advice needed: trouble fitting Campy skeleton brake to new Moots road fork

[cadence90]

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[sfhbike]

Originally Posted by cadence90

Yes, those are all good suggestions which work as long as the op keeps the existing 24mm recessed nut, right?

But if the op decides to more-or-less follow the Moots suggestion for a shorter recessed nut and go with a 14mm rather than a 12mm recessed nut, where can he make up that missing ~10mm in the brake bolt length?

I can see gaining 2, 4, maybe even 6mm by combining the suggestions, but gaining ~10mm safely seems like a lot to ask, no, if I'm understanding all the dimensions?
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I think somewhere your measurements got thrown off. It is ~25mm to the final shelf, and then another ~19-20mm of carbon around the bolt width (which is the problem area since after adding 3mm or so of washers I only have 4mm of post left) for a total hole length of ~44-45mm as you showed in your original pic.

The 12mm is just how far in the first shelf is along that 25mm, meaning that the head of the nut can recess as far as 12mm down into the hole when threading onto the bolt before the head bottoms out. The problem with a 24mm nut is that it was bottoming out on the far hole and still sticking out the back (24mm of threads, plus 2-3mm head). A much shorter bolt would be just fine, but 12mm is too short to engage all the threads possible.

[Kontact]

Originally Posted by sfhbike

Good suggestion. I was actually just using one star washer and a regular washer (I didn't have a spare star washer on hand). I only need about 1mm extra for the brake to clear the fork.


Right. Definitely not planning on going with the 12mm nut. A 14mm sounds right to get me close to the needed length with maximum thread engagement.


What would modifying this look like? Not clear on this.


Great suggestions. I think what I'll do at this point is probably pick up a new ~14mm nut and head over the the LBS for some troubleshooting.

I guess I'm a little confused about how you and Cadence and Moots are referring to the brake nut length. It needs to reach nearly to the inner shoulder, since front brakes only come with 27mm brake bolts. So you'll have to tell me if this 12mm bolt length thing makes any sense, but your diagram indicates that the distance between the two shoulders is 25mm and that you only have a few mms of brake bolt exposed past that inner shoulder. So 12 and 14mm brake nuts don't make much sense to me.

It sounds like your brake nut would need to be 25mm plus whatever thickness the head is - so 28mm in total. If not, your diagram is wrong.


As for modifying the caliper, in the picture you have black part that says "bearings" and the round silver piece on the bolt shaft that has a set screw in the top of it. Take the caliper apart and put a 1-2mm washer between those two parts. That will extend the caliper forward on the brake bolt shaft, producing more clearance so you won't need as much star washer thickness.



If a Shimano 27mm calipler works fine in this fork with one star washer, than you only need to find 1 or 2mm of extra overlap to make you 27mm caliper work the same. Or would you be rejecting the way the Shimano works as well?

[DRietz]

Gotta be honest, y’all, this thread is hilarious. How many bicycle forum engineers does it take to say:

OP, you have two options within the realm of easiest possibility: 1) find yourself the optimal nut length and live with the engagement - use blue threadlocker, it’ll be okay 2) put your old fork back on.

Finding a longer bolt that works with your Campagnolo system is going to be difficult. If you like treasure hunts, go for it. If you don’t, but want your fancy Moots fork, just don’t be too hamfisted when tightening your nut.

Godspeed, gentlefolk.

[Kontact]

Originally Posted by DRietz

Gotta be honest, y’all, this thread is hilarious. How many bicycle forum engineers does it take to say:

OP, you have two options within the realm of easiest possibility: 1) find yourself the optimal nut length and live with the engagement - use blue threadlocker, it’ll be okay 2) put your old fork back on.

Finding a longer bolt that works with your Campagnolo system is going to be difficult. If you like treasure hunts, go for it. If you don’t, but want your fancy Moots fork, just don’t be too hamfisted when tightening your nut.

Godspeed, gentlefolk.

Just because you can't imagine all of the other solutions doesn't mean they aren't useful.

[DRietz]

Originally Posted by Kontact

Just because you can't imagine all of the other solutions doesn't mean they aren't useful.

Gotta be honest, dude, the bolded portion of your statement is not only childish, but also ignoring the fact that I clearly state “within the realm of easiest possibility,” which I’m pretty sure gives credence to the fact that I recognize the other solutions.

I wish you success in this trivial endeavor, as you are obviously more committed to it than I.

[Kontact]

Originally Posted by DRietz

Gotta be honest, dude, the bolded portion of your statement is not only childish, but also ignoring the fact that I clearly state “within the realm of easiest possibility,” which I’m pretty sure gives credence to the fact that I recognize the other solutions.

I wish you success in this trivial endeavor, as you are obviously more committed to it than I.

Then let me be honest - I found your first post condescending and rude, so I responded in kind.

The OP needs to buy 2mm of thread, and there are a number of relatively simple ways of doing that on his non-trivially expensive bike instead of throwing out the fork or praying to the threadlocker God. This isn't a Huffy where you just give up because it is taking more than 30 seconds to fix.

[cadence90]

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[cadence90]

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[Kontact]

Originally Posted by cadence90

May you be so lucky to elicit similarly well-intentioned and possibly actually helpful responses if/when you ever run up against a problem that vexes you. I mean, if/when that ever happens to you, of course....
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He's also a shop mechanic, but with a bit less experience than me. So maybe/maybe not.

[DRietz]

Just a lowly shop mechanic, of the condescending variety.

Sorry, everybody. Have a nice day!

[cadence90]

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[sfhbike]

Originally Posted by cadence90

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Thank you! Perfect diagram of where the situation is with a shorter nut. Kontact, does that make more sense now? Distance between the two shoulders is ~13mm, not 25mm.

Originally Posted by Kontact

As for modifying the caliper, in the picture you have black part that says "bearings" and the round silver piece on the bolt shaft that has a set screw in the top of it. Take the caliper apart and put a 1-2mm washer between those two parts. That will extend the caliper forward on the brake bolt shaft, producing more clearance so you won't need as much star washer thickness.

Doesn't it not really matter where I put a washer? Whether I put it down by the star nut or between the set screw and the bearing section, it still will push the entire bolt further out of the fork and lose the same amount of thread engagement.

[Kontact]

Originally Posted by sfhbike

Doesn't it not really matter where I put a washer? Whether I put it down by the star nut or between the set screw and the bearing section, it still will push the entire bolt further out of the fork and lose the same amount of thread engagement.

It matters, because I'm describing keeping the set screw piece in place and moving the caliper further out in front of it. Whatever you add in front of that part is what you can subtract from washers behind it, making the back end of the brake bolt longer.

I just don't know if it will work or not - I've never taken that brake apart.

Or, you can replace the left side pivot nut with a flat one so you can get the brake bolt further into the fork.



On the brake nut, if you have 13mm inside, I'd want a 13mm nut. I wouldn't want any more than that, because the fork isn't made to be tightened down on the inner shoulder - make sure it is short enough to tighten against the outer shoulder.

[cadence90]

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