Bicycle Mechanics - 10sp road shifters and 9sp mtb cassette

Hi everybody...I would like to know if this combination is possible...

Shifters: Shimano 105 STI Levers 10sp-compatible
Cassette: Deore XT 9sp cassette (11-32)
Rear derailleur: Deore XT M771

will this work without any problem?!

thank you in advance

Yes, it will work just fine. Just make sure you don't get an XT Dyna Sys RD, those use a different cable pull ratio.

It will work even if the shifters are for a 10sp?!?
I ask this because in an italian forum they tell me that is impossible and I'm losing time...so I would like to know why is possible to understand better...

What I read is that the cable pull ratio is the same...but my doubts are about the fact that the shifters have 10 position right?! how they can manage to work with a 9 position rear derailleur...I would like to understand why this is possible...

It will work even if the shifters are for a 10sp?!?
I ask this because in an italian forum they tell me that is impossible and I'm losing time...so I would like to know why is possible to understand better...

What I read is that the cable pull ratio is the same...but my doubts are about the fact that the shifters have 10 position right?! how they can manage to work with a 9 position rear derailleur...I would like to understand why this is possible...

It will work, believe me. The indents in the shifter are what allows the shifting to index. The derailleur simply moves the chain a certain distance for each click of the shifter; there's no indexing in the derailleur. The XT RD and ten speed road shifters you mention both use the same cable pull ratio, so it doesn't matter a bit if the rear derailleur is designated "nine speed", it's the cable pull ratio that's important. The RD will move the correct distance per click to properly shift the chain on your ten speed cassette.

Here's a pic of one of my bikes; the cassette is a Shimano-compatible (SRAM) ten speed 12 x 32, the RD is a "nine speed" LX. The shifters I use on this bike are ten speed Shimano 105. I've set up many bikes similarly, and the shifting is great.

http://i414.photobucket.com/albums/pp226/wellbiked/88002.jpg

The cable pull ratio is the same between the shifters and derailleur, but the cog spacing is different between 9 and 10 speed. It might work but it's not right.

The cable pull ratio is the same between the shifters and derailleur, but the cog spacing is different between 9 and 10 speed. It might work but it's not right.

Sorry, but it works perfectly and I don't know how much more "right" you can get than that.

brokenp87, I think the others are missing the fact that you have a 9 spd cassette. :-) And yes, according to Sheldon, you can still successfully use a 10 spd shifter. Check out the section on Alternate Cable Routing: http://www.sheldonbrown.com/derailer-adjustment.html

brokenp87, I think the others are missing the fact that you have a 9 spd cassette. :-) And yes, according to Sheldon, you can still successfully use a 10 spd shifter. Check out the section on Alternate Cable Routing: http://www.sheldonbrown.com/derailer-adjustment.html

Oh wow, you're right, my apologies to all. I thought it was a ten speed cassette he was going to use. Should have read more closely.

Sorry, but it works perfectly and I don't know how much more "right" you can get than that.

We were posting at the same time, so my post wasn't directed at you. Your shifters and cassette match, so as long as your derailleur has the correct pull ratio, it doesn't have 'speeds'--it's just the go-between. Shifters and cassette different speeds is a different scenario than what you have.

We were posting at the same time, so my post wasn't directed at you. Your shifters and cassette match, so as long as your derailleur has the correct pull ratio, it doesn't have 'speeds'--it's just the go-between. Shifters and cassette different speeds is a different scenario than what you have.

I think we were posting at the same time again. :D Basically, you can disregard everything I said above, I didn't read the original post carefully enough. :)

I thought the OP was concerned that a ten speed cassette, ten speed road shifter, and "nine speed" RD would not work together.

One thing I'll add: with the widespread availability of very wide range ten speed cassettes now, for the price of an 11 x 32 ten speed cassette (and ten speed chain) you can illuminate this issue completely.

And if you do that, then all the stuff I posted above will be relevant. :D

It doesn't work.
But you could use your 10-speed Shimano road shifters with a 10-speed Shimano cassette and 9-speed Shimano mountain rear derailleur.

Okay...thank you all...
I'm not an expert and I said that I will use a 9sp cassette because I think that a mtb 9sp RD will only work with a 9sp cassette...but...as "well biked" said this configuration on my new bike will work:

Shifters: Shimano 105 5703 10sp-compatible
Cassette: Shimano Deore XT M771-10 (10sp cassette 11-32)
Rear derailleur: Shimano Deore XT M770 (9sp-compatible)

right?!

for the front the solution can be mounting the 105 triple 50/39/30...and everything will be okay...and it can be good to me...
but I'm curious...suppose I would like to mount more lower gears because I will travel with bags on hilly roads...

I'm wondering about if you can help me in founding a 48/36/26 crankset that operate with a 105 fd...or maybe a fd that will work with 105 levers and a 48/36/26...
any solution of same-quality component can be good but I would like to maintain the 105 sti levers...

as "well biked" said this configuration on my new bike will work:

Shifters: Shimano 105 5703 10sp-compatible
Cassette: Shimano Deore XT M771-10 (10sp cassette 11-32)
Rear derailleur: Shimano Deore XT M770 (9sp-compatible)

right?!



Yes, that combo will work, or you could use a SRAM ten speed wide range cassette as well (as in my pic above). As I mentioned before, just be sure and not get one of the new Dyna Sys "ten speed" Shimano mountain bike derailleurs, they WILL NOT work with your 105 ten speed shifters. It's the "nine speed" (or seven, or eight) Shimano mountain bike derailleurs that share the same cable pull ratio as your 105 rear shifter.

right?!

