Bicycle Mechanics - New rear tire old cassette?

I am really new to bike repair and I have picked up an old Bridgestone 200 road bike to repair and commute. It's back tire is not quick release and I am planning on purchasing a Sora 8 Speed/CPX Rear Wheel from REI. Can I keep the old cassette? I believe it is 7 speed, is this going to be a problem? Also does anyone have a good resource for explaining this procedure? (Sutnour ar derailleur set)

TIA,

John

Sorry,! but its not a cassette, its a freewheel big difference.
You will have to buy a cassette.

Steve33

Is the wheel size metric 700c or imperial 27". Look on the old tyre. The two are not really compatable, the brakes dont match up on different diameter rims.

The old cogs are probably combined with the screw-on freeheel mechanism. Modern units use cogs which slide onto ridges (splines) on a freehub mechanism. They are totally non-compatable, but your old cogs are probably worn out anyway.

Modern road bikes have the locknuts of the wheel 130mm apart. Older bikes used a smaller distance (126mm). Take the rear wheel out and measure the distance between the outer face of the wheel slots (dropouts).

I would be wary of upgrading a frame with older standards. You can fit a 700c wheel if you really want to, but it takes some effort. I decided to keep my 1970s standard bike as is, and build up a 700c frame as a commuter. I still use solid axle and freewheels (to deter theives), but use modern 700c tyres.

have a mechanic at REI check compatibility. He can SEE what you have and need

John,
Cassettes are not that expensive, anyway, probably $30-45. Harriscyclery.com lists the cassettes they sell and unlike most places list exactly what cogs the cassette has. So where other places might refer to a 12-23, Harris tells you it contains 12-13-14-15-17-19-21-23. That particular cassette, for instance, costs $39.95. Someone correct me if I am wrong on this, but I think any of the 8-speed cassettes will work on the new wheel you are getting. If you are doing this yourself, which it sounds like you are, you will also need a sprocket tool or chain whip as well as a cassette lockring tool, probably the Park FR-5. These can be ordered from nashbar.com. If you want to see exactly what I am talking about, check out these at nashbar.com:
PT-FR-5 PARK HG/IG LOCKRING REMOVER
BN-ST NASHBAR SPROCKET TOOL
You can probably get these from REI while you are getting your wheel. Any sprocket tool/chain whip will work, but the lockring removers are specific to brand and model. The total cost of these two tools was about $12.
You should absolutely, positively replace your chain, too. The old one is probably worn and too short anyway, and you should always get a new chain for a new cassette. SRAM makes good ones.
Any of the more experience guys out there - Will John run into compatibilty issues between his old chainwheels and new Shimano HG cassette? John, as someone suggested, check with REI's tech support on some of these questions.
For more info on this type of stuff, read Sheldon Brown's articles at harriscyclery.com. He has articles on many aspects of bicycle mechanics, including a very good explanation of freewheels (older technology) vs freehubs. He also has one on rear derailleur adjustment, which you will probably need to do.
And this may sound really elementary, but check your old tires for proper size (26 inch, 27 inch, 700 mm) to make sure you get the right diameter rim. The different sizes are not interchangable. As someone said, your brakes would be in the wrong location. Now, once you get them, you can put a range of tire widths on any given rim though you will probably stick with 23-25 mm.
Regards,
Raymond

If your Bridgeton has Suntour Index shifters, they probably won't be compatible with Shimano gear spacing.