View Full Version : My Kyoto Cruiser

03-27-2010, 06:59 AM

Here's some build progress shots on my Kyoto Cruiser.

Here's one of the donor bikes after Mr. Angle Grinder's been to town:


Here's the chassis coming together:


Who said you can't use a pillar drill to drill the chassis for the pillow block mounting holes?


More soon

03-27-2010, 07:11 AM
I had the flanges for rear wheels turned for me at a local machine shop. Not exactly ecstatic with the speed so I took home a half-finished job. The flanges were too thick still at the spoke hole diameter, a little out of true and also the inside diameter of the axle mounting hole was too large giving a pretty sloppy fit on the 'precision' 20.0mm axle rod. Apart from that it was great work. Here's me turning the flanges on my mini lathe to make the parts usable:


I did have enough donor bikes in the end, but the headsets were shot on all of them. So I made my own 'swivel post' for the governor from a bit of steel bike frame tube for the outer, a couple of ball bearings (around a (euro)dollar each), some bearing mounts turned from aluminium alloy bar and push-fitted into the outer tube, a length of 12mm threaded rod (hopefully stiff enough) for the core post that was welded to a thick plate to be be welded onto the chassis. I also made a nice cap for the top and a bit of tube to act as a spacer between the bearings. A picture says a thousand words:


I used 10mm rod end bearings that I bought from eBay for about 5 dollars each (better than the 30 dollars that the local supply shop wanted). Here's one fitted to the front forks end of the front linkage. I had to make a spacer from a 10mm washer (and turn down the O/D of the washer to allow the movement without coming up against the same problem that I would have had without the washer):


Radical Brad
03-27-2010, 10:53 AM
Great work so far... like the custom bits.

04-05-2010, 12:12 PM
More progress. Here is one of the wheels nicely laced and trued by Debs.


Hoping these don't foul the chain. I just liked the idea of the possibility of putting different seats on later without welding.


Here's my rear steering tube. I didn't like the idea of having moving parts effectively welded in place so this is an assembly rather like my conductor that comprises a pair of thin section deep groove ball bearings and some turned parts to make concentric tubes. The bottom part with the steering arm is a plug into the inner tube held in place with a grub screw. So the whole lot is removable.


04-05-2010, 12:18 PM
Rolling chassis day today! With brake (singular) and collars holding the back axles on.

Putting the brake calliper on:


Rear chassis tube seems a little bendy with me and passenger located?


Downhill test! :1eye: Shortly after this photo was taken I lost my bottle. I could feel that one brand new (with probably slightly oily disk) brake wasn't going to stop us...


04-05-2010, 12:49 PM
Downhill test! :1eye: Shortly after this photo was taken I lost my bottle. I could feel that one brand new (with probably slightly oily disk) brake wasn't going to stop us...

Don't you know that the proper way to test drive is down hill with NO brakes!? :punk:

Looks good.

04-18-2010, 08:49 AM
Rear derailluers, ugh! Mounting them is a pain. Only a couple of weeks ago - really far down the road in the project - I actually thought about how to mount the rear derailleurs.

In the Kyoto Cruiser plans, Brad used a couple of 'old school' rear derailleurs that mount on the rear axle. These have their downside in that the ideal mounting point is in the middle of the axle (which is definitely not desirable for KC). But their plus side is all's you need is an axle-diameter bolt to attach to the spur that you weld to the frame.

I have newfangled Shimano rear derailleurs ('cheapo' Alivio series). They do have some alloy castings (I think) and some steel bits. These have the advantage in that they are designed to screw into dedicated holes in the rear dropouts in a normal bike frame. The minus side is that these are a weird thread (weird thread on a bike frame, never!). It's a fine 10mm. I mean really fine. Standard coarse 10mm (M10) is 1.5mm pitch. Standard fine 10mm is 1.25mm pitch. These are 10mm x 1mm pitch.

My first thought was to machine a pair of new mounting bolts for the derailleur and throw away the ones on the Shimano. So, 'just' push that circlip off holding the bolt in place... ...hang on... ...just get the screwdriver... ...hmm, that's a bit tight... ...push... ...push... ...PING!!! @#&%!

So, there's a big spring hidden inside that body of the rear derailleur to control the chain tension and allow for a wide movement over sprocket diameters, isn't there?!? Firstly, where's that circlip gone? No idea - I have 120m2 of garage and a very large amount of junk in there. I have no spare derailleurs and no spare circlips. @#&%!

OK, we are short on time (I want to finish by the end of April (all will become clearer later)) and I need some plan B's in case I can't find that circlip. Onto eBay and ordered a second hand 10mm x 1mm pitch tap - that gives me the option of making my own dropout-style mount. Also ordered another Alivio rear derailleur (I plan to make more bikes in the future, so it won't hurt) from another eBay-er.

One day later, my wife found the circlip! Yay! Now, just push it together and we're back on track when the 10mm x 1mm tap arrives.

Has anybody ever actually tried to put one of these back together?!? It seems as though you need 3 pairs of small, yet very strong hands. @#&%!

Put my production engineering head on - after all, they must be able to make these in the Shimano factory. So I thought of making a little a jig that holds the little plate thingy and hold the jig in the bench vice.