Yes. :-) (along with a 10 spd chain rather than 9)

I'm a bit late to this thread but the original proposal of 10-speed brifters with a 9-speed cassette is doable if you use a Jtek Shiftmate to match them.
http://jtekengineering.com/shiftmate.htm

A Model #2 shiftmate will let you use a 10-speed Shimano shifter with a 9-speed Shimano/SRAM cassette and any compatible Shimano rear derailleur (post 8-speed Dura Ace, any other indexing road rear derailleur and any pre 10-speed MTB rear derailleur)

I've used Shiftmates to match 10-speed Campy Ergo brifters with both 9 and 10-speed Shimano cassettes and a Shimano rear derailleur and they work extremely well.

Another question...with this combination

Shifters: Shimano 105 5703 10sp-compatible
Cassette: Shimano Deore XT M771-10 (10sp cassette 11-32)
Rear derailleur: Shimano Deore XT M770 (9sp-compatible)

what chain I have to mount...the 105 chain is okay...is long enough?!
or any 10-speed compatible chain will work okay?!

thx in advance... :D

Another question...with this combination

Shifters: Shimano 105 5703 10sp-compatible
Cassette: Shimano Deore XT M771-10 (10sp cassette 11-32)
Rear derailleur: Shimano Deore XT M770 (9sp-compatible)

what chain I have to mount...the 105 chain is okay...is long enough?!
or any 10-speed compatible chain will work okay?!

thx in advance... :D

You have 3-speed shifters and a triple crank, right? That should be fine. If your crank is a 9-speed design there's a bit more of a chance you'll throw a 10-speed chain off the ring once in a while, but most people don't have a problem with it.

Any 10-speed chain will be fine, they come extra long and you shorten for your setup... you might have better performance with Shimano than SRAM but they'll both work... Campagnolo might not work well.

See the "Chain Sizing by Equation" method section: http://www.parktool.com/blog/repair-help/chain-length-sizing

How many teeth are on the largest chainring?

Not too long ago, we mounted a 10-speed Shimano road chain on my step-dad's bike with a 50T outer chainring and 34T largest cog, using the bib/big + 1" method. I think there was an extra inch we didn't need, but kept it on anyway.

Edit: I see you have a 50T chainring. The chain will fit.

I think I will mount 50-39-30 and 10sp 11-34...
But any Shimano model 10sp compatible (apart from the chain length) is okay?

Yes. The chain lengths seem to be pretty much the same across road and MTB lines. Road bikes have larger chainrings than MTB, but they tend to have smaller cogs, so it evens out. (Compare 53+28 to 48+34.) 50/34 will be fine.

the chains are always 112 or 114 links long, which is enough for all bikes, except long tails and recumbents... and other bikes with stretched out drive trains.

Okay...thank you all...
I'm not an expert and I said that I will use a 9sp cassette because I think that a mtb 9sp RD will only work with a 9sp cassette...but...as "well biked" said this configuration on my new bike will work:

Shifters: Shimano 105 5703 10sp-compatible
Cassette: Shimano Deore XT M771-10 (10sp cassette 11-32)
Rear derailleur: Shimano Deore XT M770 (9sp-compatible)

right?!

for the front the solution can be mounting the 105 triple 50/39/30...and everything will be okay...and it can be good to me...
but I'm curious...suppose I would like to mount more lower gears because I will travel with bags on hilly roads...

I'm wondering about if you can help me in founding a 48/36/26 crankset that operate with a 105 fd...or maybe a fd that will work with 105 levers and a 48/36/26...
any solution of same-quality component can be good but I would like to maintain the 105 sti levers...

I have a similar configuration on my touring bike, the RD is a M771 model, I also changed the inner chainring to a 26 tooth chain ring for lower gearing.

I have a similar configuration on my touring bike, the RD is a M771 model, I also changed the inner chainring to a 26 tooth chain ring for lower gearing.

Really?! great...because initially I would like to mount a 48/36/26 crankset but maintaining the 105 5703 levers and the 105 front derailleur...do you know if it's possible?!

If I understand you've mounted a triple 105 crankset and you substitute the 30 chainring with a 26 maintaining the 105 front derailleur?

I can say definitively that a 10-speed shifter will shift a 9-speed cassette perfectly if you use the alternate cable routing at the rear derailleur. Of course, the RD and shifter must be Shimano-made and not one of the oddball cable pull variety like XT DynaSys or old 8-speed Dura-Ace. I find that 9-speed cassettes are available everywhere in good ratios for touring for not much money. 10-speed not so much. Also 9-speed chains are stronger and cheaper, and the driveline just seems less finnicky to me than 10-speed. All my commuters and touring bikes are set up 9-speed, whether they have 10-speed shifters or 9-speed.

Cranks- there are several solutions- the easiest is to just get a 24 or 26 tooth inner ring for your existing 105 crank. They're cheap and widely available. Then the front derailleur needn't change.

Really?! great...because initially I would like to mount a 48/36/26 crankset but maintaining the 105 5703 levers and the 105 front derailleur...do you know if it's possible?!

If I understand you've mounted a triple 105 crankset and you substitute the 30 chainring with a 26 maintaining the 105 front derailleur?

I don't know about the 48/36/26, I changed the chainring to avoid the expense of purchasing another crankset. But being only a couple of teeth different, I would't think that changing from a 50/39/30 to a 48/36/26 would be much difference, but I really don't know.

A 48-36-26 crankset, such as a Sugino XD will work with your shifters and FD. Shimano makes the LX Trekking cranks with similar gearing and use the modern external bottom bracket. I don't have personal experience with the Shimano, only the Sugino.