CYC Pro Gen1 Belt drive

[Universalus]

My first attempt to check belt drive concept instead of 219 chain on CYC Pro Gen1.

100T and 20T pulleys used. HTD 5M 20mm belt, width 20mm.
Initial result is very positive. Gear box used in Cyc Gen1 is noisy. However, getting rid of a chain noise makes the system way more enjoyable to ride. In a nutshell, it no longer irritates me. Highly recommended mod.
I haven't made any modifications to the original system. If needed, it could be reversed back to chain version.

P.S. I don't have a drawing, made the whole mod in my garage on the go.

 

[qwerkus]

My first attempt to check belt drive concept instead of 219 chain on CYC Pro Gen1.

100T and 20T pulleys used. HTD 5M 20mm belt, width 20mm.
Initial result is very positive. Gear box used in Cyc Gen1 is noisy. However, getting rid of a chain noise makes the system way more enjoyable to ride. In a nutshell, it no longer irritates me. Highly recommended mod.
I haven't made any modifications to the original system. If needed, it could be reversed back to chain version.

P.S. I don't have a drawing, made the whole mod in my garage on the go.

IMG_2653.jpg

Nice mod! Where did you get the pulley ?

 

[SL33]

Cool!
Brass gears now available to quiet down gearbox.

 

[raylo32]

Looks like a nice mod but the OP is really teasing us by not posting a drawing or at least a detailed parts list and a few install pics. I have a CYC Gen 2 Pro coming to install on a donor Stumpjumper XC. I saw the brass gear option when I ordered but elected to stay with steel. Perhaps a mistake. We'll see.

Cool!
Brass gears now available to quiet down gearbox.

 

[Universalus]

Nice mod! Where did you get the pulley ?

20T pulley (steel) bought locally for 3 EUR
100T pulley form Aliexpress
https://www.aliexpress.com/item/4000450535929.html?spm=a2g0o.productlist.0.0.4867377ceW27u5&algo_pvid=5fc474da-cef9-458a-92cb-80d985b574e4&algo_exp_id=5fc474da-cef9-458a-92cb-80d985b574e4-0

 

[Universalus]

Some photos:
Raw:


After some machinery:


Reverse side 100T pulley:


Finished 100T (not final mod):


Mounted:

 

[raylo32]

Ah, that's the rub... needs serious machining that is waaaayyy beyond my workshop capability. I was hoping this just used off the shelf pulleys. Oh well. Let us know if you ever want to make more or sell it as an upgrade kit.

 

[Universalus]

My tools are too weak for mass production (weakest part is a mini lathe).
Total cost for the parts ~ 80 EUR.

It is not a complicated mod, although it takes time to get 100T pulley from China....

 

[raylo32]

Well, I have neither a lathe nor a drill press... or any experience trying to precisely locate holes like that. But curious why you didn't use this "AF" type pulley that doesn't have that thick hub extension?

https://www.aliexpress.com/item/4000820224088.html?spm=a2g0o.detail.0.0.27337073hT23qW&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.169870.0&scm_id=1007.13339.169870.0&scm-url=1007.13339.169870.0&pvid=35df64d9-6858-4a76-a5a1-3534d841fbda&_t=gps-idcDetailBottomMoreThisSeller,scm-url:1007.13339.169870.0,pvid:35df64d9-6858-4a76-a5a1-3534d841fbda,tpp_buckets:668%230%23131923%2350_668%230%23131923%2350_668%23888%233325%2318_668%23888%233325%2318_668%232846%238112%231997_668%235811%2327173%2313_668%232717%237560%23211_668%231000022185%231000066059%230_668%233468%2315612%23383_668%232846%238112%231997_668%235811%2327173%2313_668%232717%237560%23211_668%233164%239976%23927_668%233468%2315612%23383

My tools are too week for mass production (weakest part is a mini lathe).
Total cost for the pats ~ 80 EUR.

It is not a complicated mod, although it takes a time to get 100T pulley form china....

 

[Universalus]

Thick hub extension has been used for initial grabbing with the chuck for reverse side machinery. However, all versions could be machined. My tools have a limitation...

 

[qwerkus]

Very clean: congrats! Now all you have to do is gut a new set of gear helical instead of straight, and you d have a silent drive!

 

[raylo32]

What did you do for that idler/tensioner pulley? Is that using the OEM tensioner mech?

 

[Universalus]

What did you do for that idler/tensioner pulley? Is that using the OEM tensioner mech?

Original tensioner removed, as the belt requires constant tension. I have made a simple adjustable plate (held by two screws) holding the tension wheel utilizing the same tension hole and the hole for the second bolt that originally was present on the side panel.

