Sideway movement of the rear wheel

My rear wheel developed some wiggle room last year. I took it out to ride last Saturday, after being stored since December, and the frame broke while riding. I’ve emailed photos to the admin to have them posted. I think the Strida is unreliable after being ridden for many years.

I purchased my Strida 5.0 in March 2008.

Hello ImpairedVisions,

I’m indeed sorry to hear that.
Broken frames are a very special issue I believe…
Would you mind to send me the pics too?
I’m quite unsure if Garry has enough time to post them…

From a production engineering point of view

A There seems to be a tolerance stack buildup due to:
Torque on how axle is screwed into rear forged joint
Thickness of rear forged joint
Surface texture of rear forged joint
Finishing of of rear forged joint
Thickness and wear of Large dia Nylon washer
Thickness of Bottom tube (and its nylon insert/end cap)
Surface texture of Bottom tube
Finishing of of Bottom tube
Axle length tolerance
Spring washer biting into rear tube … or … Thickness and wear of any thin washer under Spring washer
Spring washer, thickness’
Spring washer Hardness
Spring washer edge sharpness
Spring washer surface finish
Spring washer consistency - (taiwan supplier ??)
Lubrication (clear grease).
Small washer Thickness/quality/surface finish
M8 Bolt torque & Thread lock condition.

B The part(s) that takes up all this tolerance stack buildup, and keeps the best combination of folding stiffness vs Joint stiffness/no play is the [b]spring washer/b. This/These should fit between the bottom tube and the ‘small washer’.
The small washer should be torqued up and ‘locked solid’ by the M8 Bolt, on the end of the axle. Such that the Bottom tube rotates.

The spring washer should rotate with the bottom tube (as its larger diameter, left sloping, bottom end of the cone has more friction than the smaller diameter ‘top end of the cone’ … which in turn runs against the harder, more wear resistant (and lubricated) underside of the small washer…

See Strida 1 manual for a good description (without the small washer but with an M8 Button head screw) >
issuu.com/mark77a/docs/strida1-owners-manual/19
issuu.com/mark77a/docs/strida1-owners-manual/45

Dear Sir,

thanks for your message - after a long while; I’m happy that you’re still here :smiley:

Teaching us is very nice indeed, just we did already know several of the mentioned facts and of course we’ve read all informations available.
But it seems that Ming cycle didn’t read it…

Good to know how it should be, but in reality (at least on Strida EVO and 5.0) is the small washer definitely softer than the cup spring.

I’ve been reading this thread with interest.

I have a Strida SX bought from Velorution, London UK in 2013. It’s been my daily commuting bike (5km, so not far). I started experiencing problems with the belt about a year ago - twisting there times. Velorution replaced the belts and then recently the flywheel and the belt, because they were worn. But now the bike appear to have sideways movement in the rear wheel as quoted in this thread - enough that it caused me to stop the bike whilst riding, fearing that the rear wheel had worked loose. In examining the rear washer (364) inside the bolt, it appears totally deformed. I don’t know the state of the cup-spring (367-3) because I have always left the repairs to Velorution as they are authorised Strida mechanics. I will try and post photos now. Has anyone come up with a fix for this yet? I’ve asked Velorution to order new 364 & 367-3 parts to see if I can at least get back to square one.

I’m 1.89m tall and 87kg so put a fair amount of power through the bike, but not close to the 100kg maximum. I expect mechanical parts to wear. I’ve actually upgraded to the Strida alloy chain set because the flexing in the plastic one worried me, but I had belt issues before this upgrade.

Any thoughts welcome.

Alistair :smiley:

Hi Alistair,

quick digression before: Authorised doesn’t mandatory mean knowledgeable…
(Not for the first time.)

Yes, there are two fixes existent for that,
one is here, but please note especially the last post.

Do you know a trustworthy mechanic who is able to unmount 373, 364, 367 and examine the bottom tube hole?

Thanks BSA,

Every time I have taken the bike into Velorution, I get “Oh we’ve never seen that before” which doesn’t fill me with confidence. It looks like a simple fix though…if as you say the bottom hole has not become oval.

I’m not optimistic, being two years old that it won’t be oval. I’ll have a look this weekend. Whats the solution then - drill out the hole and fit a sleeve on the axle? Or a new bottom tube?

Alistair.

