Cranks

[drewjc]

sounds like this debate will never end.

I personally believe that crank length is a function of leg length crossed with the riding style preferred by the particular cyclist (ie, higher average cadence = shorter crank length). For example a tall rider who favours criteriums and shorter races with sprints will quite often prefer cranks as short as 170mm but put a rider of similar height with a preference for time trials to the test and they may favour anything up to 180mm. A shorter rider who races crits etc. will most likely prefer to use short cranks (ie 165mm in some cases) and a similar sized rider may ride long cranks in time trials (hill climbs etc.) or races with a predominately lower cadence.

The main reason short riders find it difficult to ride long cranks is that their knees are bending too much at the top of the pedal stroke (and being obstructed by the arms). Tall riders find the opposite applies, in that they dont apply full power with shorter cranks because they r not bending the leg enough to achieve an efficient power stroke.

BTW i am 5'11" and as i mentioned b4, i ride 165mm and 170mm on my track and road bikes respectively.

 

[J-MAT]

This reminds me of the huge debate in handgunning circles over the years as to which caliber is better, the 9mm or .45. Of course, evidence over 90+ years clearly shows that the .45 provides superior knockdown power compared to the 9mm, but some people swear by their 9's, even though they would be severly disadvantaged if they had to use a 9mm in a shootout.

The crank length debate is no different it seems. Some riders swear by their cranks no matter what. If it works for you, great, but I 'm always looking to improve on what is possible. I started on 172.5 mm cranks in 1990 and didn't start messing around with cranklength until several years later. I found that once I had gone to the longer cranks, I never wanted to go back to the shorter ones for any reason!!!

In a previous post, I talked about pro riders and what they had on the line (TDF, Hour Record) when they decided to increase their cranklength.

Honestly ask yourself the following questions:

1) Don't you think these pros know what they are doing???

2) Don't you think the coaches and physiologists know what they are doing???

3) Do you know more about bicycle racing than TDF champions, coaches, or team directors???

3) Do you think a coach or team director would allow a star rider to screw up the outcome of an important race by using longer cranks if they didn't work???

4) Why do pros increase (but never decrease) the cranklength for high-power road racing events???

5) Are you so powerful as a rider that you don't need any extra help??? (if you say yes you should win every race you enter).

We can sit around and talk about physics and leg length and the diameter of circles and the like forever. I have decided to instead quote some of the sources that planted the seed for longer cranks in my head.

Here are some of my sources:

Greg LeMond's Complete Book of Bicycling (ISBN 0-399-51594-1)
On page 128, LeMond discusses setting up overall height and talks about cranklength:

"The formula for overall height that I describe here is calculated for 170-millimeter crankarms. But I ordinarily ride in 175-millimeter cranks and still use the same measurement (LeMond is 5'9"). Bernard Hinaut like to change crankarm lengths when he rides in time trial races...When Hinault changes from his ordinary 172.5-millimeter cranks to 175-millimeter cranks, he would lower his overall position..."


Cycle Sport Magazine, July 1997, page 75

Here, Indurain's top mechanic Enrique Sanz talks about his bike setup.

Fitting the Bike to Miguel
"In his early days we never knew that Miguel had such a large 'motor' and we didn't bother changing things like the length of his cranks much until he won his first Paris-Nice in 1989. As an amateur he rode with 172.5mm cranks, then in his first year as a pro (late 1984-1985), it went down to 170. Gradually after that they got longer and longer first going to 175, then to 177.5 and finally to 180."


Velo News, December 12, 1994, page 10
This is about Rominger's successful Hour (55.291 kmh).

The Record Bike
"...as the Swiss rider used 175mm crankarms (as opposed to his normal 172.5mm) to push his giant 60x14 gear."



Velo News, October 3, 1994, page 27
Describes Indurain's Record bike setup.

Miguel Indurains Equipment
"Cranks: Campagnolo 190mm (compared with the 180mm Indurain uses on the road)."

As you can clearly see, when an important, high-power race is on the line, these top pros INCREASED their cranklength.

You won't find any top rider going to shorter cranks for road racing. In Indurain's case he actually went down to 170's, but quickly started going back up, eventually to 180mm.

If the 170's were better he would have stayed with them. He won 5 tours on 180's and did his hour on 190mm cranks.

The shorter riders (LeMond, Hinault, Rominger) used 175mm arms and of course Big Mig (6'2") used 180's and 190's. I believe the "shorter" pros could have still gone faster on 180's. Even they were probably afraid to dream and really go for it and see what was truly possible, feeling that 180's would be out of the question, or "too much." Indurain wasn't afraid to dream, and clearly looked for even more with the 190's he used on the hour. If Shimano made 190mm Dura Ace cranks, I'd buy them immediately!!!

