Cycling UK Forum

Are there any tricks that allow you to use a 105 triple front mech with a MTB Deore triple shifter? Chainset is 48/38/28.

Oops sorry got hold of the wrong end of the stick

Not possible - if it's a road shifter and MTB derailleur it works by changing the clamping, but the MTB shifter pulls more cable than the front mech can handle.

(edited as I got the question the wrong way round first time, just like reohn2)

This is road FD + MTB shifter...? The above replies appear to be a better match for the MTB FD plus road shifter pairing?

If you lengthen the arm on the 105 FD (which requires making a little bracket) the mech becomes a better match for the MTB shifter (which has a longer cable pull. Or you can use a shiftmate.

However the shifter has no trim clicks and you may need those in a 'road' chainset + FD setup; I would for sure.

cheers

I'm currently running a Tiagra triple front mech with Deore MTB shifter on 22/32/42 rings.I can't see the ring sizes would make much different if the mech is moved up the seatube.
I have to say finding that the combination of mech and shifter was a surprise to me when I tried it,so if you have both mech and shifter to hand give it a try.

reohn2 wrote:I'm currently running a Tiagra triple front mech with Deore MTB shifter on 22/32/42 rings.I can't see the ring sizes would make much different if the mech is moved up the seatube.
I have to say finding that the combination of mech and shifter was a surprise to me when I tried it,so if you have both mech and shifter to hand give it a try.

What generation Tiagra and Deore?

I would suck it and see. I put tiagra 9 speed triple drop bar shifters on a hybrid for my son in law. The front mech had a MTB pull so In theory it shouldnt work as the tiagra shifters pull less cable but in practise it was ok. I may have clamped the cable inboard of the clamp to increase the leverage and make it more compatible but cant recall. All i know was it worked ok. He was running 8 speed BTW, so had to use the alternate cable routing for the rear mech.
oops misread your post and see that you are planning the opposite, ie flat bar mtb shifters with your 105 road mechs.

If you have thirty quid lying around, the Jtek Shiftmate 7 is meant to solve this problem.

Thanks for the replies. I’m about to rebuild my Thorn tourer with straight bars and I was hoping to avoid changing the 105 mechs (9 speed triple) to operate with 9 XT triple shifters. If it can’t be done (and I didn’t expect it to work!) then a new front mech is the cheapest way to compatibility. Obviously the rear mech will be fine, and I have got a pair of flat bar road pull brake levers so it’s not a major crisis.

peetee wrote:What generation Tiagra and Deore?

Shifters are two way Deore M590 .
I made a mistake on the FD it's Ultegra 6603,I was sure it was a Tiagra

How about using a thumb-shifter?

here's how i did mine a few years ago
download/file.php?id=35389&mode=view

fastpedaller wrote:here's how i did mine a few years ago
download/file.php?id=35389&mode=view

Thats very neat, how did you make it and did you calculate the extension or was it by trial and error.

Is it still the case that 'road' and 'MTB' groupset mechs and shifters still pull different amounts of cable per shift?

A friend of mine thought that was no longer the case, but certainly on my bikes I'm using different pod shifters (SL-R440) on the bike with Ultegra mechs an MTB shifters (Deore LX) on the bikes with MTB mechs....

road double FDs now use a longer cable pull than they used to and will often work with MTB shifters. But then the FD only needs two positions and one of those is set by the limit screws. I have also heard of MTB double FDs working with current road double STIs.

However road triple front mechs use the same shift ratio as they always have done, which is a shorter pull per shift. Occasionally such a FD will work with a MTB shifter eg because a wide chainline is used; the FD is at the limit of its travel on the big ring, which means that the shift ratio is changed.

If you use a road triple FD at a road chainline, the cable pull required to move the FD from middle to big is somewhat shorter than a MTB shifter will deliver. Hence the arm extension I suggested upthread, much as fastpedaller has built.

cheers