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155mm cranks for Jules

Since I started work at Cyclefit, Jules has been moaning about how he can't climb or time trial because his legs are too short (please read my previous, related post about Joaquim Rodriguez - http://tinyurl.com/2vmjoda ). This is, of course, VITALLY important for the annual GPM10 trips to Majorca, so we set about trying to improve this problem.

Traditionally riders only consider 3 crank lengths- 170mm, 172.5mm, and 175mm, but is that enough to truly accommodate the huge range in leg lengths? The table below is a rough estimation of the ratio between saddle height and crank lengths of a few riders (pulled from cyclingnews pro bike articles). Phil is 'Mr. Average' when it comes to saddle height- please no jokes. If we treat Phil as a baseline, for Jules to achieve the same ratio as Phil or Mr. Armstrong he has to ride 155 cranks.

Name	Crank Size	Saddle Height	Ratio
Jules	155	67	2.31
Jules	165	67	2.46
Jules	170	67	2.54
Phil	170	74	2.3
Sandy	172.5	78.5	2.2
Boonen	177.5	80	2.22
Gesink	175	83.5	2.1
Sastre	170	72.5	2.34
Cavendish	170	70	2.43
Armstrong	175	75	2.33

The reason this is a useful ratio is that it gives some indication of the range of angles that a rider has to handle throughout a pedal cycle. Gesink will not have to maintain nearly as acute an angle at the top of his pedal stroke as smaller riders such as Jules.

Jules finally ignored the stigma attached to short cranks, which I can imagine comes from some kind of subconscious male instinct that I won't discuss, and put on a TA Agilis 155mm crankset. We also raised the saddle 15mm to maintain the same leg extension at the bottom. Using some before and after analysis on Dartfish, Jules' hip angle at the top of the pedal stroke was consistently 10 degrees less acute than with 170mm. We also compared the hip angle when climbing, and found that it was also 10 degrees on average. The leg extension at the top of the pedal stroke was on average 10 degrees more obtuse than with 170mm. Here was Jules' initial reactions-

'Cranks are good, pedal stroke is smoother much less ‘up and down’ of legs and more open hip angle.

Less leverage from the lights when starting for the first two or three revs but once in the saddle acceleration is quicker to cruising speed.

Maybe for cross 160mm cranks would be better, or 155mm cranks with Rotor Q rings….

Do not feel the need to keep getting out of the saddle as much as before.

Climbing seems OK so far – maintaining cadence is the key.

Handlebar position good, saddle much more comfortable'

I need to put some solid numbers behind my theory, but I feel many riders should consider smaller cranks. Feel free to comment with your opinions.

Gent Six Day Leg Extension

Its the first day after my knee op, and I am already bored, so I decided to download a 30 day trial of dartfish (www.dartfish.com). This is the software we use at cyclefit analyse a rider's biomechanics.

I used it to analyse the leg extension of some of the riders at the 2008 Gent Six Day's penultimate madison. It was interesting as racing a track bike on a 166 metre velodrome has so many differences to standard road riding that we usually see. Here is a list of some of the differences.

1. possibility of shorter cranks

2.more aggressive (shorter/ lower) position as using smaller frames and always on drops

3. narrower q-factor

4. g forces pushing when through the banking

5. Non- symmetrical riding

6. very little out the saddle effort

7. higher cadence

8. fixed gear

My estimates are only rough. I can't go down there and put tracking dots on their knees! But the theme of the results for leg extension were interesting.

-Bruno Risi 32.5°

-Leif Lampater 40°

-Schep 35°

-Andreas Beikrich° 45-50

-Keisse- 43°

-Zabel 37°

With the exception of Bruno Riso, Schep, and possibly Zabel, all the riders seem to have very low saddle heights. When I am fitting at Cyclefit I get an average of about 32/33°. The demands of the track are obviously a lot different. I feel there are several reasons.

