RWP
1 kW
Woohhhh doggies...What a find!
I just need a tad smaller. :wink:
I just need a tad smaller. :wink:
RWP said:I hope I am not out of line but...I suggest...request that the motor - fan issue be moved or continued elsewhere.
Thanks for your understanding.
Roy
RWP said:Thank you offnik!
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I have been tearing my hair trying to juggle all the alternatives and finally accepted that what was driving my insanity is that the secondary belt just is not up to the job (I know - I know - I have been forewarned) (and...attached to what I think is a more element solution)...I kept dancing around trying to find a way but in the end all the options were more work or trouble or just more of the same than biting the bullet and going to chain. Means I have to figure out some kind of tensioner but this at least is do-able.
I looked at 8mm pitch but the parts are just physically too large in diameter for my configuration. I looked at wider 5mm pitch belts but there is not enough room in the drive to add to the width and get all the pulleys tightened to the shafts...in the end the chain seems to solve the issue and allow use of a more powerful motor with a lower Kv.
I very much like the idea of using belts inside the drive unit and will explore 8mm pitch from the get go in my next drive design. I can get wider 5mm pitch belts if the 8mm stuff is still too big - this is my fall back...or go to chain...
The next enclosed drive design will have the sides removable so I will not have the fussy assembly issues I have with the current design.
I just do not care for the fact that #25 chain has no rollers and is thus a constant maintenance issue. And larger chain pitches are just...LARGER.
RWP said:Thanks Matt,
Now the question I should have asked before I ordered parts...![]()
For a chain tensioner I got a case hardened 1/2" shaft, a double sealed needle bearing and Delrin tube.
I am planning to press the Delrin onto the needle bearing and then notch it a bit as a chain guide.
Hold the bearing in place with a few alu spacers grub screwed to the shaft.
And support the shaft on one end by drilling and taping into the shaft end and holding it in place by pinching the tubing I am using as the drive housing...not planning on holding a lot of tension just to take up the chain slack.
What do you think? Your suggestions are appreciated. I may have to start over... :lol:
Roy
I replaced the secondary belt with a #25 chain and tensioner. Still have a 5mm belt for the primary dirve.12p3phPMDC said:Were you able to resolve your jackshaft issues?
Did you go to a chain or a new belt?
The belt started to delaminate. It made this loud low pitched "thumping" noise at slow speeds. If you look at the torque capacity of the GT2 belts (info from the Stock Drive site and probably from Gates) you will see that at low RPM's the actual power handling capacity is very low but as one increases the RPM's the ability to handle more torque increases significantly.lesdit said:Quick question: Did you find the belt was too weak in practice, or just in principal?
( did you strip it ? ) Bike looks clean, good work !
RWP said:I probably will not make another "through the crank" drive system.
All good questions...I do not have answers for.lesdit said:Hi Roy,
Did you find that the chain update made the bike noisier than the belt version ?
If not noisier, which sounded better, for lack of better words ? Chain or belt?
How about drag, I hear how efficient belts are supposed to be, but I have a gut feeling that by the time a belt is tensioned the right amount, it would cause too much drag.
TorqueTrans makes 14t 8mm pulleys - one just has to figure out how to buy from them! Anybody have a clue?lesdit said:I am searching around for gates belt data right now, and it seems that the 8mm pitch carbon belts have a lack of
small drive pulleys, I think that 20 was the smallest, with an OD that was close to 2 inches, which is huge!
I'm thinking that the reason they don't have small pulleys for the M8 belts is that they don't like the small tooth count or maybe the radius is too tight for the belt. What was the smallest 5mm gates drive pulley you found ?
lesdit said:My offroad only bike is using an 8 speed hub, but it is serving as a jack shaft right before the final rear sprocket. I am increasing the rear wheel sprocket from 32t to 56t , to lessen the torque transmitted through the shimano hub, in hopes of giving it a longer life.
Anyhow, thanks again for posting this thread detailing your bikes workings!
Hi Roy,RWP said:TorqueTrans makes 14t 8mm pulleys - one just has to figure out how to buy from them! Anybody have a clue?