Small Hi-power bike Concept, reality?

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
Trackman417   10 kW

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Re: Small Hi-power bike Concept, reality?

Post by Trackman417 » Aug 29 2015 9:41am

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

What kind of CAD modeling software do you use?
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H4065 36 mph
20s2p 10aH lipo battery pack
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Bluefang   10 kW

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Re: Small Hi-power bike Concept, reality?

Post by Bluefang » Aug 30 2015 1:58am

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.
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RobertC   1 W

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Re: Small Hi-power bike Concept, reality?

Post by RobertC » Sep 02 2015 11:54am

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?

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magna_503   10 W

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Re: Small Hi-power bike Concept, reality?

Post by magna_503 » Sep 03 2015 6:30am

RobertC wrote: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.

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macribs   1.21 GW

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Re: Small Hi-power bike Concept, reality?

Post by macribs » Oct 26 2015 7:08pm

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.

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crossbreak   100 MW

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Re: Small Hi-power bike Concept, reality?

Post by crossbreak » Jun 03 2016 5:18am

Miles wrote:
myosis wrote: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.

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Miles   100 GW

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Re: Small Hi-power bike Concept, reality?

Post by Miles » Jun 03 2016 5:34am

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.

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Re: Small Hi-power bike Concept, reality?

Post by crossbreak » Jun 03 2016 3:24pm

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.

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Miles   100 GW

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Re: Small Hi-power bike Concept, reality?

Post by Miles » Jun 03 2016 3:33pm

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

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macribs   1.21 GW

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Re: Small Hi-power bike Concept, reality?

Post by macribs » Jun 03 2016 7:31pm

Miles wrote: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.

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spinningmagnets   100 GW

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Re: Small Hi-power bike Concept, reality?

Post by spinningmagnets » Jun 03 2016 10:18pm

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

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Miles   100 GW

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Re: Small Hi-power bike Concept, reality?

Post by Miles » Jun 04 2016 12:51am

macribs wrote: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.

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nutnspecial   1.21 GW

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Re: Small Hi-power bike Concept, reality?

Post by nutnspecial » Jun 04 2016 9:16am

cheapest Walmart full suspension bikes
. . . and a link to my bike, klein mantra . . . worst product/ design :lol: :evil:

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 :)
100_1779.JPG
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   10 mW

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Re: Small Hi-power bike Concept, reality?

Post by myosis » Oct 20 2016 2:58pm

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 ;)

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macribs   1.21 GW

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Re: Small Hi-power bike Concept, reality?

Post by macribs » Oct 22 2016 4:16pm

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.

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