Viewing 17 posts - 1 through 17 (of 17 total)
  • Potentially stupid question – SRAM GX Eagle…
  • Premier Icon Kryton57
    Subscriber

    Sorry but I’ve been a Shimano man for 20 years.

    I’m 2 years in and the GX cassette isn’t looking “shark tooth”, so I’m guessing this is good news and I don’t need a replacement yet.  However, I’ve never changed the chain, and without using a chain checker I’m guessing it might be a good idea before the racing season commences.

    Do I need to replace cassette and chain at the same time?

    dhrider
    Member

    There’s a fine line. I find changing the chain regularly means you don’t need to change the cassette each time.

    If the cassette isn’t worn, and the chain isn’t overally won’t you should be fine to just replace the chain.

    Only 1 way to find out tho……

    Premier Icon chakaping
    Subscriber

    I’ve got two years out of the 11sp GX cassettes but I would definitely have changed chains during that time. Have you not ridden it much?

    Get a chain checker that shows 0.5 wear, that’s when you need to change 11 and 12sp chains.

    DickBarton
    Member

    I got 3 years out my previous 11_spd system – chain, ring and cassette. Shifting was very good all the time.
    Decided it best to change as cassette was like throwing stars and chain was utterly goosed when I removed it.
    Hoping was similar out the 12-spd system I’m running now.

    Premier Icon Kryton57
    Subscriber

    Have you not ridden it much?

    Its my race bike so maybe 1300KM estimated since Jan ’18?   The reason I asked is that I had gear change problems 2 weeks ago which today I found was the cassette is loose on my winter wheels – not sure why as yet.  During that race chain & cassette was crunching all over the place.

    Now with the cassette not loose on the good wheels and properly indexed in the garden the chain looks “thin” and shiny.   Its just an observation, but the changes aren’t as crisp as I can remember.

    Maybe time to invest in a chain checker also.

    DickBarton
    Member

    If you don’t ride it often then the changes will never be as crisp as you remember them.

    Premier Icon Trimix
    Subscriber

    Dont worry with shark shaped teeth and chain checkers. The first time one gear slips, change the lot. It will probably take 3ish years of riding 2-4 times a week like it did on my Jeffsy for it to do that.

    Easy and simple.

    Or you can spend ages trying to work out how much you might save if you clean, lube and measure your chain all the time. Then start to think about what sort of conditions you may ride in, how far and what time of year. The start a spreadsheet of mileage with a column for conditions.

    Pick the scenario that suits you. On might save you a few quid if that, one may just free up your mind for riding your bike.

    daern
    Member

    Dont worry with shark shaped teeth and chain checkers. The first time one gear slips, change the lot. It will probably take 3ish years of riding 2-4 times a week like it did on my Jeffsy for it to do that.

    Easy and simple.

    Definitely easy and simple, and plenty do it, but there are a couple of disadvantages. For me, the biggest is that once a chain gets beyond 1% wear (and less with modern 12-speed groupsets), you’ll never be able make a new one work as the rest of the transmission will have also worn to the same amount. This is fine if you manage to ride it into the ground, but if you ever trash a chain and need to fit a replacement, you’ll be facing an immediate, expensive bill as a new chain almost certainly won’t work…and if you’re somewhere remote, good luck getting the rest of the bits anyway!

    The other one is simple mechanical fatigue. I rarely (never in the last 10 years) snap chains and I’ve put this down to being pretty rigorous with maintenance and retiring them. A snapped chain is a pain in the arse and, if it happens at the wrong time, probably uncomfortable and potentially dangerous too. Each to their own, but the chain (and wheels too) is something that I’d keep in perfect condition.

    Each to their own, as you say, and others have argued long as to which is the most cost-effective route, but it’s not quite the simple choice you make out. Also, who really keeps spreadsheets? I just measure the wear on mine from time to time and if it needs replacing, I replace it. Cheap and takes < 5 mins. No stress.

    Premier Icon linusr
    Subscriber

    Get a new chain and cassette and fit it ahead of racing. Rotate the chains on the new cassette and get a chain checker (as advised above). Keep the old chain and cassette and put it back on next winter and ride it until it is unusable.

    Premier Icon Kryton57
    Subscriber

    Good idea.  Bike-discount.de do a wear and tear package which although expensive is less than buying both individually.  Even so that’s another 2-3 years of the bike so I’ll take the hit now.

    Ive added a chain checker so if everything is ok I’ll race next week as is then swap the old stuff onto the winter wheels, and try to work out why there’s 2mm of movement in the hub / cassette.

    Premier Icon joebristol
    Subscriber

    If the gears aren’t slipping I’d try a new chain on it first. I think most of the gx eagle cassette is steel (bar maybe the top few cogs?) so you’ll be surprised how long you can use it for before changing a chain.

    I have a gx 11 speed 10-42 cassette that I forgot to change the chain on for ages – the chain checker would almost drop into the chain on the 1.0 setting but definitely would for the 0.75 setting and a new chain went straight on. A year later and it’s still running fine.

    If the new chain slips then stop straight away and change the cassette and you haven’t lost anything. If you have a direct mount crank the sram steel direct mount chainrings are dirt cheap at under £20 if you have a look round.

    Premier Icon Kryton57
    Subscriber

    Good point Joe, although my next ride is a race scenario (although I’m non compete) and I do need to get 3-4hrs in so I don’t want to stop on the first lap.   I’ve ridden it about at home with the brakes on & some effort and it seems OK with the old chain so I’ll “race” with that then change the train after and ride it locally to see what happens.

    ogden
    Member

    800km in with chain worn to 0.6% and a new chain had terrible shifting for me, it was jumping gears all over the place. I ended up buying a new chain ring as well but it still jumps every so often, I’m hoping the new chain will ware into the cassette.

    Hey mate.
    I bought a chain checker a couple of years ago. Bloody thing will have you replacing chains every few months. Friends in the bike shop joke how much they love them.
    So back to the traditional method. You just know when it’s time to refresh your drivetrain. Ghost shifting, shifting under load, and the real tell; when you index one end of the cassette perfectly yet it’s imperfect at the other end. If indexing takes more than five mins then it’s time to change.
    I change everything at once and am usually good for at least a year.

    It’s a shame that some enterprising manufacturer doesn’t make new chains with various levels of wear built in so you could buy a new chain with 0.1 wear to say 0.7 built in .

    I’ve got a KMC digital wear checker. It’s very accurate.

    nickfrog
    Member

    I am sad enough to actually measure the chain length and compute the wear.

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