Hi Alistair,

thank you for the feedback :smiley:
Yes; there are still companies which are interested to sell - but not support :confused:

Hmmm…hard to tell; it will be oval; but how much?
If it is much deformed will be a new tube the easier way, they are not that expensive as one might think (accidentally depending on distributor).

I believe the bottom tube, once worn, could be saved just one way:
Replacing of part 100-07 (plastic tube insert) by Aluminium, equipped with needle bearing.
One, two securing bolts of the perhaps also elongated insert across the tube in 90° alignment to the axle. Creating of a fine adjustable pretension mechanism (= friction between bottom and seat tube) would complete a durable rear joint.

Maybe you want to help me forcing Ming for realization? :smiling_imp:

Perhaps you’re just too pessimistic and the tube hole is fine.

Chris

Took off the rear bolt to assess the state of the cup-spring and washer, plus the damage to the bottom part of the frame from the cup-spring.

Washer is totally deformed - you can clearly see the shape of the bolt imprinted into it.

Sideways view shows the deformation further:

Cup-spring has eaten into the frame:

I didn’t want to take the bike apart further, so hard to judge how ovalised the bottom hole might be. Both your fix Chris, and the Canadian option which Bill emailed me about seem like the way to go. Can I order one of your kits Chris please? Thanks Alistair

Uargh… :open_mouth: this frame is looking awful :confused:

I’m really in doubt if my usual shims are suitable for that deep grooves,
might be better to try thicker ones…wtf…
However…of course you may try - please pm me - thanks.

Looks like this bike was much more often folded than ridden…

Edit:
But once disassembled it’s clear why the cup spring can’t generate much tension, no?

It’s folded and unfolded four times a day! The freewheel and belt are new. So I guess it appears that way. I will PM you. Alistair

Hello Alistair,

your kit was shipped already at Monday, so it should arrive soon :smiley:
Good luck!

The kit arrived yesterday - great instructions and impeccably packaged up, so thank-you very much.
Fitted it today, and the sideways movement of the rear wheel has gone completely. I’ll keep you posted to how it fairs over time, but hopefully this is a great fix for the cheap components supplied with the bike. I’m convinced that the belt twisting problems all stem from the movement of the rear wheel… which in turn comes from one cheap washer. :unamused: :unamused: :unamused:

The thin washer seemed to cover the damage to the frame well:

Thanks so much for your help and generosity Christian - especially since as you explained, you have no official links to Strida other than being a fellow rider.

In contrast I have yet to even be called back by Velorution, where I bought the bike, and asked 10 days ago about ordering the replacement existing washer and cup-spring. Pretty poor customer service.

Best regards
Alistair :smiley: :smiley:

Hello Alistair,

I have to say thanks to you for being my test pilot :smiley:
Looking forward for your experience…

Best wishes,

Chris

Six months now of riding daily with the modification and I can report that it seems to have fixed the problem and more importantly lasted. I can thoroughly recommend this simple upgrade to any other Strida rider. It has stopped by belts coming off and removed any sideways movement from the rear wheel. In my opinion it should become a manufacturer’s upgrade. Result!! :smiley: :smiley: :smiley:

Dear Alistair,

thanks so much for your feedback :smiley:
I’m very happy that it lasted :laughing:

Best wishes,

Chris

Hello everyone,

Came across this thread due to exactly the same problem on my Strida SX. Actually it developed on both SX’s I’ve had - I sold the first one to a friend and he discovered the rear wheel movement afterwards.
I haven’t disassembled my SX yet, but I expect the damage to be quite serious - the sideways movement of the wheel is ca. 1 cm, although it’s not present all the time.

Blackstridaaustria - would you be so kind and post (or re-post) the pictures and specs of the repair kit you developed? I would be very grateful indeed!

All the best,
Maciej

Hello Maciej,
or should I say Lachman?

Well, that’s no problem, all the info is still here:
crackling noise repair kit instructions
Note that the last post is leading also to an official kit source of Strida Canada West!
stridacanada.ca/?product=strida- … pgrade-kit

Please feel free to rebuild the kit and/or let me know if you want a complete sample from Vienna :wink:
Pm below…and kind regards :smiley:

Chris

Hi,

It’s a very late reply but the obvious solution would be a washer between axle 340 and bolt 373 that is as thick as the washer between the frame tube and the cup spring 367.

regards: Klaus

Yes, that is correct - in theory.

But in practice, we had to notice (much later) that the basic conditions can be pretty different - from Strida to Strida :thinking:

rear-hinge-finally-the-sad-truth

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