Germanicus

My current 2008 Tricross sport setup:

Brifters: Shimano Tiagra 9-speed
FD: Shimano Tiagra 9-speed Triple
Crankset: FSA Vero 9-speed Triple 50-39-30
RD: Shimano Deore LX 9-speed
Cassette: 11-34 MTB 9-speed
Chain: 9-speed

What I would like to do (if possible) is to leave the back drivetrain as is, and just upgrade the front end to a 10 speed setup so that it would be as follows:

Right Brifter (rear): Shimano Tiagra 9-speed
Left Brifter (front): Shimano 105 10 speed
FD: Shimano 105 10 speed double
Crankset: Shimano 105 compact double 10 speed
RD: Shimano Deore LX 9-speed
Cassette: 11-34 MTB 9-speed
Chain: 9-speed

Is this possible? what would be the negative effects (if any) of such a conversion?
Thanks.

IthaDan 

Yes, none.

Maaaaaaaaaaaaybe an issue with a 9speed chain on 10speed chainrings on paper, but in practice, I've done this for almost two years now with no problems.

What's wrong with your left brifter? Not much to be gained adding the 105 brifter if you don't have to. If you're thinking you need a double brifter because you have a triple now, don't worry about it, that's what limit screws are for.

caloso

I did have that problem using a 10-spd double FD on an otherwise 9-speed set up. Too much chain rub and could never seem to get it adjusted. Fixed the problem by "downgrading" to an ancient RSX triple 8-speed front derailleur. Worked like a charm.

You could probably save yourself some pennies and a bit of a headache by just keeping the Tiagra FD, adjusting the limiting screws. Oh, and a chain minder is always a good idea.

Germanicus

Thanks guys,

IthaDan, I have heard that if you use a triple STI brifter you run the risk of damaging it if you try to force an extra shift. The Tiagra internals are plastic rather than metal.

Calosa, What chain rub would I get if the shifter derailleur and chainring are all the same? I assumed that would solve that problem as using a 9 speed derailleur might not move the chain to the exact spot that a 10 speed would.

The way I figured, all the 9 speed components from the shifter to the rear would take care of each other and all the 10-speed components up front would do the same. Cross gearing exists anyway. Where would the rubbing occur? by using a 9 speed chain on a 10 speed crank?

caloso

Yes, I think it's because the 9 speed chain was just a little bit wider than a 10 speed chain.

adclark

I don't think you would damage the shifters unless you really, really push on it hard. I have a tiagra triple shifter and derailleur that is set to a double 10 speed crank using the limit screws on the derailleur. I have yet to have any problems but I don't have all that many miles on the bike yet either.

IthaDan 

Some bikes ship OEM with triple brifters and double cranks.

Honestly i think your money would be best spent on a crank and nothing else. If your cranks are 110 BCD, get smaller chainrings, if you have 130BCD cranks, then 38t is the smallest you can go for your middle triple or small double.

fietsbob

Just don't think new 10 speed is an upgrade , it is spending money, which is what the marketing people had in mind. Simon Burney in1st edition of his book even questioned going into a 7 speed , as the crud packed into those narrow spaces made the drive train work poorly in the muddy sticky courses.. but lots of posters in this section are not racing anyhow. Happen to change a $15 chain without worrying, .. a $50 chain and a $120 cassette is another story..

thenomad

put the double crank on, 9sp FD, adjust the limit screws, and call it a day. I''d change the FD because the triple FD will have a lower guide on it which would interfere with larger cahinrings.

Possible that 10 sp FD will be slightly narrower than 9 possibly and will give chain rub top and bottom few gears. That's what happens with 9 to 8 speed.

Germanicus

Thanks,
But if I use 9 speed FD on a 10 speed crank, wouldn't that rub even more? I assume if it shifts the distance of a 9 speed it would not line up with the 10 speed crank. Isn't 9 speed spaced further apart then 10 speed? Though on a double that is only one click, I still want to maintain smooth shifts.
I have heard elsewhere that 9 speed chains work on a 10 speed crankset but not vice versa. I don't want to have to buy the darn thing to find out though..

thenomad

The 9s chain is wider so it'll fit on the 10s chainrings. 10s chain is narrower and wont fit on the fatter teeth of a 9s chainring.
Having the 9s shifter with 9s chain and 9sFD will have it all matched up nicely.
The 10s crank spacing is only going to be narrower by a fraction of a millimeter in width as you are splitting the difference between two rings.
Theoretically this will center the chain more in the FD as opposed to widening out the spacing where the chain falls but in reality I think a good tune will have it snapping easily from gear to gear. Some FD shifters have a micro-ratchet to "trim" the chainline when cross-chaining anyhow.

caloso

Campy anyone?

Germanicus

I didn't think campy worked with Shimano shifters. Will they work with Tiagra or 105 shifters?

caloso

Sorry. I was making a bit of a joke. Campy shifters have a microadjust ratchet. When set up properly, they are the ideal anti-chainrub solution. But in the context of this thread, that's just another needless complication. Ignore that I said it.

Germanicus

Sorry, i'm afraid I'm not knowledgable enough about component compatibility to share in these intraindustry jokes. Right over my head..

bluenote157

Yes.. done it both with the jtek device and without.
campy 10 speed ergo shifters and shimano 9 speed cassette, and shimano rear derailleur

I think your triple sti tiagra has a trim feature. If it does, i think your current fd setup will work fine. If it were me, I'd get the crank you want and be done with it. As someone said above..it is all marketing. We went from top tube shifters to downtube shifters, to aero brake cable routing, to stis (which defeated the "aero" look and point of the cable routing), to completely aero, etc.. I really have no point with that statement. Sorry for my rambling.. its early and the coffee has yet to kick in.