Idea:


Some photos:

 

[raylo32]

Very nice, works a bit like a motorcycle chain tensioner. Lathe looks like fun and a useful machine. If I ever get the space I might get one. But that would be another rabbit hole to go down like when I am designing and fabricating functional stuff on my 3D printer. Sometimes many iterations to get things right.

 

[Universalus]

My personal experience that the whole CYC Pro Gen1 system is not worth to begin with. No mater of good quality workmanship of the whole kit, the system has to many mechanical issues.

 

[raylo32]

What kind of issues? I haven't had any problems with my Gen 2 but I'd like to know what to be on the lookout for. They do have new improved controllers so that should not be a continuing issue, at least. And it seems pretty solid mechanically.

My personal experience that the whole CYC Pro Gen1 system is not worth to begin with. No mater of good quality workmanship of the whole kit, the system has to many mechanical issues.

 

[Universalus]

I am referring to Gen1:
1. Bottom bracket and sprocket ball bearing are too small and too weak to hold the stress. It gets crushed after 50 km, although it continues to function with cracking noise. Gen 2 no longer uses the same design.
2. Ball bearing in the the gear box seems to last longer than at the bottom bracket, but in my system it is worn pretty bad and needs replacement. Mileage ~1500 km; it should last at least 10x longer.
3. Due to a small size, 219 chainring is wearing out at excess rate. Bad design, the whole 1st stage reduction planetary box has to be redesigned to adopt a bigger chainring.
4. Bad Gen1 chain tensioner design.
5. Noisy Gen1 gearbox.
6. Using ASI BAC855 controller, the whole force from the motor is reached only at top rpm, which limits climbing capabilities. With stock controller at low rpm, the motor has much more force (although the stock controller is a piece of junk).

 

[raylo32]

Could this be improved by swapping to Phaserunner and CycleAnalyst or some other controller setup?

6. Using ASI BAC855 controller, the whole force from the motor is reached only at top rpm, which limits climbing capabilities. With stock controller at low rpm, the motor has much more force (although the stock controller is a piece of junk).

 

[Universalus]

I would pair the motor with KLS-S - Mini Sinusoidal Brushless Motor Controller. They proved to be very good controllers (easy to program, very powerful and fairly cheap), I have used them on many projects.
I do have a new KLS-S. However, I am not going to test it with CYC Pro Gen1. Enough is enough...

 

[12-C]

Great setup. Do you think a gates carbon drive or Veer belt conversion would have held up? They are quite a bit narrower.

 

[Universalus]

I think there are no short belts available from your mentioned brands.

 

[scianiac]

Also I think the 11mm pitch of gates carbon for instance is way too large for such a compact reduction, but I would be curious to see if a maybe a narrower belt or a greater reduction could be had with some of these marketing claims that gates makes about how much better polychain, GT3, etc is than HTD. They claim 4 times the capacity (1/4 the belt width) with Poly chain GT carbon and 2 times with powergrip GT3 but those almost sound too good to be totally true and of course finding off the shelf sprockets might be hard.

 

[banshee28]

It would be nice if CYC offered this setup with their latest models: Gen 2 and Stealth. I know I would be interested when I eventually get one of these!

 

[napaharp]

Universalus I am looking at copying your Belt Drive system. I have access to a commercial lathe and have the skill to use it. From what I can get from the posts and the pictures the belt is a HTD 5M-700 with a 20mm Width. The large pulley starts out as a 5M100T-BF - AliExpress 21mm Width. The small gear looks like a 5M20T 21mm Width with a keyway. AliExpress also has these; however, not sure on their keyway dimensions. What did you use for an idler wheel? You posted a good sketch on the adjustable idler bracket but not what wheel to use.

Main Question: Did this quiet the motor down? I would hate to spend all the time to make this mod and find out it did not solve the noise issue. I have a Gen 2 CYC X1 Pro and it has brass gears and still very noisy.
Also: Any help on what parts you used for your mod.

 

[JRR-1]

I copied his ideas to my bike, gen2 and brass gears. It turns the noise down some but it doesn't make it silent.

Keyway is 4x1.8mm, if I remember correct, axle diam 12mm.

21mm pulley is kind of a tight fit on the motor side. Not too much clearance between the pulley and the cranks. It can be made to work, look closely how Universalus did it. 5M belt may be little on the small side for this purpose. Also the 20mm belt width seems to be kind of rare size. Aliexpress has them, but watch out for the quality. My first belt broke on first time giving the full throttle with 2kW. If I make a new version to fix some of the the mistakes on the first one, I will see if I can fit 8M belt.