Brake Reach Pitfalls

           We have a vintage Raleigh "Competition" road bike in the workshop for a complete makeover at the moment. It is an interesting project and will probably feature again in this blog before the transformation is complete. One thing that has cropped up already and is very common when doing these kinds of makeovers is 'brake reach'. It is not however just a problem with older style bikes it can cause issues on modern frames too, especially on those catch all frames that are designed to be built up in a variety of styles and need to accommodate a wider range of tire widths than a standard 23 or 25.
            Brake reach is basically the distance between the caliper mounting hole on the bridge,  to the center of the brake wear track on the rim.

            On a modern standard road bike this distance is going to be around 39-49mm and a standard short reach caliper from the big 3 will work just fine. Lots of manufacturers nowadays though are producing frames that can be equiped in various formats, a bike for all seasons if you will. This is where the brake reach figure can differ from standard and purchasing a short reach caliper is probably not going to work. The pads will hit somewhere on the tire instaed of the rim. Another problem scenario is with the older style frames as we have mentioned, the mounting bridge on these guys are usually set for the older style center pull styles that had a reach of around 61mm. Therefore a standard 39-49 short reach is never going to work.  Even what we commonly refer to as medium reach will have trouble as their range usually runs from 47mm - 57mm. The last tool in the box for a modern caliper is a long reach 55mm - 73mm.
             All this goes to show that you can never take anything for granted when changing parts on your bike. Measure, measure and measure again.
Posted on October 30, 2012 .