converting a 6 speeder

[losidan]

hi,

a few weeks ago i bought this from tony on here:

tis a 12 speed and so far i have popped a new seat post and a black rolls saddle on. i do like it but i was wondering how easy/difficult it would be to convert it say 8 or nine speed brake lever mounted gears?

thanks
dan

 

[barry2017]

New hub
New mech (possibly mechs)
New shifters
New chain
New cables
(optional, I wouldn't bother) cold setting the rear triangle to fit a 130mm hub
You won't notice the downtube shifters in a while!
Does your bike have a band on or braze on shifter?

 

[hamster]

Assuming it's a cassette hub, then you'll need a new hub.

Or fit a 7s,
- or take a cheap 9s cassette and remove the largest cog and spacer and run with 9s shifters until you have to rebuild the wheel.

(You cannot do this last mod with an expensive cassette as they have the exotic alloy sprocket carrier thingies.)

 

[pigman]

if you can live with 6 cogs, but just want ergos on the bars, then provided your cogs are shimano spaced and your rear mech is shimano, you can simply put on some campag 8 ergos and everything will work - faultlessly. I ran a bike like this for years

 

[legrandefromage]

Nine speed Sti conversion:

The rear mech will do 9spd, the front will need replacing if it doesnt index well with with STi (experimenting is required).

The rear stays will need widening by a couple of mm each side to accomadate the cheap 9spd wheels you'll buy (instead of faffing with old cassettes/ hubs) or the rebuilt 9spd rear wheel.

You'll need the frame stops in place of the existing downtube shifters.

You'll need a nine speed chain, cassette and sti.

Eight speed STi conversion

By going 8 spd you can still reuse the original chain/ rear mech. You will still need the rear hub replacing to fit the 8spd cassette. The rear stays will still need widening for the slightly wider rear hub.

regarding frame widening - your frame is steel, it wont even notice.

I offer this advice from personal experience of running 1988 Deore mechs on 2006 Tiagra 9 spd STi for one of the freaky bikes i make.

I've just done 8spd RSX STi with exage motion road mechs.

The anti faffing Cheese hase spoken

 

[pigman]

Nine speed Sti conversion:

The rear mech will do 9spd

I'd add caution here. My 7/8 speed XT mech wont do 9. I had to buy a new ultegra. The throw (how wide it moves) wasnt enough for 9. Only works up to 8. Some filing on the adjuster stops may make it work, but I didnt want to butcher a mint mech.

 

[legrandefromage]

Nine speed Sti conversion:

The rear mech will do 9spd

I'd add caution here. My 7/8 speed XT mech wont do 9. I had to buy a new ultegra. The throw (how wide it moves) wasnt enough for 9. Only works up to 8. Some filing on the adjuster stops may make it work, but I didnt want to butcher a mint mech.

I only say this as I've done it with those mechs on his bike ( a bit like 200GS/ 300LX)

Not sure why your XT wouldnt do 9 (unless it was a really early XT?) as I ran M730 XT on the Zaskar for a few years with LX 9spd shifters (same shifting width as 8spd ).

 

[legrandefromage]

New I had a pic somewhere:

9 cogs, an old 1991 XT mech, 9 spd STI

Very long chain and a Ging slack remover!

 

[legrandefromage]

9spd Campagnolo Ergo on a 1982 Motobecane frame

 

[hamster]

I'd agree with LGF as the throw for 8 and 9 is the same...it may have been due to a very thick dropout, which takes the mech too far outboard. :?