1. It enables the riders to maintain a more stable pelvis for the much higher cadence's used

2. The lower handlebar position puts more strain on the hamstrings so reaching a larger extension is very difficult- especially repeated night after night

3. the fixed gear at high cadences puts less torque on the joints (just speculating)

4. It is more stable when doing a madison change

On the other hand, the wide range (32.5° to almost 45) shows that I might be completely over analysing their reasons for having a lower leg extension, but the mean of the extension's is 39 degrees. Personally, I think that around 35-37° (on average) is perfect for the Gent track if we look at the two extremes, Keisse and Risi. I am not convinced that Keisse is achieving his full power output, as we can see when he drops his heel during a sprint to achieve a larger angle. I think that Bruno Risi is slightly too high as his hips are rocking and he grips the handlebars quite tightly in comparison to the other riders to stabilize himself. Just some thoughts...

Stem Length, the Pro's Shoe Size?

Recently on the Cyclefit's trip to the Etape Expo, I got to have a look at one Andy Schleck's bikes on the Specialized stand. This was interesting for me as we are pretty much the same height, weight, and have similar body proportions (long body/ short legs).

From a fitter's point of view, it was horrific. The drop from the handlebars to the stem was approximately 15cm. He had a 140mm/-17degree stem on a special pro short head tube model frame, combined with having the brake hoods low on the bar! I remember reading that his hamstring flexibility was something in the range of 60-70, which is the average flexibility we have with our clients at Cyclefit (mainly city workers). In my experience, an Olympic Gymnast would have issues with a 15cm drop.

The only explanation I can see of having such a huge drop is some kind of macho theory that the more drop and longer stem you have, the more of a man you are. It seems to be rampant among the pro peleton with virtually every rider with the longest lowest set up possible, regardless of frame geometry, body shape, or flexibility. The position has far too many drawbacks to be for any other reason.

• His back is rounded like a scared cat to try and open up the hip angle to produce power.

• His legs are going everywhere because he cannot control the lateral movement (see previous post) in such an extreme position (maybe the cause for his early season knee troubles?).

• His hips are rocking in the saddle due to the tension in the hamstrings

• He seems to have a recurring Achilles problem- maybe due to constant high tension in the hamstrings and calves?

• His bike handling and descending is widely accepted to be sub-par. How can you descend or handle the bike correctly if you are straining to reach the hoods and don't have a hope in hell of reaching the drops?

Considering how close he was to winning the tour this year, he's doing pretty well with all these handicaps. Maybe he could beat Contador next year if he came to Cyclefit!

Fitting for a Younger Rider- my experience

For 10 days last August, Cyclefit was visited by Spanish Bike Fitter, Jon Irriberri. Jon is based in Pamplona and owns his own fitting company, custom4us. He has taken a different route to Cyclefit and has been a pro bike fitter for Caisse D'Epagne and Euskatel, before doing fits for amateur riders.

My experience with Jon in achieving my optimum fit is interesting as I am sure it is applicable to many younger riders. A little background info- I have had a successful youth and junior career representing GB for several years and specializing in hard hilly races. I have always felt very uncomfortable on the bike- twisted and lacking power on the flats. I am also amazingly slow in a TT position, especially in the pursuit, which is strange as I am always one of the strongest riders when I have done power tests.

I have been brainwashed since I have started road cycling that the longer and lower you go on the bike, the faster you will be. After all how can all the 1000's of professional cyclists be wrong? Surely you just put on a 140mm stem and put it on the top of the head tube?

It wasn't until the end of last season that I picked up a serious injury. I now know that it was was an inflamed plica due to poor knee tracking. It wasn't painful, just a popping sensation in the knee and a sensation of weakness. My shoe, cleat, and saddle set up was perfect, courtesy of Jules and Phil, so I assumed I just needed to do knee stabilising exercises (confirmed by a world renowned knee surgeon) . So I set about doing hours and hours of exercises and stretching under guidance of a physio; improving my core and strengthening my muscles and I got pretty good. But when I came into the first race of the season in March, I soon realized that my knee situation was not improved since September. Despite all my exercises I didn't feel amazing on the bike either. So what was wrong?

