Unexpected Down Grade

Postby Buggy on Tue 20th Mar 3:36pm

Hello, long ramble follows

I recently took my year old bike for its 2nd service and I've been to told by the bike shop that the original XT rear derailleur is not really compatible with the cassette that came stock on the bike (something to do with the number of teeth) and it was affecting shifting etc. The bike maker has offered to replace the derailleur for no charge, however the only model compatible is the Deore, which it seems to me is quite a down grade. I did ask about swapping the cassette but they seemed to think I'd lose heaps of climbing gears and that the current derailleur is prematurely worn anyway from the compatibility issue.

I don't know much about the mechanics of bikes and compatibility etc, but is this a common practice and technically its now not what the bike was advertised as spec wise. Probably wouldn't have gone with this specific model if it wasn't for the XT, probably a long shot but even being a year old is there a chance of a refund?
Buggy
Member for: 4 months 4 weeks

Re: Unexpected Down Grade

Postby AgrAde on Tue 20th Mar 4:04pm

Do you have a 10 speed XT derailleur with an 11-42t cassette?

The deore derailleur uses thin stamped steel parts and is easy to bend. It's not a fair replacement for a mountain bike where you're likely to knock it. I'd argue for a new XT derailleur like you currently have that has been modified with a One-up "rad cage" to make it compatible with the cassette.

The rad cage is a product designed for exactly this purpose and it works very well. I do remember seeing some bikes sold with the XT derailleur and a wide range cassette and thought it was a bit rubbish, it "worked", but the performance was poor and it accelerated wear on the whole drivetrain.
Last edited by AgrAde on Tue 20th Mar 4:26pm, edited 1 time in total.
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Re: Unexpected Down Grade

Postby Buggy on Tue 20th Mar 4:24pm

AgrAde wrote:Do you have a 10 speed XT derailleur with an 11-42t cassette?

The deore derailleur uses thin stamped steel parts and is easy to bend. It's not a fair replacement for a mountain bike where you're likely to knock it. I'd argue for a new XT derailleur like you currently have that has been modified with a one-up rad cage to make it compatible with the cassette.



Yes that's what I've got

I sort of made a rushed decision agreeing to the Deore replacement over the phone but now I've had more time to think it really pisses me off. They made out the Deore will perform the same as my old XT derailleur given it will be newer. Have yet to pick the bike up so I'll mention it to them when I do

They already said they can't get an XT derailleur compatible with my cassette though and they certainly didn't mention that it would be possible to modify it to make it compatible. Mildly pissed they didn't pick it up at the first service and its been grinding away on the big rings for the past year....
Buggy
Member for: 4 months 4 weeks

Re: Unexpected Down Grade

Postby AgrAde on Tue 20th Mar 4:32pm

Bugger.

The deore is not a horrible product, just delicate. If the rest of your drivetrain is worn I'd rock it until you break it then throw the 10sp in the bin and buy 11sp XT cheap off chain reaction UK. (I recently did this at a cost of roughly $300 exc chainring)

If you've replaced the worn parts and bought back into the 10sp system then I'd argue for a tougher derailleur with the rad cage.
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Re: Unexpected Down Grade

Postby matnz on Wed 21st Mar 3:13pm

I presume its a 1x setup, can you post up details of the bike, especially cassette size and if its 1x or 2x,3x. I suspect they are yanking you chain.

You are covered by the consumer guarantee act - 10 Speed XT on a cassette bigger than 36tooth is outside manufacturer spec, so not fit for purpose.

Find the model number of the derailleur they are installing, if the Shimano specification is for a smaller tooth cassette than you have, then its not fit for purpose even if brand new and working perfectly (as it won't be soon). Approach them on the basis the bike was not fit for purpose when manufactured, and you want your money back or you want it restored to an XT level component group, with components installed according to manufacturer specification.


Looking on the Shimano Website, the Deore 10 speed is not specified for 1x use and on paper is the same as the better quality SLX (One down from XT) (RD-M7000-10-SGS).
matnz
Member for: 3 years 3 months

Re: Unexpected Down Grade

Postby Buggy on Wed 21st Mar 3:18pm

Its 2x.
Last edited by Buggy on Thu 22nd Mar 9:04am, edited 1 time in total.
Buggy
Member for: 4 months 4 weeks

Re: Unexpected Down Grade

Postby matnz on Wed 21st Mar 4:05pm

2x makes a big difference as (unless they have done something really weird) that means the components are operating inside the manufactures specifications.

