8 speed chain through 10 speed front mech?

[TheDoctor]

Bit of an oddball one, this.

The sora front mech on my winter bike has fossilised and will not change gear, or indeed move at all. I have a 10 speed 105 front mech in the bits bin. Will 8 speed chain run through it OK, or will I be trimming it continually as I change up and down the cassette?
Or shall I just throw a single chainring on and have done with it?

 

[swee'pea99]

You have of course tried liberal apps of 3-in-1, 24 hrs for easing its way in, then a bit of brute force as necessary...?

 

[TheDoctor]

I'll see your 24 hours of 3-in-1 and raise you a week of WD40 as well.
And a hammer.

 

[swee'pea99]

Hammers are good - big hammers especially. I'm not sure about the WD-40 tho'...I've always thought of it more as a water-repellent than a lube. I'd be inclined to at least have a try with the 3-in1+24hrs...probably won't work, but you never know, and what've you got to lose?

 

[GrahamG]

Then heat it up!

On the 10 spd mech + 8 sp chain front, I've done it on a shimano double set up and it was fine with just a little extra rub to factor in when trimming. For a triple i just wouldn't go there unless it was with campag or friction shifters so that it's easy to trim.

 

[TheDoctor]

It's a double.
I'll clean it again, soak it in 3-in-1 and stand the whole lot on top of the boiler so it gets all warm...

 

[Davywalnuts]

When I was changing over slowly over a month from 8 Speed Tiagra/Sora to 10 speed Dura-Ace, that was one of my biggest grippes, and yes it works, but I didnt like it. I didnt like the rub and with pressure chain slip too..

The differances in width is marginal, but, tbh, it does make a differance, and I did get miffed off with the trimming, but tbh, ild spend £10-£15 on ebay..

 

[TheDoctor]

I would, but I need to be up and running by Sunday...

 

[Davywalnuts]

I would, but I need to be up and running by Sunday...

Ahhhh!!

 

[gbb]

Bit of an oddball one, this.

The sora front mech on my winter bike has fossilised and will not change gear, or indeed move at all. I have a 10 speed 105 front mech in the bits bin. Will 8 speed chain run through it OK, or will I be trimming it continually as I change up and down the cassette?
Or shall I just throw a single chainring on and have done with it?

This is so common on my winter bike with Sora, its guaranteed to happen every winter, without fail.
Quick and simple fix fortunately...
(assuming 8 speed) there's a dome head bolt facing the rear wheel, at the point the whole mech pivots.
Loosen (not remove) that bolt and get some WD or similar into the bolt/pivot. Waggle the mech pivot about a bit, it always frees up. Re-tighten the bolt.

Ought to be a sticky about this ive done it so many times. Maybe one day i'll get some better lube in there and maybe it'll stop it being an annual occurence.

 

[TheDoctor]

Tried this. I agree that usually this sorts it, but not this time...