Smallest Cog Swap

[comish83]

Currently I am riding a 2005 Trek 1200 that is a 3x9 (30/42/52, 12 - 26). Can I pop off the smallest 12T cog and simply replace it with an 11T cog or is the entire cassette bound together? I have a chain whip and lock ring coming in the mail for a separate repair but it would be nice to know this ahead of time. Thanks!

http://bikepedia.com/QuickBike/BikeSpecs.aspx?year=2005&brand=Trek&model=1200

[ultraman6970]

My best answer??? Probably will work straight as you have planed, not familiar with shimano, sorry.

[weisan]

Yes, simply replace 12 with 11.

[ColonelJLloyd]

Yes, you can install a new 11t 9s outer cog. But, don't. Buy a brand new cassette. The price difference is negligible.

[jtbadge]

Yes, you can install a new 11t 9s outer cog. But, don't. Buy a brand new cassette. The price difference is negligible.

+1.

You're not going to want a 2-tooth gap at the top end.

[oliver1850]

HG50 11-25 cassette is $11 at Ribble.

http://www.ribblecycles.co.uk/shimano-9-spd-hg50-sora-tiagra-cassette/#pid=19726

If you want to keep the 26 you can grind the heads off the rivets and swap the large cogs.

SRAM made the PG950 in 11-26 but it will cost more than the HG50.

[oldpotatoe]

Currently I am riding a 2005 Trek 1200 that is a 3x9 (30/42/52, 12 - 26). Can I pop off the smallest 12T cog and simply replace it with an 11T cog or is the entire cassette bound together? I have a chain whip and lock ring coming in the mail for a separate repair but it would be nice to know this ahead of time. Thanks!

http://bikepedia.com/QuickBike/BikeSpecs.aspx?year=2005&brand=Trek&model=1200

Yes but(always a butt), need a smaller, 11t lockring and Lotsa chain wrap on 11t so the shift to 13t 'may' not be great...you may have to go up 2/down 1 to get on 13t. Depends on chin nd 'tightness' of rear der.

[berserk87]

Yes but(always a butt), need a smaller, 11t lockring and Lotsa chain wrap on 11t so the shift to 13t 'may' not be great...you may have to go up 2/down 1 to get on 13t. Depends on chin nd 'tightness' of rear der.

Ditto on the lockring. If you use a locking from a 12t cassette on an 11th cog, the ring may protrude a bit much and bump the chain off of the cog. I had this happen last year. Always thought a lockring was a lockring, but I was wrong. You will need a lockring specifically for a cassette with an 11 to make it work.

[ColonelJLloyd]

Ditto on the lockring. If you use a locking from a 12t cassette on an 11th cog, the ring may protrude a bit much and bump the chain off of the cog. I had this happen last year. Always thought a lockring was a lockring, but I was wrong. You will need a lockring specifically for a cassette with an 11 to make it work.

Which makes replacing the single first 9s cog make even less sense. A new cassette comes with the correct lock ring.

[berserk87]

Which makes replacing the single first 9s cog make even less sense. A new cassette comes with the correct lock ring.

My scenario assumes that you have an 11t cog from another cassette already, with the correct locking. I've got scads of cassettes lying about. I would not buy a lockring just for a one-tooth change on one cog. I agree with what you are saying about buying one separately. Not worth it.

[cachagua]

I'd do it. Most of my cassettes start with either 11 and 13, or 12 and 14. A small gap between the smallest and next-to-smallest isn't particularly useful, the way I ride, and the opportunity to narrow the gaps in the rest of the cassette is more than worth it.

[comish83]

HG50 11-25 cassette is $11 at Ribble.

http://www.ribblecycles.co.uk/shimano-9-spd-hg50-sora-tiagra-cassette/#pid=19726

If you want to keep the 26 you can grind the heads off the rivets and swap the large cogs.

SRAM made the PG950 in 11-26 but it will cost more than the HG50.

Went with the 11-25. Hard to beat that kind of price. Thanks!