Problem with Deore Hollowtech chainset on road bike?

[CMC-24]

I wanted to replace my road double with a touring triple for my second-hand Hewitt Cheviot SE road bike so bought a new Shimano Deore Crankset (26/36/48), a new left Tiagra triple STI lever and a Tiagra triple front mech. All are now fitted but the large chainring sits too far out to the right for the Tiagra front mech and, therefore I cannot change to the large ring.

The chainset is fitted to my 68mm bottom bracket with two spacers on the drive side and one on the non-drive side as recommended by Shimano. I have used the ‘mountain’ bearings that were supplied with the chainset. I thought about missing out the spacers but cannot do this as then the internal plastic sleeve, and maybe the crank shaft, will be too long to fit.

Is it possible to use a Deore Chainset on a road bike? If so, how do I get it to work with my tiagra derailleur and sti. If it won’t work, what alternative parts do I require.

I am doing LEJOG next month so need to get it to work reliably.

Thanks in anticipation for your help.
Colin

[Redvee]

You need to match the front mech to the chainset. I had the same issue when I had drops on my MTB. I had Sora shifters and front mech and problems with the shifting on the M440 chainset but as soon as I changed the front mech to Deore the shifting issues vanished.

[JosephCallard]

I don't think you need a new front mech, I have a Deore hollowtech chainset and Tiagra Triple mech on my Dawes Galaxy and there are no problems, I didn't put it together myself though so can't help any more than this.
Joe

[Mike Sales]

Is it possible to move one or both of the drive side spacers to the LHS?

[Brucey]

the mtb front mech will reach ok but it won't index because it needs more cable pull than road mechs. I'm assuming that your left shifter indexes; if so I'm not sure what the solution is....unless you can revise the chainline somehow (shorter bb maybe)

cheers

[CMC-24]

Dear Redvee,
Thanks for your reply. It would certainly be easy to change the front mech but I am given to understand that will not, in itself work, as an MTB front mech would not be compatible with my Tiagra Shifter. Howevere, if anyone knows of a MTB triple front mech that would work properly with STI shifters then that would be great.

[CMC-24]

I could move the two spacers from the drive side to the non-drive side and that would enable me to chang to all three chainrings but the cranks would then be offset to the left which might cause physical discomfort over long distances. If I use a narrower bottom bracket then the shaft of the crank will be too long for it.

I am sure there must be an answer as I cannot be the only person who wants to use a MTB Hollowtech chainset on a road bike.

Thanks.

[Mike Sales]

I could move the two spacers from the drive side to the non-drive side and that would enable me to chang to all three chainrings but the cranks would then be offset to the left which might cause physical discomfort over long distances. If I use a narrower bottom bracket then the shaft of the crank will be too long for it.

I am sure there must be an answer as I cannot be the only person who wants to use a MTB Hollowtech chainset on a road bike.

Thanks.

I would be surprised if it did cause any discomfort. I write as one who cycled for many years with an injury to one hip which dictated an irregular action in one leg.

[CMC-24]

Thanks Mike, I suppose I could try moving the spacers and see what it's like. Cheers.

[Mike Sales]

Thanks Mike, I suppose I could try moving the spacers and see what it's like. Cheers.

BB axles come in such a variety of lengths, differing on both sides by more than the thickness of a couple of spacers, that it can surely not cause any problems. I have often used such dodges to get things to work, without problems. I know that Graeme Obree and others have seen "Q" factor as important to reduce, but if the extra width of a longer axle was crucial, then triples would cause problems, compared to a single.

[Malaconotus]

I have no answers but I would love to see some definitive ones as I am currently planning to build up a Salsa Vaya with the same set-up.

One solution which will work is to use an MTB mech and the appropriate J-Tek shiftmate as discussed here... viewtopic.php?f=5&t=52096, but that solution is, to me, inelegant, overly complex and involves a tight curve in the cable.

The Ridgeback Panorama was specced with Tiagra STIs and a Deore chainset as discussed in this blog... http://cycleseven.org/hollowtech-ii-cha ... d-q-factor I note that the current Panorama uses an Alivio chainset and a square taper BB, which presumably reduces the chainline from the 50mm Shimano Deore/MTB standard to(wards) Shimano's 45mm road standard. (Shimano's square taper MTB chainsets are specified as 47.5mm or 50mm chainline)

I wondered whether using a Tiagra road external BB (which it seems has fewer spacers... http://techdocs.shimano.com/media/techd ... 614887.pdf) might cure the ill, but with the integrated axle of the Deore chainset being a fixed length this presumably wouldn't work.

The three spacers are effectively one which would be replaced by a chaincase or e-type derailleur, and two which space a 68mm shell out to 73mm. If you were to put one on the driveside and two on the non-drive side, the chainline would reduce to 47.5mm, and the Tiagra mech would probably work. This is what seems to have been done on the Panorama in the blog, but of course it means the pedal is 5mm further out on the left of the bike relative to the right. Whether this would be discernible in use, I don't know. I guess it could be corrected with 5mm of pedal washers on the drive side, but that would give an even wider Q-factor.

Can you post precisely the part numbers of the chainset and mech? FD-4503 and FC-591, I assume? And the mech is band-on, not braze-on?

[Malaconotus]

I found a bike which has this set up as stock...

The transmission we have selected is really very special, we have used a Shimano Deore 26/36/48 chainset and 11-32 Cassette with a Deore rear mech, Tiagra front triple mech and Tiagra STI levers. This 100% Shimano transmission works really well and give an awesome range of gears, which should give most people a gear for every situation likely to be encountered on the Mk3. (from http://www.sjscycles.com/thornpdf/Thorn ... lowres.pdf)

Might be worth ringing SJS and finding out whether they do it by moving a spacer or two to the other side, or whether they find the limit screws alone enable it.

[patricktaylor]

... Is it possible to use a Deore Chainset on a road bike? ... with my tiagra derailleur and sti.

Same as my drop-bar tourer (road bike with Deore XT chainset). I moved a Hollowtech II spacer over to the other side, with 2 on the left. The chainline is actually better.

[Malaconotus]

Same as my drop-bar tourer (road bike with Deore XT chainset). I moved a Hollowtech II spacer over to the other side, with 2 on the left. The chainline is actually better.

Can you tell that the left pedal is 5mm further out than the right?

[CMC-24]

I am using an Tiagra ST 4503 shifter, a Tiagra FD 4503 front mech and a Deore FC - M590 Chainset (26/36/48).. On the rear, I have a Deore Long cage rear mech. I can,t remember the model - it's either a RD 590 or RD 591 (whichever is the 'top normal'.

I think that I'll try moving one on the spacers from the drive side to the non-drive side and see if that works and what it feels like. An alternative might be to remove the plastic tube and take out a spacer either side, although that might not work as the axle might be too long and it would also remove protection from the inner side of the bearings..

I might also phone SJS, although I did not buy the bike or any of the components from them.

I'll post my findings.