Getting rid of the belt - how to retro-fit a chain ?

Dear friends,
I’ve been riding my Strida 5.0 for almost 5 years now morning and evening to commute back and forth between home and office, no matter the weather, covering around 5.000 kilometers.

Now I’m getting more and more frustrated because of the kevlar belt: tooth jumps, difficulties to tune and maintain the correct tension, snubber position needs to be set with laser-like precision, etc.

I am basically fed up with the belt and would like to put a chain instead, because I love my Strida and all the rest corresponds to my needs.

Any idea on the technical feasibility of this ? My main issue would be on how to tune the chain tension. Would the existing setup be sufficient ?

Thanks for your help.

Hello Googleg,
maybe you should change the freewheel?
However, a Korean strider modified his bike to a chain operated fixie,
few pics are here:
(Look for Strida FX of J. W. Won)

Okey, I’ve started working on my transformation.

I have removed the manifold and the chainring, using a manifold extractor. That was pretty easy.

Now, I’m stuck at the next level: I wanted to remove the chain ring from the manifold, but unfortunately I don’t have the tool to lock the chimney bolts and unscrew the thing.

The chain ring size is standard, 4 holes at 75mm from each over. I’m confident I’ll manage to find the replacement part easily.

I’ll keep you updated, stay tuned. :wink:

One side of the bolts is 5 mm Allen key, vice versa might be this useful:

Caution, quality adequate to price…

Yes, this is exactly what I need :slight_smile:

Worst case scenario I’ll go to the bike shop with the set and they will unscrew those things for me.

OK, I am progressing with my transformation. I have ordered some parts on bikester to replace the transmission.

The beast waiting for the transplant:

New crank in place:

Closer look:

Same, from above:

The new freewheel (I was happy to be able to remove the old freewheel without too much of effort):

…AND ohhh sh1t:

The new freewheel has the correct width but the inner diameter is too small. I thought this was standard but obviously it’s not !!

Soooo, now I need to find the right freewheel, hoping that such a thing exists !

I took the opportunity to inspect the belt and there are signs of fatigue on it. I believe that by fliping it I should be able to reduce the slipping.

To be continued…

All right, I have the explanation: I took a BMX freewheel (30mm threadiing) instead of an ISO one (34.92mm).

:sunglasses: :sunglasses:

Thanks to

Hi, :wink:

I just read your step of retrofit a chain, any updates? And…is it possible to let me know your teeth of chainrings? I also want to know have you check the ratio of chainwheel and freewheel yet?

any updates will be appreciate.

Hi FB-Strida,
Sorry for the late response, I was on ski vacation in the alps :wink:

Even being there, I took some time to do some shopping at a bike store and I finally found my freewheel…!!

In terms of ratio I will have 42x16, a little bit smaller than the original 100x30. This is going to reduce my top speed a bit, but I’ll see on the long run.

I’ve made some good progress with the transformation now, the only missing part is the chain which I need to install and tighten.

I’ll try to post some pictures tomorrow.

Good day Googleg,

Ski vacation sounds nice to me, too! Even there might no chance to have this kind of vacation :wink:
Also, I am very happy to heard that you found your freewheel! And I hope you will find the chain in the shortest time, too!

Hum… I have to tell you that I was feel a little bit strange about the your last freewheel 13T one, because I think 16-18T may more common, maybe I am wrong? ( And, if it’s a common parts, it will be easier to get a back up one, this is what I am thinking about, you know stuffs sometimes will broken… :smiley: )

yes, you are right, it’s indeed smaller than current one, but I think it’s ok, no? :slight_smile:

Anyway, good luck! can’t wait to see the whole new Strida with chain system! ¡ánimo! :wink:

All right, back to my workshop in the basement…

I just fitted the chain, here is the result, does that look good ?

Well, … in fact it’s not good at all !! The crank chain ring is too small (42 teeth) and the chain is rubbing against the frame !

It’s just a matter of few milimeters, too bad :frowning:

SOoo, now, I have the choice between buying a larger ring (48 or even better 50 teeth) or completely replace the crank…

Stay tuned !

All right, here are the latest news:

I’ve managed to find a second hand 51 teeth chain ring to replace the one above (42t). I was delighted because the 51/17 ratio is exactly the same as the original ratio.

Guess what ! Still too small ! The chain is still rubbing against the frame. If a give it the maximum tension I can barely obtain a few millimeters of clearance.

Sooo, now I’ve decided to really really take something much much bigger: 56t ! With that it shouold be finally OK.

The huge drawback is that my gear ratio will skyrocket to 3.29. I’m a bit anxious to see how hard it is going to be for me to pedal with such ratio.

I’m attaching some pictures below:

No, it is not, 51/17 means a gear ratio of 3,00 - the original ratio is 3,33 (100/30).
56/17 means a ratio of 3,29, and that would be very close to the original ratio.

Gear ratios information about different models of Strida

You are totally correct, thank you :wink:

Now I feel better, because I may have some margin to even go with a bigger chainring if needed (58t or 60t)…

Very good :slight_smile:

60/18 would match the original ratio 100%.

Mission accomplished !

I would have preferred more clearance for the chain, but that would require me to change the chainring and the freewheel. Right now I have 56/17.

The chainring, 56T, from Stronglight:

The freewheel, 17T (mounted with the original washer taken from my plastic freewheel):

I really like how the bike looks:

Sorry for the bad quality of the picture, weather is not really good today in Geneva !

Now I’m going for a test drive !


it looks very nice! please let us know how do you feel after the first ride. :smiley:

Well, I only did a quick ride today…

The first impression is very positive. It feels ‘lighter’ (although I doubt it really is, even if the chainring is lighter than the original, there is the extra weight of the chain). I would say mainly the feeling is to have a more ‘rigid’ frame, more responsive, which is what I was expecting.

So far, so good !

:smiley: :smiley: :smiley: very good! and thanks for share your feeling, too!

Here is an other picture under a sunny sky…