After approx. 2 years and 3.000 km the belt of my Strida suddenly twisted and got torn:
At the first glance it appeared that the belt was worn, so I ordered and mounted a new one. However after a few days the force for pedalling suddenly became a bit stronger for two or three brief moments and then the new belt twisted again before I could stop (due to traffic):
Therefore the belt cannot be the origin for this rather odd problem and as there is no Strida-shop within the next 100 km I’d like to ask for your advice.
Another issue with my Strida, is kind of a vaque cracking sound (“knacksen” in German) when pedalling uphill with strong force. This sound has been around for a while and it appears to be related to the pedals as it was almost gone after adding some lube.
As for Belt twisted issue, I have not seen issue like that. But one thing I would like you to check is if freewheel is properly “free” or not. If freewheel sometime does not work well, the belt will have unbalanced tention between top and bottom, although this is just my assumption.
I have had a kind of cracking sound issue in the past after riding my Strida under rain few times. My recommendation for this issue is to loosen screws from where the sound is produced, and tighten with proper torque, on top of rubing proper position(s). Using torque wrench is best.
That fault could happen only because the belt tension was too low, I believe.
Could you try to mount the belt again, but with a little more tension as before?
Seems that the Hong Kong Strida fans also have never seen that, there was no problem solution posted.
Now I’ve posted above at Thailand Strida forum, will see…
If the friendly fans there also have no idea, we should ask Ming cycles directly I mean.
Agrees - low belt tension.
But also check for alignment, pulley flange damage / bent ?
Loose rear joint (bolt from RHS / nylon washer between bottom tube and rear ‘part’ ? … causing poor rear pulley alignment (but I’m sure you notice this amount of ‘looseness’).
Problem with Front bottom bracket bearing - loose ?
F pulley not aligned on crank
F Pulley cracked or warped in heat ???
Now I’m stuggling to guess any more
good luck and please let us know what is the cause of this very weird happening.
On the Strida, the front pulley is not foreseen with full flanges, certainly not on the inside. So, if the belt is too lose and there is a slight misalignment between the pulleys, the belt could start bouncing, move sideways on the front pulley where there is no flenge and then get grabbed by one of the flenge portions and finally twist.
What they say, I think, is that once the belt twists, some internal damages appear (some cords break). So it creates a permanent distortion of the belt when loaded, which will trigger a new twist even if the root cause has been identifed and solved. This suggests that twisted belts should always be replaced.
I am back. It took me a while to answer for several reasons. The one reason is that the twisting happened two more times. The last time 5 minutes ago, when going to the office…
The cause for the twist appears most likely to be the fact, that the rear wheel twists towards the frame from time to time. It seems that the wheel has some kind of freedom as the frame has a u-shaped scrap mark from the rubber of tire on the lower/horizontal pipe of the frame.
The question is how I can fix the movement of the wheel. I assume that some axle-parts and/or ball-bearings have to be exchanged?
However as I am a bit below the 100kg payload maximum of the Strida and the roads I have to take are not the best, I assume that I will have to switch to another bike
It has been a while and the good news is that the belt twist did not happen again - thanks to Blackstridaaustria and his friend! At the beginning of July I had to chance to to visit them and bring my Strida all the way from Germany to Vienna, where they fixed it.
Most likely the problem was part no. 338, where the “disc part” was bent. This allowed the rear wheel to twist several degrees under heavy load (=myself). The other part exchanged by Blackstridaaustria was the Freewheel, which was partially worn and the belt guard was beaten up a bit. From my point of view the main fault was part no. 338. Together with the worn Freewheel and a heavy rider the belt could twist.
In the meanwhile have been driving at least 200 km (11 km per working day for three weeks plus visiting friends on the weekend) without any problem.