New Chain, old chainset. - mtb

[cliff123]

Hi. I've just replaced my chain as it had stretched a ridiculous amount and was starting to misbehave while cycling. As such the chain is now new, but the chainset (gears front and back) are the originalz which I guess have done 1000-1200 miles. Riding it last weekend I was getting chain suck at the front, and whenever i loaded up the gears at the rear for climbing I would get chain jump, moving half onto another gear (the xtr derailleur is set up perfect, it all works perfectly on a bike stand and when lightly cycling).

Do I simply need to replace all the sprockets and chain set elements, front and rear? Or could it be something else? Thanks.

[Fluffsri]

Ive had this before, I left the chain untill it was proper knackered and then had to replace the outer and middle rings and the cassette. I change the chain roughy twice a year and the drive train seems to cope better now.

[zebedee]

You definitely need a new cassette to stop the skipping. Would be surprised if you needed new chainrings after 1200 miles, but then if your chain had stretched a lot and your chainrings weren't strong, possible. Try a new cassette and see how you get on. Buy a chain wear tool and replace chain early enough, I tend to get a new cassette every 2-3 chains.

[Gooby]

new race face chainrings, new SRAM hollow pin chain... all has just shown the cassette is worn...
PG990 from chainreaction with £40 off! Yay!

[shalmaneser]

Yup, new cassette and probably chainrings needed!

[zebedee]

shalmaneser said:

Yup, new cassette and probably chainrings needed!

though chainrings cope far better with wear than cassettes - my FSA ones must have managed about 6-7000 miles I reckon, and aren't particularly well cared for as I don't like them that much! Soft, light ones could have worn, but 1000-1200 miles sounds like not a lot to me.

[shalmaneser]

zebedee said:

though chainrings cope far better with wear than cassettes - my FSA ones must have managed about 6-7000 miles I reckon, and aren't particularly well cared for as I don't like them that much! Soft, light ones could have worn, but 1000-1200 miles sounds like not a lot to me.

Very true, but the OP specifically mentions chain suck - normally a good tell-tale.

[Koing]

I had this exact same issue. I've had the bike for about 5yrs now 2nd hand so not sure how much it was used before. I had a new chain, casette, front chain rings and a bottom bracket done...rides well now but still skips in the hardest gear when I really put the power down. If I cycle smoothly it works...but it works on the next biggest gear fine.

Koing

[zebedee]

Koing said:

I had this exact same issue. I've had the bike for about 5yrs now 2nd hand so not sure how much it was used before. I had a new chain, casette, front chain rings and a bottom bracket done...rides well now but still skips in the hardest gear when I really put the power down. If I cycle smoothly it works...but it works on the next biggest gear fine.

Koing

that must be a gear indexing or jockey wheel issue then. If the rest of the drivetrain is new, you shouldn't have issues. You might find your limit adjustment screw on the rear mech wants relaxing a little bit to allow the mech to drop further down the cassette and engage properly with your hardest gear. Just try 1/8th turns at a time, you don't want the chain falling off the cassette completely and jamming in the seatstay... Alternatively, if you have barrel adjusters on your rear mech and fiddling with the limit adjustment screw hasn't made any difference, you may need to decrease the tension very slightly on your rear mech cable to allow it fall properly onto that gear. HTH.

[cliff123]

New rear cassette ordered, gone with the XT version as can't justify the price of the xtr. Will be fine for me. Thanks.

[Parrot of Doom]

Replace the chainrings with cheapo Deore steel ones. They won't ever wear out again.

I had to do the same after about the same mileage, through thick Lancashire mud. XT chainrings might be lightweight but they're crap in mud.

[Koing]

zebedee said:

that must be a gear indexing or jockey wheel issue then. If the rest of the drivetrain is new, you shouldn't have issues. You might find your limit adjustment screw on the rear mech wants relaxing a little bit to allow the mech to drop further down the cassette and engage properly with your hardest gear. Just try 1/8th turns at a time, you don't want the chain falling off the cassette completely and jamming in the seatstay... Alternatively, if you have barrel adjusters on your rear mech and fiddling with the limit adjustment screw hasn't made any difference, you may need to decrease the tension very slightly on your rear mech cable to allow it fall properly onto that gear. HTH.

Cheers for the advice. I'm a bike n00b

Koing