Small Hi-power bike Concept, reality?

[Trackman417]

Edit: Completely off-topic, but curiosity has gotten the best of me.

What kind of CAD modeling software do you use?

[Bluefang]

Maybe abit late but why not use one of John from CRs hub motors? Its not too wide for a custom frame and would make for a much simpler drive line as its rpm/V is only around 16. So at a common 20S lipo its ~1000rpm loaded. Plus if you are happy with normal controllers john might even be able to supply some really wicked controllers to power it all. Or go crazy and get a twin min-e or max-e system.

[RobertC]

Looks good, but I think adjusting belt & chain tensions will be a killer. I just finished a one week journey through 125 pages on LightningRods drive thing. Torque braces, adjustment slider slots and bigger thicker plates etc absorbed a lot of his (very mechanically experienced) time.

Do not under-estimate final fitment and fiddling. Even though it looks like it should work even +/- 1 mm can be a big problem in the wrong place.

I am a software guy, so figure on getting it right about version 2, feature complete is v3, and usable at 3.11 with Windows.. And they had tons of money and engineers, with no manufacturing costs.

Also, what is your budget, both $$$ and time to make this ride-able?

And subscribed, too!

[magna_503]

Looks good, but I think adjusting belt & chain tensions will be a killer. I just finished a one week journey through 125 pages on LightningRods drive thing. Torque braces, adjustment slider slots and bigger thicker plates etc absorbed a lot of his (very mechanically experienced) time.

Do not under-estimate final fitment and fiddling. Even though it looks like it should work even +/- 1 mm can be a big problem in the wrong place.

I am a software guy, so figure on getting it right about version 2, feature complete is v3, and usable at 3.11 with Windows.. And they had tons of money and engineers, with no manufacturing costs.

Also, what is your budget, both $$$ and time to make this ride-able?

And subscribed, too!

I think you're spot on about final fitment/chain alignment. I built an 212cc motorized bike before building an electric bike. I spent a lot of time adjusting chain alignment and tension before riding, and I adjust them every 4 to 5 rides or so. On my ebike build, I didn't want to deal with chain tensioning and went with a hub.

[macribs]

How goes this project? Any progress you care to share?
Some solid thinking gone into this and I would love to hear more about what you landed on, how to get best chain line and whatever else you have in mind for this project.

[crossbreak]

There both on the swing arm so the distances will stay the same, it frees up a lot of space in the frame as well........

For me it just seemed simpler to put the both on the swing arm

Sure, it's what's known as a "unified rear triangle" design. You'll get some front to back movement of the pedals and the suspension is pretty useless when you're off the saddle.. The motor doesn't have to be concentric to the pivot point, though. As long as it's reasonably close to it.

the suspension is pretty useless when you're off the saddle

i can't second this. I ride a Rotwild with this linkage and a Fox??Air damper. Through rough terrain, suspension is no worse than the 4 linker i drove before. Even when i stand up on the pedals. IMO this is the most practical solution. chain tension adjustment by adjustable dropouts and a simple derailleur for the pedal chain.

[Miles]

Well, perhaps "pretty useless" was a bit of an exaggeration.. Anyway, I agree that it's a very practical solution for our needs. The Moulton TSR is like this (U.R.T.) - some other Moultons aren't.

[crossbreak]

Still not sure whether to mount the BB on swing arm or frame though. Does this really matter? 4links are more complicted, but gain freedom in frame design.

[Miles]

Well, if the BB is not on the swing arm, it's not a U.R.T. design...

[macribs]

Well, if the BB is not on the swing arm, it's not a U.R.T. design...

What is a U.R.T. design?

Still not sure whether to mount the BB on swing arm or frame though. Does this really matter?

What I can think of that sets them apart is that if BB is on the swing arm but not the pivot point pedals will move along when swing arm/suspension is working.
If BB is on the pivot point of the swing arm, then you will see some chain tension as the swing arm moves.

If BB is on the frame pedal will not move with swing arm.

[spinningmagnets]

URT = Unified Rear Triangle, not a two-link or four-link swingarm. See the cheapest Walmart full suspension bikes for an example.

https://dirtmountainbike.com/bike-revie ... er.html/16

[Miles]

What I can think of that sets them apart is that if BB is on the swing arm but not the pivot point pedals will move along when swing arm/suspension is working.
If BB is on the pivot point of the swing arm, then you will see some chain tension as the swing arm moves.

If BB is on the frame pedal will not move with swing arm.

You have it. The "unified" refers to the structural unification of the BB and rear axle.

[nutnspecial]

cheapest Walmart full suspension bikes

. . . and a link to my bike, klein mantra . . . worst product/ design

I have been very happy with the design for 17 years, though high pivot urt was unique at the time and is basically obsolete now. I also have a long stem and fingerless gloves, now that's some stuff I never heard ripped on before

Works for me and is a treat to ride, E or not.

Btw, great drawings op, I like the latest version for the simplicity!

[myosis]

I'm terribly sorry I feel like I kinde own every body here a result.
I felt insecure about the project so decide to build a simple bike first, however sadly I had to drop that too.
I made a quick topic about it here:
viewtopic.php?f=3&t=84315
I did learn a lot thanks to you guys! can't stress this enough

[macribs]

Really to bad this was not completed. But that is life, things rarely goes as planned. Your new carbon fiber project I will follow. Hopefully one day you will find the time to pick up on this project again.

You got some awesome rendering skills. Does people contact you to do custom work for them? If not, try to advertise your skills in here. Maybe you can have a cool side job that you can bring with you when you go traveling.