Upgrading Mixed Groupset

Rivers_Nick

Probably a simple answer, but I thought I'd ask before starting to mash bike bits in vain...

I'm in the process of upgrading shifters on my Boardman from Tiagra 4600 to 105 5700... this bit I'm ok with. Mainly because the rest of the setup is all 105 5700.

However; I'm planning to install the Tiagra to my winter bike, a Forme Longcliffe 4.0. It's currently equipped with the following mix of 8 speed double compact components:
Microshift ST-R80 shifters
Shimano 2300 front and rear mech
FSA Tempo chainset
I know that I will have to change the rear mech and cassette to 10sp, but will I have to change the FSA Tempo chainset?
The Forme is due a good service, so would be good to know if I'll need a new chainset before rather than after.

Cheers.

jomoj

You shouldn't need to change the rear mech, just the cassette and chain. Not so sure about the chainset, it may be OK, may not. Probably worth trying first before you change it. I've run 9 speed chains on 10 speed chainsets and vice versa without problems but not sure how the spacing on 8 speed works out.

desweller

Just chain and cassette. You will be OK on everything else.

Terrytibbs

Technically, if you're going from 8speed to 10 speed you would need a new cassette as you know, the chain would need changing as a a 10sp is narrower, both the dérailleurs need changing, and the chainset because your 10speed, narrow chain is going to get stuck between the chainrings on your 8speed chainset and cause problems shifting up and down too.

It depends how perfect you want your gears. I'm sure you could get it work with by just changing the chain and cassette, but how nice do you want your gears to work and how much do you want to spend. If not much then you could just try it, but I'd certainly recommend chaining it all.

Rivers_Nick

Thanks for the advice guys. Will prob replace both derailleurs on the basis of getting a smooth ride.

keef66

I'd just do the chain and cassette and see how it works. You'll probably be pleasantly surprised.

dgunthor

as above, chain and cassette and should be all good

drlodge

+1 just chain and cassette.

desweller

Spacing on 8-speed chainset is the same as 10-speed. Terrytibbs is giving you duff gen. Likewise the derailleurs will be perfectly OK with the 10-speed shifters; they don't care what chain they have as long as the cable pull is correct.

Rivers_Nick

I'll go for just chain and cassette and see how it turns out... as it's going on the winter bike, it'll be hooked up to the turbo whilst the sun is out and the summer bike is out, so i'll be able to keep a close eye on it. Thanks again!!

Terrytibbs

DesWeller wrote:

Spacing on 8-speed chainset is the same as 10-speed. Terrytibbs is giving you duff gen. Likewise the derailleurs will be perfectly OK with the 10-speed shifters; they don't care what chain they have as long as the cable pull is correct.

I'm not giving anyone a 'duff gen'. The spacing on a 10speed chain set is smaller than an 8speed chain set because the chainrings are thicker overall. There will be problems with the chain not catching the chain rings properly to get the perfect set up (The ramps on the chainring will be different for each 'speed'), you'd also find that changing down could get the chain to get stuck slightly causing some chain suck. If you want to muck about not doing things properly, then fine, but I'd prefer to give correct advice and save this guy from the possibility of having an accident when his chain gets jammed.

There's also the fact that an 8speed chainring is slightly thicker than a 10speed and a 10 speed chain will not be a nice fit on an 8 speed chainset. The same applies to the jockey wheels and the spacing between the jockey plates could cause problems. The front mech would need to be 10 speed as an 8 speed front mech will be wider and won't match the 10 speed chain, the cable tension won't be right. It'll be too tight to try and push the chain further than it should do to compensate for the wider gap between the chainrings which means shifting down will cause problems and this is where the shifter struggles to push the chain far enough, causing it to jam/catch slightly between the chainrings.

But hey, duf gen ay. Back to Halfords you go Des with your jarg advice. Give correct and accurate advice, then let the customer decide what he wants to do, not the other way around.

desweller

Terrytibbs wrote:

DesWeller wrote:

Spacing on 8-speed chainset is the same as 10-speed. Terrytibbs is giving you duff gen. Likewise the derailleurs will be perfectly OK with the 10-speed shifters; they don't care what chain they have as long as the cable pull is correct.

I'm not giving anyone a 'duff gen'. The spacing on a 10speed chain set is smaller than an 8speed chain set because the chainrings are thicker overall. There will be problems with the chain not catching the chain rings properly to get the perfect set up, you'd also find that changing down could get the chain to get stuck slightly causing some chain suck. If you want to muck about not doing things properly, then fine, but I'd prefer to give correct advice and save this guy from the possibility of having an accident when his chain gets jammed.

There's also the fact that an 8speed chainring is slightly thicker than a 10speed and a 10 speed chain will not be a nice fit on an 8 speed chainset. The same applies to the jockey wheels and the spacing between the jockey plates could cause problems. The front mech would need to be 10 speed as an 8 speed front mech will be wider and won't match the 10 speed chain, the cable tension won't be right. It'll be too tight to try and push the chain further than it should do to compensate for the wider gap between the chainrings which means shifting down will cause problems and this is where the shifter struggles to push the chain far enough, causing it to jam/catch slightly between the chainrings.

But hey, duf gen ay. Back to Halfords you go Des with your jarg advice. Give correct and accurate advice, then let the customer decide what he wants to do, not the other way around.

Can you let my bike know that...been running 8-speed chainsets & derailleurs with 10-speed chains & back blocks for yonks! It all seems to work so perhaps you can let me know where I'm going wrong?

Terrytibbs

DesWeller wrote:

Terrytibbs wrote:

DesWeller wrote:

Spacing on 8-speed chainset is the same as 10-speed. Terrytibbs is giving you duff gen. Likewise the derailleurs will be perfectly OK with the 10-speed shifters; they don't care what chain they have as long as the cable pull is correct.

I'm not giving anyone a 'duff gen'. The spacing on a 10speed chain set is smaller than an 8speed chain set because the chainrings are thicker overall. There will be problems with the chain not catching the chain rings properly to get the perfect set up, you'd also find that changing down could get the chain to get stuck slightly causing some chain suck. If you want to muck about not doing things properly, then fine, but I'd prefer to give correct advice and save this guy from the possibility of having an accident when his chain gets jammed.

There's also the fact that an 8speed chainring is slightly thicker than a 10speed and a 10 speed chain will not be a nice fit on an 8 speed chainset. The same applies to the jockey wheels and the spacing between the jockey plates could cause problems. The front mech would need to be 10 speed as an 8 speed front mech will be wider and won't match the 10 speed chain, the cable tension won't be right. It'll be too tight to try and push the chain further than it should do to compensate for the wider gap between the chainrings which means shifting down will cause problems and this is where the shifter struggles to push the chain far enough, causing it to jam/catch slightly between the chainrings.

But hey, duf gen ay. Back to Halfords you go Des with your jarg advice. Give correct and accurate advice, then let the customer decide what he wants to do, not the other way around.

Can you let my bike know that...been running 8-speed chainsets & derailleurs with 10-speed chains & back blocks for yonks! It all seems to work so perhaps you can let me know where I'm going wrong?

You're going wrong by not using the correct components. Every mix match of components will be different, different chain sets, different dérailleurs, different chain rings etc. I've come across plenty of mix match drive trains to know setting up a drive train with miss matched components isn't very nice and is a pain to get, just simply, as good as possible. Maybe you're just used to having poor gears/shifting and haven't actually felt a precise, correctly set up drive train. But that's fine, that's up to you.

desweller

Your contention is that I'm wrong because I'm wrong?

What chance do I have against debating technique of that calibre. Now that you've shored up your argument with that, I'm convinced.