Rear Mech

[Cope]

I've been told by LBS that I can't upgrade my rear mech beyond the Sora 3300 I currently have.

I have a 7 speed HG70 rear cassette, and 7 speed STI changers, and apparently the newer, higher quality rear mechs won't work with a 7 speed chain.

That's a bit of a bottleneck isn't it? Is anyone aware of any other options? I can't afford to upgrade the whole lot to move to 9 / 10 speed.

 

[Dave5N]

Why do you want to upgrade the rear derailleur first? That would be a way down on my list.

 

[Cope]

Why do you want to upgrade the rear derailleur first? That would be a way down on my list.

The teeth on front and rear are worn, so I'm replacing the rear cassette, chain and front chainrings. This might involve a change of gear ratio, which might exceed the capacity of the current mech, which I think is 30. So it's not first on my list either, but if I do have to replace it, I'd like to get something of better quality than Sora. But maybe that's not possible without upgrading everything else.

The frame, forks and wheels are all fine - what would your upgrade path be?

 

[PrettyboyTim]

The whole business of propelling a ton of metal faster than a speeding cow inches away from other cars, bikes, pedestrians, pushchairs, small dogs and pigeons terrifies me. I’m a terrified bad driver, which actually makes me an exceptional driver, because I’m one of the few who knows it.

I am very much like Mr. Gill in this respect except that I'm not foolish enough to think that somehow knowing I'm a bad driver somehow makes me into a good one...

 

[Landslide]

^^^
And the prize for non-sequitor of the year goes to...

 

[bonj2]

What cassette are you intending to end up with, and what chainrings are you intending to have?
you say "this might involve a change of ratio". Do you want a change of ratio?
when you say capacity, do you mean max capacity or total capacity.
max capacity is maximum largest rear sprocket size, total capacity is difference between smallest and largest for front + the same for rear.

anyhow if there's nothing actually wrong with your current mech I'd be inclined to keep it as I would hazard a guess that it's more likely to be long cage than short cage, so will probably still work if you do change the ratios slightly.

unfortunately the choice of parts you get for anything lower than 9 speed is limited nowadays.

 

[jayce]

i ran a 10 speed ultegra rear mech on my seven speed worked fine i had a kmc 8 speed chain

 

[brady37]

can i put a 9 speed rear mech on my 8 speed bike it is an ultrega 9speed a friend is giving me as an upgrade

 

[Landslide]

can i put a 9 speed rear mech on my 8 speed bike it is an ultrega 9speed a friend is giving me as an upgrade

Yup, you'll be fine (assuming you've got 8spd shifters).

 

[brady37]

can i put a 9 speed rear mech on my 8 speed bike it is an ultrega 9speed a friend is giving me as an upgrade

yeah i have 8 speed shifters thanks for your help

 

[HLaB]

can i put a 9 speed rear mech on my 8 speed bike it is an ultrega 9speed a friend is giving me as an upgrade

As other folk have said yes, my sirrus 8 sp came with a 9sp mech.

 

[NickM]

Surprisingly, there is no particular bottleneck...

1. 8-speed chain is the same thing as 7-sp chain; 9-sp is narrower (and 10-sp narrower again)
2. Shimano 9-speed derailleurs accept 7/8-speed chain
3. Shimano 9-speed rear mechs therefore work fine on all systems with 9 or fewer sprockets
4. 9-sp chain runs perfectly happily on 8-sp and 7-sp cassettes

Other possibly relevant facts:
5. 9-sp spaced chainrings require 9-sp chain
6. Shimano 10-sp derailleurs accept 9-speed chain

I think you should use 9-speed chain and a 9-speed rear mech, and whatever else you like.

 

[Landslide]

Other possibly relevant facts:
5. 9-sp spaced chainrings require 9-sp chain

Not necessarily true, I've used a 7/8spd SRAM chain on a 9spd Campy chainset, which indexed fine with 8spd Sora shifters.

 

[NickM]

I only speak Shimano... (and KMC chain)

 

[brady37]

thanks everyone ur all very helpful