Sekine RM40 1980, Miyata 1000LT 1990, Raleigh Mixte Sprite 1980, Raleigh Grand Prix 1979
Weinmann 610/750 Front/Back... Why Was This Done?
Just an observation on most of the Weinmann brakes I've accumulated - it seems often that they had a 610 up front and a longer reach 750 in the back. On a 27" wheel on my bikes the 610 will have the pad at the max extension position, and the back will be about mid-
So, this brings questions to mind:
Why was this done if a 610 would have reached on both ends?
Would the 750 be adequate to accommodate 700C rims?
Is the any reason the rear 750 couldn't be used as a front brake?
I think that there is a real reason, and it has to do with long chainstays on older bikes (which, apart from ride characteristics, helped allow getting the wheel in and out of a frame having both horizontal dropouts and fenders). Once the fender is set to have clearance in front of the wheel, it looks funny if the clearance at brake bridge is much closer, so additional clearance was provided there too. Result: you need a longer reach brake in the rear (how much? Oh, about 14 mm according to Weinmann). Without fenders, the "roughly equivalent clearance" problem isn't really a factor; so the brake bridge can be lowered, as it is on many bikes that followed the "please, no fenders, we're not British" fad.
Last edited by Charles Wahl; 08-13-12 at 08:59 PM.
From Charles answer: the 750 have an extra 14mm reach and that should be enough to reach to 700c wheels since these are just 4mm lower (622mm diameter rims vs. 630mm). Depends on how high the brake bridge is on the frame.
I have an old English frame that originally took a Weinmann 750 on the rear (with 27" rims, presumably) -- I converted it to 700C, and the 750 works for that too. Pads are near the bottom of the slots, though. As leecycle says, the difference is only 4 mm in reach.