My Scott Sub 10 (2012) got damaged during transit and requires the front sprocket replaced. I have ordered the part which has since arrived but would like some advice on how to replace this.

From my understand it is just a case of just removing the four pins holding the existing one in place and replacing this with the new one.


  • Is there anything that I should be aware of?
  • Are there any guides online?
  • Will the belt require adjusting?

1 Answer 1


I'm Ryan with Gates Carbon Drive. The fix is not difficult, but there are a couple of things that I would recommend. Simply removing the 4 chainring bolts is not the best course of action. I would recommend removing the rear wheel from the dropout. If you are unsure about this, we have put together a video here: http://www.gatescarbondrive.com/tech/resources It's the 5/5 video. Once you remove the rear wheel, place the belt around the bottom bracket, and remove those 4 chainring bolts. There is a special tool used to hold the back of the bolts from turning while you loosen the front part. While it may not be necessary to use this tool, please be careful if you use anything else. Mount the new sprocket, center the sprocket on the spider as much as possible, as this will reduce the amount of tight and slack spots you will get, and then torque the bolts as stated by the crank or bolt manufacturer. Replace the belt on the front sprocket, and then on the rear sprocket. With the belt on the rear sprocket, place the wheel back in the dropout. Make sure that the wheel is fully seated in the dropout, it may help to place weight on the seat to make this happen. If you can get the wheel to fully seat in the dropout, re-tighten the axle nuts, and reconnect the hub - refer to the video above for detailed instructions. If you can't get the wheel to fully seat, you may need to play with the EBB to loosen the belt. After this, you will need to readjust both tension and alignment. Either way, after you have re-installed the rear wheel, make sure that the belt has proper tension and alignment before riding. If you have any questions, please don't hesitate to contact. You can find our phone and email info on our website. If you are at all uncomfortable, please take your bike to a local shop. Better safe than sorry. Best of luck!


  • Couldn't have got a better answer!
    – Malachi
    Commented Jun 6, 2014 at 10:06
  • Normally, the special tool for removing chainring bolts is called ‘chainring peg spanner’ or something similar like ‘chainring bolt tool’ or ‘chainring nut wrench’. It fits round the back in the nut, with an Allen key (or torx key) in the head of the bolt.
    – Swifty
    Commented May 29, 2019 at 7:37
  • 1
    Chainring tool question found here: bicycles.stackexchange.com/questions/45304/…
    – Swifty
    Commented May 29, 2019 at 8:22

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