robo

On my way home tonight, the Gates CDC carbon drive belt on my winter commuter bike snapped. This was my 4th winter season on it, in pretty crap conditions (subzero F temps, slush, road salt etc), so while I was pissed that it broke at the time, in retrospect it was probably past time to replace it.

Problem is, my bike has the Gates CDC system, and I cannot find a replacement CDC 118t belt for sale anywhere. All that they sell now are CDN and CDX.

Are CDX belts compatible with CDC sprockets? Or do I have to replace my sprocket and chainring as well? Kind of frustrating if it's not compatible and they no longer make replacement parts...

Thanks,
robo

02Giant 

https://www.gatescarbondrive.com/oem-factory-support

CliffordK

Odd, they look identical, other than the center groove, but nothing seems to mention if that is in fact the case.

Are your sprockets in good shape, or are they showing signs of wear?

If you are working with a local bike shop, or can otherwise find test parts, I might just try out the CDX belt.

Or, if online is your only choice, and you wish to keep the same gearing, then just get the belt first and sprockets later if needed.

Rajflyboy

Harley Davidson May have a belt that works

i thought belt drives were supposed to be NO maintenance?

I hope you you can find the belt you need

robo

They are actually no-maintenance, but they don’t last forever...

2old

Good cautionary tale to procure an extra belt (or two) when you get a new belt-driven vehicle, and maybe carry one with you.

Crankycrank

+1 for contacting Gates. Who better to ask?

WizardOfBoz

They are available, at least in England: https://www.bike24.com/p2141028.html

Not sure if they ship to the frozen Northern Tundra.

tomtomtom123

Yeah, I'm not sure what your problem with finding a belt is, but I was able to find several in 1 minute of searching on Google. With exactly 118t
https://www.modernbike.com/gates-car...-118t---1298mm
https://www.ebay.de/itm/Gates-Carbon...-/273331506411
https://bikemarkt.mtb-news.de/en/art...-118t-blue-neu

Darth Lefty 

Iirc it’s a standard timing belt

CliffordK

I searched and missed a couple of those. Wrong keywords? Mostly shipped from Europe? Modern Bike (above) lists it as out of stock.

The OP's question about using the CDX with the center groove is still valid. Otherwise, perhaps buy up those last remaining belts in bulk.

CliffordK

I don't think I've seen timing belts/sprockets with that large of teeth. But, it is possible it is a brand I'm unfamiliar with.

Is the width right? No doubt the Harley Drive belt is a touch too wide, and would need a modification.

Unfortunately, I've frequently found parts descriptions inadequate for those of us willing to try to adapt from one application to another. In this case, I think the width between the CDC and CDX was the same as noted on some pages, but nothing seems to note the tooth profile.

Likewise, I can find a Ford or Chevy or Fiat timing belt, but it is difficult to find the specs on teeth, width, tooth profile, etc.

robo

"Yeah, I'm not sure what your problem with finding a belt is" Gee, thanks.
The first one is out of stock, and the others are in German, so I have no idea if they are in stock or not but they didn't come up in my search results. There are a lot of places that still list this item in their inventory but have no stock since it's no longer made. A 1 minute Google search for this is kind of misleading.

robo

They only have 3 sizes left, none of which are the size I need (118t) unfortunately.

robo

I don't have a definitive answer, but a number of sites (eg. modernbike.com) have warnings that CDX stuff is not compatible with CDC. So maybe it's more than just the groove.

CliffordK

What we do know is that the CDC belt will not work on a CDX sprocket (missing the center groove). I'm not seeing visa-versa.

I am seeing references of both the CDC and CDX being 118T, 1298mm long. So, apparently both use an 11mm tooth pitch.

I thought I had seen 11mm wide, but I also saw 10mm wide, so the 11mm may have been the tooth pitch.

Anyway, if you can verify the width, I'd be tempted to try one of the CDX belts. Then also snag a couple of those German/European belts for stock, assuming your sprockets are in good shape. If the sprockets are wearing, then don't over-stock.

gearbasher

Here's one. Don't know if the price is good. https://www.bikebling.com/Gates-Carb...18t-1298mm.htm

dedhed

The E bay link specifically states no shipping to USA

tomtomtom123

All you have to do is ask the seller if they're willing to ship to the USA. Shipping from Germany by airmail is just $5. Plus around $3 for tracking. FedEx also offers 24 hour shipping from anywhere in Europe to the USA. For a small 500g package, it might cost around $30 if you have a business account.
Chrome has a built in translator. If you don't use Chrome, all you have to do is copy and paste the text into Google Translate.
For the other sites that are out of stock. All you have to do is email or call them on the telephone and ask them if they are able to order the out of stock item.
The site that I linked before for the guy in Spain who has 2 of the belts, his email address is on the page. You could ask him if he would ship to the US.
For ebay, you could change the .de to .com to switch to US eBay, press the "contact seller" button and ask the seller if they would ship to the US.

You could also contact the manufacturer, and ask if the other belts are compatible, or if they have any of the ones you want in their stock.

robo

Thank you! That does look like the part, and the 10mm width sounds right. I ordered two!

As for the suggestions to contact Gates, of course that's an option, but it's the weekend and until I can get a replacement my bike is out of commission, so that's why I was asking here.

CliffordK

That BikeBling price looks like about $20 less than the retail on the CDX belts (depending on the vendor). I might have bought more than 2.

robo

I wasn’t 100% sure it was the right unit, due to the lack of info on the site. I’m sure you’ve encountered situations where the wrong photo is used etc.

If they turn out to be the right part I probably will order another, but frankly I’d guess that by the time I get through 2-3 more belts I’ll need new sprockets anyway.

gearbasher

I worked as a conveyor mechanic for 30 years. Around 1992 we had a new system installed and they used Gates polychain drive belts in place of chains and sprockets. I worked on that system for over 20 years before retiring. The only times we needed to replace sprockets was when the side flanges would snap off (basically due to poor alignment). I never saw a worn out sprocket. I'm talking about 100 drive/driven sprocket combos running 24/7 for over 20 years. As far as the belts went, the blue carbon ones tended to snap and with the "plain" ones (I forget what they were called), the teeth would shear off.

Edit: Then again, our sprockets were steel. I'm guessing the ones on bikes are alloy. I've never seen one.

robo

Interesting. On the bike the rear is stainless and the front is aluminum. And yeah, it was black with blue teeth and snapped.

robo

A few updates, that might be of interest:

1. The bikebling.com order came through (thanks gearbasher!), and they are indeed the correct and hard to find CDC belts. I have one mounted now and it's working fine.
2. I got in touch with Gates support, and they provided some useful info: CDC and CDX are compatible in a limited way: the tooth profile is the same. Early CDX sprockets were of the 'mudport' (ie. no center ridge) design, same as CDC. These sprockets are thus compatible with CDC belts. However, CDX uses a 12mm belt, vs 10mm for CDC, so you can't throw a CDX belt onto CDC sprockets, as the belt will be too wide and will be unevenly tensioned (it'll extend off the edge of the sprocket teeth).
3. While putting the new belt on, I realized that my front sprocket is very worn as well (see attached photo). Like the belts, CDC sprockets are hard to find, but I was able to locate a replacement CDX Mudport (no center ridge) sprocket of the correct size on eBay. Given the info from #2 above, this CDX Mudport front sprocket should work with my CDC drivetrain.
4. I figure this is the end of the line for the CDC parts on this bike. After the replacement sprocket, and the remaining spare belt I have on hand, I think it'll be a full upgrade to CDX when I need to replace something else.

Worn CDC Mudport sprocket teeth