escuta

Hi, Novice question here: I have a Gipiemme recessed type brake that I need to mount on 1980s recessed forks. The brake came with a toothed washer. With that installed on the bolt at the front of the forks the recessed nut reaches the end of its travel before tightening the brakes fast. ie. the bolt seems to be a bit too long for the forks (by about 2 or 3mm).

I was thinking of taking the brake to a machine shop to get a proper job done of shortening the bolt. Should I factor in the washer? ie. Is it standard to use one, or should I have the bolt shortened such that it fastens the brake without the washer?



Thanks,

smd4

A machine shop? To do something you can easily do with a hacksaw??

escuta

Yes, that's my prerogative. It is not expensive. Are you able to answer my question?

dedhed

Get a Dia Compe washer for the back of the fork. Straight or curved depending on the fork crown shape

​​​​​​https://www.porkchopbmx.com/dia-comp...0aAk9GEALw_wcB

​​​​​​https://www.porkchopbmx.com/dia-comp...IaApu6EALw_wcB

Frkl

Calm down.

If you want advice here, don't react like that to someone who gives it. Everyone has the point where they let a professional do it. Do what you feel comfortable with, live with the fact that others will do it themselves.

I would just stick another spacer in there, either a brake specific one (often a thicker aluminum washer) or a stack of a few hardware-store steel ones. New brakes often come with a few spacers for exactly this reason. the teeth help prevent rotation. but this actually hinders the wonderful self-centering capacity of side pulls.

dedhed

or a shorter bolt.
​​​​​​https://www.porkchopbmx.com/dia-comp...or-rear-r.html

smd4

Yep.

Frkl

another thought, if the nut is bottoming out on the non-threaded part of the bolt, ie, running out of threads, shortening the bolt won't do anything. You need to shorten the nut. If the bolt is essentially pushing your hex key out of the nut, then shortening the bolt will help.

You say the bolt "reaches the end of its travel," but this bolt doesn't travel. This bolt is fixed, and the nut travels over bolts. And it makes a difference what is actually happening here in terms of where you place a spacer and what you shorten.

maddog34

questions aren't advice, and that was a very good, even tempered, response to the questions.

your response is the over-reaction.

the OP needs to find a shorter "bolt", or shorten the one he already has... how he chooses to do this is his choice.
i'd get the shorter "bolt", since they are chromed for a good reason..... rust resistance.... since it's a more-rare brand, i'd just shorten it 5mm and call it good.

a shorter nut will not work, in this case... the brake was designed with a longer "bolt" to fit a thicker crown fork... most likely a Carbon Fiber fork, or an older, non-internal nut, fork.

thread a regular nut onto the "bolt".. Cut the thing down about 5mm(or whatever is needed)... remove the nut to clean up the thread.. Test install... put anti-seize on the threads... re-install... hook up brake cable, adjust to taste... go ride.

LesterOfPuppets

Seems to me it needs a shorter nut, not shorter bolt.

I'd probably just put one more toothy washer on the front myself

maddog34

seems like the nut is running out of threads and "bottoming out" into the hex drive, internally.

a shorter nut won't solve that issue.

LesterOfPuppets

Ah, yes I guess that is another possibility.

If that's the case, I'd still try just adding another toothy washer on the front.

Troul 

Cutting additional threads onto the bolt shank might be another option.

escuta

Thanks for the comments. It's a vintage part, which Is why I'm reluctant to hack some length off myself and the original shaft/bolt has a nice point at the end of it, to help guide on the nut. That would be lost if I did it myself. And I don't want to run the risk of making a mess of the threads - the brakes were expensive for me to import, etc., etc.

Yes, a shorter nut doesn't actually help. The rear brake actually came with one, which I tried - same problem. As said above, the thread is bottoming out into the hex head - which is why neither length works. Fortunately the rear-brake mounts without any problem.

I like the idea of the counter-sunk Dia-Compe washers, thanks, I'll try and track one of these down or try other washers. If not that, look for a shorter shaft.

All the best,

maddog34

i might dig into my small parts collection, find an old center pull curved spacer for mounting to an old biplane fork, and slip it into place... one of the cool aluminum ones...but not everyone sorts and saves parts from obsolete center pull brakes, and side pulls, and... etc, or wants their front brake setting out 4mm farther than needed...

JohnDThompson 

Campagnolo used to supply two of those for the front brake, so the centering flats on the pivot would clear the headset.

_ForceD_

That toothed spacer looks familiar to me. I mean yeah…I guess it’ll work as a spacer, but that looks like a gear that came out of a down tube shifter. I have one in my loose parts box that I know did.

And I know you said you want to take to a machine shop to do. But you might have a difficult time finding one that wants to take time away from their regular work to do this. As mentioned above…it would be quite simple. Take off the barrel nut. Screw on a traditional nut with the same threading. Hacksaw off the required threaded portion of the brake mount stud/lug. Use a file to smooth off the cut just bit. Unscrew the nut you screwed on to chase the threads at the end so that the barrel nut screws on correctly. Done. — Dan

LesterOfPuppets

I'd go for that if that part of the crown is curved, but some are flat there, like on this Schwinn. They put a nice fat 5mm thick nut on there, so the back nut doesn't bottom out. Added bonus is you can actually get a cone wrench on the brake for centering purposes (see Mr. Thompson's reply above). I've had a couple of olde bikes with flat crowns where they just put one thin toothy washer on there and the stack was so short the headset cup was in the way so you couldn't center the brake without flipping the bike over and removing the front wheel.

LesterOfPuppets

Here's a Tektro part if you decide to put another washer on the front. Shipping will probably kill the deal here (if they even ship to Brazil), but if you have any well stocked old-bike-parts dealers nearby I'd go digging there.

https://www.universalcycles.com/shop...76&category=34

_ForceD_

Wait! Someone correct me if I’m wrong…but isn’t that a rear brake caliper? In the OP picture…based on the side where the brake cable would go (rear caliper left side, front caliper right side)…and the width of the unthreaded portion of the lug/stud in the pic…I’m thinking that’s a rear brake caliper.

Dan

bboy314

I’ve dealt with this issue many times by just adding another spacer between caliper and fork crown.

maddog34

you need to work on more bikes.
the brake is mounted toward the front on a fork, toward the rear on the brake bridge in back... guess what that does to the brake caliper? it reverses the SAME side pull caliper design.

now slap yourself and grin.

the pivot "bolts" can be exchanged to make a front caliper into a rear caliper...

LesterOfPuppets

I usually judge by the bolt lengths, the only way that could be a rear caliper if it was originally intended for nutted (non-recessed nut) setups, but even then the bolt might be a tad long.

Also some brake calipers were made with right side cable attachment points (presumably for the British market which preferred right lever front brake setups). The OP is the more common left side cable anchor though.

escuta

Here are photos of the pair with the front brake on the right. Second photo from above. It's seems the same configuration as my Ultegra brakes on my other bike.

maddog34

i'm jealous.. those would look stunning on my '79 Razesa project... drool.....