[Welsh boy]

I am looking to convert a drop bar bike to flat bars and am running Tiagra hydraulic discs. Can I use any of the Shimano mtb levers with the callipers or will I need a complete setup? If I need a whole new system is there a reasonable priced flat bar/flat mount system out there worth looking at?

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[oceandweller]

Hi, I’m not certain but I

Hi, I’m not certain but I think for hydraulic brake systems the levers & calipers must be the same. I’d guess it’s something to do with the volume of fluid pushed by the levers matching the volume of the pots in the calipers? The good news is that perfectly serviceable MTB brake kit is dirt cheap by road standards (little bit heavier but hey!). Quality is amazing. I have SLX brakes (umm, iirc about £70 x 2 10 years ago) on my MTB & they’ve never needed bleeding in the 10 years since I built the bike!

MTB brakes are all post mount but Shimano does a flat mount adapter, widely available for about a tenner a pair, so no probs mounting on a bike with flat mount (I have another bike with this arrangement). Note there doesn’t seem to be any way to do the reverse, mount a flat mount brake on a post mount bike.

One other thought on this, I suspect MTB brakes will need at least a 160mm disc rotor, but that just means you have better brakes.

I have a flat bar road bike & it’s an absolute dream – light, flicky, manoueverable & comfortable & the straight bars give far better & more natural handling than you’ll ever get with drops. I use small bar ends to give me a sort of on-the-hoods option. Just don’t expect to be toughing it out with the big boys in the final sprint…

You might have an issue with gears. I found MTB gears a bit stiff for my straight bar road bike build – they need stronger clutch springs to limit chain slap when bouncing around off road. Even top-end MTB gears feel like trying to pull bricks through a bush compared with Ultegra. In the end I settled on a SRAM 1x road group (Apex-1 @ t’mo, but I may upgrade to Rival-1 sometime) coz (a) I’m never in a hurry & 1x is beautifully simple, & (b) SRAM make flat bar levers for their road groupsets (altho they might take some finding post-Brexit, pre-Brexit I got mine from Germany).

Hope that helps. Good luck & good hunting!

[Welsh boy]

Thanks Rich, at £14 each for

Thanks Rich, at £14 each for Deore M4100 levers I will give it a try 

[Rich_cb]

I’ve been running mountain
I’ve been running mountain bike calipers (SLX M7000) with road shifters (RS505) with no issues.

Can’t see why that wouldn’t work in reverse.

If that fails a full set of SLX7000 brakes and calipers is £150. Far more sensible prices in the world of baggy shorts.

[Author]

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