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Converting from downtube to brake lever shifting(8 posts)

Converting from downtube to brake lever shiftingBankerdanny
Mar 26, 2003 7:57 AM
Has anybody converted an older SIS equipt bike from downtube shifters to brake lever shifting?

As far as I can tell it would involve a new freewheel and rear derailer because most downtube bikes are 6 or 7 speed while modern shifters are 8 or 9.

The difficult part would seem to be finding a way to attach a boss for the end of the cable housing where the levers used to be.

Thanks
Your new shifters...Nater
Mar 26, 2003 8:07 AM
should include a bolt-on cable stop that will fit over the down tube shifter bosses. I think that is the least of the problems you'll encounter depending on the age of the bike in question. You might run into rear triangle spacing, hub/cassette compatibility, etc...The cable stops will be included with the new shifters though.
Good Luck...
More info..Rusty Coggs
Mar 26, 2003 8:56 AM
If your frame has bosses for the downtube shifters,no problem as mentioned above.If no bosses,then some frames can accomodate a clamp on cable stop.Other frames would be too big in daimater to use the available stops. If you have index shifting(sis)6 or 7 speed shimano, the easy way is to find Shimano 7 speed RSX STI shifters,and just use your present setup and a STI compatible front derailer.Even tho cog spacing is different,8 speed shimano shifters will usually shift a 7 speed shimano cogset. If you are thinking 9 speed than as the above poster mentioned there are even more expensive issues to consider.Ir generally is not recommended to sperad aluminum or CF rear trialngles to accomodate the wider 8/9 speed hubs......This kind of stuff is done all the time.The cost may not be justified,depending on the value of the frame. And it works alot better if one knows what they are doing,knows all the ins and outs and does it themselves.
First, you need to know exactly what you have now.Spoke Wrench
Mar 26, 2003 9:13 AM
Freewheel or cassette, 126mm or 130mm. This is the kind of project that I love to do because there are so many fun possibilities. It's also the kind of project that can having you repeatedly buying one more new part to make the rest of it work. Plan carefully.
re: Converting from downtube to brake lever shiftingBankerdanny
Mar 26, 2003 10:13 AM
I am looking at a 90's Raleigh Technium Pro with Shimano 105 7-speed components.

I don't really care about moving to 9 speeds. 7 is fine, but I don't know how many options I would have for 7-speed compatible brake shift levers. I would prefer an RSX or better style with the separate shift lever.

I am not sure if the downtube shifter on the bike now are braze on or bosses, but based on my experience with the first generation Technium I owned in the mid 80's, I would guess bosses.
re: Converting from downtube to brake lever shiftingRusty Coggs
Mar 26, 2003 10:47 AM
RSX 7 speed are probably no longer available new.Used ones show up on ebay. If your current setup is indexed,clicky,click.Then all you need is a STI capable shimano road front derailer,,which has the arm the cable attaches to perpindicular to the drailer cage.Some say you can use the old 105(non sti?) derailer,by fudging the cable mount.Havent tried it tho. 8 speed shimano sti other than dura ace usually work too even tho the cog spacing is different......Considered bar end shifters?
re: Converting from downtube to brake lever shiftingBankerdanny
Mar 26, 2003 10:57 AM
The bike is definitely indexed already. Even my entry level 440 I bought new in '84 had indexed shifting.

It sounds like I would need to look for a used 7 speed RSX setup
Sora is still available...Nater
Mar 26, 2003 11:49 AM
in 7 speed and is listed in the QBP catalog so any shop should be able to get them for you. Sheldon Brown also has some at www.harriscyclery.com if you're interested.