brokenp87

Hi everyone, I'm from Italy...it's two days that I googled seeking tips for Shimano mtb - road component compatibility and most of the times the results link this forum, so I decided to sign in...

I will explain my "problem" and hope that someone can solve or tell me something...
I'm working on creating my new travel-bike (it's an auto-gift for my degree ) and there are a lot of things that are not so clear to me...I'm not a bike component expert at all but in these days I read lots of things and started to understand something...

Since now I travel with a mtb with a 44/32/22 crankset and a 9sp cassette 11-32 but on this new bike I would like a more race attidute, I would like to mount a race handlebar...

During the decision process I started to think to mount a Shimano 105 group, but the rear derailleur of 11-28 (10sp) and a triple front crankset 50/39/30 is not so good for climbing with panniers on the back so I moved my mind on another solution...mixing a mtb group like XT and the 105...

here my big questions

1) I would like to maintain the 105 STI levers (5703 10sp-compatible) and I read that the compatibility of them with an XT 9sp M770 rear derailleur is okay...you confirm this?

2) I read that the XT M773-3 front derailleur is not compatible with the 105 STI levers (5703 10sp-compatible)...you also confirm this?

3) If 2) is not possible, can I mount the XT M771 crankset 48/36/26 with the 105 front derailleur and use it with the 105 STI levers (5703 10sp-compatible)?

4) The last one (but it's only a curiosity for now) ...105 STI levers (5703 10sp-compatible) are okay with mechanical disk brakes Avid BB7?

In conclusion...this is the solution I would like to mount
- crankset: Deore XT M771 48/36/26
- front derailleur: 105 5703
- rear derailleur: Deore XT M770 SGS
- cassette: Deore Xt M770 11-32 9-speed
- chain: HG73 or HG93
- movimento centrale: M771
- hubs: 105 5700
- levers: 105 5703 STI
- brakes: some Shimano cantilever or Avid BB7 mechanical disk brakes

hope I don't bored you
can you help me?

Jeff Wills

From where I sit, option #3 is your best bet. The XT derailleur will not work well with the 105 STI levers, if at all.

Question #1: yes, for a "road" 10-speed with that cassette, a 9-speed "mountain" rear derailleur is required. Avoid the Shimano Dyna-Sys rear derailleurs.

Question #4: use the Avid BB-7 brake calipers made for "road" levers: https://harriscyclery.net/product-lis...13-m3990-qc49/
These are compatible with the shorter cable pull of "road" brake levers.

MichaelW

On my touring bike I use Tiagra 9-speed. The Road style gear levers operate a Deore rear derailleur and a Tiagra front deraileur. They will not operate a Shimano MTB front derailleur.
There are several styles of Tiagra front derailleur. Some of them hit the chainstays when you try to change to the small ring.
The 9 speed cassettes road/MTB are interchangeable.
Modern Shimano is 10speed from Tiagra upwards so the old 9-speed compatility rules may not apply. You need to look at the cable pull per shift.

brokenp87

Thank you Jeff...two other questions:

Q1: what do you mean with "These are compatible with the shorter cable pull of "road" brake levers."?? sorry if it's a stupid question

using Shimano 105 5703 STI levers (10sp compatible) AND a Shimano 105 5703 front derailleur => I CAN'T use the 48/36/26 XT crankset...this seems to be impossible...
I see in this bike https://www.ridgeback.co.uk/bike/panorama that they use a Sora FD with an Alivio cranckset and Tiagra STI levers...I would like to use more top level component...

given that I'll mount 105 5703 STI levers...how can I solve this FD-FC problem?

grinningfool

Addressing your original post, you say you are using an XT 9 speed cassette with 105 hubs. The 105 hubs are 130mm, and you will need a 135mm mountain rear hub with the XT cassette. Otherwise, you'll need to use a road cassette with your 105 hubs, which won't give you the low gearing you desire.

brokenp87

You're right...there is no problem in mounting XT rear hub instead of 105...what I would like to solve is the FD-FC problem...

HillRider

No, that's not true. A MTB cassette will work fine on a 130 mm road hub.

As to the OP's question about disc brakes. Road brake levers (STI's among them) pull less cable than brake levers intended for V-brakes and some mechanical disc brakes. Thefore you need disc brakes that are compatible with the shorter cable pull of road levers and Avid's BB-7's are compatible. Their other disc brake models are not.

brokenp87

perfect...so the "rear" problem is solved...XT cassette is okay also for 105 hub...nevertheless for more robustness I think about mounting 135mm hubs...
also the XT rear derailleur 9sp is okay with the 105 5703 STI levers...
105 levers are okay with a possible mounting of the Avid's BB7...perfect also this...

now...help me solve the "front" problem...how to combine the 105 5703 STI levers with the XT 48/36/26 crankset?! which front derailleur?!

HillRider

A road front derailleur should work fine with the XT crank and STI levers. Your 5703 should work but try it and see. At worst, you may need to find a 9-speed version (5503) or a Tiagra. Front derailleurs are one of the lowest cost components so it's no a big waste of money if you need to try an alternative.

cobba

As long as you get the BB7 Road version and not the BB7 Mountain version.

https://www.sram.com/avid/category/283

You haven't actually mentioned what sort of frame you have and whether it needs a top pull front derailleur or a bottom pull front derailleur.

Shimagnolo

For using Shimano road brifters with Shimano mtn crankset, this is the solution: https://store.interlocracing.com/alfrde.html
It uses the road brifter cable-pull, and works nicely with a 48T large ring.
I have it on two of my bikes.

brokenp87

I'm not an expert and don't know the difference...I'm sorry...I have no frame yet and I will buy an artigianal one so any solution can be good I think...