I upgraded to a slightly bigger rear sproket not too long ago (6-9 months). Was out riding about 2 months back and my chain fell off the rear sproket. Come to find out that the left wheel adjustment block had snapped in half and fallen out somewhere along the ride. Luckily, at the house I had a 93 frame that had the same wheel adjustment block. Stuck that one in, made sure everything was tight and right. Went out riding again this weekend. At one of the stops someone mentioned to me that my chain was awfully loose. Went to look at it, and noticed that the replaced adjustment block was snapped again and missing. I relayed the info to some of the riders and the majority thoughts were that because of the bigger sproket, there was too much torque on the rear wheel and the block can't take it.
The sproket I put on was only +6 I believe, I'm out of town atm and my memory is crap :P

This sound about right to everyone else? I still have the stock sproket so I can switch it out, just need to find another adjustment block. Any thoughts/ideas are greatly appreciated.

btw, it's a 94 F2, w/ 33k miles on the clock.

 

I've seen lots of people run bigger sprockets with no problems so I wouldn't think that would do it, if your axle was loose it would put more strain on it though, not sure but good luck

 

The adjustment block is only there for adjustment (IMHO), not to hold it in place, and if you're breaking it, that tells me that you don't have the axle bolt tightened up enough. [8D]

 

I've got one more adjuster block. I'm fairly sure that I'm tightening the **** out of the axle. Guess I'll know in another month or so :P