Belt and Carbon Gates

I transform an old bicycle from chain to Carbon Gates belt drive system and I found the belt really nice and strong compare to my first try with a similar belt like the Strida one which i snapped after 600 km.
As I need to replace the rear freewheel of the Strida does anyone here tried to change to a Carbon Gates belt system ? I think the problem as mostly for the freewheel as it seems specific from strida.

Hi flectalux,

principially you’re right, the Strida’s freewheel is in fact a proprietary part.
But not the thread, that is a common ISO thread with a diameter of 1,375" and 24 TPI.

That means, theoretically, that CDX freewheels should be available - for example this one:

A matching beltwheel should have 72 or 74 teeth to keep the original Strida gear ratio.
Here’s possibly the first problem, the highest amount of teeth I could find so far is just 60, that’s not good:

The next obvious problem will be that of the belt - as you know are belts available in certain sizes only and the “adjustment window” of the Strida’s excenter is not that big.

And the excenter becomes also important in the case that you need a completely new crankset!
(You noticed the beltwheels five - arm spider; just the Strida has four arms.)
That is doable, but only by using a modified ATS excenter (like that which I made for the efneo drive).

Wow this freewheel is much more expensive than the one i bought, i give up.
New crank + gates set = maybe around 500 usd, like a full new Strida.
I always believe that a too expensive Strida is killing the point of the Strida…
But thanks for the info. Yes the length of the belt is always the tricky part compare to using chain.
I just complain how fast the freewheel get used compare to a standard chain cog bicycle.
My Gates One seems really durable, really stiff. But different cost.

Btw…if you managed to snap a Strida (like) belt within 600 km I’d say there must have been something pretty wrong with your bike - but the belt wasn’t guilty.

These HTD belts are primarily intended to last 50 000 or more km - but used in a car!

No not on a Strida, i should have mentioned. I installed a belt system very similar to strida, this belt have been used for a long time in Japan on city bikes. Anyway i mounted it on a city bike and after 600km snapped it. My freewheel was made from plastic by the way. I am not sure if it’s because this bicycle is more heavy than the strida or the overall design etc. Anyway i moved to Gates.

Here is a picture of the kind of bicycle I ride so you can understand it is very different than Strida design.

According to my understanding of a belt it must be impossible to mount on these bikes because the right chain stay is welded and not separable?

Here is the bicycle with the frame you can see can be opened

Ah I see, thanks :smiley:
Honestly I’d never expected a construction like this on a that simple bike.
Also interesting the two roller brakes, these types of brakes are highly weather resistant but heavy I’ve read.

They do not break very strongly, but fine for city use for me. And i really like the fact that they are careless, same like using a belt and no grease.
Also I am using this bicycle on a fixed gear hub so breaking power does not need to be too strong.
But yes they are heavy, but this bicycle is heavy. This is a very old design, when frames were not welded. Riding a Strida in comparison is like being in the future…

Hello all,

Just a note to let you know that despite the bicycle-specific Gates “CDX” style carbon belt drive system not being available in sizes to accommodate a Strida, there is a nice alternative…

Gates manufactures a “PolyChain” series of industrial timing belts using the same 8M tooth configuration as the Strida belt. These “PolyChain” belts use the same carbon reinforcement technology as the bicycle-specific belts and can be found in the 1440 tooth count length used on Strida 5.0 and LT and allow you to use standard Strida freewheels and beltwheels.

You can see the specifics here: … 00180.html

I found one eBay for ~ $30 USD and installed it on my 5.0 with great success - it feels a bit “snappier” the rubber version and looks better in my opinion.