My venerable Ritchey road frame is set up for cantilevers. I went through many a set before settling on MAFAC's. In the course of trying to understand how to calculate MA, I measured the dimensions of the posts. The horizontal and vertical displacements relative to the rim are notably different front and back, and, in a spectacular math fail, I concluded they had been designed for MAFAC Touring cantilevers up front and the smaller Racers in back, and so set the bike up that way.

In truth they have served well. They look great polished up, aren't really fussy despite what some say, and modulated my speed well up and down my 1000' neighborhood. But when I reach the bottom of the hill, or swoop down to my driveway, I really wasn't getting that crunching roll back stop at any time. Having finally figured out cantilever MA, (the projection of the yoke cable onto the line through the posts will give the equivalent horizontal lever arm), I decided it was time to get some newer components and fiddle with yoke length.

Well, none of the threaded post models will fit the old-time dimensions, so by the process of elimination I found my way to Shimano's CT91's. Actually they are great! Nice polish and incredibly cheap, taking first place away from my Ultegra headset in the bang/buck contest. And in measuring the post to rim distance in order to calculate just exactly what was what, I discovered it was 30mm in front and 27mm in the rear...blush. So my Touring front was giving a 4:5 ratio and the rear a 2:3! Serviceable, but low. No wonder MAFAC's are legendary for mud clearance. They simply pull further away from the rim because they so lack leverage.

The 91's set up easy. Between the rack and the low hanger in the rear, there is only so much variation available. Setting up for minimal MA gives about 3:2 which is easily matched in front. The main concern was whether the spring in the yoke wire would cause the pads to drag when open, but Tektro's thick but slack cables seemed to do the trick. I took it out for a shakeout, started up in the driveway, and hit the brakes as my wife returned in her car at the moment. Wow! Yes you can certainly feel the difference and it's going to take some time to recalibrate the fingers!