Hi, I’ve got a spare frameset and a load of spares in my garage and thinking of building a half decent (light as financially possible) flatbar bike for use on the road when weather permits during the autumn/winter and only really need to obtain the cockpit and a chainset.
The frameset I have at hand is rim brake and I have spare callipers, wheels etc.
A few q’s.
Would “V” brake levers operate 105 callipers correctly? (a specific make/model that 100% works would be good)
I have a set of Ultegra 10 speed flatbar shifters, is there anything I need to look out for on levers to enable both to be mounted together without issue? fixing lugs etc
Is 22.2mm the standard diameter for flatbars? ( with 31.8mm being the stem/clamp diameter)
Is there much comfort benefit to a carbon handlebar over Alu? (my frame has carbon forks/seatpost)
Thanks in advance
MTB flat bar brake levers pull about twice as much cable as drop bar levers, this reduces mechanical advantage by half, you’ll need strong fingers to stop if using MTB levers and road calipers.
You can buy flat bar brake levers specifically for caliper brakes or if you can find a pair of pre V-brake, MTB levers designed to work with cantilever brakes they should work as well.
Some Shimano brake levers are dual pivot that are 2 places you can fix the cable in the lever to adjust the pull so they work with both brake systems.
Great article here
Compatibility  Mechanical brakes | BikeGremlin
Thanks Jon, i’m glad i asked!
You wouldn’t know which product “family” of Shimano/Tektro levers I should be looking for?.. (I’ll probably be buying used, but not sure what to search for on fleebay.
You can search by model number and read the dealer manuals here, Manuals Search | Manuals & Technical Documents (shimano.com) which will show whether or not the levers you are looking at have the dual pivot to work with V-brakes orCaliper brakes
@JonGreengrass Good man, thank you
The cable pull between sti’s and v brakes are slightly different. Sti’s don’t quite pull enough for vbrakes and you need Problem Solver Travel Agents. I’m not quite sure in your case the reverse (flat levers pulling callipers).
Apart from once my bikes have only ever had alu bars; there might be a little bit of extra damping in carbon bars but with carbon forks I don’t think its 100% needed (you already have some damping) and the weight saving for cost in my mind isn’t worth it. When I did have carbon bars I was also too worried about failure sometimes after they took a knock.
Going by @JonGreengrass link on brakes, i think these would do, it say’s SLR on the box… yeah?
@HLaB yeah, probably right on the bars.
Yeah that should be fine but that box has only got one brakelever in it, you’ll need a BL-4700-R i.e a righthand lever as well
@JonGreengrass Could you tell me how I swap the lever from V-Brake set up, to caliper.
The instructions show how it should look but don’t tell me how to do it.
Do I push the little black plastic thing out, slide cable head part down to “C”, then refit the plastic thing?
I don’t need to loosen any screws etc?
If you scroll down to page 8 it shows you
Some brakes have a little screw on the underside, some you just have to pop out the little plastic spacer move the cable head as you describe and then pop the plastic thing back in