My #2 road bike is a 2002 Trek 5200 with Shimano Ultegra 9 speed and a triple chain-ring. I'm thinking about changing out the triple for a compact crank. I have a question for those of you more involved in the technical aspects of cycling. Should I think about upgrading to 10 speed at the same time? What minimally should be traded out to make the switch? Front and or rear derailleurs? Brifters both sides? Help!
Login or Register
Technical help - Shimano upgrade
-
-
Best I can tell from looking at the Tech Docs on the Shimano web site, they did not make a 9 speed compact crank.
A lot of people will tell you they had success mixing and matching 9/10 speed parts. I don't like mucking around with that stuff because I'll always question whether my less than perfect shifting is due to a mongrel setup or poor wrenching. You have to decide.
If you really want a compact setup and don't want worries, I'd say you have to upgrade to 10 speed. Otherwise you're looking at a 10 speed compact crank running a 9 speed chain and a 10 speed compact front derailleur. Shimano runs closer chainring spacing on 10 speed cranks so either your chain will make noise or the shifting will be questionable.
-
Are you saying the cranks are specific to 9 and 10 speed setups? I was hoping I could just get brifters, and front and rear derailleurs (in either 9 or 10 speed) then find a compact crank compatible with my bottom bracket.
-
No; the chainline is the same and I believe even the thickness of the mounting tabs for the chainrings are the same, so it's not the cranks that are 9/10 speed specific. It's how they profile the chainrings to provide a specific spacing between the two rings on 9 speed vs 10 speed. So you can't reuse your Ultegra 9 speed crankarms and just buy compact ratio chainrings because the smallest ring you'll fit on the crank is 39T.
It appears you're only going to find compact cranks in 10 speed versions. That is, the chainring profiles will place the rings fractions of a millimeter closer together. A 9 speed chain will be too wide to perform properly.
Also, if you look at the Shimano Tech Docs you'll notice some setups have triple specific brifters, some do not.
Another potential conflict would be the front derailleur. I don't think anyone makes a compact, 9 speed, double ring front derailleur. So, if you decide to use a 10 speed compact front derailleur on a 9 speed crank with chainring spacing it's not designed for, you may get less than optimal front shifting, incurable chain rub, or dropped chains.
-
I am running an Ultegra 10speed compact crank on my cross bike with an otherwise 9speed 105 drivetrain with no issues. The 9sp front derailleur shifts fine with the 9sp chain and 10sp crank.
I would evaluate the total cost/benefit of swapping though. You may be able to pick up an ultegra ten setup a very reasonable price.
-
Thanks for the input Peter and System7. I'd just as soon have this set-up work well, so I'll hunt for 10sp stuff.
-
May need to order new braze-on plate from Trek. I had a 2002 and I believe the plate was specific to 53/39.
Tai
-
On my road bike I'm running a 10speed Chorus crank whilst the the rest of the drive train is 9speed. Works fine. Better than fine actually; flawless.
Prior to the Chorus crank I had a FSA compact 9speed on the bike.Jam Econo -
For a triple to double, you will need a double FD, I think they are different. I would just get a clampon as trek uses some mounting system that will not line up when you drop the FD to match the crank chainrings. Other items... 10spd chain, cassette & 10 spd shifters, everything else will work ok.
-
@durielk front derailleur going from Triple to Double doesn't require a change other than adjusting the stops. You may even be able to go from a 9spd triple to a 10spd double using the same front derailleur.
As far as the crankset is concerned, you may need a new bottom bracket to adjust for the change in chain line. If you aren't wedded to shimano for the crank, I'd look at some other brands such as Sugino, FSA, etc. You may easily upgrade to a compact double going that route. I'd stick with 9 speed unless you want to completely change your drivetrain and shifters. But I'm still using 8spd Shimano 600 components...
Reply
You must log in to post.