Hi Sunkisk-EVO3, did you check the rear spokes for a loose spoke?
Even with your test #1 I still would not rule out the rear hinge.
There is a lot of torque on that joint and loosening it may make it worse. Also if the hole is enlarged the axle and end cap will still move inside the tube.
Is there much damage to the tube from the sharp edge of the cup spring?
I would separate the tubes, clean and lubricate the nylon washer between the tubes, install the cup spring, try and replace the small washer with a harder 8 mm washer, I am sure you will find that the small washer is deformed. Strida put a light oil between the small washer and the cup spring and if that is all you have then do it, but it may not last very long. The Never-seez compound that I have in my upgrade kit is much better. Then locktight and torque the bolt. Let the locktight set for awhile and then check that when you fold the bike the pivot point is between the cup spring and the small washer.
I noticed that the washer beetween the bolt and the cup spring was not deformed.
And when I fold the bike, this washer move, not the cup spring.
But I noticed that the axle has been damaged (is not smooth and has becomed black on an area of 1 cm by 2 mm). It seems there is a friction beetween this axle and the end cap of the tube.
And the creaking noise is still here
Not tried to replace the washer with a harder 5mm one yet.
Do you know what are the 3 bolt on the KS3 for ?
Are they for tuning or do they need to be more tightened ?
You didn’t take pics accidentally?
There shouldn’t be friction, the hinge should move smoothly without the spring load.
Seems that they hold together the two gear “covers” part 61 and 62 vice-versa. Re: installing strida alloy chain wheel on stride evo
(62 not marked at the thread above, but you can find the part in the KS3 patent).
Well I don’t think that these small marks may cause the creaking.
Of course I’ve no clue where they’re coming (at the axle), the mark at the frame isn’t that tragical.
At the second pic (opening in a new tab will show it full size - for the other readers)
I can see a silver ring close to the cup spring’s edge - you will find the negative (a groove) at the outside of your bottom tube - am I right?
Yes I can see the negative.
But on TEST 1, the cup spring was not in contact with the tube, and it creaked…
There was a space of 1 mm beetween it and the tube : this way :
Rear tube / 1 mm / nylon washer / bottom tube / 1 mm / cup spring / washer / bolt.
But maybe there was something wrong when doing the test.
You loosened the bolt and separated the tubes - but how did you assure that the bottom tube doesn’t tilt while riding?
If you’re sure the spring didn’t touch the frame (and could therefore logically not creak - I do agree of course) there are two contact points left over:
Axle to tube insert
Axle to tube hole
When you unmounted the bottom tube form the stump did you notice if the hole is much bigger than the stump?
If possible (without belt) you might try checking play without the insert…
I’m really sorry but without having the bike in hands it’s always very hard to find issues…
Do you ride during winter?
I hope we can find help near you, but that may take some time…
As mentioned before, no problem to send you one of my kits.
Would be just a problem if it doesn’t help…
I’d change the complete rear parts group including insert and acrylic washer between the tubes.
Unfortunately the inserts are not in stock here and we’d have to order them.
Thank you a lot for you help and your proposal
I replied to your on you mailbox.
I will try to analyse more in detail the problem with a third person with his/her ear close to the tube.
The objective is to be absolutely sure that it comes from the hinge.
And then come back to you.
Well, today with a friend of mine we have confirmed that the noise is coming from the rear hinge.
So, maybe TEST 1 is still creaking because the hinge is not under tension (bolt not tightened).
2 steps :
1- Removed the end cap of the bottom tube, to replace it by a new one
2- Used the grinding tool to remove the burrs, with the bottom tube in place
I am also looking forward to seeing your results. From my experience that much wear on the tube would make some noise and the apparent movement might cause the belt to move out of alignment and come off. For anyone reading this who has missed my post regarding the Strida rear hinge, here is a link, stridacanada.ca/?p=3208