Tech stuff - Compact cranks

[Barry McKee]

Anyone want to weigh in on the topic? I am currently using 53-39 rings with a 12-25 cassette. Yes, still using 9 speed technology. Got dropped on the Maple Bay hill on Sunday. Not completely blaming the technology as I'm not yet in race shape. Looking for any technology that will help. Seemed like many have gone to compact cranks with 50-34 rings. Would love to hear any views on this topic. Thanks.

[Roland]

I use a 50-34 compact crank with a 12-25 on my road bike. My 'cross bike has a 48-36 with a 12-25. I think it makes a huge difference on long climbs, it lets you stay seated longer, fatigues the legs less. It won't help much on short, power climbs like Ash and King George.

The 10 speed cranks work just fine with 9 speed drivetrains. You may notice a little more noise from cross chaining.

I do miss the top end speed, the next cassette I buy will have an 11 rather than a 12.

[Lister Farrar]

still using 9 speed technology.

Me? Not yet. Gotta wait till they're proven.

But some considerations I've heard from actual users are: big cogs run a little smoother than small ones, but small rings run smoother than big ones. (Sorry not much help there...). As for gear, the actual gear matters much more than the combo that gets there. One option is a wider range cassette. I always tried for a narrow range cassette when racing to minimize the jumps between gears when 'on the rivet'. But lately I had a 13-26 on instead of 13-23, and actuially found it fine, and in a way, a little better because I could get a lower gear on the big ring, and wasted less time doing a ring change when responding to Pete taking off. But not enough to actually change casettes for daily riding, but would do 12-27 rather than change chainrings on my museum pieces.

[shawnc]

I have a compact setup: 50-34 on the front and 12-25 on the rear. It feels really natural to me and I quite like it.

I find that I'm able to stay on my big crank most of the time, which helps when you need to accelerate quickly. As Roland points out, the low gearing allows you to stay seated on hills more often, but for the long steep stuff you're going to have to get on the small crank and stand up.

Occasionally I find myself on my hardest gear and wishing I had one or two more, but I suppose becoming better at spinning would help too...

Having said all that, I don't have much experience on a 53-39 setup so I can't provide a good comparison.

[gav_eaton]

I'm still running a 53/39 up front, but have this wonderful cassette from SRAM in the back - an 11-26!

I love it and refer to it as the 'sprinters cassette' as I have the power hungry 11 for teeth gritting sprints, but the extra tooth with the 26 to lug my sprinter body over the climbs.

Works wonders for me - but I guess it won't help if you're running a 9-speed setup, as this is a 10-speed specific cassette.

[Ramsey]

Barry, I run both:

52 / 39 rings with a 13-23 10 spd cassette on my Gios (we used to ride 52 / 42s back in the, er, 80s - the lower gear ratio forces me to spin) and a

50 / 34 compact paired with a 11-23 on my summer bike.

Prefer the aesthetics of the compact, and that's about it. The other guys covered the main points: some cross-chainring rub (sounds like an untrimmed front derailleur), and the need for an 11 tooth cog if you're going to try to keep pace with Gavin and co.

I've heard it said that the compact is the "vain cyclist's triple": the wide gear range of a triple chainset without the "unracerly" third ring. Whatever. I just think it looks sleeker. The compacts are marginally lighter, supposedly the main benefit.

By far, the biggest drawback is the need to shift the rear derailleur 3 or 4 cogs over when changing between the front rings (as opposed to 1 or 2 rear shifts with a more conventional setup). Lister covered this in mentioning the advantage of running a narrower range in the back.

Apparently, the trendy new setup is a 52 / 38, something of a compromise between the two..

For what's it's worth, I think a simple change of cassettes to a ratio that better fits your needs would be easier - and way cheaper - than buying a new crankset!

A gear ratio calcutator:

http://www.sheldonbrown.com/gears/

[Josh.E]

I run a 53-39 with a 12-27 cassette on my summer bike. I'd actually prefer to have a bit more of a climbing gear than that for longer steeper stuff, and am thinking of going to a compact with a 34 and an 11-25.

