Changing Cassette/Cogs on bike - is it difficult??

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2006-06-22 7:14 AM

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Subject: Changing Cassette/Cogs on bike - is it difficult??

Bought a used Cannondale multisport - and it came with Shimano Ultegra, 11-21 (9 speed)..  We do have some hills here in Colorado so it has been recommended to me that I should change the rear cassette.     Three questions:

 

1) Should I get the 12x23 or the 12x25??  What are the advantages/disadvantages to both?

 2)  Is this something my very mechanically minded hubby could change for me - or are there factors involved that might be difficult for him to account for?

 3)  Newbie/dumb question - bike has 650 wheels - does it make any differance which cassette I buy - (I've started looking on Ebay)

 

Thanks everyone!! 

2006-06-22 8:26 AM
in reply to: #462498

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
Ouch!!! 11-21 in Colorado?? That's crazy! :-P

1) You will lose one of the "intermediate" gears between the 23 and the 25. It really all depends on the type of rider you are and the abilities you have. That will determine if a 23 or a 25 works better. I'd probably recommend leaning towards the 25.

2) Yes, it is pretty easy. You need a "chain whip" and the appropriate "cassette tool" and a big azz wrench. Takes about 5 minutes to swap them out.

3) Oooh, yes, having a 650 wheeled bike means that the lower gears are actually more appropriate, so reverse my statement in #1 and go with the 23. But any cassette (Shimano 9-speed) would fit on the wheels, that's not an issue.
2006-06-22 8:39 AM
in reply to: #462498

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??

1)Should I get the 12x23 or the 12x25?? What are the advantages/disadvantages to both?


the advantage of the 12X23 is that you will have fewer 'gaps' between your gears. ie. the difference between gears will be smaller so you can finer tune your cadence. the advantage of the 12X25 is that you will have one extra gear for climbing hills. unless you are very picky about your gearing, 12X25 would probably be better as you are doing it for the hills.

2) Is this something my very mechanically minded hubby could change for me - or are there factors involved that might be difficult for him to account for?


it is really easy IF you have the right tool. depending on what type of cassette you have (shimano, etc.), it will require a special piece to remove the lockring.
more detailed info: http://www.sheldonbrown.com/k7.html
tool for shimano: http://www.performancebike.com/shop/profile.cfm?SKU=12775&subcatego...

3) Newbie/dumb question - bike has 650 wheels - does it make any differance which cassette I buy - (I've started looking on Ebay)


i'm pretty sure that wheel size doesn't matter. 9 speed does matter though. if your new cassette is not 9 speed, you would probably need a new derailleur.
2006-06-22 8:43 AM
in reply to: #462572

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??

Daremo - 2006-06-22 8:26 AM  3) Oooh, yes, having a 650 wheeled bike means that the lower gears are actually more appropriate, so reverse my statement in #1 and go with the 23. But any cassette (Shimano 9-speed) would fit on the wheels, that's not an issue.

If she's having problems riding hills on the 21, is the 23 going to make that big of a difference? She might even consider a 12-27 until she builds up some strength.



Edited by the bear 2006-06-22 8:44 AM
2006-06-22 8:45 AM
in reply to: #462498

Master
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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
It is not hard to do at all.

Go ahead and buy Zinn and the Art of Road Bike Maintenance.

It will help you understand many things about bike maintenance. Including how to change a cassette.

It is easy to read and understand.

It is a must for any road biker.

BTW, I would go with the 25 or 27. You would be much better off.



Edited by mnewton 2006-06-22 8:45 AM
2006-06-22 8:46 AM
in reply to: #462572

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
Yes, it is pretty easy. You need a "chain whip"


oops. good call rick. how did i forget the chain whip? it's needed to keep the cassette from spinning while you take off the lockring:
http://www.performancebike.com/shop/profile.cfm?SKU=14456&subcatego...

basically, i would decide if this is something you want to learn and get into. if you just want different gears and bike maintanence is something you don't care about, a shop should do the work for you in 10 minutes for about the same cost as the tools. if you want to learn and do it yourself in the future, this is a perfect project to start with.

