Road Brifters with MTB Derailleurs

Question

I've just bought a lovely Surly touring frame and I simply stuck all of my mountain bike components on it.

That means I've retained a flat handlebar. I'd really like to stick drop bars on though and change to road "brifters" without changing the drive train.

I've tried Googling this and it seems to be complex issue so any advice would be most welcome. I have Shimano Alivio gears, front and rear plus a Shimano Diore crank (with the external bottom bracket type). The rear is a 9-speed cassette (11-30) while the Diore triple crank is a 48-36-26.

I really want to stick with this, not just because of the expense of buying a whole new drive train but also this set up gives me a really low bottom gear (30 on rear 26 on front) for getting up hills with a fully laden touring bike.

I understand I may need a new front derailleur but I may be able to get away with keeping the rear derailleur and using a ten-speed brifter such as a Tiagra with the 9-speed cassette. Is this right? Any suggestions would be greatly appreciated.

Answer 1

I don't see any problem with doing this on your bike if you use Shimano drifters. Generically there are two areas you'll need to consider:

1. The actuation ratio of the shifters, and
2. The brake pull.

Shimano 9-speed road and mountain derailers use the same actuation ratio. You should be OK here.

You don't mention which Surly touring frame you have so I can't be specific, but if its a Long Haul Trucker or Disc Trucker, your odds are good that the brakes will be compatible as well. With cantilevers you'll be OK as road and mountain versions use the same pull. V brakes will be a problem, they are not common on road bikes and the pull is different. I don't think know of a set of brifters for V-brakes. Similarly with discs, make sure that you are have, or are willing to switch, to road discs.

Answer 2

If you want to run drop bars and don't care if you actually have brifters or not, I've had a really good experience using Gevenalle Shifting system. It mounts bar end shifters on the front of brake levers and offers configurations for Shimano compatible 9/10/11 speed setups and use a friction shifter for the front (you wouldn't need a new front derailleur). Just make sure you find the model with the right brake levers, they have short pull (road brakes) and long pull (mtb brakes).

I've been running these on my cross check for quite some time and they are reliable and shift well if you prefer to mostly ride on the hoods. The disadvantage is that you can't shift from the drops and you can't hide the shift cable routing under bar tape. They are way more convenient than traditional bar end shifters, though those may also be an option for you as well.

Answer 3

9 speed road gears and 9 speed mtb gears are cross compatible (unlike some 10 speed etc!) but as others mention, you may have brake compatibility problems. If you are running discs, you could fit road versions of cable disc calipers, but it will add expense.

Answer 4

I just pulled this stunt in an attempt to have a better touring arrangement. I have a Shimano Deore 3-speed crankset (I don't know the actual cog count). Upon installing Shimano Claris 3x8 brifters, I got everything to work smoothly except the front derailleur (back derailleur worked like a charm on my current 8-speed cassette).

The issue I am facing is the cable pull length of the STI is too short to match the range required of the Deore (I can shift from the lowest to the middle chainwheel, but no higher, and also not back to the lower one!).

To conclude, with the caveat of potentially replacing your front derailleur/ crankset, this move is not unreasonable. [I will update with the necessary replacements I end up making when I do.]