For the discussion we really need to know what the configuration is. What is the largest cog on the cassette and what sized chain rings do you run.

It is very strange the derailleur has worn, it should last thousands, if not tens of thousands of km. Unless you doing huge miles, I think its more likely its not worn, maybe its bent. I suggest you insist on keeping the old derailleur and take it (and the bike) to another bike shop for a second opinion.
matnz
Member for: 3 years 3 months

Re: Unexpected Down Grade

Postby Buggy on Wed 21st Mar 5:28pm

The largest cog on the cassette is 42T. Crankset is RaceFace Aeffect, 36/24T. I
'm confused because the bike specifications list exactly what is on my bike so I'm not sure how this can be a one off stuff up, unless they've made all the drive trains on this model incompatible. Sorry I don't have much knowledge on the specifics of how a drive rain works, which I guess is my disadvantage when trying to argue with the shop
Buggy
Member for: 4 months 4 weeks

Re: Unexpected Down Grade

Postby matnz on Wed 21st Mar 9:42pm

The mind boggles.... They should never have put a 42 on that setup, no wonder you are having problems.

As far as I am aware, the biggest cassettes the 10 speeds were designed for was 11-36. 10 speed 42 came out due to consumer demand when people wanted to go 1x, but you had to go replace the entire drive with 11 speed XTR. Third parties came up with ways to make what people were doing anyway work better (Sunrace cassettes, rad cage, goat link), but they were all ultimately franken-engineering.

The correct cassette on that setup is an 11-36. I would not recommend putting a standard 10 speed derailleur on that cassette unless you want to learn more about bike tuning and drive train maintenance than you currently think is possible, or make the bike shop rich getting them to do it for you.

My understanding is the only reason you don't want to go to an 11-36 is they believe you will loose climbing gears. You have a 24 chain-ring to drop onto - 24/36 is a pretty low gear - I hit that occasionally, but to be honest, in those gears, pushing the bike is often faster. If you look at current 1x setups, 24/36 is the same as a 1x 28 tooth chaining and 11/42 on the back - most people run 30 or 32 chain rings. You won't need the lower gears unless you are very unfit or ride really big hills. Bigger gears will get you fitter in both cases. If you want 1x, you really need to upgrade to a 1x designed drive line. 10 SPeed 2x and 3x can be made to work, but as you are experiencing, there are degrees of "working" ......

If you want a robust, reliable, long term fix, you have two choices - a radcage or a new cassette. My preference would be a new 11-36 cassette as it moves your bike back to stock, in spec Shimano components.

I suggest you break the issue in two - Whats the best thing to do to get you the bike you thought you bought, and then who is going to pay for it. You do have a claim under the CGI of fit for purpose, and I suggest if the bike shop does not play ball, go to the distributor and you may get progress going to the NZ Shimano distributor.
matnz
Member for: 3 years 3 months

Re: Unexpected Down Grade

Postby Buggy on Wed 21st Mar 10:33pm

Thanks for your reply, that's helpful. Will keep in mind when I got to the shop
Buggy
Member for: 4 months 4 weeks

Re: Unexpected Down Grade

Postby Cycl1n on Fri 23rd Mar 9:22am

Buggy wrote:The largest cog on the cassette is 42T. Crankset is RaceFace Aeffect, 36/24T. I
'm confused because the bike specifications list exactly what is on my bike so I'm not sure how this can be a one off stuff up, unless they've made all the drive trains on this model incompatible. Sorry I don't have much knowledge on the specifics of how a drive rain works, which I guess is my disadvantage when trying to argue with the shop

Out of interest what is the bike?
Cycl1n
Member for: 6 months 4 weeks

Re: Unexpected Down Grade

Postby Conners on Fri 23rd Mar 11:47am

matnz wrote:My understanding is the only reason you don't want to go to an 11-36 is they believe you will loose climbing gears. You have a 24 chain-ring to drop onto - 24/36 is a pretty low gear - I hit that occasionally, but to be honest, in those gears, pushing the bike is often faster. If you look at current 1x setups, 24/36 is the same as a 1x 28 tooth chaining and 11/42 on the back - most people run 30 or 32 chain rings. You won't need the lower gears unless you are very unfit or ride really big hills.

Another option would be to go 22 tooth at the front
22x36 isn't a lot taller gear than 24x42.
Conners
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