Chainset/Chain Query

[ChrisKH]

I've had problems with the rear shifting of my (cheap, yes I know) Dahon Cadenza 2007 model since I acquired it last year. Even got the LBS to take a look and they said they could only adjust it so far (ie as well as me) because of incompatability issues of the equipment used. Anyway, the long and short of it is I can't seem to use the rear 29/24/21/18 t on either of the front cogs without slippage and various wonkiness.

Just got round to looking at the individual equipment bits. It has :-

Shimano Tiagra shifter

8 speed, rear cogs:

29/24/21/18/16/14/12/11

Front double (50t/36t)

Chain (now here's what I thought was odd):

SRAM PC 971 (D7), Gold SRAM connector for 9 geared chains.

It struck me on looking at this that the bike is eight speed and the chain is meant for nine speed - would this account for all of the crappy rear action?

Cog use on 16t/14t/12t and 11t is okay but not mind blowing. Occasional slippage but not major stuff.

Is the chain the issue? Any advice appreciated.

 

[ChrisKH]

Bump. Too much information in original post, obviously.

Re-phrased:-

If I put a 9 speed chain on an 8 speed bike, will it affect the shifting? I presume so, but would like confirmation.

Thanks.

 

[4F]

Chris, a good question but sadly I do not know the answer however have now bumped this back to the top for you

 

[ChrisKH]

Bump.

I've ordered a new chain in any event as it was relatively cheap and will test my hypothesis. It will also test my non-existent chain fitting experience which is no bad thing. I can't believe I'm the only person on this forum who has ever come across this issue.

 

[4F]

Bump.

I've ordered a new chain in any event as it was relatively cheap and will test my hypothesis. It will also test my non-existent chain fitting experience which is no bad thing. I can't believe I'm the only person on this forum who has ever come across this issue.

Chris, just bin the gears mate and go fixed Problem sorted

 

[jpembroke]

9 speed chains are narrower than 8 speed chains. You should really use an 8 speed chain. Also, if you have a large 29t sprocket on the rear then you need a medium cage rear mech. That can also lead to problems when using the lower gears (i.e. larger sprockets).

Hope that helps.

 

[Joe24]

Chris, just bin the gears mate and go fixed Problem sorted

The drop outs wont be right for fixed, however, i do have a folder(its a cheapo one) that has track ends on
I think it takes a screw on block aswell.
Its what everyone else uses though, and they are all panzies and wont ride fixed so i cant change it to fixed
Sorry, off topic, it gave you another bump though.
My thoughts are the same as jpembroke

 

[MartinC]

Chris, 9 speed chains are narrower than 8 speed. Mostly on the outside though - the gap in the middle is much the same. Sometimes if you use a 9 speed chain on an 8 speed transmission the jockey wheels and the cage plates in the rear mech may be a problem.

You say the shifters are Tiagra - these are 9 speed shifters and won't index correctly on your 8 speed cassette.

Theoretically a Shimano short rear road mech will only cope with a sprocket of up to 27 teeth but in practice I'd expect you to get away with a 28 or 29.

Is your problem that someone has put an 8 speed 12-28 MTB cassette on a road 9 speed transmission? If so then you should change it for a 9 speed 12-25 or 12-27 (more expensive) road cassette.

 

[jpembroke]

You say the shifters are Tiagra - these are 9 speed shifters and won't index correctly on your 8 speed cassette.

Ooh, good point. Well spotted.

Unless they are old 8 speed Tiagra, of course.

 

[mickle]

A nine speed chain will work perfectly well on an eight speed cassette, better than with an eight speed chain I reckon, certainly easier to index. Mrs M has had this set up for a decade with no issues.

Sora is 8sp, Tiagra is 9sp. Was there ever an eight speed Tiagra? I can't remember. Count the clicks to be sure. A new cassette will fix it methinks.

 

[ChrisKH]

Bum. I'm really confused now.

This is meant to be the standard issue for the bike:

No. of Gears: 16
Front Derailleur: Microshift, Forged Alloy (Yes, got that)
Rear Derailleur: Shimano Tiagra SS (Yes, got that)
Shifters: Shimano Trigger for Flat Bars (yes got that, not sure no. of clicks tho.)
Cassette: 8-Speed, 11-28T (Yes, got that)
Chain: KMC Z82 (No have 9 speed chain)

Why supply a nine speed derailleur for an eight speed bike?

Mickle, you think a new nine speed cassette will resolve the issue? Does it matter if I have eight speed bar shifters and don't use the granny cog?

I'm looking for the easiest resolution here - I suppose I do need to count the clicks on the bar shifters to be certain of my position.

 

[mickle]

Count the clicks.

 

[ChrisKH]

Count the clicks.

Oh, alright then. Thanks mickle.

 

[jpembroke]

He's right. If you have 9 speed shifters and an 8 speed drivetrain then it's all wrong.

 

[ChrisKH]

7 clicks. It says Shimano 8 speed on the front of it, so I'm certain of that now.

So I've got 8 speed shifters and cassette and nine speed chain and derailleur.

And now I've got an eight speed chain as well.

Quickest/easiest/cheapest resolution?