Post crash, baffling brake alignment problem, bent forks or frame?

Afternoon All, so I recently had a spectacular but fortunately low speed crash on my daily ride... Immediately following I checked for damage and other than my shifters being knocked out of position there only seemed to be cosmetic scuffs etc, phew.

However I later noticed my front wheel had developed a bit of a wobble and that my front calliper wasn’t springing back properly, so last night I got out the truing stand and sorted the wheel and investigated the brake problem. Wheel sorted I moved onto the brakes, which after rerouting the cable housing were fine. It was then I noticed my brake blocks were way out of alignment with my rim. One side was perfect, while the other was way too high where it’d foul the tyre under braking.

The brake blocks were already in their lowest position to make contact with the rim correctly, but now no matter what, one side is way off! I’ve checked my forks (carbon ones) for damage and they’re fine and seem aligned, the aluminium frame looks ok, the wheel is true and round, the calliper looks fine, I’m totally stumped.

Does anyone have any ideas what’s going on here please? I can’t think of anything that would effect the brake drop like that... I did build this bike myself, basically transplanting a Shimano 5700 group onto one of those ubiquitous blue Ribble 7005 frames, but I’m sure I would’ve set up the brakes properly and I’ve been riding it for about 2 years, so the pads and rim would’ve worn unevenly by now, while everything looks as you’d expect from properly aligned pads etc.

I’ve tried another calliper, another Shimano 105 one but the previous generation and that seems to have the same issue to a lesser degree, and so far the only solution I’ve found is swapping out the forks, but that’s going to mean cutting down a carbon steerer and more faff.

Thoughts gents? Any input greatly appreciated!

Pics pls

I’ve tried another calliper, another Shimano 105 one but the previous generation and that seems to have the same issue to a lesser degree, and so far the only solution I’ve found is swapping out the forks, but that’s going to mean cutting down a carbon steerer and more faff.

that would tend to suggest problem is with forks..
how flush does the fork crown sit with the bottom of the head tube? is it an alloy steerer? that could be bent

Sure, here are the callipers, rim and hub:

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Moar pics, fork blades, drop outs, underside of fork crown and headtube:

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Yeah I figured the issue can’t be the brakes given swapping them didn’t help.... not sure if the steerer is alloy or carbon, from memory probably alloy, the fork crown and bottom of headtube all look as normal though, and I thought if it was a bent steerer then both pads would be equally misaligned. That said I suppose if the steerer was bent sideways that could result in uneven misalignment. Will remove the forks and have a look, thanks.

Edit: thinking more about it if the steerer was bent that shouldn’t effect the brake pad alignment should it, as the position of the callipers in relation to the wheel would be constant, as the callipers are attached below where the steerer could be bent.

Put wheel in the fork, use vernier to measure distance between wheel and fork legs, both sides.

With wheel in fork, sight up to brake hole, are they centred to each other?

forgetting about the calliper for a moment - with the wheel axle securely in the drop outs, does the rim sit nicely in the middle of the fork?

Yup, wheel looked centred, hard to capture in a picture but here's one, also just measured with callipers and the space from the bottom of the braking surface to the inside of the fork blade is 9.4mm one side and 9.49mm on the other, seems ok.... thanks for your suggestions Gents!

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could it be that you are over-tightening the calliper to the fork (maybe around drill hole has been a bit damaged?) and that is impeding the proper spring function of the calliper arms?

aso, with the clipper off the fork, do the arms & spring function move freely?

The callipers are fine now, I think when the shifters got knocked in the crash it messed up the cable routing which was making the inner cable snag a bit. I unwrapped the bars, removed the outer housing, straightened it, cleaned the inner cable and now the callipers spring back fine.

I just tried removing a spaced from the callipers though, which in effect reduces the distance from the pads to the forks fractionally, and that's helped a bit, but as you can see from these pics the problem pad is still too high, even in its lowest position...

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could it be that the calliper arm(s) have been bent slightly?

edit: but you said with fork swapped out the problem disappeared...
it must then be the interface between the fork and the calliper somehow...no?
makes sense also if removing spacer in that interface affects problem..

I would guess that either:

One of the caliper arms has bent or warped (or the bolts securing the pad to the caliper arm)
The bolt that mounts the caliper to the fork has been bent slightly.

It could be a number of other things I guess. But I've seen a lot of crashed bikes and damaged calipers were quite common.

I reckon the fork dropouts may be bent, causing a tilt in the wheel. that would give one side higher than the other

hard to tell without seeing it but the issue would be with the fork somewhere

Have you got another bike you can try the brakes on?

Otoh, I've got a carbon / alu fork you can have for cheaps...

my final suggestion is to smash the shit out of it all with a hammer - you will feel momentarily better and then you will have nothing to fix, because it will all be broken.

Lol, almost went medieval on the callipers, was going to just grind the hole for the brake pads longer, so the offending pad can sit lower, but think my neighbours might kick off, so removed the forks to inspect them instead. They look fine and measured them all over and they seem symmetrical.... I’m boggled, but don’t want to switch brakes, because matchy matchy, so new fork it is, or fire the power tools come daylight!

Good call, will try the brakes with another frame and forks, and another wheel as well... Will pm about your fork though, thanks.