In a previous post, I mentioned the famous Velo News crank study done years ago. Even a 5 ft tall female went faster on 180mm cranks. I think she started on 165's or 170's. Why would you be any different???

This is the real world. Look at the evidence regarding longer cranks our sport has produced over the years. The trend is always longer, never shorter.

My advice is to go out and buy some 180's REGARDLESS OF YOUR HEIGHT!!! You will never know what is possible if you don't go for it. Don't waste time messing around with the next bigger size, go to the 180's even if you are currently on 165's!!!

Give them a shot for at least 4-6 weeks before you make up your mind, as it always takes awhile for your body to adjust to any position/pedalling change. Compare your best speed on a local test climb with the shorter cranks and later with the 180's. If you are not sure which is best (most know right away), go back to the shorter cranks. You will probably find in the first mile you would rather have the longer cranks on your bike!!!

You can rationalize that you are somehow different and don't need longer cranks because you are shorter, an amateur, or whatever. The laws of physics STILL apply to you, EVEN IF YOU DON'T WANT THEM TO!!!

Good luck!!!

 

[drewjc]

I am by no means saying that i am better than the pros, or that physics dont apply to me, but i would wonder what size cranks do the best sprinters (road) in the world use...If u can get to the finish using shorter cranks is there an advantage in a sprint with shorter cranks?

You say that using longer cranks will make us better in power events ie climbing, TT etc. Could it be said that the pros actually shorten their cranks for a normal road race (rather lengthening as you say for the important ones?) I am not sure why they would want to do this if they have such an advantage with the longer cranks. Surely there must be some disadvantage with using long cranks. Maybe not with performance but with the longevity of ur knee joints or something of the like (i am not sure just something that came to mind)?

I will (for the moment at least) be keeping my "short" 170mm cranks on, with the thought of keeping my body used to driving the track bike at high cadences. Maybe also boosting my strength aswell?

 

[ant evans]

Too much talking, not enough riding. I've just got a new bike. See you all later.

)

 

[J-MAT]

Drewjc: All the references were for pure road riders in high-power events like hills/TT's. I figure most riders are on the road. You sound like more like a track enthusiast, so longer cranks are not part of your world. No track riders use 180's or anything even close. I don't think you would ever find a track rider on anything over 170mm and that might be long. I believe LeMond is also 5'9" and he always used 175's.

By the way, just today I was reading an interview on top U.S. sprinter Marty Nothstein. He was talking about using 170's for the kilo and 167.5's for the keirin, and 172.5's on his road bike.
Check it out:

http://www.cyclingnews.com/interviews/nothstein012.shtml

Ant's right. I'm getting the hell out of here and going for a ride!!!

 

[Kristian]

Longer crank length equals greater leverage, sure, but at what physiological cost??? Big Mig was a freak of an athlete but if he were to jump infront of a moving train I wouldnt follow. What worked for him may not work for others. There is the consideration to knee flexability, but there is also a function of muscle fiber type to take into account.

 

[J-MAT]

Kristian:

There is a slight physiological cost due to the fact your legs have to travel in bigger circles. Muscle-fiber composition is not a consideration.

The Velo News study tested a variety of riders, from a short 5 ft tall female to a tall male over 6'3." ALL the riders went faster on 180 mm cranks.

Look at the evidence over the years. Even if a top rider did not go to 180's when switching cranks, they did INCREASE the length of the cranks for important high-power events.

Cycling is a sport that requires tremendous experimentation. Try longer cranks and see what you think. They will help mostly with time trialing and climbing. Whenver I switched back to shorter cranks, I HATED it!!!

Try it. You might like it!!!

 

[ant evans]

Have a look at

http://www.bsn.com/Cycling/cranks.html

for a review of the various approaches and some interesting results.

Doesn't matter what cranks I have, I can't use them at the moment because of my knees

:-(

 

[Tezza]

I specified 175s when I got my new road bike. I'm 6'1" and 103kg (and over 50yo hence the metric/imperial mix). I find the 175s great. I also added a 12-27 cluster so with the longer cranks and lower gear, I can manage to keep up with the young guns on the hills.

 

[J-MAT]

Ant:

Sorry to hear about your knees. Too much training??? Hopefully, you will get back into the swing of things shortly. Good luck man.

Tezza:

If you like the 175's, experiment with 180's. We are the same height and I love my 180's, but height doesn't really matter. You might find climbing to be even easier!!!

Later!!!

 

[ant evans]

Thanks. No firm diagnosis yet but at least both knees are the same. I now have orthotic inserts for my shoes and I've been taking it so easy I can't remember which end's the front.



Only happens when I sprint or climb. I think cranks are a big part of the problem, so I will experiment and see what happens.

