I have a frame that has the top-tube cable guides on the right-hand side. Cable exit to the rear brake is therefore out of line with the cable housings on the (left-hand side) of the dual-pivot brake caliper. (I guess the frame was originally fitted with centre-pull calipers and the cable routing - running to dropper off the seat pin binder bolt - was not an issue.) There is space to mount the rear caliper in reverse (i.e. on the seat-tube side of the brake bridge, behind the seat stays). Although this might look decidedly odd, it would make the cable run nice and smooth.
QUESTION(S) - is there a good mechanical reason why this should not be done? Obviously front brake calipers are mounted forwards (relative to mounting point on the fork crown and wheel rotation) and front brakes tend to do more of the work - so why shouldn't a rear brake also be mounted this way instead of the (traditional) backwards mounting (backwards relative to the mounting point and wheel rotation)? Is it only aesthetics that has given us the 'standard' mounting positions?

Thanks for any thoughts or advice. Steve

Apart from looking odd, the only thing that could stop this from working is if the frame has a recessed nut mount, if not and you have enough space, nothing stopping you giving it a go to see if it works.

you might want to take a close look at your brake pads. some have an opening in the holder to facilitate removal of the ablative part. if reversed, the opening may allow that part to slide out a little. even if there is no opening, many of them have an orientation that may be more or less critical. probably less critical.

https://sheldonbrown.com/calipers.html

"Bicycle frames designed for nutted brake bolts don't care which way you install a nutted brake. As already described, a rear brake intended for recessed mounting may be installed ahead of the seatstays after drilling out the back of the brake bridge, the radiused washer, and the rack brace, if any. To mount a brake ahead of the seatstays on a frame designed for recessed mounting, you may use a front brake made for recessed mounting, or a rear brake made for nut-type mounting.
A centerpull brake mounted this way will have a slightly odd cable pull and will work best on a tall frame."


hope that helps

Yes, this is a very important point but it's easy to just flip the pad holders over or switch them left for right so the open ends point toward the rear of the bike.

Actually there might actually be an advantage to mounting the brake forward of the stays aside from the cable routing issue.

One of the functional differences between front and rear brakes is the effect of brake arm flex. On the front the arm flexes upward when stopping, on the rear it's down. The difference becomes significant on rims whose braking surfaces aren't parallel, and flare out toward the outer edge. Flex moving the shoes outward increases brake force as the shoes move to a wider part of the rim, while flexing inward reduces it.

This is one (among many) reason that front brakes tend to have a more positive feel, and if your rims flare outward, you'll feel the improvement.

The only negative issue you might have mounting the brake forward is that the bridge might not have as large a flat mounting surface on the front as it does on the back. Possibly this might make it hard to keep the brake centered, but there are various ways to solve that if it becomes a problem.


BTW- as others mentioned, don't forget to reverse the shoes switching left/right and forward/back.

Would running a full cable housing help? IE.. full cable housing to under top tube to get to brake on the correct side.

king_edward - thanks for that - fills me with more confidence - esp after FBinNY's comments
hueyhoolihan - thanks for the heads up re cartridge pads. Think I can get round that by swapping L/R over
Leebo - yes, I considered a full cable housing but didn't want (a) redundant cable stops; and (b) cable clips or zip ties cluttering the top tube. I've run other (winter) bilkes with full cables - for brakes and gears - to avoid the additional maintenance issues you get with exposed inner cables ...

Thanks all - will give it a go and will try to post result pics here.
Cheers - Steve

No problem. Hope it works out for you. Keep us posted!