Rail (625Wh) 2021 Trek Rail 9.8 rear wheel not centred

obiwun

Member
Mar 22, 2021
25
24
Australia
Hi,
Has anyone encountered this issue I have? Any rear wheel I install is not running centred in the bike. It is offset towards the drive side by probably 10mm.

I have double checked the dish on my wheel, it is nearly perfect, less than 1mm out of centre.

I have tested 2 other wheels and the result is the same. The same wheels are perfectly centred on my wife's 2021 Rail 9.

All my pivots look good.
The drop outs in the rear look good.
The axle looks good.

Any advice would be appreciated.



1669951357407.jpeg


1669951390385.jpeg

1669951675276.jpeg
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,567
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Coquitlam, BC
Not seen this before. I wonder if the lower pivot bearing is misaligned? Which is causing the Triangle to tilt slightly. Is there a way to carefully measure 📐 the squareness?
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,567
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Coquitlam, BC
You seem to have eliminated any wheel or tire issue. Hub, axle, dishing issues eliminated. Any access to a frame alignment tool? How new is your bike.
Since it’s a carbon frame I would suspect attachment/bearing points.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,567
5,058
Weymouth
............. or..... wheel is OK but axle wrongly assembled.....maybe drive side/non drive side end caps are reversed?
 

Paulquattro

E*POWAH Elite
May 7, 2020
2,314
1,289
The Darkside
............. or..... wheel is OK but axle wrongly assembled.....maybe drive side/non drive side end caps are reversed?
This would have to be on all wheels thou not just one as he has tried multiple wheels in the frame and this wheel in another bike so it has to be a bike issue .
 

Paulquattro

E*POWAH Elite
May 7, 2020
2,314
1,289
The Darkside
Hi,
Has anyone encountered this issue I have? Any rear wheel I install is not running centred in the bike. It is offset towards the drive side by probably 10mm.

I have double checked the dish on my wheel, it is nearly perfect, less than 1mm out of centre.

I have tested 2 other wheels and the result is the same. The same wheels are perfectly centred on my wife's 2021 Rail 9.

All my pivots look good.
The drop outs in the rear look good.
The axle looks good.

Any advice would be appreciated.



View attachment 102418

View attachment 102419
View attachment 102420
Does the disc line up with the caliper
Only asking as im just trying to understand the problem from a distance
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,567
5,058
Weymouth
Are the wheels being tried in this bike non standard? Ie not the original wheel? Could it be that the original rear wheel for this particular model was offset...not centred??
 

obiwun

Member
Mar 22, 2021
25
24
Australia
You seem to have eliminated any wheel or tire issue. Hub, axle, dishing issues eliminated. Any access to a frame alignment tool? How new is your bike.
Since it’s a carbon frame I would suspect attachment/bearing points.
Hi, The bike is over a year old. I'm not sure if the misalignment is something I haven't noticed previously or its a new problem that has appeared. I usually notice things like this so I feel like the issue has happened recently.
A frame alignment tool, thats exactly what I need. I'm not sure how to find one in my area.

I'm visiting my local Trek dealer tomorrow but I'm not sure they are going to help me much, their workshop is really busy and they're more interested in building new bikes for Christmas.

From what I can see, the pivot bearings all look good and clearances are even from from frame to swing arm etc. I popped out the Minolink pivots and the bearings and offset washers are all good there. Interestingly, the seat stays needed to be slightly flexed to line up with the shock linkage for re-assembly.

The axle drop outs are not damaged, the faces where the hub engages are good.

The rotor lines up fine.

The clearances between the tyre and chain stays are more even compared the clearances between the tyre and seat stays. Like the rear axle has a twist to it relative to the centre line of the bike.
 

obiwun

Member
Mar 22, 2021
25
24
Australia
Are the wheels being tried in this bike non standard? Ie not the original wheel? Could it be that the original rear wheel for this particular model was offset...not centred??
I have tried my original wheel, my newer wheel and the wheel off my wife's Rail 9.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,567
5,027
Coquitlam, BC
The dishing tool eliminates a lot of issues. You’ve done that. And your bearings are good.

