General Cycling Discussion - Can I swap cassettes?

Ok, this will probably sound stupid to most of you, but...

right now, i'm riding an old 10 speed Peugeot with 2 speeds on the crank and a 5 speed cassette. Climbing hills in SF is hell, and i'm not ready to take the plunge yet and buy a new/used bike. I was wondering if i could switch the cassette i have on the back for one that had 8 or 9 speeds. Probably not, i'm guessing, but it's worth a shot.

The short answer is "No", you can't just swap cassettes. That being said let me add my favorite truism. Anything can be done, depends on how much money you want to throw at it.

Some things to consider for 8 speeds. Your going to need to increase the spread between the rear dropouts, best left to person with frame experience. Your going to need a new rear wheel or new rear hub at a minimum. Add in a new rear deraileur, most likely an accompanying shifter and might as well replace the cable and housing while at it.

For nine speeds, new chain, front chain rings, new... well let's just say forget it.

Better to take all that money and find a new or used bike IMHO.

You can probably fit a 7speed freewheel. I swapped from 5 to 6 to 7 with no modifications. The max cog you can find is probably 28. If you want to get a lower gear, you need smaller chainrings.

I would think that by the time you shelled out the cash for a new rear wheel, cassette, rear derailleur, shifters chain, etc... you would have been able to buy yourself a nice entry level or used 8-9 speed road bike. The amount of work neccessary to do the upgrade you want doesn't seem to be worth the end result. I would keep the old bike as a spare in case you ever need it. Just my 2 cents.

Chuck

PB, also keep in mind that what determines hill-climbing ability is not the number of speeds, but the range of available gear ratios. You could have the same low gear ratio on your 5-speed cassette as you would with a 9-speed, if the biggest and smallest cogs are the same size. There are "megarange" cassettes on the market, but they won't work with vintage derailleurs (amongst the many other compatibility issues).

Depending on what parts you have, it's conceivable you may be able to substitute either a smaller inside chainring in front, or a bigger inside cog in back, and thus give yourself a better low ratio for climbing. But customizing a vintage bike is not a project to be undertaken lightly.

Since you could buy a decent entry-level city bike (a hybrid from Jamis or such) for under $300 that would have all the climbing gears you'd need, that's probably the direction to go.

RichC

Almost certainly your 5 speed is a FREEWHEEL not a CASSETTE. I agree with some of the others that a 7 speed FREEWHEEL is your easiest and cheapest option.

Dave

Originally posted by MichaelW
You can probably fit a 7speed freewheel. I swapped from 5 to 6 to 7 with no modifications. The max cog you can find is probably 28. If you want to get a lower gear, you need smaller chainrings.

Not true at all, i have a six speed freewheel with a 31 big ring, and here is a link to megarange freewheels with these specs:

New! 11 - 13 - 15 - 18 - 21 - 24 - 34 "Megarange" "C" Type $24.95
or
NEW! 13 - 15 - 17 - 19 - 21 - 24 - 34 "Megarange" $19.95
or
14 - 16 - 18 - 20 - 22 - 24 - 34 "Megarange" $19.95

http://www.sheldonbrown.com/harris/freewheels.html

So, $20 for a freewheel, and with that you'd need a long cage rear der. If you go over so many teeth with your current der, you will over-wrap it and it wont work.

Tourney MegaRange Wide $19.95

http://www.sheldonbrown.com/harris/derailers.html


so, for $40 you can have the mother of all bailout gears.

peas,

Steve

EDIT: with friction shifting you can use pretty much any rear derailer with any model shifter FWIW, few compatibility problems in that world.

phat bahsturd - thanks for asking the question, and to jester69 - super thanks for the tip. I was just going through the same problem, and this is the best solution I've heard of yet!

Hmm, i realized i'm really dumb at bikes.

Well anyway, keep in mind my rear derailleur isn't stock... I broke it a while back ( a simplex one) and replaced it with like a 20 dollar shimano 515 or something. It's decent. I managed to bend my front derailleur, and replaced it with a suntour one or something.

That actually doesn't modify what jester69 proposed much at all. I was just curious, the original simplex deraulleur mounts differently to the dropout than the shimano. The Tourney MegaRange Wide one comes with an "adaptor claw mount", to take care of mounting the deraulleur to the dropout. When you switched from the Simplex, did you have to tap the original dropout adapter? The original Peugeot one is not threaded. Anyhow, you must have a threaded mount now, since you have the Shimano on the bike now, so it will make the conversion even easier.

Originally posted by phat bahsturd
Hmm, i realized i'm really dumb at bikes.

Well anyway, keep in mind my rear derailleur isn't stock... I broke it a while back ( a simplex one) and replaced it with like a 20 dollar shimano 515 or something. It's decent. I managed to bend my front derailleur, and replaced it with a suntour one or something.

Well, the rear one you bought may or may not be a long cage one. My megarange compatible rear der. says "megarange" right on it, so it makes my life easy. Heh.

You can either ask someone if yours will work, or just buy the right one, dunno. I'm no expert, but I am smarter than a rock (usually.)

take care,

Jester