followed the plan correctly, this just proves the benefit of the forum and posting pictures.
Thanks for the advice, my intention was to use tab washers anyway, but with you mentioning if disc brakes to be used to change the dropouts, then the dropouts need to change, but not until the frame is all welded up, wheels on and I can see exactly where they need to be.
Thanks again, not just for the plans, but for this level of support during the build process.

Radical Brad
10-13-2012, 11:27 AM
No prob, thanks for your support.

Your rear fork angle is only slightly upwards, so I wouldn't worry about that part. And your dropouts would probably be fine once the front of the frame is lifted. But if your plan is a rear disc, then you want to make sure that when the brake engages, it forces the axle into the dropout, not out. Think of the brake pad as a pivot point on a line drawn though it and the axle. On a hard lockup, the axle will be pushed or pulled in the direction of wheel rotation from this imaginary pivot point.


10-14-2012, 03:18 PM
Managed to get another 1.5 hours garage time today, got the down tube and lower boom welded up and smoothed out.
Also finished weld filling the rear fork to boom connection looking good.

Next is the tabs to connect the front and rear booms, then the all important head tube fit and getting the correct angle.

Having struggled in the past in not having enough hands to hold everything, I have got a couple of ideas I would like to try out.
First idea is welding a temporary stub to the front of the head tube to be able to clamp this to a temporary frame/jig.
Second idea is to weld some 10mm all thread to some spare 40mm x 40mm section, to create a slave rear axle, fit the rear fork to this. Then weld another 10mm stud to another piece of 40mm x 40mm section, but offset the centreline of the front slave axle by 40mm to allow me to slide the two sections relative to each other to obtain the correct fit for the head tube, I could even weld a temporary straight edge to give me a guide for the head tube, effectively make a jig. Can't see why this will not work, just working without the wheels basically.


10-15-2012, 05:29 PM
Amazing a whole weekend passed and no garage time, then out of the blue, all chores done and got 2 more hours tonight.
The real beauty of following a plan is knowing what is to come next.
So tonight got the boom tabs on and cleaned up post welding.
Really pleased with the fit, then the tricky (in my head anyway) head tube angle and getting everything held.
If you have seen post #19, you will see my concerns, what a load of rubbish, just look at the photo.

Managed to be able to ensure the wheels were properly square relative to the ground, the vertical steel holds the frame at the right height, the old cross tube helps to keep the frame upright and rigid.
At the front wheel the block of wood stops it pushing away, then I tied an old brake cable round the head tube and then able to adjust the angle by changing the tension and clamping it in the vice.

I also marked the head tube before I started so I had a point of reference. My adjustable angle finder has a spirit level, so it was simple to change the angle by adjusting the brake cable and checking the angle with the spirit level feature.

I have left enough room to allow for a front mudguard to be fitted, hopefully by allowing for this the handling will not be affected, as the plans say to get this as close as possible !!!!

Sooooooo pleased with progress, it should be easy with this setup to get a really good fit of the head tube before welding it all in place.

10-15-2012, 07:40 PM
Looks great, love the disc brakes on it

Radical Brad
10-15-2012, 07:40 PM
Nicely done! I like the whitewalls as well.


10-16-2012, 01:48 AM
Hi All,
The white walls are a trick of the camera flash, they are actually a reflective rim, painted on the tyre, as they were bought from the shop (decathlon).

10-19-2012, 03:00 PM
Hi folks,

Well pleased with myself, got some more time in today having finished work and head tube now fully welded in place, to the correct angle and everything square.
Surprising how a word in the plan "careful" can equate to 2.5 hours disappearing.

My only slight concern is the position of the boom relative to the bottom head tube bearing cup, but it all fits together and it has all the relevant clearances as per the plans, it even looks like the one in the plans.

Pictures to follow in next post.

10-20-2012, 07:47 AM
Hi folks,

Photo as promised, the hour count has gone up, got a bit more time today.
The fit of the seat is a bit of an illusion, still need to fit things permanently.


10-20-2012, 08:01 AM
Looking good and like you'll be riding soon.

10-21-2012, 06:44 PM
Dropped real lucky, when I started this build I had a few options on the crank, but yesterday got an old GT mountain bike, Ali frame, but had a nice crank and derailers for the grand cost of nothing.
I nearly didn't bother with the bike because of its Ali frame.
So the dump can have the frame and I have all the components to finish this project.
What was really nice was my eleven year old daughter helped strip the frame and loved doing it.

Got the seat mounts fitted today.

Radical Brad
10-21-2012, 09:23 PM
Thanks for the updates, it won't be long now.


10-28-2012, 12:50 PM
Hi folks,

Good a few hours in last night and today.
Bottom bracket fitted, not without concerns. The fitting to the seat tube, as per the manufacturer of the original bike.
It turned out to be not square, but cut the tube most of the way through then used this little tab to be able to realign everything.

Some outstanding jobs on top of the build plans are
1. Fitting a holder for a rucksack behind the seat for a water bladder, tools pump and stuff.
2. Rear dropouts and brake disc holder.

