Anyone actually tried it?
I’m aware of the issues: why it shouldn’t work and what the shortcomings will be even if it does.
However I’ve often used flat bar canti levers with V-brakes on MTBs and that’s been fine. Just means keeping the rims really true because the pads needs to run closer to them.
Mainly my thought is whether I can get the bite point in the right place: I suspect not; at least not without constantly skimming the rims.
The correct answer is that I should try it (I’ve got all the stuff) but that means speculatively recabling an internally-cabled bike 😉
FWIW they’re old callipers (“BB MTN”, before the 7/5 variants appeared), and I’ve got either 2016 Tiagra or 2010ish 105 STIs. Don’t think there’s any difference in cable pull between those.
Experiences…?
None of a direct nature. But you're right, it should work but not ideally. Sounds like a lot of the bodging we do; Shimergo etc.
You could measure the cable pull of your STI's to help decide which to use if they're not the same. IIRC, MTB needs more cable pull and at least you'd have a data point without installing/deinstalling/reinstalling levers.
If the result is not to your liking, there might be a travel adapter available. There are for dérailleurs - not certain about brakes, try SJS. Or buy some secondhand Spyres/road BB7's.
Nothing is ever easy...
I have a pair of Road BB7s sitting in the garage should you want to try that option. I'm pretty sure it's just the actuator arm that differentiates them.
Just run the cables externally at first.
APF
short pull levers and long pull calipers.
Youll have to run the pads really close to the disk
you increase the chances of going from having brakes to the levers running out of pull to make the pad contact PDQ
MTB levers with road calipers is reasonable bodge in that the brakes will feel mushy due to excess leverage but theres not a potential situation of full lever travel with no pad contact that exists on the road sti / mtb caliper solution
Just run the cables externally at first.
Typically enough that exact thought occurred to me shortly after sending my post 😀
Time to fit two sets of bars Sheldon Brown-style and see what happens 🙂
If it doesn’t work then I’m in the market for a pair of road BB7s (or Spyres).
Travel agents allegedly fix this but new calipers might be cheaper at £30 a pop.
https://www.sjscycles.co.uk/cables/travel-agent-br0411-black-each/
Or a cheaper version for £20 a pair...
https://www.sjscycles.co.uk/cables/vdaptor-for-front-or-rear-silver-alloy-per-pair/
Had BB7 MTB calipers on my Cotix X with 105 levers and just felt like there was no power in. Changed to 105 calipers and suddenly I could lock the wheel up and there was loads more braking power available with less lever throw.
It'll work but obviously you'll need dead straight calipers to run the pads near enough to take tip the extra length of the arms. Also (and this goes with any cable brake) run compression less outer cables to stop the mushy feeling
I did it for years on more than one bike with 105 ten speed. Not easy to set up but i'm still alive.
I had a pair of road BB5 which I ran with road pull levers, they were gash.
I then bought for just a quid each a pair of the MTB pull roller cams assemblies for the BB5 and some tektro RL520 linear pull levers, I fitted the levers and changed the roller cams and so I essentially now have drop levers that pull V brakes and the MTB version of the caliper and they are... Adequate, at best. They work but like all cable pull disc brakes they need regular attention to keep them in trim...
I can't imagine your proposed bodge will work as the roller cam mechanism tends to need all of the intended cables stroke to work effectively, and it's much harder to just run the pads close without significant rub/drag (IME)...
I might still have to old road pull roller cams knocking about for you if they'll fit a BB7, it does mean fully disassembling the caliper and pressing the old ones out to replace them though...
Edit: Another option would be using travel agents to bump up the cable pull...
I've got 5600 105s and road calipers and it's tricky enough to get them to not rub without so much lever travel that they pull to the bars.
Can't imagine that the mountain bike calipers will work well, but would be interested to hear. I think it was 5700 (2nd gen 10speed) that cable pull was increased a bit.