My winter bike has a 46-39 on the front and an 11-32 8 speed xtr mountain bike cassette on the back. I love climbing on that bike. For a given climbing speed, sitting and spinning saves a ton of energy over pushing a bigger gear at a slower cadence on longer climbs.

For what it's worth, by far my favorite bike setup to date was a dura-ace 9 speed triple front and an 11-23 on the back. All the best of both words. Small jumps between gears, not alot of chain ring overlap, and a very wide overall gear range. Also you had smaller steps between your easiest climbing gears, so you could really dial in the gear that felt the best.

[AlW]

Winter bike runs 53/39 with 12-26 on the back which is generally ok, but I often find myself wanting another gear so I could sit on the steeper climbs.

Summer bike has 53/39 with 12-27 on the back. Haven't tried it on a long climb yet, but definitely felt the difference on the short ones (sinclair, newton heights)

[Barry McKee]

As a newcomer to TC board I want to thank all of you for all the great information. Your thoughts, views, opinions and friendly jibes at fellow TS mates has given me much to ponder and consider. My wife tells me that if I want to get somewhere sooner I should just go faster. She too has a good point. On a separate issue, are newbies welcome to drop in on one of your rides? I'm thinking this Friday. Thanks again for weighing in on the issue of Compact Cranks and gear ratios. Cheers!

Barry

[Josh.E]

New riders are always welcome.

[Brian S]

Still the best had to be 42-52 on the front and 13-17 5 speed campag record on the back. Young stupid fit and those were the days. Lister, back me up here. Anybody want to sing some Springsteen?
http://www.youtube.com/watch?v=VsEkhy7fGLw

[sylvan]

Still the best had to be 42-52 on the front and 13-17 5 speed campag record on the back.

54/42, and the 13-17 on hilly days, 11-15 on flat days, back in the day, of course.

I had a good climb up Apex Alpine a few years ago and put a few minutes on a dude with a compact, just because all I could do to keep the 39/25 turning by leveraging leg mass was faster than spinning the grannier gear.

I'm still running a 53/39 up front, but have this wonderful cassette from SRAM in the back - an 11-26!

I have almost the same right now, but it's the monster 11-28 SRAM on the back (11,12,13,14,15,17,19,22,25,28). It's pretty epic. Maybe I'll get fit enough to not need that 28 some day not soon, but it's sure nice now.

SRAM cassettes have all these options in 10-speed:

11-23 : 11, 12, 13, 14, 15, 16, 17, 19, 21, 23
11-25 : 11, 12, 13, 14, 15, 17, 19, 21, 23, 25
11-26 : 11, 12, 13, 14, 15, 17, 19, 21, 23, 26
11-28 : 11, 12, 13, 14, 15, 17, 19, 22, 25, 28
12-25 : 12, 13, 14, 15, 16, 17, 19, 21, 23, 25
12-26 : 12, 13, 14, 15, 16, 17, 19, 21, 23, 26
12-27 : 12, 13, 14, 15, 16, 17, 19, 21, 24, 27

[Lister Farrar]

Still the best had to be 42-52 on the front and 13-17 5 speed campag record on the back.

54/42, and the 13-17 on hilly days, 11-15 on flat days, back in the day, of course.

Imposter! It was 13-17, because there were no 11's or 12's. Americans called them 'corncob clusters' (pre 'cassette' days) because the cogs looked almost the same diameter. (Sidebar: On one occasion they were the same diameter. A wily Italian ex-pat. racing in Ontario in the 80's used a freewheel with 2 13 tooth cogs. He said it was so he could appear to upshift, and trick the other guys into overgearing to their 12's for the sprint.)

13-18, was next, then the world went to hell with that newfangled 7 speed....

I have almost the same right now, but it's the monster 11-28 SRAM on the back (11,12,13,14,15,17,19,22,25,28). It's pretty epic. Maybe I'll get fit enough to not need that 28 some day not soon, but it's sure nice now.

Nobody ever said after a ride or race, 'gee, I wish I hadn't had that low gear'. The opposite however, is common.

Good info though, thanks!