Mountain Biking - Cassette or Freewheel?

I have a ~'94-'95 Diamondback Topanga and am looking to replace the cassette/freewheel (along with a new chani). How do I tell if it's a cassette or a freewheel? Any things I can look for, minus taking it apart?

TIA

The lock-ring will be clearly visisble with some instructions on for turing directions. It may have some wordage like "Hyperglide"
If you cant see a splined lock-ring, and the splines are inside the large hole, you have a freewheel.

Dear Pringle,
If the spacers between the cogs are the same diameter, then it's a cassette, but if the spacers' diameters increase as the cogs get larger, it's a freewheel.
Gruppo

thanks for the replies. both tests were passed: "hyperglide" was visible and the spacers all had the same diameter.. time to go pickup a cassette! thanks for the help.

You'll also need a cassette lock ring remover tool, and a chain whip!

L8R

yea, i'll most likely buy an SRAM 5.0 and bring it to a LBS to have them install it. don't see myself spending $30 for these tools, esp since i'll only use it 2-3 times max.

If you continue to ride a bike, it'll be worth the investment. Not just for buying the tools, but learning how to replace them yourself.

L8R

hmm... good point.

another question!! i currently have a 12x28 cassette on my bike... would it hurt to toss an 11x32 cassette on there? or should i stick as close to the original as possible -> 11x28

thanks again

Uh...If his bike is that old there is a good chance his could be the thread on type. DOH!

hmmm... i mean i did see the word "Hyperglide" on there. im pretty sure i measured the spacers correctly but ill check again tonite. any reason why a freewheel would have "hyperglide" stamped on?

any word on fitting a 11x32 on an existing 12x28 platform?

I'm pretty sure its going to be the old threaded type. If so you will have to buy a new hub or rear wheel.

Actually it is indeed a cassette.

http://www.sheldonbrown.com/free-k7.html

Based on the above page, i have all the signs of a cassette and not a freewheel. (spines, lockring, "hyperglide", buldge in hub, wtc..) Thanks for making me double check..

so now back to the question... any word on fitting a 11x32 on an existing 12x28 platform?

That will not be a problem. Just some fine tuning is all you'll need. I'm sure your LBS can take care of that for you if you don't know how.

No concerns with changing your gear ratio. Just realize, the big cog is for the lowest gear and the small cog for the highest. Now the tricky part. The difference between switching from a 32 to a 28 isn't as significant as switching from a 12 to an 11.

When you ride, take note as to what gears you spend most of your time. Are you using the inside of your cassette more (easier gears) or do you spend a lot of time hammering long flat stretches and you use your outside gears (higher gears) more?

If you hammer more, then it makes sense to go down to an 11 as it will give you more top end speed.

If you climb more or ride slower more technical trails then a 32 makes more sense.

Now, the question about whether you CAN put a 32 comes to mind. Is your rear derailleur the right size? Probably! There is a long cage derailleur, medium and a short cage. Most road bikes (with tighter gear ratios) use short cage derailleurs. Most mountain bikes come with Long cage, but there are a few odd ball Medium Cage ones that hit the market and show up once in a while.

If you go up to a 32, you will probably need a Long cage. If you buy a Shimano Mega which has a 34, then you DEFINATELY need a Long cage. You may also have to add a link to your chain to make sure you don't overstress your derailluer in the event of a big-big cross chain situation. WHICH YOU SHOULD NEVER DO, BTW!

L8R