2006-06-22 12:18 PM
in reply to: #462498

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
You probably also want to check your front chainring size (It should be stamped on the chainring). I just bought a used bike that came with a 11-21 also, but the small front chainring is a 42 (rather than the more common 39).

Even with 650c wheels, there is no way I can push 53-11, so I'd go with a 12-25 cassette. When compared to the 11-23, you are trading the 11 tooth gear for a 25, with all of the gears inbetween being the same.

Edited by camy 2006-06-22 12:19 PM
2006-06-22 1:27 PM
in reply to: #462878

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??

camy - 2006-06-22 1:18 PM Even with 650c wheels, there is no way I can push 53-11, so I'd go with a 12-25 cassette.

If you lived in CO, you'd be able to spin a 53-11 out on those mountain descents. 

2006-06-22 1:43 PM
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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
run4yrlif - 2006-06-22 1:27 PM

camy - 2006-06-22 1:18 PM Even with 650c wheels, there is no way I can push 53-11, so I'd go with a 12-25 cassette.

If you lived in CO, you'd be able to spin a 53-11 out on those mountain descents. 

Yeah, even with 700c wheels, a 53-11@120rpm is only 45mph. Even I'm brave enough to get up to 50 (although I quit pedaling back at 35)

2006-06-22 2:06 PM
in reply to: #462878

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??

camy - 2006-06-22 11:18 AM You probably also want to check your front chainring size (It should be stamped on the chainring). I just bought a used bike that came with a 11-21 also, but the small front chainring is a 42 (rather than the more common 39

 

Thanks - but mine does come with the 39 :-)  and I've put the Zinn book on hold at the library - but am still torn between the 25 and the 27....decisions...decisions.....

 

 

2006-06-22 3:22 PM
in reply to: #463036

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
workoutbunny - 2006-06-22 12:06 PM

 Thanks - but mine does come with the 39 :-)  and I've put the Zinn book on hold at the library - but am still torn between the 25 and the 27....decisions...decisions.....

I have a compact crank w/ a 12-27 cassette, and I've found it to be incredibly versatile.  I noted you live in Colorado, so if you're riding a lot of hills the 27 might be the way to go.   In the bay area, it's quite hilly - not quite like CO - but hilly enough (I often find myself riding 10-18% grades in some places) that a 12-27 works for everything.  However, if I gravitate toward a flatter route, I find that I don't need the 27, and 21 is probably my outer limit.  The reality is that I could get-by with a 12-25, but the 27 is always a nice option on a 16% grade. 

I suppose the difference btw the 12-25 & 12-27 is not enough to warrant having both, but I find that having the option of the 27 outweighs the change.



Edited by betyoursilver 2006-06-22 3:28 PM

2006-06-22 3:58 PM
in reply to: #462498

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Runner
Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
Kinda along the same lines....

My bike has, according to the specs I found online at least, a 14-28 for the rear. Anyone ever seen this before? I ride mostly outside of Philly, so I get quite a change up in terms of elevation. Recommendations on possible changes to the gearing would be helpful.

Old Schwinn World Sport 12 speed. If anyone happens to know the front chainring sizes, that'd be great too.
2006-06-22 5:14 PM
in reply to: #462498

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??

Ok...bought a new Shimano Ultegra 12-25 off of ebay for $39.95...have the book on hold at the library, and will get the tools in the next couple of days!!  Thanks everybody - you are the BEST!!

 

 

2006-06-22 6:29 PM
in reply to: #463289

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Subject: RE: Changing Cassette/Cogs on bike - is it difficult??
workoutbunny - 2006-06-22 3:14 PM

Ok...bought a new Shimano Ultegra 12-25 off of ebay for $39.95...have the book on hold at the library, and will get the tools in the next couple of days!!  Thanks everybody - you are the BEST!!

Excellent.  Keep us posted on how it works out for you.

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