new cassette ?

greenspurs

I am thinking about buying a new cassette, if I replace the one on the wheel at the moment, will I have to realign the rear derailleur to suit the new cassette ?

Cee-Jay-Cee

No you shouldn't have to as both should have the same spacing, ie your replacing a 10spd with a 10sod however you may have to adjust the cable tension and/or the B-tension if the ratios are different.

I changed my cassette (12/27 changed to 11/28) last week and had to adjust the cable tensioner to get the derailleur to slot and run smoothly in each gear ( I think it's called indexing) it was a 5 minute job with the bike upside down on the black & decker workmate.

Pawlie

Change your chain too if it hasn't been already,

greenspurs

thanks guys....
Im changing from a 12-26 to a 12-32 ...

quozl

Do you have a long enough chain?

If it's cut correctly for the 12-26 then you don't, and shifting into the big front ring and the big back ring will be potentially fatal for your derailleur.

Another reason to get a new chain at the same time!

greenspurs

Thank you quozl !!! I never thought of that !!! I need to change the cassette for the Sean Kelly tour

NeedMoreGears

Make sure your rear derailleur can handle the bigger sprocket - some useful info here

http://sheldonbrown.com/harris/derailers-rear.html

http://www.parktool.com/blog/repair-help/chain-length-sizing

Brian?

greenspurs wrote: »

thanks guys....
Im changing from a 12-26 to a 12-32 ...

12-32? What are you going to be hauling up hill?

greenspurs

Brian? wrote: »

12-32? What are you going to be hauling up hill?

have you seen the hills ?? Its better to be looking at them, than looking for them

greenspurs

NeedMoreGears wrote: »

Make sure your rear derailleur can handle the bigger sprocket - some useful info here

http://sheldonbrown.com/harris/derailers-rear.html

http://www.parktool.com/blog/repair-help/chain-length-sizing

I think I will need a new derailleur ! There is a Shimano RD2300 ss double fitted on the bike at the moment. Reccomended max is a 26 or maybe a 28 ?!
cost rises ......

shaka

greenspurs wrote: »

I think I will need a new derailleur ! There is a Shimano RD2300 ss double fitted on the bike at the moment. Reccomended max is a 26 or maybe a 28 ?!
cost rises ......

Perfect reason to buy a new bike

greenspurs

shaka wrote: »

Perfect reason to buy a new bike

Bike snob ??

Brian?

greenspurs wrote: »

have you seen the hills ?? Its better to be looking at them, than looking for them

That only applies up to a certain point. I find a 10 speed 11-28 very gappy, an 12-32 would be horrific.

shaka

greenspurs wrote: »

Bike snob ??

Ha ha no but one should always be encouraged to by new bike

cdaly_

Brian? wrote: »

12-32? What are you going to be hauling up hill?

My sorry ass...

Brian? wrote: »

That only applies up to a certain point. I find a 10 speed 11-28 very gappy, an 12-32 would be horrific.

It's not gappy if you make up a custom cassette. I took a 9-sp 13-25 and swapped out the two biggest sprockets for a 27 and 32. It now runs
13-14-15-16-17-19-21-27-32 and the last two only get used on serious hills. They get so little use that I can swap them in to new cassettes as old ones wear out.

Brian?

cdaly_ wrote: »

My sorry ass...

It's not gappy if you make up a custom cassette. I took a 9-sp 13-25 and swapped out the two biggest sprockets for a 27 and 32. It now runs
13-14-15-16-17-19-21-27-32 and the last two only get used on serious hills. They get so little use that I can swap them in to new cassettes as old ones wear out.

Sorry man, but that sounds terrible. The shift from. 21-27-32 must be horrible.

I'd spin out a 13 in even a minor descent. I'm a big lad and I have a compact with an 11-25 in, never needed anything else.

cdaly_

Brian? wrote: »

Sorry man, but that sounds terrible. The shift from. 21-27-32 must be horrible.

That's a bit of a jump all right but when facing into a wall it's just the thing. As mentioned, I rarely go there and the rest is nice and close for flat.

As for spinning out, I find gravity to be a great man on the descents...