Rear wheel appears to be off center

SchrodingersCat

Hi all,
I was wondering if anyone would have any advice on the following. I have a giant Defy 0 2015 roadbike.
I have always had trouble adjusting the rear brakes to so that one of the brake pads wouldnt rub off the tyre side wall.
Even with the brake pad at its lowest possible location on the brake leaver, it would still touch the tyre side wall.

Taking a measuring ruler to the wheel and the chain and seat stays I found that the wheel pulls 5mm closer to the left away from the chain side. I believe that this is the reason that I have difficulty adjusting the brakes as the wheel does not sit center between the stays.

To troubleshoot this, I have removed the quick release and double checked that the axel sits snugly in the frame. The wheel also spins true.

The only other thing that I can think that could cause this is that the dish of the wheel is off. However, as this is the original Giant P-R2 wheel, I am doubtful that they would have got it wrong. Would anyone have encountered something similar or know how to fix it?

SchrodingersCat

C3PO

Have you adjusted the screw on the top of the caliper (shown in your first photo)?

SchrodingersCat

C3PO wrote: »

Have you adjusted the screw on the top of the caliper (shown in your first photo)?

Thanks for the response! If you mean the centering grub screw, then yes, I have. I can change the centering of the caliper closer to the left. However, as this is now so far left, the brake pad on one of the side has risen so high as it is rubbing the side wall of the tyre. I cannot compensate by lowering the brake pad as it is already at its lowest point on the caliper. Unfortunately, I dont believe that this is the root-cause of my issue.

ted1

How about a video of the wheel spinning

07Lapierre

It looks like the axle on the drive side is not sitting in the dropout correctly. It needs to sit a fraction higher.

Is there something stopping the axle sitting correctly?
Remove the wheel and take a photo of the dropouts from the inside.

Gerry

Hi, I have the exact same bike and no issues. In the second pic the alignment looks way off. I'd suggest trying a wheel from another bike. What about installing the wheel with the wheel on the ground?

Gerry

07lapierre is spot on. It's not sitting correctly on drive side.

route66

From what I can see, your rear brake pads are swapped over. The tab-thing should be pointing to the ground - as yours are - but the screw on the pad itself should be facing the other way. In other words, it looks like you put the LHS pad on the RHS and visa-versa.

I'm not sure if this would cause the pad not to descend properly, but you should swap them anyway - the screw is at the closed end of the pad so that in the event that it gets loose, the pads will be retained by the closed end. Otherwise they would get ejected at high speed.

Generally, having pads touch the tyres is a very bad idea - I suffered a blow out recently (link) at 60 kmph downhill. Not nice ...

Apologies - fake news :eek:

Didn't look carefully enough to see the brake blocks were open at the correct end.

WRT the blocks touching the tyre, that is a major issue. After my blowout (that wasn't fake news!), I'd stay off the bike until this can be resolved.

07Lapierre

route66 wrote: »

From what I can see, your rear brake pads are swapped over. The tab-thing should be pointing to the ground - as yours are - but the screw on the pad itself should be facing the other way. In other words, it looks like you put the LHS pad on the RHS and visa-versa.

I'm not sure if this would cause the pad not to descend properly, but you should swap them anyway - the screw is at the closed end of the pad so that in the event that it gets loose, the pads will be retained by the closed end. Otherwise they would get ejected at high speed.

Generally, having pads touch the tyres is a very bad idea - I suffered a blow out recently (link) at 60 kmph downhill. Not nice ...

Disagree...pads are fitted correctly. Once the axle is sorted, the pads will line up correctly.

triggermortis

Agree with 07Lapierre totally. Brake pads are ok but the axle isn't fully in the drop-out on the drive side

Alek

To me it seems that the axle on the drive side rests on the gear hanger ... If its original and has not been replaced with a dodgy 3rd party one, and therefore it has been designed to work like this, its the wheel that needs re-dishing.

07Lapierre

Alek wrote: »

To me it seems that the axle on the drive side rests on the gear hanger ... If its original and has not been replaced with a dodgy 3rd party one, and therefore it has been designed to work like this, its the wheel that needs re-dishing.

A dodgy gear hanger could be the problem alright. I looked a bit closer and yes, it does look like the axle is in as far as it can go. I doubt the wheel needs to be re-dished. if the hanger is incorrect, either replace it, or if you're handy at DIY, file it down so the axle sits further up into the dropout.

SchrodingersCat

@07Lapierre, @Gerry, @route66, @triggermortis and @Alek thank you very much for all the help.

So it appears that the issue could be caused by two things: either the dish of the wheel was off, or the hanger was causing it not to sit properly in the hanger.

I took your advice onboard and went to check the dropouts and hanger this evening. I couldnt find anything that appeared to stop them from sitting snugly, and I cleaned them out to be sure. The axel seemed to sit snugly too. None of these components were changed after purchasing the bike new, so I was a bit unsure.

Before I committed to filing the hanger down, I wanted to discount the dish of the wheel. So I took off the wheel, flipped it around, and put it back into the dropouts. Assuming that the hanger was causing the mis-alignment, we would expect to see the same direction of mis-aligment. However, the wheel was actually closer to the side of the bike away from the drive side! So it must be caused by a wrong dish of the wheel.

I swapped around the wheel a few times and took measurements to make sure, but yes, it appeared that the dish was off by around 3mm.

So I loosened the spokes all the way around on the drive side by 1/4 turn, and tightened them on the opposite side by 3/4 of a turn. The wheel was aligned much closer now, even when I swapped the wheel around.

