specific brake calliper needed...

so i’ve got this new tarck bike. its’ fork is drilled but in an old-timey manner. basically, the hole in the back is the same diameter as the hole on the front so i need an old-timey brake calliper with a longer bolt that goes all the way thru the fork so i can put a nut on the back of the fork rather than a recessed one that screws into the fork (modern-style).
But, as you can see in the photos, there’s also not a whole lot of vertical real estate to put a brake, so i need something that will also fit in the rather limited space on the fork crown and not obstruct the tyre as well. The reach is only about 37mm. (i measured this from centre of brake hole to centre of rim braking surface, idk if this is how its meant to be measured)

i asked shifter dan’s opinion and he said something like an old Shimano Exage might work, but i don’t know what vintage i’m looking for.

any help appreciated.

maybe try and take it down to the abbotsford swap meet tomorrow (9am-1pm) and see what people have there.

might be a needle in a haystack kinda deal, but i get the impression those guys have nearly everything…

Tough break.

You can drill the rear out to take a recessed nut, it’ll take you 2 minutes. But do it properly and don’t end up with an angled hole!

There are very few brakes with reach that low. Usually 39mm is the minimum (you measured it correctly BTW).

These go to 37mm: VeloBase.com - Component: Dia-Compe AGC-300, Aero Gran Compe

I saw a pair at the fyxo swap meet last year, but they’re still no good for you.

that’s pretty tight in there; something very ‘race’ like an old Gipiemme Crono sidepull would probably fit, but in looking at the photos you have another problem to address. There’s likely to be insufficient clearance for mounting under the overhang of the headset; you may need to grind a chamfer on the spring housing or space the caliper out slightly with a thick washer or two. Unfortunately, that will also mean less exposed thread at the fork rear, which might become an issue. Then you’re sort of back to square 1.

I have had some success with reaming out the hole in the fork rear and mounting brakes using recessed nuts (modern style) even with older calipers, and it’s turned out very neat. Never with a track crowned fork though. Proceed cautiously, measure calmly, don’t do anything which cannot be undone until you’re sure it will work. Good luck.

yeah, i wanted to try and avoid drilling out the rear, although i’ve asked both Shifter and Abbotsford and they seem to think it wont do anything negative in terms of structural integrity…
if it comes to that i’ll definitely let someone else do it.

as for getting the calliper under the headset, i think that can be fixed easily enough by a thick washer with a bit of the top taken off and/or a bit of work with a file.

the brake is really just there for the cops and emergency-type sitchy-a-tions

hey i may have one that would fit , what the measurement from the hole to the braking area of the rim ?


the one i have is 45mm from the bold to the pad section

I have drilled ou the back of my max fork and just did my wifes double crown then on her berretto i also had to space out the brake to avoid the head set.
I also have the same problem on hers with the short reach im thinking of drilling a hole above the brake adjustment area and increasing its adjustment slot and lifting the pad as her new brakes have enough meat up there to handle it.

Clamp on brake instead?

i’ve just pulled a pair off a road bike, the calipers are in average condition (but appear too long in the reach dept for you anyway).
if you just wanted the long mounting bolts you’re welcome to them.

Shimano Exage BR-A250 MAX 57mm - MIN 42mm

I’ve got a very similar issue when trying to put a brake on a Hillman track fork. But my only issue is the 23c tyre rubbing on the brake calliper. Does anyone know of any callipers that maximise tyre clearance.

I know I can use a smaller tyre but I don’t want to go any smaller for comfort on the road. My other option is a clamp on, but these look shit. Another idea is to file out the section that’s causing the issue but this could effect the structural integrity of the brake.

Here are some photos…

I dunno if a track crown is any more delicate than a road crown but I got my fork drilled to accept a ‘modern’ brake at commuter they have a jig to hold the fork to do it straight, was cheap from memory.

Also, maybe get a cheap short reach (39mm) calliper at the swap meet tommorrow and file the pad slot holders another 2mm?

edit: that was aimed at the jams, and kinda pretty much what other people said, carry on.

Just braze-on some canti mounts, Spider. Not only will you barely be able to stop you’ll be on-trend.

I reckon gather together a bunch of calipers and try them out. Some will have more clearance at the bridge I reckon, but it’ll be a matter of finding that one brake that does the job.
I wonder if a single pivot might have more clearance? Blakey?

Yeah I have been trying quite a few heavymetal. This is the one that worked the best. Duel pivot gave me better clearance than the single pivot ones I tried

Ah, righto. If it was me I’d just hit it with a flat file… and hope for the best.

650B on the front.

I drilled out the back of a fork for a recessed brake and it was fine, and I’m a hack mechanic at best. Or… coaster brake!

I’m thinking the file. Unlike the jams fork mine is recessed for a modern brake. Probably should have mentioned that sorry nexus.

And thanks Lyndon for bringing the LOLz

Thought I was being quite helpful…oh well.