Bicycle Mechanics - 105 7 speed DT shifters

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RichCT
08-03-09, 04:01 PM
I would like to upgrade my cannondale to an sti platform, but since I don't have the $$$ for an entire group, I plan on doing it piece by piece. My first upgrade will be the wheels. After that, I'm not too sure where to go. Will the 105 DT shifters and the 105 derailleur be able to work with a 9 speed cassette if I have the shifter in friction mode?

Al1943
08-03-09, 04:09 PM
The friction shifters should work with the 9-speed cassette, but you'll need a rear wheel that will accept a 9-speed cassette.
You know it's really easy to get too much money tied up in upgrades. In the long run you would have a better and less expensive bike if you'll wait and buy a completely new bike. Components cost more than the sum of the parts.

Al
bluenote157
08-03-09, 04:21 PM
yes. I did this with a 6 speed 105 with no problems. You need to flip the switch from sis to friction on your lever and get a 9 speed chain.
I'm not entirely certain on the wheel thing but if you have a cassette instead of a freewheel, you might be able to throw a 9speed cassette on?? You might want to ask around if this is possible. Then, with money saved on wheels, you can just get your STIs. haha

shelbyfv
08-03-09, 04:44 PM
The 9 speed cassette will not work on the 7 speed freehub. You can buy a 9 speed freehub to replace the 7 speed for about $30. However, unless you have a really special frame or access to really cheap parts, you're probably better off saving for a newer bike.
fatsoforgotso
08-03-09, 04:58 PM
For $40.00 or less you could go with Shimano SL-7700 Dura-Ace DT shifters instead. Best indexed shifting I've had in my life, even with my home assembled 11-26 cassette made out of remnants of old 8 and 9-speed cassetes.
Can also be run in friction mode, of course.
Al1943
08-03-09, 05:58 PM
How many cogs are in the back? Freewheel or freehub with cassette?
Assuming that your Cannondale has an aluminum frame, you should know that it is not recommended that you spread the rear triangle enough to accept a 9-speed hub. That's not to say that it can't be done.
8, 9, 10, &11-speed hubs have 130 mm dropout spacing. Measure the dropout spacing across your frame where the rear wheel fits.
wharfrat
08-03-09, 07:20 PM
How many cogs are in the back? Freewheel or freehub with cassette?
Assuming that your Cannondale has an aluminum frame, you should know that it is not recommended that you spread the rear triangle enough to accept a 9-speed hub. That's not to say that it can't be done.
8, 9, 10, &11-speed hubs have 130 mm dropout spacing. Measure the dropout spacing across your frame where the rear wheel fits.

Al,

I'd like to hijack the thread and ask you if you happen to know what it would take to convert a bike with all RX-100 components including crank (double) that is 7 speed to 9 speed STI? I already understand that it's expensive and, I've seen your advise on going the new route ... don't wanna do it. I have a 9 speed compatible rear wheel (Aksium w/spacers for 7 cassette currently..easy to change) and the dropout spacing IS a confirmed 130mm. Can I pull it off with just a cassette, chain, and shifter change? Will the RX100 chainrings work with the 9 speed chain? I'm thinking yes. Do you know? Thx.