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Chain tension

Discussion in 'Technical and Troubleshooting Torque' started by O_Rider, Aug 13, 2015.

  1. I was riding the other day on my commute to uni. Enjoying the ride.... just as i reach the final turn, suddenly out of the blue, I felt a vibration in my bike that didn't feel quite right. Got off and took a look, and behold what i found... the bike chain had suddenly lost a lot of tension, to the point where I could actually lift it off.. Had to do an impromptu chain tensioning to get home, now it's pretty much sitting at the edge of the green range on the marker. Any thoughts on why that suddenly happened? The previous time i did the tension, it was fine and had no issues, and all the screws and nuts were tightened as needed, (about a month ago).Chain has been lubed and cleaned frequently. My suspicion is that the chain is wearing out and I need to get a new chain.

  2. Pics? Is it off the sprocket itself?
  3. I think chains stretch quicker as they get more worn. (Or it might be me checking it more when I know its nearing the end)
  4. Check all the links carefully 1 by 1 especially the joining link and take the countershaft sprocket cover off and check both sprockets as well...
    chain would not just stretch 20+mm overnight without something being NQR

    Choice is 1/2hr on your arse in the garage going over the final drive or 1/2hr in the pouring rain waiting for a lift after being stranded by a broken chain.
    • Agree Agree x 1
  5. If it changed that quickly, I would replace the chain and sprockets as a set. It isn't worth the risk of failure. It the chain breaks at speed it can do considerable damage.
    • Agree Agree x 2
  6. Your chain wont wear out suddenly like that. It takes weeks even in the worst conditions.

    I'd say your axel nut wasn't tight enough. The wheel moved forward under braking, accelerating or a downshift.

    Happened to me when I forgot to do up the pinch bolt on my single sided swing arm.
    • Agree Agree x 4
  7. Chain wear's a funny thing, most of us believe we are tensioning it correctly, lubing with right lube and with enough frequency. Sadly I find that most do not do either correctly resulting is premature wear, and once the wear starts it can't be stopped. Always replace chain and sprockets as a set, your sprockets might look ok but rest assured they are worn and your new chain will be worn out in no time at all even with correct lubrication.
    I have a customer with a Yamaha R1, he was going through chain and sprockets ever 18-20,000km. I kept showing, and lecturing him about how to correctly lube his chain and to make sure it was done every 2-300 km, even giving him a can of lube so he had no excuses. By the third set it finally clicked and he started to pay attention. The next set lasted 80,000 km, he hardly ever had to adjust it between service's and saved him self around $1000.00
    Life's better when you ride, feel the difference!
    Dynobike Motorcycle Performance Workshop
    • Like Like x 1
  8. I didn't really manage to get pics.. as I said, kinda had to fix it on the spot else I wasn't going to be going anywhere. Regarding the chain.. I actually took care of it really well, only problem is, I don't know what the previous owners did regarding maintenance. I'm super paranoid about my bike and crashing on it due to the chain coming out (Might be due to watching too many youtube videos, high sides are bloody scary). I'm considering replacing the whole set just for the peace of mind. Anyone got any reccomendations for mechanics? I might as well send it in early for the servicing at the same time, since its only about 2-3000 km more to go before the 24000km service. In the meanwhile, i'll check the links again to make sure nothing major happened. Thanks.
  9. Technically chains don't stretch but the pins in each link wears causing the total length of the chain to increase and the chain to go slam.

    Chains do wear faster as they get to the end of their life and require adjustment at shorter intervals to maintain correct tension. The last time I replaced a chain it had been tensioned correctly only a week earlier but still had ecessive slack again.

    So you might be at that point in you chains life. If not the next obvious culprit would be the axle nut wasn't correctly tensioned and the axle moved forward.