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Crank & Cassette Size

if you can get your hands on one i'd suggest test riding a 170mm crank set. i used to ride 175mm on everything but after switching to 170mm on my bmx about 10 years ago riding anything longer make feel like i'm going crazy. i find that 170mm is much more comfortable to spin and as i recall we're pretty close in height, so maybe 170mm will also work for you.

Thanks for the feeback, Patrick. Whether or not there is any real correlation or not is still yet to be proven, but I've get extra long legs for my height and have been very satisfied with the 175mm length. I'm really hesitant to make any length change more than the switch to 172.5m would provide.
 
Patrick, this is where the falcrum effect does matter. On fixed gear bikes or single speed crank arm length does have a mechanical effect - however on variable geared bikes this is negated so comes down to personal choice/feel.

In your case due to prolific BMX riding you have become accustomed to the 170's - for me and MTB riding it was the 172.5's but now the more I ride the 175 I now prefer these.

Pete, another thing to add is that I don't really use the 28 or 27 any more and are basically there for emergencies :D
 
I agree with FE here. Alot of the crank arm choice is based on 'muscle memory' - when your body developed its cycling 'habits' as it were. And in addition - for fixed gear, riders tend to have slightly rounder stroke patterns than freehub riders - and of course, longer crank arms will strike the upper banks, so, you just learn to ride on shorter arms. There have been many exhaustive studies on crank arm length vs leg length and while there seems to be some correlation between longer arms for longer legs, there's just as many inconsequential and negative findings. At the end of the day, it just comes down to how you feel (and perform). You might even try getting a spin scan done to see just where your best power curve really is - as that is probably the best way to know exactly.

I can tell you one thing , though. The longer crank arm just cost me 20,000 yen as I 'bought' a new saddle due to a toe-clip overlap in an unexpected position! I'll be thinking seriously about dropping my 172.5 back to 170's just because of this.
 
That's because I've become stronger - you improve much faster when you can keep the high cadence rather than going in to lactate overload pushing a larger gear.
 
In your case due to prolific BMX riding you have become accustomed to the 170's - for me and MTB riding it was the 172.5's but now the more I ride the 175 I now prefer these.

James, you're taller and have longer legs than both Pete and myself. for my size (me personally) 170 works. I'd expect the same size arm to feel cramped for someone taller the way 165s feel cramped to me. I get the feeling that 175 or 172.5 are the "standards" and because of that shorter cranks often aren't even considered. I know Pete's height is close to mine and that he's a spinning fool, so because of that I'm suggesting he try a 170 set before settling on a new size.

everyone who's saying personal preference is right. I wouldn't argue that there's a significant mechanical advantage to longer cranks on a geared bike. all the more reason to try out shorter arms!
 
I just want to look back and see a couple more options when the sh*# hits the fan! I'm more like Javes on this - I don't really care if the lighter gear is not 'perfect' - the difference will only be a kph or so anyway - usually I just need to settle back a bit and accept it. Which will be fine for the majority of riding I do, or intend to do. (Including the grueling 8 days in the Alps). Now for hardcore racing, it's super important to have those 'micro steps' as it will make or break your cadence and ability to stay right on the bitter edge of optimum power transfer and performance. Personally I love the 12-25 as it totally favors my standing / seating / standing style - 2 Up - 2 Down with a perfect gear step no matter I'm in the top range or bottom. When the spread gets farther, I lose rhythm and will overspin or over mash accordingly. But again, facing 10-20km at 9-12% grades daily and I aint gonna be the proud one playing Pantani - well, at least once I will - for the Alpe d' Huez TT, but I will be totally destroyed in the process.
 
I have a 165 50/34-11/28 set-up. The 165 crank is due to my size - I used to get a slight pain at the back of my knees. Being small, I figured it was due to the longer cranks forcing my leg to come up too high at the top of the stroke (above horizontal) so the pain was coming from the knee being forced to do work (I like big gears) whilst over-extended. With the 165`s I haven`t had any problems.

As for gearing, as others have mentioned, the 15-17 jump is noticeable, however, I do use the 11 (see afore-mentioned liking for big gears) and the 28 is workable. Sometimes, I would use a 30 or even a 32 if I had it as there`s a few climbs here I do quite often that hit 18% (or even 20%) and I can`t hold cadence on those stretches. Alternatively, if it`s a day where I want to climb but don`t want to have to ride at my limit, then lower gears would allow me to maintain cadence without riding too hard, but like I said, it`s workable. My own personal view, is that most people are over-geared. I haven`t done many events in Japan, but I`ve lost count of the number of riders on said events who I pass who are in 1st gear when I`m sitting in 3rd or 4th (some are even struggling just to turn that 1st gear). If you`re in 1st gear on a slope less than 10%, where do you go when the real climbing starts? As is often cited, Contador himself sometimes switches to bikes with a 34 x 32 gear for climbing stretches and that`s with his W/kg figure. Guess I need a 40 on that basis...
 
His results when he was Junior weren't so different. Blood packing, etc will of course give you a bit more stamina and raise the LAT level, but it doesn't really make you 'stronger'. People pretty much get it all wrong when it comes to PED's and how they REALLY work for cyclists. You are not turned into a 'superman' by any stretch of the imagination. You can simply ride 'fresh' for longer periods of time and shorten recovery sessions.