Got a couple of days holiday, so hopefully get some more time to finish the front end.

Already thinking of paint, red for the rear and yellow for the front, let me know if this sounds good.

Crank and derailers fitted, free from Ali bike, as per previous posts, need cleaning up.5534

10-30-2012, 06:06 PM
Hi again,
Days off work allowed further time on front runner build.
Handle bars feel good.
Added a bar to hang a rucksack for all those little bits needed on a ride.
Need to add rear dropouts, they are made almost.
Few bits of detail such as cable retainers rather than cable ties,then should be time to cable up and go for a test ride.
It sounds real close, but in reality I know there is a few more hours to go yet.
Been really pleasing build so far.


Radical Brad
10-30-2012, 07:51 PM
Your bike came together nicely.


11-04-2012, 02:04 PM
Just completed 4 hours, in which time I errrr well

Where does the time go.

No more photos at this stage of the build.

Mounted rear mudguard, got bag support to be removable, changed the rear dropouts, got the rear disc brake mounting sorted.

Chain on and that is it for now, I guess there are a few more hours until test ride time.

John Lewis
11-05-2012, 09:36 AM
Looking good.

I think it should be just as nice as one of John Tolhurst's Cruz Bikes and a darn sight cheaper.
Got to say I like the latest Cruz Bike a lot though.


11-05-2012, 03:03 PM
Hi John Lewis,
If we are talking http://www.cruzbike.com/vendetta then yes I really like it too, but have a limited budget, so hoping the end result will look similar.
Making me think yet again on choice of colour, as I have a look of spare yellow paint, do I go all yellow, or yellow front fork section and the rest red as per original thought, what do we think?

11-10-2012, 04:52 PM
Yes first test ride tonight, it was dark so the neighbours could not see me!!!!
Anyway all held together well, even me, given that the last FWD recumbent, my first ever bike build just scared me silly.
The handle bar twisted a bit in the extension clamp, I tightened it, but it maybe the shiny chrome will have to go, or fit a tab to prevent the twist.

Getting starting is a bit of effort, then once going, I couldn't believe it so then I wobbled again.

Few bit still to finish off and make adjustments to, but overall still most happy with this build. Another test ride tomorrow.

Radical Brad
11-10-2012, 07:39 PM
Glad to hear you got your craft flying on the first launch.


11-20-2012, 02:39 PM
Hi folks,
Update on the build. Test rides are well worth doing, noticed one of my welds that I had ground flush had come apart, so I added a metal collar to this section.
Got some colour on the front fork/drive section last night.
Bit more to do on a few little bits before other parts can be done.
Can't wait to ride it, but equally loving this build

01-06-2013, 01:44 PM
Where does the time go.
Been out cycling a lot,Xmas things and family, then house improvements, have all got in the way (in a nice way) to prevent this build being finished. Hope to get the last few mods done and painted, but realistically still can't see this being finished until end of feb.

02-16-2013, 05:18 PM
My previous prediction of completion for end of feb is now looking good.
Finally the weather is better and got to do the final mods and got coat of primer on today.
It is amazing the thrill of grinding and welding when so close to finishing those last few details

02-17-2013, 03:58 PM
I know I should not, but having painted the front section several weeks ago, having painted the rear this morning, I could not avoid putting a few bits together this evening.
Having been given some paint, which I had thought was red, it actually was ...... which was a surprise at first, but well what the heck.
So a different colour combination than I thought, but it is looking soooooo good.
Hopefully get all the assembly finished tomorrow, if so pictures to follow very soon.

02-18-2013, 03:57 PM
Assembly complete, minus one important part, the chain.
Fitting disc brakecalipers was so good, getting them running true to the disc, then attaching the cables, sweet.
All the cables have restraints welded to the frame, m6 nuts work a treat for this job.
The rear brake got a special restraint fabricated which allows the cable to slot in, then be removed should the frame come apart, just releasing the cable from the brake lever.
When the chain is on it is ready for riding, complete with mudguards, water bottle carrier and small rucksack for pump and things. Also fitted to the the side of the rucksack are two rear lights.
Even fitted a bell.
It is so close to finishing now, hopefully get some time to finish it on Wednesday and post some photos, really can not wait to ride this one.:sunny:

Radical Brad
02-18-2013, 04:17 PM
Look forward to seeing the photos.


02-20-2013, 08:37 AM
Ok folks here are the photos.
Build complete




All photos will be in gallery.

Radical Brad
02-20-2013, 09:57 AM
Most excellent work, thanks for the photos!


02-20-2013, 04:04 PM
Very nice work- I really like the added fenders and the color scheme. Thanks for sharing.

02-23-2013, 12:54 PM
Just for fun, whilst out on first ride today I recorded it using Strava app, and whilst the distance is low the squiddly picture got me thinking, who can come you with the best picture using satellite tracking software, any takers for the challenge and do we start a new thread for this ?