I was then able to set my brakes properly without them touching the side wall of the wheel.

Its strange that the dish of the wheel was off, esp as I hadnt chaged any of the spokes or wheel since I bought it. But im glad now that it appears to be fixed.

Thanks for all your help!

Gerry

Bit crazy but glad you got it sorted. Is it typical for the likes of giant to ship rims and spokes and have the shop build the wheels?

SchrodingersCat

I was actually wondering that myself. I would have thought that Giant would have shipped the wheels to the shop pre-built. However, I'm pretty definite the dish was off as the wheel was also mis aligned at the chain stays *and* the seat stays. If it were an issue with the axel not sitting in the drive-side dropout correctly you expect it to be misaligned at the seat stays more so than the chain stays.

I hate having to touch the spokes as it never really worked well for me in the past. I don't think I had much choice in this scenario.

It's a weird one.

07Lapierre

SchrodingersCat wrote: »

@07Lapierre, @Gerry, @route66, @triggermortis and @Alek thank you very much for all the help.

So it appears that the issue could be caused by two things: either the dish of the wheel was off, or the hanger was causing it not to sit properly in the hanger.

I took your advice onboard and went to check the dropouts and hanger this evening. I couldnt find anything that appeared to stop them from sitting snugly, and I cleaned them out to be sure. The axel seemed to sit snugly too. None of these components were changed after purchasing the bike new, so I was a bit unsure.

Before I committed to filing the hanger down, I wanted to discount the dish of the wheel. So I took off the wheel, flipped it around, and put it back into the dropouts. Assuming that the hanger was causing the mis-alignment, we would expect to see the same direction of mis-aligment. However, the wheel was actually closer to the side of the bike away from the drive side! So it must be caused by a wrong dish of the wheel.

I swapped around the wheel a few times and took measurements to make sure, but yes, it appeared that the dish was off by around 3mm.

So I loosened the spokes all the way around on the drive side by 1/4 turn, and tightened them on the opposite side by 3/4 of a turn. The wheel was aligned much closer now, even when I swapped the wheel around.

I was then able to set my brakes properly without them touching the side wall of the wheel.

Its strange that the dish of the wheel was off, esp as I hadnt chaged any of the spokes or wheel since I bought it. But im glad now that it appears to be fixed.

Thanks for all your help!

I stand corrected so. Glad you got it sorted.

route66

SchrodingersCat wrote: »

@07Lapierre, @Gerry, @route66, @triggermortis and @Alek thank you very much for all the help.

So it appears that the issue could be caused by two things: either the dish of the wheel was off, or the hanger was causing it not to sit properly in the hanger.

I took your advice onboard and went to check the dropouts and hanger this evening. I couldnt find anything that appeared to stop them from sitting snugly, and I cleaned them out to be sure. The axel seemed to sit snugly too. None of these components were changed after purchasing the bike new, so I was a bit unsure.

Before I committed to filing the hanger down, I wanted to discount the dish of the wheel. So I took off the wheel, flipped it around, and put it back into the dropouts. Assuming that the hanger was causing the mis-alignment, we would expect to see the same direction of mis-aligment. However, the wheel was actually closer to the side of the bike away from the drive side! So it must be caused by a wrong dish of the wheel.

I swapped around the wheel a few times and took measurements to make sure, but yes, it appeared that the dish was off by around 3mm.

So I loosened the spokes all the way around on the drive side by 1/4 turn, and tightened them on the opposite side by 3/4 of a turn. The wheel was aligned much closer now, even when I swapped the wheel around.

I was then able to set my brakes properly without them touching the side wall of the wheel.

Its strange that the dish of the wheel was off, esp as I hadnt chaged any of the spokes or wheel since I bought it. But im glad now that it appears to be fixed.

Thanks for all your help!

... but if the problem with the brakes was to do with the vertical position of the rim, I don't understand how adjusting the dish would change this. I.E. a lateral movement of the rim relative to the hub of ~ 3mm; how could this change the vertical position of the hub such that the brake blocks no longer touch the tyre?

Anyway, maybe it doesn't matter - as long as you can apply the brakes knowing you are not going to rip the sidewall out of the tyre, that's success!

Footnote: I do lots of things on my bike but have never touched a spoke in my life (too afraid!) I'm therefore very impressed with anyone who is willing to tackle this "black art"

SchrodingersCat

Good question, it took me a while to figure out. Ive attached a crap drawing to trry and explain how the dish of the spokes can effect the height of the brake caliper.
In (A) we can see how the straight wheel results in the two brake pads being at the same position on the wheel rim. However, looking at (B) we can see how if you have a bad dish, the rim ends up out of alignment. The brake caliper has to be re-aligned to compensate for this rim mis-alignment. After this step, if you were to look at the caliper "head on" as is shown in the image, it will look like the caliper is "leaning". Because of this, one brake pad is higher on one side than the other.

This is why one of my brake pads was so high that it was touching the side wall of the tyre. Normally the brake pads are mounted on a channel that allows you to compensate for this. However, mine was even at this limit of this channel. 

I too hate touching the spokes. Its a skill that I never got the hang of. Hopefully the wheel will be ok after my messing and I wont get snapped spokes after a while.   

Alek

Badly dished wheel may still be well trued. If your wheel was like in the drawing above, it would wobble like hell when turning... but its most likely true that the wrong positioning of pads was caused by the rotated caliper.