And remember, especially for climbers like Pantani, keeping weight down is an absolute -so you wouldn't find him on anabolics or other supplements to increase muscle mass.

Some riders are just naturally very good. With or without PED they will excel. I think alot of the doping 'witchhunts' are due to marginal riders just being jealous. Like the kid who scores poorly on his tests, then looks for blame elsewhere.

There was a famous frame builder in my hometown (no names mentioned) who claimed that pushing ANY big gear would damage your knees permanently and sold this cool-aid to thousands of cyclists. This was more than 25yrs ago, mind you. Well, I know PLENTY of riders who push bigger gears with ABOSLUTELY NO problems. 90% of this 'knee problem' is just the rider not training properly to increase the strength of surrounding muscle to support the knee and also allowing the knee to aclimate over time for the increased range of motion and / or load. The primary reason rider's knees hurt is because they don't ride enough or ride exactly the same way ALL THE TIME. So, yeah, of course their knees will hurt if they get out of the saddle more than 15s on a stretch every once in a blue moon or push 2 teeth higher for a km or so, or increase their range of motion by 1-2cm.

As Jens Voigt so aptly puts it: "Shut Up Legs!"

Interesting to see if he could have turned those gears without his rocket fuel.
 
Great blog on the subject...

Having recently bought a brand-new bike for myself, I am currently in the process of doing the same for my wife :rolleyes:
I have a 172.5mm FSA carbon crank & BB left over from a previous incarnation, and I was thinking about putting on my wife's new bike. In my quest for knowledge, I came across this gem:
http://bicyclecranklength.blogspot.jp/

At the top of his page is another link to Kirby Palm's Crank Length Formula, according to which, my optimum crank length would be 186mm, and my wife's would be 155mm.

Guess who's not getting an FSA crank?
 
Blood packing, etc will of course give you a bit more stamina and raise the LAT level, but it doesn't really make you 'stronger'.

If PED`s don`t make you `stronger`, then how come climbing times/rates of ascent from recent Tours are above what is deemed physiologically possible? But anyway, it isn`t about strength, it is about sustainable power – I could climb using Pantani`s gearing, the question is how long I could sustain it for: strength certainly isn`t the limiter. If you want to know what drugs cyclists take, then click below (the list is staggering) – I think Rumsas was classed as a climber.
http://www.timetriallingforum.co.uk/index.php?showtopic=66059

As mentioned, the pain (I decided) came from my thigh being above the horizontal with the crank vertical (at the top of the stroke) - small riders have problems with high bottom brackets. For example, if I climb many flights of stairs taking too many steps at a time (2 or 3) then after a while I will get the same pain. So sure, the majority of knee pain is related to lack of conditioning, but bio-mechanics still play a part.
 
If PED`s don`t make you `stronger`, then how come climbing times/rates of ascent from recent Tours are above what is deemed physiologically possible? But anyway, it isn`t about strength, it is about sustainable power – I could climb using Pantani`s gearing, the question is how long I could sustain it for: strength certainly isn`t the limiter.

That's just another way to say exactly what Tim said. He was indicating that what they used or are using, more than adding raw strength, allows them to sustain their high level output for longer.
 
allows them to sustain their high level output for longer.

I was trying to indicate (however badly) that as well as sustaining high power for longer, they can actually produce more power i.e. W/kg figures above what is deemed sustainable (6.0-6.2) - so they increase sustainable power as well as stamina and reduce recovery times - and that increasing raw strength was irrelevant anyway, as more strength doesn`t necessarily increase sustainable aerobic power. If that is what Tim was indicating, then yes, I misread his comments.
 
Sorry to dig up an old post, but I came across this article* giving yet another view on crank arm length and rather than start a new post, I thought I would just add it to this one.

What amused me was a comment beneath the article that reads,
"A few years ago we sold a Santana tandem bike that we'd ridden for 5 years, several thousand miles......
......It wasn't until our LBS disassembled the bike for shipping that we realized the original dealer put the cranks together wrong. The captain's position had 175mm on the left and 170mm on the right; the stoker's was reversed. We never noticed in 5 years of riding! So much for crank length."



*which had been linked from a review on the nice SRAM Red 22 hydraulic groupset I am lusting after
 
49 - 44 (or 42?) - 28

An even better idea, purely from the point of gearing choices for steep Rindos, would be a tripple front crank. However that would require even more investment (derailleurs, Left STI lever) [. . .]

Front derailers are cheap.

STI lever? For those too young to have experience of such matters, allow an old fart to explain how to move from chainwheel to chainwheel with a properly adjusted front derailer:
  • big chainwheel: slam the lever all the way down
  • small chainwheel: slam the lever all the way up
  • middle chainwheel; put the lever very roughly in the middle
[. . .]and looks rather uncool. Come on, with a tripple crank you are not taken serious any longer.

That's me! I'm just kicking myself for not having asked Tim to install a dork disc for my rear hub, to complete the effect.

But yes, I admit it, I'm a sissy. And I'll bet most of you are too. By contrast, real men don't need cables.
 
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