First of all, I'm very new to cycling and it's terminology, so please forgive me if I don't explain something properly. I have been working with EnduroSport in Toronto to try to find better gear ratios for my old road bike. It's a 12 year old titanium Miyata with Shimano 600 components. The problem is that the back cassette is 7 gears and goes from 11 to 22. I'm finding that the 22 isn't an easy enough gear to be able to spin up hills (the front is 53/39). With my first 1/2 Ironman coming up, I really need to solve this problem.

Endurosport found a 7 gear cassette from Shimano that would go from 12 to 28. However, their mechanic thinks that there's a good possibility that my bike will not actually shift into the 28. So, making this change will only give me a 24 in addition to the 22 that I already have. I also looked into changing it to a 9 gear rear cassette. That's physically possible, but would cost close to $1,000 CAD. I'd rather put that kind of money into a new bike.

I really don't want to buy a new bike until I have one more year of racing under my belt, but at this point I'm not sure I have any other options (other than suffer a bit more at the 1/2 IM). Anyone out there have any other options for me? Is it possible to buy an old 7 gear cassette somewhere? Is it worth trying the 12 to 28?

Thanks for any help you can give me. I usually just lurk on this site, but I've learned quite a bit from all of you.

Dawn