Hi all - managed to smack up my chain ring rather well on my Cube Acid at the weekend.
Pre-pandemic I'd set it up perfectly for commuting and had replaced the 38T with a 46T which matched my leg power and just took me outside of the 15mph band, however over the last year I've been thrashing it around Epping Forest as I've not got to commute anymore..
Anyhoo - fast forward to the weekend and I was out with my daughters mountain bike club; we set up a nice series of logs to build a ramp up/down from a fallen tree for them to test some skills on. When it was my turn, despite having caught a bunch of kids who didn't get enough power down to get over the obstacle I did exactly the same thing - got most of the way up and then ran out of speed and dabbed my foot which slid the bike out and smacked the chainring onto the tree, bending it enough to cause the chain to come off with every rotation.
Some trailside repairs with a weatherman bent it back into shape and got me back to the car, ego slightly bruised.. the only permanent damage is < 1mm of material taken off the shoulder of the chain stay where the oversize chainring rubbed - looks very superficial and is only in a smallish spot..
Have now pulled off the offending chain ring and re-attached the 38T that came with the bike and I might have bent the shaft slightly - there is about a 1-1.5mm run out on the chainring measured at the chain stay.
Video is
Two questions for the masses:
1 - Does the amount of material taken off weaken the chain stay too much to make it unusable ? I'd like to think not as it seems too small an amount of material to make a material difference given that the other 3 sides are complete. Its not like anything is going to stab its way through the weak area....
2 - Is the runout on the motor going to cause issues further down the line (currently on about 1500Miles so could be due a service particularly given the beating its had). Again, I'm guessing that its within what I think a tolerance should be but thought I'd ask...
Pre-pandemic I'd set it up perfectly for commuting and had replaced the 38T with a 46T which matched my leg power and just took me outside of the 15mph band, however over the last year I've been thrashing it around Epping Forest as I've not got to commute anymore..
Anyhoo - fast forward to the weekend and I was out with my daughters mountain bike club; we set up a nice series of logs to build a ramp up/down from a fallen tree for them to test some skills on. When it was my turn, despite having caught a bunch of kids who didn't get enough power down to get over the obstacle I did exactly the same thing - got most of the way up and then ran out of speed and dabbed my foot which slid the bike out and smacked the chainring onto the tree, bending it enough to cause the chain to come off with every rotation.
Some trailside repairs with a weatherman bent it back into shape and got me back to the car, ego slightly bruised.. the only permanent damage is < 1mm of material taken off the shoulder of the chain stay where the oversize chainring rubbed - looks very superficial and is only in a smallish spot..
Have now pulled off the offending chain ring and re-attached the 38T that came with the bike and I might have bent the shaft slightly - there is about a 1-1.5mm run out on the chainring measured at the chain stay.
Video is
Two questions for the masses:
1 - Does the amount of material taken off weaken the chain stay too much to make it unusable ? I'd like to think not as it seems too small an amount of material to make a material difference given that the other 3 sides are complete. Its not like anything is going to stab its way through the weak area....
2 - Is the runout on the motor going to cause issues further down the line (currently on about 1500Miles so could be due a service particularly given the beating its had). Again, I'm guessing that its within what I think a tolerance should be but thought I'd ask...
