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chain, cassette & outer chainring replacement

andyh01andyh01 Posts: 518
edited March 2014 in Workshop
Hi all, so after just over 12 months and aprox 3000 miles in, on my new Trek 2.1 it looks like the chain needs replacing, as no matter now much adjusting I do, I can only get half of the rear gears to work at any one time so either biggest to middle cog or middle to smallest cog on the cassette. I also got a LBS to have a look, they measured the chain and said yep its stretched and without even looking at the cassette, said need new chain and cassette. I also have a chain measurer, when I measured the chain length, whilst the 1.00% was quite tight the 0.75% was quite loose, I've never seen a stretched chain but I would have thought the chain measurer, if really stretched, wouldn't fit in the chain at all?
Also prior to the shifting issues, I was experiencing, in some gears, some chain slipping which is why I thought the cassette teeth may have worn down, but on closer inspection doesn't look to bad, could I just replace the chain with out replacing cassette? I know some say the shifting won't be as smooth and others say get 2 or 3 chains per cassette, although I do want to eventually change the gearing ratios, as current cassette that came with it is Tiegra 12-28 (I think) when it does need replacing, I'll look at 11-23 as 99% of my riding is done in the outer chainring and small - middle on rear, very rarely in big front big rear (like now I'm limited to middle to small on rear cassette anyway) so not using the full range of gear ratios and can spin out in places on my commute.
My current chainring outer is a compact with 50 teeth (well actually one toth has completly snapped off) and some are looking pointed so I'm also looking to replace this, can I just swap out the outer chainring for a doubble ie bigger 53T outer chainring? one lbs said no need a need chainset as current one won't be big enough and another lbs said yes take a bit to source one but could just replace chainring with out the need of new chainset? It's a 5 bolt I'm sure bcd140 when I measssured the distance between the bolts they're at 7cm - I didn't really want spend £132 on a new chainset just to get 3 extra teeth and hoping I can just replace the chainring for biggetr one? Also if went for new cassette, chain and chain ring can I mix and match as was looking at Ultegra chain and cassette and 105 chain ring (if I cant get an ultegra 53t to fit my cuurent chainset) or would I be better off keeping also same ie 105?
Thanks sorry for long post!!

Posts

  • Be unusual to have the chainring wear out after that mileage unless it's been ridden in particularly manky weather a lot and not cleaned. Are you sure your teeth have snapped, you know that some are shorter to facilitate shifting? Why not try the chain and cassette first and then chainring on it's own later if you need to?
  • gozzygozzy Posts: 640
    The problem you have at the moment is that your front mech will only take a 16 tooth difference, 50-34 = 16.
    If you fit a 53 tooth big ring, you'll increase that to 19 and I suspect that may be too much for it to work with.

    You can buy 53t rings with a compact 110bcd, Spa cycles do them; you're measurement of 140 is unlikely as no-one makes that size.

    You mention riding in big/big, which is a combination you should be avoiding anyway; it's not good for your drivetrain.

    Mixing and matching is fine btw, as long as you're using shimano or shimano compatible parts.
  • andyh01andyh01 Posts: 518
    Cheers guys
    - been ridden in particularly manky weather a lot and not cleaned - Guilty :oops: I'm sure one tooth has snapped but will take another look and others also look more pointed rather than square.
    - Yes was tempted to swap out bit at a time, chain first than cassette than chainring - wasn't sure if cause issue as the chain beds in to old cassette/chain ring and then cause issue if then change to new cassette?

    You can buy 53t rings with a compact 110bcd, Spa cycles do them; you're measurement of 140 is unlikely as no-one makes that size. - Ah thhanks for that just what I wanted to hear :D I'll take a look, yeah think my meassurements were off just looked on wiggle on how to messure and now think 65mm

    Mixing and matching is fine btw, as long as you're using shimano or shimano compatible parts. - Again hjust what I wanted to hear as lbs thinks otherwise!

    You mention riding in big/big, which is a combination you should be avoiding anyway; it's not good for your drivetrain - I know :oops: It is only on very rare occassions save me changing the front down and then going back up on the rear as find front sghifting more cluncy - note to self.
  • gozzygozzy Posts: 640
    andyh01 wrote:
    Mixing and matching is fine btw, as long as you're using shimano or shimano compatible parts. - Again hjust what I wanted to hear as lbs thinks otherwise!.

    If my lbs told me I had to stick to one shimano range and not mix say, tiagra with ultegra, for example, I'd not be asking their opinion on too many things in the future.

    It sounds like you may be better off with a 52-36 compact set up.

    There's no need to physically measure how far apart the bolts are btw. If you've a 50-34 compact shimano set up then the BCD is 110, if it's a standard 53-39, then it's 130.
  • andyh01andyh01 Posts: 518
    Is there any difference in quality in the brand of chainrings? I'm looking at changing from the compact with a 12-30 Tieagra cassette to a standard 53/39 chainrings from spa cycle' strong light made out of zical as these are the only ones I found to fit the 110 bcd but never heard of them. Rear cassette and chain going for a ultegra 11-25 or 11-28with 105 shifters and derailers
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