Bicycle Mechanics - Alright, I bought some shifters...

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA
ChipRGW
03-13-03, 06:19 AM
...to upgrade my DT shifters to STI.

I picked up some Tiagra 9-sp shifters. My bike is currently equipped with full RX-100 7-sp w/ indexed DT shifters. I have a 8-9 compatible Ultegra hub on the rear, with the spacer to run the 7-sp. gears. The chain is fairly worn and probably needs to be replaced very soon. The crankset is a 53-39 double.

Q1) Will the Tiagra shifters work with the RX-100 derailleurs to shift the 7-sp cogset?

Q2) If not, can I just replace the cogset/chain to a 9-sp, or will the RD need to be changed as well?

Q3) If I DO go up to 9-sp., do I have to replace the chainrings up front to accomodate the narrower chain? (also, is RX-100 bolt spacing @130mm?)

Q4) Is 8-speed an option that would make any of the above easier to deal with?

Q5) Am I missing anything?

Thanx in advance for any help...

ChipR

1oldRoadie
03-13-03, 07:05 AM
RD, chain, chainrings = 9speed.

not terrible expensive upgrade, and you will like the 9speed STI ability.
ChipRGW
03-13-03, 01:16 PM
Well, I've already spent more in upgrades than I paid for the bike in the first place, but I figure if I buy decent upgrade parts now, I may be able to just buy a nice frame when I'm ready for a new bike...

D*Alex
03-13-03, 05:05 PM
Q1) Will the Tiagra shifters work with the RX-100 derailleurs to shift the 7-sp cogset?

No.


Q2) If not, can I just replace the cogset/chain to a 9-sp, or will the RD need to be changed as well?

Yes, and probably yes.



Q3) If I DO go up to 9-sp., do I have to replace the chainrings up front to accomodate the narrower chain? (also, is RX-100 bolt spacing @130mm?)

Most likely, and probably yes.



Q4) Is 8-speed an option that would make any of the above easier to deal with?

No. 8-sp spacing would work, maybe, with your old stuff, but not 9-sp.


Q5) Am I missing anything?

Cold setting your dropout spacing? You need, from what I can figure, a new cain, a 9-speed cogset, 9-sp rings, 9-sp rear derailleur. I can't imagine a bike with rx-100 components is worth it.