ac29593

After reading that poll where people were posting what cassette they use, I noticed 12/25 was the most popular. (this was about a week or two ago). After reading the latest thread here about crosschaining, I am now wondering why anyone who rides a 12/25 would not opt for a 12/27 instead. Considering the only difference in gearing is the last two cogs (23,25) and (24/27), here is what I was thinking....

In the big ring, most people dont like to use the lowest two cogs often to prevent crosschaining, and this will equate to the exact same cassette with the addition of two cogs that are just a bit easier to push if needed (considering they are the same once you hit the 21T). Better? Same on the small ring. A 39T or 36T ring with a 21T cog is not too big of a gear, and Im assuming most people dont ride much lower than that unless they really need to drop into that 23 or 25.....wouldnt you rather have a 24 and a 27 to use instead? Even if the argument would be that the route is not hilly, you would never be in those gears anyway if it was all flat and the cassette would be the exact same for the remaining 8 gears.

Just overthinking things maybe, any opinions? I was close to buying a 12/25 cassette until I thought of this. Wondering what people that actually ride them have to say.

Thanks

msheron

Seems like what most bikes come with. Maybe it's the universal cassette....LOL! I don't know. I do know when I went with my compact crank set I went with the 12-27 rear cassette. It has worked out very well. That being said, I have no further to add.

DrPete 

A 12-25 vs. a 12-27 really has nothing to do with cross chaining. It's really a matter of smaller differences in teeth between the cogs--allows you to fine-tune your cadence a bit more as you're riding.

I switched from a 12-27 to a 12-25 just because I didn't really need the 27T, and now that I've started racing it's more important to me to have smaller jumps between gears.

DrPete

NoRacer

My TCR came with a 12/25 cassette w/ 39/53 chainrings. I think what happens is that people ride that combination for awhile until they find out that it may not suit their needs and then they change it. That's what happened to me, since many of the bike club rides are on rollers and hills. I decided to switch to compact gearing (34/50 chainrings).

Since switching to compact gearing, I decided to modify my 12/25 Ultegra cassette to an 11/25 Ultegra cassette (11,12,13,14,15,17,19,21,23,25) so that I can have the extra climbing gears, but also keep top end.

mscycler

My riding is done here in Mississippi. There really isn't a need (IMHO) for a 27 when the highest point above sea level is only 600'. There really aren't that many hills where I ride (central part of the state). I ride a 12-25. It's what came on my bike when I bought it and honestly haven't thought about changing it...well, I thought about it when I took the bike to Lake Tahoe last month, but didn't make the change.

mscycler

jbrians

My bike came with a 12-23 9sp and 39-53. In S Ontario where I live the hills are amazing. Maybe not up to pittsburg standards but impressive none the less (I am on the escarpment and some of these hills (HA) are 1000+ft of elevation change.
I went to a compact 34-50 with a 12-25 and now I can motor up anything without feeling like I need to get off and push. It was that or a triple but the compact was a lot easier to impliment.