(Wooden) design help/advice needed

[Ming the Merciless]

How does the gearing work if the pedal cogs are fixed on the frame but the front wheel twists to steer, how is it the chain doesn’t come off?

The idlers will keep the chain in place and you don’t really turn the forks much when steering, it more about lean.

 

[stuckinthemud]

Thanks

 

[Andy in Germany]

How does the gearing work if the pedal cogs are fixed on the frame but the front wheel twists to steer, how is it the chain doesn’t come off?

I asked my colleague that but apparently as @Ming the Merciless says, the wheel doesn't turn that much. It does rub slightly though so the Mk II version will allow the chainwheel to turn with the wheel, so his feet will now have to follow.

 

[stuckinthemud]

That triggers a design decision: front wheel drive or rear wheel drive. Probably a can of worms, but, are there clear advantages to either one?

 

[stuckinthemud]

So I’ve been reading around a bit and now am really knotted up. I mean, first off I thought a plank or slightly bent laminated plank was my best option, then Andy posted his colleague’s bike, and that remains my favourite but then that led through mid racers to low racers and then the dark world of pythons and flevo bikes and now I feel completely befuddled. To whit I need a compact machine, light in weight I can bundle into the back of a small car and where I thought there were few options, it turns out I am literally spoiled for choice.

 

[Gareth]

I have built and sold a few of these "bent plywood" bicycles in derailleured, IGH and flip-flop configurations.
For the flip-flop and IGH versions I used eccentric bottom brackets so the chains could be properly tensioned. Thorn Tandem "stoker" bottom brackets are the ones I used.

One of them that I built was laminated from 1.5mm layers of Hazel, Holly and Hornbeam that I harvested from my local woods after a storm. This I seasoned for 2 years in my garage before ripping the timbers down and planing to size using a thicknesser in a friend's joiner workshop. I made an internal style form from OSB and plywood and worked inwards when laying up and glassing down. This kept the strips of wood under tension against each other by clamping up and without having to clamp it down and this process made the whole laminating of the curved frame so much easier.

Here is a link to the Instructable on how to laminate the plywood: www.instructables.com/Bent-Plywood-Bicycle


Next year I hope to make a bent wooden laminated frame sail-touring tadpole trike.

 

[stuckinthemud]

Ok, so I bought a pair of 20” wheels from Cardiff Cycle Workshop- great place gonna be going there a lot I think! One came with a Shimano 6 speed gear set (cassette???) . Result. Time to do some drawing and make some firm decisions. Got a LOT of yellow pine I cut into 10mm thick strips to build a strip canoe. I am really taken by the flevo cycle concept as a light weight compact bike I could easily put a hinge in to make a crude folder a bit like the Sticky Toffee Pudding on
mosquito-velomobiles.com except with the seat less laid back. Any thoughts?


Thanks Gareth, that bike is very lovely

 

[stuckinthemud]

I am thinking of something like this: 2 x20” seat height about 14”, fwd (probably) I could do with some input on this

 

[Scoosh]

This might help you with some of the details ...
Raptobike Low Racer – notice the mahoosive front ring !

 

[stuckinthemud]

Yes, I see what you mean that really is pretty big. I’ve never looked at the raptobike as it’s a 26 20 and I’d always intended going with 20 20 but now you pointed it out I can see it is quite similar to my sketch