i know this has been done, but i’m putting together kind of a drop bar gravel bike using a disc braked hydrid frame/fork/wheelset using my the 5600/5700 (mixed) groupset i’m taking off my road bike in to fit a 5800 setup on it.
i know BB7 calipers are different as per comparison picture and parts list the BB7 has a different cam system internally that ramps up quicker which is why the actuation lever sits futher up into it’s stroke

but all thats listed for the BB5 is that the MTN lever is satin black no silver and looking at the pictures the stroke on the actuation lever is identical

so to put it to bed has anyone actually used the MTN and Road BB5 calipers and compared them??

sorry, can’t compare the two BB5s but I can say that BB7s are much nicer to use

thanks, it’s clear the BB7 have at least a 1/3rd less stroke to engage the pads. plus the bb7 have pad adjustment on both sides.

but looking at the BB5 there both the same

Yes I’ve used both, they use a different internal cam too, but I think as the arm position can be changed with a grub screw those pictures might be misleading. You can use mtn calipers on road controls but the pads need to be set very close to the disc (or you run out of pull) so they can rub. If anything they were a bit too sharp.

on the BB7 front the cost of them is so high and so hard to find used it might actually be better to wait for a used Hope V twin system to come on ebay again, they usually go for £150 for the complete setup

possibly founds some bb7 road in Canada for cheap 😀

As fooman says, you can use both with some judicious setting of the arm whilst clamping the cable. In all honesty, my BB7 road with 5800 levers are not much better than the old bb5 I was using. The BB7 are less temperamental, but no more powerful.

Using some tektro v-brake levers and BB7 MTN provides amazing power though