Originally Posted by
masiman
It depends on the cassette. Some of them have the larger cogs "permanently" together. In quotes because you can drill out the rivet to separate them. The individual cog cost may not be worth it compared to a new cassette. I think this is an 8 speed, no? If not then likely a 7. I don't think Trek is selling any 6 speeds in their kid bikes, but I could be wrong. In any case, a new cassette might be the simpler route.
Nashbar has some pretty inexpensive ones. You may need to lengthen the chain with the larger cog.
No, it's a 6-speed. SRAM shifter. We wouldn't be having this conversation if it was a 7- or 8-speed! I've got them laying around the garage. All the big brands - Trek, Specialized, Giant and Schwinn were selling essentially the same bike. Some had Shimano, others SRAM. According to Trek it's a Shimano cassette. Loose Screws did have one with a 32T big cog but with a 24 - 32 jump between the two biggies. Maybe the answer is to get that, drill it out and make my own.....
Yeah, the crank's a one piece deal. I'd have to replace the whole thing with a new crank. I know a place that'll do a 140mm crank, but they're as much as the bike cost! THE reason I chose the Trek over the others was the 32T chainring - the other brands all had 36T. All non-swapable. What the heck a little kid is supposed to do with a 36-12 I have no idea - haulass down hill I suppose!