Short reach brake not short enough (wrong wheelsize?)

[MorganFreeman]

Hi I have a vintage track frame that has fork with a brake hole (there's no brake mount on the rear, and yes the fork seems to match the tubing and appearance of the rest of the frame). I'm running 700c wheels but the front rim seems to be about 2-3mm too high for my short reach brakes (standard 39mm Dura Ace 7800). i.e. the brake pads are sighting slightly lower than the braking surface and there's not enough space in the calipers to file the brake slots out a bit more. I was wondering if there's a way to measure for the correct wheel size as I can't seem to find any shorter reach brakes. Gran compe aero compe's are hard to find and I'm not sure they'd fit anyway?

Any help would be appreciated. I really want to put a front brake on since the law changed where I live and it's now required to have at least a front brake.

Thanks

MF

[Joe_W]

Well, if it is a vintage frame the wheelsize could have been 27". Oh, and it is sensible to ride with a front brake (not only 'cause it's required now, but 'cause of plain physics).

[MorganFreeman]

(05-12-2010, 09:58 AM)Joe_W Wrote:  Well, if it is a vintage frame the wheelsize could have been 27". Oh, and it is sensible to ride with a front brake (not only 'cause it's required now, but 'cause of plain physics).

Thanks Joe. Yeah, I agree and I've always ridden with a front at least... until this bike when I had some difficulty finding a brake that fits. I do generally pride myself on being sensible cyclist.

I think if the wheelsize were 27 though the brake would be even further away from the rim, given that a 27 inch wheel is bigger than a 700c??

That's what's making me confused. I thought maybe it was meant to have a 650 on the front but I'm confused as to why it has a brake mount.... And then I guess I'd need a long reach brake? I just was wondering if anyone could help with a method of measuring before I rush out and buy a new rim??

[trevgbb]

You describe this as a vintage track bike, how old? country of origin?
it's possible this was originally fitted with something like 26 x 11/4 wheels, which would just about fit your 39 reach, or even a 43.
I don't know of any shorter than 39, unless there were some specials about for track use.

[MorganFreeman]

(05-12-2010, 12:26 PM)trevgbb Wrote:  You describe this as a vintage track bike, how old? country of origin?
it's possible this was originally fitted with something like 26 x 11/4 wheels, which would just about fit your 39 reach, or even a 43.
I don't know of any shorter than 39, unless there were some specials about for track use.

Thanks Trev. 26 11/4 maybe? It's an Australian frame from at least the 70's from what I can tell but the lugs aren't particularly distinctive. There are dia compe clamp on brakes for undrilled track frames but I figure if the frame has a brake mount it' be much nicer to use that. With a 700c wheel there's tight clearance and the bottom bracket is quite high, which is good for street riding so I guess a smaller wheel might be what's happening here...

It'd be great if there's a way to measure forks for appropriate wheel size.... I really can't find any resources on the net and alas I don't have a 650 or 26x11/4 lying about.

[DaveM]

When it comes to resources on the net...see Sheldon Brown.
http://www.sheldonbrown.com/tire-sizing.html

This article is about tire sizes, but he lists all the common wheel sizes so you may be able to figure out what it came with originally. What you do then is another question...