Bicycle Mechanics - upgrading sora sti levers to tiagra or 105

I have a sora equipped (8spd/triple) bike with a rear tiagra derail. everything else relevant is sora. I want to change from the sora shift/brake levers to tiagra or 105. I am assuming if I can find old 8spd tiagra/105 levers than I can just use those with my existing set up, right? If I cannot find 8spd levers, what is the minimum I need to change in order to use 9spd tiagra/105 levers with my 8spd set up? Will I need a new rear or front derail, cassette, chain, etc? I have no desire to move to a full 9spd setup unless I have to. All I want are different levers if possible. thanks.

I was discussing an upgrade from sora with my LBS. To go to the new levers you minimally require levers, cassette and chain. He strongly recommended comparable derailleurs too.

If you buy new levers, the only other part you'd need for a 9-speed upgrade is a cassette. The Tiagra RD is 8/9 speed, and a 9-speed cassette will fit the same hub as an 8-speed.

Your current chain, if it works with a Tiagra RD, will work with a 9-speed cassette.

I believe Tiagra was introduced as a 9-speed group, so you won't find 8-speed Tiagra levers, but I still see new old-stock RSX levers occasionally. It's hard to find Tiagra levers aftermarket, because AFAIK they're not packaged for retail sale. So for brand new levers, 105 will be the choice. But you never know what you might find on ebay.

RichC

Thanks for the replies. So I guess I cant use 9spd 105/tiagra levers with a rear tiagra derail and an 8 spd cassette.

Originally posted by descartes
Thanks for the replies. So I guess I cant use 9spd 105/tiagra levers with a rear tiagra derail and an 8 spd cassette.

It's the levers that determine how many stops there are, so the 8-speed cassette would have to go. The Tiagra rear derailleur could stay.

I know one guy who did a 9-speed upgrade from Sora by leaving the Sora levers connected to his brakes, but installing 9-speed bar-end shifters. I think he had to do something to keep the big lever from rattling with no cable attached, but it worked.

RichC

Apparently 9-speed Campy levers will shift 8 speed shimano stuff. you can find relatively low end campy levers around.

I recently made the same upgrade.I got by with shifters, cassette and chain.For some reason my bike already had a 105 front der so I didn't have to get that.Performance had the best deals going for everything.

Originally posted by FOG
Apparently 9-speed Campy levers will shift 8 speed shimano stuff. you can find relatively low end campy levers around.

can anyone else confirm this? not that I doubt you fog :)

I am seeing some 105 8spd sti levers but they are for a double. Is there any way these can be made to work with a triple?

Originally posted by descartes
can anyone else confirm this? not that I doubt you fog :)

I am seeing some 105 8spd sti levers but they are for a double. Is there any way these can be made to work with a triple? I got that from the following thread:

http://www.bikeforums.net/showthread.php?s=&threadid=29666&perpage=15&highlight=campy%20ergo&pagenumber=3