advice needed for replacement cassette for trek 420 (1989)
I'm brand new to road biking, but I have done my best to do my research. I bought the trek used for a good price as it seemed like a great beginner bike. The only problem is the rear cassette badly needs to be replaced. The chain skips nearly every gear when it hits a chipped tooth. It is the original cassette, and I got the specs for it from www.vintage-trek.com (from the '89 catalogue).
Original: shimano 13,15,17,19,21,24,28 7-speed cassette
The site also pointed me in the direction of a couple websites that make hard-to-find cassettes. I 'THINK' i found the right one listed as: CS715 HG-70 here: http://sheldonbrown.com/harris/k7.html#7cassettes .
My other concern is getting a new cassette on a 19 year old bike. Do you think there would be any compatibility issues?
Can someone help me on this? The bike is irritating to ride right now and I want to make sure to get a cassette that will fit perfectly and keep my indexed shifting.
If this is the right one, how hard is it to install on my own? Would I need to buy a lot of special tools?
Thank you all in advance. This site has been a tremendous resource!
Go to your trek dealer and buy the cassette tool and cassette remover.
I don't know that particular model trek, but I had an HG70 on my 93 Trek 830 before I upgraded it, as far as I was aware that was a mountain bike specific cassette, someone correct me if I'm wrong.
Originally Posted by mlclark2
Also you will need a chain whip to remove the old cassette, and a freewheel tool to put the new cassette on. See the Park Tools Repair section for more info, and also Bicycle Tutor has some good videos on these repairs.
What is a mountain bike specific cassette? All cassettes are the same. Mountain/road is just marketing terms. Mountain cassettes usually have a wider and lower gear range. The Trek 420 is a touring bike, so it also has lower gearing.
Originally Posted by trek830
The cassette you mentioned will be fine. You can actually use any of the 7-speed cassettes. Well, you might not be able to use the 11 tooth cassettes. It depends if you have the compact freehub body or not.
If your chain is skipping because of wear, you will most likely need a new chain also. A worn chain and new cassette will also skip.
Are you sure it is the cassette? Your derailer hanger might also be bent, this will cause skipping.
My bad I thought the roadie hubs where a bit different from mountain hubs, hence why I said correct me if I'm wrong
Originally Posted by SweetLou
Shimano & Sram make 7 speed cassettes that will work. If your LBS does not have the specific one you are looking for in stock they can order one for you form J&B or QBP.
You will need a chain whip and the cassette wrench to remove the old cassette. THe LBS can do this for you at a nominal cost. Probably less then the cost of the tools.
That states the hub is a Shimano UG aka Uni Glide?
IF that's the case, you have to get a new Free Hub body to install an HG cassette.
Ok, I think I have a good idea of what I need to do. It is a uniglide cassette, and I will need to upgrade it. Thanks for all your help! I've also found a local bike shop that is going to help me out.