ajst2duk

I'm thinking about ultegra cassette ratios, specifically the 12-21, 12-23, 12-25 & 12-27. All have the same small gear, so whats the benefit in having a narrower spread of ratios over wider. Is it weight or smoother shifts?

LordOpie

I do believe the two smaller cassettes have an 11.

As for narrower spacing, a tighter cassette will allow you to spin much closer to whatever your most comfortable cadence is.

mrballistic

also, doing hard hillwork with only an 11x21 on the back will make you less of a girly-man. at least that's what 53-11 told me.

sydney

The bigger cogs give you lower gears. If you don't need low gears, go with a smaller big cog for closer spacing. Eat enough spinach and you can just use an 11x53 for everything.

LordOpie

How fast would you have to spin to keep the bike up and moving?

53-11 alltheway

Don't forget the creatine as well

ajst2duk

Yeah but if 12-27, 12-25, & 12-23 have 12/13/14/15 then different combos up from there, why wouldn't I just get a 12-27 which gives me the biggest range if you know what I mean, they all have the same lowest 4 ratios.

53-11 alltheway

Honestly.....that's why the 12-27 cassette is so popular and why retailers sometimes charge a premium for it. THere was actually a shortage of 12-27 cassettes for a while because every body wanted it. THe benefit of some of the "tighter" cassettes is that they give you a 16T.

If you ride in flat areas you may not need or even want a 12-27 cassette.

ajst2duk

No flat areas here, I'm doing a hilly century next weekend so I might just stick this 12-27 on for that one. When I have developed legs of steel, then I can promote myself up to a 12-23 then 11-21 ********** do people wear these like badges of honour :-)
Am I going to get many riders coming up on me around the century going pheeww - whooarr, look at that whimp's 27 toother !!!!

khuon

Actually, the reason the 12-27 is more expensive has to do with the fact it's constructed differently. In order to support the larger big cog, the 12-27 has a carrier assembly with spider arms for the three largest cogs (21-24-27) which the other cassettes do not. The smaller cassettes mount their larger cogs on a simpler less costly carrier without spider arms. This was technology that trickled down from their MTB group. I believe the XTR cassettes first introduced this design back in 1992.

53-11 alltheway

True ( I understand the spider designs cost more....that's why XT cassettes cost more than LX cassettes), but most places (including Performance) list them for the same price as the others.....because although it costs shimano more to make them they still wholsale all cassettes in a group at the same price.. THe law of supply and demand allows other retailers to jack up the price. Even Harris cyclery said they had to jack up the price of their 12-27 cassettes by $20 just because no distributor had them in stock except for one distributor with unusually high pricing.

Harris cyclery also mentioned that Shimano was unprepared for the unusually high demand for these.

wlevey

If you can only afford one cassette go with the lower gearing. It gives you more options in the long run.

I just got a set of "fast" wheels from a friend to try and they have a DA 11/21. My regular training wheels have a 12/27 (old man living in hilly area).

Here is what I have noticed - With the 12/27 I rairly go above the 19 cog and I ride mostly in the 53 up front. When I get to steap and or long painful climbs I will use the 24 (and on occasions I have dropped to the 39 up front to get a really low gear). The downside to this is that I have noticed that I am still strugling to turn the cranks and I have slowed to a snails pace (which makes the hill longer and more painful). I am working on developing my ability to "turn circles" going up hills and on developing the stamina to stay out of the sadle longer so I don't have to resort to the really low gears.

I took my usual 12 mile moderately hilly morning spin yesterday and today with the new Rolf Vector Comp wheels and found that I did about the same average speed and I also rode in a higher gear (15 or 16 instead of mostly 17) because I had the closer spacing. I also rocketted down decents in the 11 tooth (as opposed to the 12). I did notice that I will have to use the 39 a bit more when I start focusing on spinning and maintaining a higher cadance.

I think the bottom line has to do with what you want out of the bike. Are you a racer? If so, 11/21 or 11/23 are your choices. Are you more interested in finishing long rides without walking ANY sections (yea, you will be called a whimp for that [except on really murdorus hills that most guys have to walk]).

Bill