So today I finished it (with some tortuous milling in my little mini-lathe (tip for those thinking of setting up to do milling in a mini-lathe: don't, just buy a mill)). And it worked! Here's the re-assembled derailleur (showing that pesky 10mm x 1mm screw held in by that even peskier circlip and hiding that very naughty, big tension spring inside):


In the meantime, still waiting for the 10mm x 1mm tap to arrive by post from UK, I thought, hey, why not just cut off a bit of frame which is tapped correctly and weld it on to the spur from the frame? So that's what I did (and the tap still hasn't come from the UK eBay-er (nor the spare derailleur)):


04-18-2010, 08:55 AM
As you can see, the bike will be yellow. Very yellow (with some black ancillaries).


The second colour coat's on and I have a pile of bits which I'm eager to bolt onto the frame.


Here's an accessory which is work-in-progress that will be bolted on to some of those extra tabs on the frame.


04-19-2010, 03:06 PM
That is one nice looking cruiser you have there!
I am liking your one of a kind machined parts.
I am enjoying your pictures and looking forward
to seeing the finished product...

Radical Brad
04-19-2010, 04:10 PM
Great progress!


05-12-2010, 04:43 AM
Well, I finished it in time for local Fiesta (end of April) and it got some good trials.

The first thing we noticed was that the chain kept leaping out of the idler wheel. So I made a quick and dirty 'keeper' to stop it from jumping out.


I grounded the rear derailleurs quite a few times - we have a dirt track of some 200 m / yards leading to the house. Shifting still appears to work, but I winced every time it graunched the ground.

The local teenage lads at the fiesta had fun. Some had more mechanical sympathy than others. In fact some were just downright vandalistic. (My late, great school Physics teacher, Tim Gibson, coined a verb: 'to boy'. So when something has been 'boyed' - that means it's been well and truly screwed up by a ham-fisted male teenager. The bike got 'boyed'.)

First item: the steering. I was aware that the governor that I made wasn't that strong. It had a bit of 12mm studding as the axle that was poorly welded to a plate that was (extremely strongly!) welded to the chassis. Well, the dodgy steering geometry coupled with some 'boying' meant that this broke loose on day 1. Here are the battle scars and the rework:


I thought I did a nice job when I reworked it. I got some 12.0mm bar and put M12 coarse threads on both ends. One for the nut at the top and one to go into a newly-made, threaded plate. Getting the old plate off was a swine - I had really welded that one on good. The new axle was screwed and Loctited into the plate. It came loose again ('boyed') the next day, aargh! I will completely re-fabricate the whole governor using a 20mm axle which I intend to screw into a plate using a fine-pitched thread and Loctite. I really hope that will be that - for ever.

Next up for being 'boyed': the stoker handlebars. I did a reasonable weld on the split-ring handlebar mount to the bottom of the frame. However, this is clearly not a strong enough design for teenage lads with a vandalistic bent. On day one they had ripped the bars from the chassis, leaving a hole in the chassis tube where the welded portion of the bar mounting ring parted from the bike. For day two I welded a beefy plate over the hole and the bar mounting ring to that plate. It came off again. Clearly some ape-like manoeuvres had been done on the bars, with full body weight and / or arm strength. This design isn't going to hold up long-term anyway, methinks, but I was pretty disappointed how short a time it lasted. I'm thinking that some bracing arms will be needed to reach out to collars clamped onto the stoker bars further out. It will need support up and down (bracing from above) as #1 important and also some bracing front-to-back. Here's the current sorry state of the stoker bars (lashed on by a well-meaning but not very competent member of the troop of teenagers).


05-12-2010, 05:22 AM
Steering Geometry: Brad Please Help!

I'm not sure my steering geometry is that great, although I'm fairly sure that I followed the instructions. It has a poor 'on-centre' feel and is 'nervous'. Furthermore, once the front wheel departs more than about 20 degrees from straight ahead, the weight of bike + driver + passenger is now lifted by some significant distance due to the amount of rake. This has, no doubt, contributed to the very rapid failure of my governor assembly which, I will admit, wasn't exactly a mega-strong design, but when the steering went to full lock and the bike was stationary and loaded with humans would take a real beating from a brute-force driver trying to straighten the handlebars.

In short, I feel there's way too much 'flop'. Although once you get going it does, indeed, feel stable.

I am fairly sure I am going to have to introduce an angle grinder with cutting wheel to make the steering steeper. What I would like to know is, how far out of whack (in terms of degrees) do you think I am? I really don't fancy having to do more than one more cut and weld cycle on the head tube area - I want it right next time!



John Lewis
05-12-2010, 10:18 AM
In general I don't think you need anymore than 2" of trail or rake as you have called it. I always go for about 1.5" give or take. If the frame moves obviously up and down as you rotate the front wheel then you have too much in my opinion. Like salt on your food. You need a little but not too much or it won't be nice.

John Lewis

Radical Brad
05-12-2010, 04:53 PM
I brought your image into TrueSpace, and did a little messing around. looks like you could lessen the head tube angle by at least 10 degrees... maybe as much as 15 to get rid of the lift and flop effect.