Belt or Sprocket Adapters ???

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Jun 20, 2015
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I have been reading this thread “Belt drive Sprockets on the Cheap!” and did not see any mass production solutions.
https://endless-sphere.com/forums/viewtopic.php?f=28&t=26122

Has any one done any 3D printing of large pulleys?????

I need some for using “large-as-possible-diameter” (over 100 teeth?) 8mm Gates GT2 or 3 belts to drive the brake side with disc brake. Or a sprocket drive like below photo.
I need to slow the bike down to about 17mph to get enough power at 1500 watts when moving 400 or more pounds up a 9 % grade.

Some one here should be doing that or at least adapters for existing pulleys. Or some other way to mass produce adapters to attach a belt pulley to the inner-side of the disc mount, off set enough to clear the brake so it can still be used (and also use 2” tires).



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clearances.JPG
 
Hugh,
Here are a couple of JPGs of an actual build, JPGs are from 3D CAD. The hub flanges are 58mm apart. The hub was a 12x135 and a spacer was added to make it 12x142, with the spacer only on the disc hub side so there would be no dishing of the rim/tire. I made the 74BCD spyder for the 30 tooth cog and the cog is already 7mm toward the hub center from the disc mount face. The rotor shown is 160mm. I will have to go to a 180mm rotor or else put a 12mm spacer between the disc mount face and the rotor (as shown in the JPG) so that the disc caliper body (Hayes Ace 4 piston) clears the chain. Fortunately, I have a two stage reduction so the smaller (<32) will work OK. This is a trike rear swing arm design but is similar to your issues. A two stage reduction may help solve your problem, just a suggestion.
 

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thanks... you had to make ab adapter for the brake also?

but has no one made one to just buy?
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I found this adapter with Aluminum sprockets.
http://www.kingssalesandservice.com/top-hat-sprocket-adaptor/

Why do these people use aluminum for their candy colored sprockets?
Don’t they realize that even aerospace aluminum if wimpy compared to aerospace steel? And for a motor they can’t possibly last long.
 
Find you how much clearance you need on the back side of the brake caliper. Also note that the disc adapter you found will move your brake rotor outwards by the amount of its thickness. Your brake might or might not have enough adjustment to accommodate.
 
yes there maybe a problem moving the brake over the thickness of the adapter. I am trying to find pictures.

Chalo said:
Find you how much clearance you need on the back side of the brake caliper. Also note that the disc adapter you found will move your brake rotor outwards by the amount of its thickness. Your brake might or might not have enough adjustment to accommodate.
 
Hugh-Jassman said:
thanks... you had to make ab adapter for the brake also?

but has no one made one to just buy?
file.php


I found this adapter with Aluminum sprockets.
http://www.kingssalesandservice.com/top-hat-sprocket-adaptor/

Why do these people use aluminum for their candy colored sprockets?
Don’t they realize that even aerospace aluminum if wimpy compared to aerospace steel? And for a motor they can’t possibly last long.

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have a look at my norko build thread - ive made one for the disk side adapter myself to suit a shimano centerlock. Where about do you live? as i can probably make another for a few $$$. They're a bit of work though...

Works a charm now that i've got the motor running well with the controller, though i've still got issues with my pedal chain line.

Aluminium sprockets are fine for the larger chainring (like, sprockets over 30t or so) particularly with hard anodizing. They wont last as long as a steel one sure, but they're lighter and (sometimes) much cheaper. You can pick up decent 70t 219 sprockets for about $10 on flebay.
 
Hugh-Jassman said:
How much wider is the adapter; what axle width? And do I need to spread the forks a bit?

It looks like it may need a special hub....??

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standard 150mm 12mm hub, cut up an old disc to get the adaptor. No wider than standard, though i had to mod the caliper adaptor to fit it all in.
 
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I'm glad you said that....I think it maybe ok for a belt drive.? a wax lube may keep it reasonably clean.....mabe.

are there any right side sprocket adapters, or is the only way to custom mount the large procket onto the hub?


BHT%2Bmotor.JPG


boisrondevens said:
I love the idea of have the adapter on the left side but my problem is grease. I don't even like to touch my disc brake with my hangs by fear of putting grease on them. I can imagine the greasy chain splashing grease on them. Very clever idea but not practical for that aspect. My two cents
 
boisrondevens said:
I love the idea of have the adapter on the left side but my problem is grease. I don't even like to touch my disc brake with my hangs by fear of putting grease on them. I can imagine the greasy chain splashing grease on them. Very clever idea but not practical for that aspect. My two cents

yea i trialed it ona old set of pads, thinking that id have the same issue. been fine thus far, atleat 500km of riding. there;s a good 20mm seperating the sprocket and teh disk.
 
Thanks for the link! the picture of the black sprocket adapter was one i was selling. I'd commit a felony to get my hands on another one, but i'm sure i bought one of the last ones :cry: :cry: :cry: :cry:

The king's sales and service adapter is trash.. tried one.. threw it away.
That clamshell adapter mentioned earlier also only works on some bizarre single speed hubs.
The bicycle designer one you mentioned looks like the only legit option for now, and is worth a try.

Hugh-Jassman said:
I really like this one. Does anyone know why it may not work?

like where can I get large sprockets for it? I need to do a 9:1 reduction so maybe a 144 tooth?

Looks like I will need a longer axle, about 1/4 inch?

http://www.bicycledesigner.com/rotor-and-sprocket-adapter.html


bicycledesigner%2Badapter.JPG
 
Now I am thinking that some one should make an adapter for motorcycle sprockets to go right onto a freehub body behind a cassette of a smaller kind. Like behind a 7 speed cassette?



neptronix said:
Thanks for the link! the picture of the black sprocket adapter was one i was selling. I'd commit a felony to get my hands on another one, but i'm sure i bought one of the last ones :cry: :cry: :cry: :cry:

The king's sales and service adapter is trash.. tried one.. threw it away.
That clamshell adapter mentioned earlier also only works on some bizarre single speed hubs.
The bicycle designer one you mentioned looks like the only legit option for now, and is worth a try.
 
Given that the rear brake can only provide about 25 percent of maximum braking, why not just use a rim brake and have the rotor mount freely available for a sprocket? Trying to stack both of them on the same mount introduces spacing and contamination issues that will make a disc brake less effective than a rim brake anyway.

If the frame isn't equipped with brake bosses, a brake plate that has them is a simpler and easier machining project than a sprocket carrier for the rotor mount.
 
Chalo said:
Given that the rear brake can only provide about 25 percent of maximum braking, why not just use a rim brake and have the rotor mount freely available for a sprocket? Trying to stack both of them on the same mount introduces spacing and contamination issues that will make a disc brake less effective than a rim brake anyway.

If the frame isn't equipped with brake bosses, a brake plate that has them is a simpler and easier machining project than a sprocket carrier for the rotor mount.

I dont always agree with everything you say, but I agree with you here.
High quality pads on a rim brake would be much better than cramming a disc and caliper in a sprocket.
 
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