Stability

[silva]

A try to understand what happened if the wheel is indeed not built (spokes) like it should (centered)
I don't know a thing about wheel building, but is there any problem that may prevent a wheel from being built like it should?
Looking back the entire story from the start, the big chainline due to the frame that is designed to allow 62 mm tyres, posed a problem during the bikes production. Probably, the "closest" achieved towards a straight chainline was initially a 10 mm off, way too much to be acceptable, so (again) likely the hub was mounted 5 mm towards the driveside in order to reduce that 10 mm to 5 mm, which was how the bike was delivered, and used until the chain wore so asymmetrical that link sections hung 45% tilted, clearly indicating something was seriously wrong.
So, the wheel should have been dished to compensate for that hub being 5 mm off the wheels mounts center.
How is this done? Through a part of the spokes at higher tension than the other part? Or by longer/shorter spokes at one side? Is there a criterium that makes the decision former or latter?

 

[Notafettler]

I have two Santos's travelmaster. One has done 25,000 kilometres with the same chainwheel and sprocket. Neither has stability problems. I think you talk bollocks.

 

[silva]

I have two Santos's travelmaster. One has done 25,000 kilometres with the same chainwheel and sprocket. Neither has stability problems. I think you talk bollocks.

I don't care about your mileage and also don't care what you think.
I had a specific question: the hub center sits 5 mm off the frames dropout center, this should be compensated for because the rear tyre would run 5 mm aside the front tyres trail. How is this normally done, different spoke lengths left/right, or tension difference?

 

[Shadow121]

Santos is the brand of the bike, partly mounted by a mechanic of the brand, partly mounted and sold to me by a dealer of the brand. Who of both screwed up stability, in the bike I received, I really don't care. My goal is to hunt causes of problems and solve them.

The most plausible explanation for the instability is rear tyre not lined up with front tyre.
Fact 1: the center of the spokes flanges sits 5 mm away from the center of the frame dropouts - towards the drive side.
Fact 2: the rear tyre wears away from its middle - towards the non drive side, verified on both rear tyres that have been mounted so far.
If I put some kilo's luggage on top of the rear rack, the instability (which makes it harder to follow a road marking line), is gone.
A plausible explanation is that the inertia of the added fixed-position (unlike the rider of the bike) mass gives the bike more laterial stability, thereby reducing the required steering corrections.

So the first time I have the chance (bike needs work) I'll try to check the rear versus front tyre center. A couple ways I can think of is trying to mount the rear flipped and compare distances to rim brake mount. If no difference then the rear tyre isn't umbrella-spoked which means the rear tyre indeed doesn't run in the front tyres trail (spoke flanges center not in center of dropouts). A wheel spokes trueing stand would help but don't have one.
Another (additional) method may be holding a straight stick/whatever along the tyres or better the rims, and see if the stick sits parallel to the frame tube. That would take into account any out of center cause. Of course, judging 5 mm may be hard on this relatively short distance.

Oh, and I don't have problems with 50 kilo loaded on top of the rear rack. It's just harder hill up that's all. No problems staying on a line on the road. For the same reason: mass inertia - it's harder to change the path of a bigger mass than of a smaller mass, meaning, yes o dear fellow forum users, more stability when riding.

You should never pay for a bike until you look it over, ride it and are happy with it, then you would not have the problems you bought and paid for. The reality is the bike builder took the piss out of you and sold you rubbish that was all out of line, and you accepted it instead of getting your money back.
There is nothing you can do now other than start fresh with a bike that works.
There are plenty of people touring with weight that wouldn’t want 62mm wide wheels, why, they fit nothing
unless you mess up the frame like you ordered, and that’s why your bike is out of line.

 

[silva]

You should never pay for a bike until you look it over, ride it and are happy with it, then you would not have the problems you bought and paid for. The reality is the bike builder took the piss out of you and sold you rubbish that was all out of line, and you accepted it instead of getting your money back.
There is nothing you can do now other than start fresh with a bike that works.
There are plenty of people touring with weight that wouldn’t want 62mm wide wheels, why, they fit nothing
unless you mess up the frame like you ordered, and that’s why your bike is out of line.

I was unaware at the time. Bike dealer didn't tell me. Rather the opposite: lied. One at a time, I discovered the problems the hard way. For ex the chainline, when chain parts hung tilted like 45 degrees with the dealer saying no idea why. Seen afterwards, obvious, but during the bikes production he sent me a mail that the chainline wasn't 100% straight but that they found a solution and that I needed just a little patience.
The 62 mm tyres were given to me as 1 of 2 options, I wasn't informed about the consequences. They even name such a tyres set "vacation wheels", clearly suggesting the opposite of what you say.
And I like the 62 mm tyres. They serve as shock absorbers and done with getting stuck in rails in cities.
Why would I not be able to do something about that stability issue? I solved the chainline.
So again my specific question:
The hub center sits 5 mm off the frames dropout center, this should be compensated for because the rear tyre would run 5 mm aside the front tyres trail. How is this normally done, different spoke lengths left/right, or tension difference?

 

[Ming the Merciless]

Right spoke lengths and correct spoke tension range. You centre (Dish) the rim between the locknuts as you build it.

 

[silva]

Right spoke lengths and correct spoke tension range. You centre (Dish) the rim between the locknuts as you build it.

Ofcourse right / correct, my question was if on a 27.5" wheel/tyre size a 5mm hub offcenter can be compensated for by spoke tension alone - so not requiring spokes replacement (by another length).
My motivation for this question: it's quite possible (based on the communication back then) that the rear wheel was first build with a centered hub, that subsequently was discovered as resulting in a 10 mm wrong chainline (rear cog on 6 bolt brake disc mount), which was again subsequently reduced to 5 mm, along spacers/whatever to move the hub 5 mm towards the driveside, and whoever did it didn't bother to correct the wheel to bring the tyre back to the center.

Recently (couple months), the rear rim got replaced due to failure (crack), and for reasons ungiven and untold to me either, the wheel has been shipped to the producer. I only knew because they had forgotten to remount the spacers and cog on the wheel when they told me ready to pickup, which apparently required a shipment from the NL producer of the bike, clearly proving that not their dealer replaced the rim).
Now, in aboves case, this would give them a chance to correct the wheel. I had also informed the dealer of the possible requirement for tyre centering (due to the symptoms harder to stay on a road line and the tyre wearing away from its center). I think that was the third time I asked about the problem, so far he never responded specifically.

So, if I would now know that 5 mm on this wheel size cannot be compensated for by tension difference alone, then that would support that whoever indeed didn't bother to correct the wheel centering after the chainline error reducement by hub position change.