Shimano gears from different years!

[Razor]

Hello,I have been trying to resurrect my bike after a crash and have bought a few bits of eBay to sort the gears out but no shifters as yet .i have a 9 speed 105 rear mech and a 7 speed uniglide block on old shimano ultegra hubs .i have the offer of shimano 8 speed sti shifters from the 90s .Will the 8 speed shifters have the correct cable pull for the 9 speed mech with a seven block ?

obviously I can block the rear mech with the limit screws.
I realize this may seem odd but I am just trying to make do with what I have to make up a cheap bike and get on the road again.

Thank you

Mike

 

[Star Strider]

I wont bore you with pull ratios as you will get away with 7 speed on an 8 speed shifter.

It will work.

Not super smooth but it will work.

 

[biggs682]

must admit got similar idea at mo and i cant see why it shouldnt work as the changers are slave units

 

[Razor]

Thanks for the prompt replies .was just wondering though why it won't be smooth ?

Mike

 

[TheDoctor]

Because the the sprocket spacing isn't quite the same between 7 speed and 8 speed - 7 speed is 5 mm and 8 speed is 4.8 mm IIRC. It's close enough to work, but won't be as good as if everything was perfectly matched.

 

[Razor]

Thank for the replies,I got the 8 speed Sti s and the rear mech lever works ok .the left I think has a faulty ratchet even after much lubrication .it will work but I have to move the brake lever the opposite way to reset it after I have shifted back to the small ring .they look a pain to dissmantle but I will give it a go just to make sure nothing has seized.
Levers are st6400 if anyone can offer any advice .

Mike

 

[Razor]

 

[biggs682]

nice chrome and purple mix

 

[smokeysmoo]

The early sti shifters are prone to becoming sticky over the years.

Basically the original lube eventually turns to a paste and gums the mech up.

I'd avoid dismantling unless your particularly skilled in such fields TBH.

A good clean with a decent degreaser to clean them out, and a re-lube should work wonders IME.

 

[Razor]

nice chrome and purple mix

Thanks the frame is a 90s cadex cfr3 .The paint was rough so I polished the ally bits and left the main tubes ,as they are composite.

 

[Razor]

The early sti shifters are prone to becoming sticky over the years.

Basically the original lube eventually turns to a paste and gums the mech up.

I'd avoid dismantling unless your particularly skilled in such fields TBH.

Thanks I might try soaking again with solvent

A good clean with a decent degreaser to clean them out, and a re-lube should work wonders IME.

 

[Star Strider]

I would not use a solvent as the lube in there was water based to start with and doesn't need petro chemicals to shift it.

Silicone spray lube is what you want for plastic on plastic moving parts, Finishline also make a thicker silicone lube in a tube originaly designed for SRAM Gripshift, this works well once you have blasted the gunk out with the aerosol can of silicone.

 

[smokeysmoo]

I would not use a solvent as the lube in there was water based to start with.

FWIW I used a brake and clutch cleaner aerosol, this one in fact as I have access to it at work.

It's very impressive stuff. I also use it to clean chains and mechs, cleaning sticky residue off just about anything and as it evaporates to nothing it's perfect for fitting bar grips as well.

Anyhoo, it worked for mine and then I regreased them with a light machine oil

 

[Star Strider]

The break cleaner stuff is fine, we used to use it to clean plastic paslode nail guns.

 

[Razor]

Thanks ,I had been using a thin oil with PTFE .it worked ok for the right lever but the left is still not resetting .will have a go at using the brake cleaner but I suspect something has broke as I can move the lever both ways which I cannot do with the right hand one.
I ,ll post some pictures if I take it apart .might a few days though.
Thanks again for all the input.

Mike