It took me until meeting Jon in August to realize that I was fighting an uphill battle. I essentially had the correct idea that poor knee control was the cause. The major problem was that I could not possibly control my knee in my current bike position, regardless of how many exercises I did. My hamstring flexibility was not matched to my handlebar drop and extension. By lifting and shortening the handlebars 7 cm into my range of motion, I was able to release the tension on the hamstrings, and in turn activate the long neglected muscles on the inside of my knee (VMOs)(also combined with wedges to promote knee tracking). The balance between the inner and outer muscles of the quadricep is the key factor in knee control (along with the Gluteus Medius). I also noticed a dramatic increase in comfort and felt more powerful on the bike- especially climbing. My inner thighs were in overload for several weeks of cycling however now my knee tracking is far better, despite a marked decrease in off the bike exercises. I even use my core muscles far more in the more upright position. Jon Irriberri calls this theory the 'Lumbar Paradox'.

My plica is still inflamed, but this is no surprise as I have been aggravating it for about a year. The key ideas learnt from my fit though were-

1. Match the handlebar height to the range of motion. ESPECIALLY for younger riders, otherwise the stabilising muscles in the knee and back will not be able to develop and bad patterns will be learnt which could lead to injury. The rider should be able to maintain a neutral spine while riding on the hoods and there should be minimal tension in the hamstrings.

2. Younger riders are not more flexible than older ones (in my experience), just more resilient to injury- don't be tempted to go too low or long. My friend Joe Perrett, Junior European Time Trial Champ, had the worst hamstring flexibilty I have seen since working at Cyclefit.

3. In general, standard bike frames are too aggressive for the vast majority of people, even racers. We have not had one client in the last 12 months who we think is capable of riding a standard frame with no spacers underneath the stem.

4. You can develop more power if you are pedalling inside your range of motion, and its more comfortable (obvious point but I was guilty of ignoring it). I am convinced that one reason I was terrible at the pursuit was because I was completely out of my range of motion.

5. Focus your stretching on the hamstrings

Making these mistakes have destroyed my whole season, so be careful! See http://sandykingcycling.blogspot.com/2010/10/medial-plica-removal.html

for the aftermath of my surgery

TT for the Smaller Rider

It was interesting watching the Vuelta time trial the other day. Joaqim Rodroquez's horrific time trialling essentially cost him his chance of winning the overall, and likely the podium.

When you see Rodriguez on the road and mountain stages, he is almost always on his brake hoods with straight arms, or out the saddle. This suggests to me, along with his rounded back, that he is virtually on the limit of his flexibility on this road bike (on the hoods). His time trial position has his torso in a horizontal postion. How is he possibly supposed to pedal efficiently when he is completely out of his range of flexibility? The picture below shows just how tight the hip angle is at the top of the stroke.

http://velonews.competitor.com/2010/09/news/peter-velits-stuns-field-with-tt-victory-as-nibali-leads-vuelta_140717/attachment/rodriguez-3

In my opinion, Rodriguez is not helped by riding cranks that are far too long for him. Although they are probably the standard 170mm length, in proportion to his leg length they are huge. If you look at riders such as Indurain, they're hip angle is far less simply due to the ratio between leg length and crank length. It is far easier to maintain power with a larger hip angle, as anyone who has climbed in a hill knows. Jules' complaints about not being able to pedal at the top of the pedal stroke and knee pain are likely to be shared by many smaller riders. Mike Burrows is a believer in small cranks, and claims that they provide an increase in time trial power. Karpet's (below) angle at the top of the pedal is far less than Rodriguez and more manageable.

So what do I suggest? Raise his aero bars, fit smaller cranks- maybe 160mm as a guess, and do lots of hamstring stretching. Unfortunately I can't see Rodriguez adopting my ideas. The pro peleton are quite clearly an image conscious bunch, especially concerning bike set up. He is most likely to blame his poor time trialling on the traditional idea of power to weight not applying on the flat. Of course this has some merit, but I don't believe it is the whole reason for his 4 minute plus loss on Peter Velits, who is clearly not heavy himself.