 

[J-MAT]

Ant:

Climbing and sprinting are the most stressful things you can do to your knees as a rider. I can't stress enough how important it is to have a rock-solid "base" comprised of many many miles of low-moderate intensity with the progressive and gradual introduction of more intensity like climbing, sprinting, TT efforts, etc.

Continue to ride, just go easy on the flats. Don't push hard. Ride easy for at least 3-4 weeks before attempting any more intensity. It might take a lot longer than that to have everything settle down. Dealing with knee injuries requires the highest degree of patience, more so than with probably any other cyling-related injury. Broken bones heal progressiviely and on schedule usually, but knees have a mind of their own and can take much longer to heal.

Take it easy and be patient!!!

Good luck bro!!!

 

[ant evans]

Thanks.

A medical friend described the problem with knees in terms of blood supply... there just isn't much of it. Injury is quick, healing is slow.

I know someone who is on crutches recovering from a knee injury she ignored, and I like to learn from other people's mistakes, but I have a real problem going slowly. Riding to work is interval training! Slow or dead!

I need to grow up I guess.

 

[J-MAT]

Ant:

I know what you mean about going slow. I can't stand it either. As hard as it may be to hold back, you need to. It's a lot better than getting really screwed up and needing surgery or crutches.

As long as you don't have something serious like a torn meniscus or damage to the inside of the patella (kneecap) you should be allright. Tendon and ligament pain is part of the business if you push hard.

Tendons and ligaments are often described as "avascular." The body heals from oxygen and nutrients delivered in the blood. Without good bloodflow, healing is slow to non-existant.

I've had my share of knee problems over the years. It takes experience to know when you can ride through a problem and when you need to get some help.

Consider driving to work since you have a hard time holding back. Plus, when you are in traffic the adrenaline flows a lot more, and you automatically push harder. I usually drag race cars off the line from a light and see how long I can hold it, no matter how tired I am. If you ride like this, by all means drive to work for a few weeks, and ride easy after work or ride a trainer. Don't put yourself in a environment where you will be tempted to push hard.

When it comes to knee injuries, patience is truly a virtue!!!

Good luck man!!!

 

[ant evans]

Thanks for the advice. I can ride slowly, I know I can. I did it once in 1999. I am also reducing my mileage by getting a lift every second day. I don't have a car because if I got one, I wouldn't need to ride.

I am beginning to think that there is some damage under the patella, because laying off isn't helping as much as it should. There's no real pain, just swelling and heat. Like I say, I learn from others' mistakes and stop before it hurts.

My other sport is rowing... can't do that either because of knees and bad wrist -- hit by fast-moving road.

Cranks schmanks.

 

[J-MAT]

Ant:

Bummer about your wrist. Sometimes life beats us up. Coming back from injury will only make your constitution stronger. Refuse to give in. Be determined that you will come back stronger than ever.

If you think your patella is damaged, get it checked out soon to make sure nothing serious is going on. The inside of the patella is about 200 times smoother than the smooth surface of a drinking glass. Anything that effects this surface like tears, erosion, or debris can cause accelerated wear on this ultra-important surface.

Some things you can leave alone, some things you should have examined professionally. Put your mind at ease and find out what is going on.

Good luck!!!

 

[Randal Lovelace]

The Areo on the Lotus Elan is 170mm, would like to increase it to 175mm, I don't think 180mm would do well on that frame due to the shape of the bottom end of the bike.

 

[ant evans]

I have had one of the best sports orthopaedic surgeons in Britain look at my knees (the MRI scans are beautiful, if I say so myself), and the diagnosis is that I have very slight hardening of the posterior surface of the fibular condyle, which shows up as a tiny grey blush under the hyaline cartilage. There is no cartilage damage. All the symptoms of swelling and post-exercise pain, including around and above the patella, are due to increased vascular activity in response to bone stress.

My interpretation of this is that I am applying too much power at the top of the stroke (which is when the back of the fibular condyle is used). I think it began because I had my saddle too low at a time when I was getting much faster.

The reason I had my saddle too low? I went to shorter cranks without raising the saddle.

I am trying to teach myself to delay firing the quads so that I am nearer the point of best mechanical advantage, but I will need a coach to do that properly.

The good news is that this doesn't mean I have to stop riding.

Just been for a 2 hour hilly torture session and feel as if I've ridden 100 miles.

The moral of the story is that knees are difficult to self-diagnose. All my theories (patellar abrasion), and those of my GP (patellar tracking problem), were completely wrong. Get an expert.

 

[guised]

I'm 6'8" tall and have TA 185mm cranks these work really well for me, at last I feel like I can unleash my legs.

Dan

 

[zakeen]

6'8!!!!!!!!!!!!! What size bike to you ride??????????????

I use 180mm longer easier, no more to be said!

However if you want to make a move to longer cranks, train on them before you race with them!!!!! must DO!