I think a frame alignment tool might be your next step. Definitely not something to buy but your LBS should have one. At least it might find or eliminate some issues. (This is perplexing). I’m curious as to what it could be.
 

obiwun

Member
Mar 22, 2021
25
24
Australia
Cool I'll ask my LBS tomorrow if they have a frame alignment tool. If they don't I'll head into the Trek store when I'm visiting the big city (2.5hrs away) :)
I'll push my LBS to maybe change the split pivots / drop outs and the swing arm bearings
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,567
5,058
Weymouth
Another area to inspect are the dropouts. I dont know the arrangement on your bike but if it is a carbon frame the dropouts will be ally and bonded into the chainstays. Perhaps check to see that neither has moved.
 

gfunkmc

Member
Jan 9, 2019
79
62
wales
I had similar issue .. my backend of the bike was twisted .. trek were not having any of it even sent it back to them to check for alignment and came back all ok (even tho as from pics you can clearly see it was bent) ... Within a few weeks of having it back I heard a twang and noticed the weld had completely split on the chainstay as seen in 3rd pic .. trek soon changed there mind and kindly sent a new chainstay and seatstays under warranty 👍👍
PXL_20220414_130356135.jpg
PXL_20220413_121933327.jpg
PXL_20220523_133320328.jpg
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,567
5,027
Coquitlam, BC
Looks like a poor alloy weld. Maybe the paint hid the flaw for a while, until it finally snapped.

I think the OP’s frame is carbon, but it could still fail.
4E4EF1C1-70FE-4F96-9A8A-1372DD610F40.jpeg

Here’s a pic of the same area on my carbon frame. I carefully measured the wheel centring as best as I could (3mm from the rim), on both sides. The wheel is centred.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,567
5,058
Weymouth
I had similar issue .. my backend of the bike was twisted .. trek were not having any of it even sent it back to them to check for alignment and came back all ok (even tho as from pics you can clearly see it was bent) ... Within a few weeks of having it back I heard a twang and noticed the weld had completely split on the chainstay as seen in 3rd pic .. trek soon changed there mind and kindly sent a new chainstay and seatstays under warranty 👍👍
View attachment 102636 View attachment 102637 View attachment 102638
that broken weld looks more like the result of a misaligned back end than the cause.
 

obiwun

Member
Mar 22, 2021
25
24
Australia
So my local Trek dealer took a good look over my bike yesterday and agreed that it's not right. There is a bearing alignment issue. They have filed a warranty claim with Trek.
They believe the issue is most likely around the Active Braking Pivots where the seat stays join the chan stay and on the non drive side in particular.

As you can see in the pics, the clearance in the pivot between the seat and chain stay is very tight on the non-drive side compared to the drive side. There is a spacer in the pivot that should maintain even clearance both sides. The stays are basically touching on the non drive side.

Hopefully Trek will come to the party and get me rolling straight again..

1670378324298.jpeg


1670378375728.jpeg
 

obiwun

Member
Mar 22, 2021
25
24
Australia
Just an update to round out this post if anyone was interested. Trek supplied a warranty replacement seat stay and chain stay and my local Trek dealer fitted it for me (at a cost of around AUD$300).

My rear end is running dead straight now and my problem is resolved.

Cheers for your input.
 

Paulquattro

E*POWAH Elite
May 7, 2020
2,314
1,289
The Darkside
Just an update to round out this post if anyone was interested. Trek supplied a warranty replacement seat stay and chain stay and my local Trek dealer fitted it for me (at a cost of around AUD$300).

My rear end is running dead straight now and my problem is resolved.

Cheers for your input.
Fantastic and Thanks' for the update so many people leave threads with no solution or answers .
 

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