compact cranks

[marmatt]

anybody here have power data to back up claims that compact cranks will help with climbing

 

[TiMan]

anybody here have power data to back up claims that compact cranks will help with climbing

Careful to look past the marketing "hype"..... They only help increase power IF you can't turn over a 53/23-25 fast enough on a climb to generate your best power.
They can help in very long steep mountain stages for this reason. Lots of guys refuse to use them cause they think it isn't "cool"....then they grind away on steep climbs with a 23 rear cog!

 

[RapDaddyo]

anybody here have power data to back up claims that compact cranks will help with climbing

I went to a compact crank to get my preferred cadences on long climbs >6% grade. I found that on steep sections my cadence got into the 60s and I prefer to keep my cadence up in the 70s or higher. I now have a lot of flexibility because cassettes are cheap and I can switch cassettes quickly and with few tools. My power would be lower if I had to ride cadences in the 60s, but some people are quite happy in the 60s.

 

[TiMan]

I went to a compact crank to get my preferred cadences on long climbs >6% grade. I found that on steep sections my cadence got into the 60s and I prefer to keep my cadence up in the 70s or higher. I now have a lot of flexibility because cassettes are cheap and I can switch cassettes quickly and with few tools. My power would be lower if I had to ride cadences in the 60s, but some people are quite happy in the 60s.

Good choice RapDaddyo. The pro's use 21-23 rear cogs and even 25's.....a few have used easier gearing with compact cranks. SO...why the hell do most of us use a 53 X 23?
I use a 27 on long tough climbs and I have a decent 4.8 watts per kilo at threshold.

Most guys should keep their seated cadence at least 75 on long climbs. I prefer 80-85 for best power.

 

[RapDaddyo]

Most guys should keep their seated cadence at least 75 on long climbs. I prefer 80-85 for best power.

I agree, and I have proved this to a few people.

 

[Pureshot78]

I use a 27 on long tough climbs and I have a decent 4.8 watts per kilo at threshold.

4.8 is "decent" ??

I just swapped to a compact 34/50 and will be running either 12-25 or 11-23 based on the course.

 

[joemw]

Good choice RapDaddyo. The pro's use 21-23 rear cogs and even 25's.....a few have used easier gearing with compact cranks. SO...why the hell do most of us use a 53 X 23?
I use a 27 on long tough climbs and I have a decent 4.8 watts per kilo at threshold.

Most guys should keep their seated cadence at least 75 on long climbs. I prefer 80-85 for best power.

I'm on a 34-50 as well. Generally I have a 12-27 cassette out back, though I do live and train in the mountains during the week. I use the 34-27 on every ride. The 50-12 is enough for me to spin up to nearly 50mph on downhills. With an 11-23, for racing or flatter courses, there is plenty of gears to choose from. It's hard to imagine how a 50-11 isn't enough gear for anybody.

As for power data to back it up, I've also got a "decent" 5.5 w/kg at threshold, although I prefer about 90-100 rpm for tempo or threshold climbing and 105-115 for VO2 climbing.

 

[Shawneebiker]

You can get an 11 x 25 now from Campy! Finally.

 

[frenchyge]

SO...why the hell do most of us use a 53 X 23?

Um, I can't speak for 'most', but I use it because 39x23 is sufficient for most of the climbs I expect to face and I prefer the gear spacing that an 11-23 cassette provides. If there's a steep climb on the route that will play an important role in the race, I'll switch it for a 12-25 or -27.

To the OP, there's nothing magical about compact cranks as long as you have sufficient gearing to maintain a comfortable cadence. That all depends on the individual's power, and the gadient of the climbs they typically face.

 

[Bullseye_blam]

Um, I can't speak for 'most', but I use it because 39x23 is sufficient for most of the climbs I expect to face and I prefer the gear spacing that an 11-23 cassette provides. If there's a steep climb on the route that will play an important role in the race, I'll switch it for a 12-25 or -27.

To the OP, there's nothing magical about compact cranks as long as you have sufficient gearing to maintain a comfortable cadence. That all depends on the individual's power, and the gadient of the climbs they typically face.

Oh really? In what parts of Kansas City do you ride?

I agree with you for the most part... I had a compact (50x36, and 12x25) and went to a standard 53x39, and only miss it in the rarest of occasions...

but if your cadence is too low and you're mashing, you just need to get fitter so that you can produce more wattage/a higher cadence, right? ~

 

[Pureshot78]

I've also got a "decent" 5.5 w/kg at threshold

What category do you race? in order for me to match your 5.5 w/kg at my current weight (80 kg) i'd have to have a threshold of 440 watts...

Please tell me you weigh 125 lbs.

 

[frenchyge]

Oh really? In what parts of Kansas City do you ride?

I live in Olathe and typically ride south and west from here to Spring Hill or Gardner. You?

While there are certainly hills that are steep enough to warrant a smaller gear, they are typically short enough that I'm climbing at well over FTP (ie, 1-2 min power, as opposed to 60-min power) which means a bigger gear can be turned at a comfortable cadence.

 

[Bullseye_blam]

I live in Olathe and typically ride south and west from here to Spring Hill or Gardner. You?

While there are certainly hills that are steep enough to warrant a smaller gear, they are typically short enough that I'm climbing at well over FTP (ie, 1-2 min power, as opposed to 60-min power) which means a bigger gear can be turned at a comfortable cadence.

Yeah, I ride on the Missouri side more, often heading south from Westport. It might be my imagination, Olathe seems flatter than some of the areas I ride in.

I agree on the anaerobic capacity however, and I think it's something I'm going to target...

-Eric

 

[joemw]

What category do you race? in order for me to match your 5.5 w/kg at my current weight (80 kg) i'd have to have a threshold of 440 watts...

Please tell me you weigh 125 lbs.

Cat 2
You got the numbers right, just out of order. 152lbs.

Additionally, I'll add that compact cranks are super for training, but I'd rather have a 39/53 for racing. I just can't afford both, so I lean towards a better training setup.