Bike Fit Question - Leg Length Discrepancy

[Mr. SR500]

The first system is cool cuz it consists of a stacked system in 1 mm layers, if you aren't sure how much of a lift is needed, or want to work your way up, and they are quite long making for a very gradual transition that is very comfortable. But, I found they don't last as long, since the layers start to come apart over time. But, they do look good in sandals, etc. since they are not very visible. The company in the second link is where I buy both. They are very fast and good (think TE, priority mail package arrives within days of placing an order). Both are firm which is also very important, but comfortable. If shoes allow it, sometimes I also replace insole with a superfeet insole, and place lift under insole on short leg side, but not all shoes have room for both the superfeet and lift.

Any pics of your setup, sounds very interesting.

[Triskeliongirl]

Any pics of your setup, sounds very interesting.

I did take some pictures once, for my son to show his engineering buddies at MIT, but I can't find them now. I'll try to take some again when I have time. If you click on the link I posted you can see the dropped pedal. Whats harder to see in that pic, is the idea that the dropped part can rotate throughout the pedal stroke. Then my chain rings are offset and elliptical, but the ellipses are not like the old biopace rings, but in the direction of the modern ones favored by the CSC time trialists. The idea is they put you in effectively an easier gear at the top of the pedal stroke to get you through it faster with less stress on your knees.

[Triskeliongirl]

Ok, I just managed to blow up two pictures. They are taken from two diff. bikes but the crankset is identical. On the view marked right side, you see my normal length 165mm crank arm (fit to my short leg) and on the left side you see a 165mm crank arm to which Tom's dropped pedal is built in (fit to my long leg). Again, its hard to see how the dropped pedal can rotate throughout the pedal stroke, but imagine that it is attached by a flexible joint the permits rotation. He can build it with any pedal system, I happened to choose frogs. Likewise, he can use whatever chain rings you want, I specified a 50/34 set-up.

[KnottedYet]

Very elegant solution!

[Triskeliongirl]

If its not obvious, when I cycle, I do not put lifts in my shoes since the correction is built into the crank set. I only use the lifts for the regular shoes. They are pictured in the original links provided.

[melissam]

Trisk,

Thanks for posting the pics of your crankset! It looks like it could be a permanent solution for my LLD problems, at least on the bike. I have a couple of questions:

1. What benefits are there to getting a full custom crankset vs. only having a dropped pedal setup?

2. What was involved in getting "fit" for the custom crankset?

3. How long did it take to get the custom crankset?

4. How long did it take for you to get accustomed to the new set up on your bike? Were you sore for a few rides?

Thanks again for your help!

-- Melissa

[Triskeliongirl]

Hi Melissa:

1. I imagine the benefits of the full crankset vs the dropped pedal only is that the leverage is balanced throughout the pedal stroke, and that the elliptical rings improve movement throught the dead spot in the pedal stroke, decreasing the stress on your knees, but I suggest that you discuss this with Tom. I am sure that overall cycling performance is optimized with the entire set up, but perhaps the dropped pedal alone could make your body be a lot more comfortable. What you have to worry about is long term injury prevention and I just don't know if the dropped pedal alone is enough or not for this. Another point about the full system is you have the option of having the crank arms also offset relative to each other if your body requires this.

2. There was zero break in period. I went from not being able to ride at all due to the pain and SI joint damage, to riding 100 miles my first week. More specifically, the more I road my old setup, even with shimmed cleats, the more damge to my SI joint from the imbalance to the point where I was in constant pain even off the bike. So, my orthopedist had me stop riding while we first healed my SI joint. For this I needed intensive 3X per week physical therapy for about a month. During this period I flew out to visit with Tom. I'll tell more about that in a bit, but to get back to the issue of how it felt when I got my system, as I said it didn't hurt at all, but felt completely natural, as it should have since it was designed to work with my body. I remember riding about 100 miles my first week, and then just sliding into my normal pattern of daily 16 mile commutes, with 2 long club rides (30-60 miles each) on the weekend.

When my bike was stolen, again I couldn't ride during the 1-2 months it took him to build me a new system, but the day after it arrived I rode a century with no pain. In fact, until I got my shoe lifts, I found cycling more therapeutic than walking, as if it was necessary to restore balance to my body. So, when walking gave me pain I would ride to work it out.

3. The fitting. I flew to Tom's center in Mammoth Lakes, although I believe he also does fittings in other major cities in CA periodically. For me, it felt like a spiritual quest. I had arranged to rent a car at the airport, but there was a snow storm in progress. I was nervous about driving in the snow, since I hadn't done it for 10-15 years, but headed out determined to do it. It got scarier and scarier as the snow was blinding me. Finally, I was turned back as they wouldn't let anyone up the mountain without chains on their tires, so back I went and returned the car. Then I went to inquire about other forms of transportation, and managed to snag a ride with a ski shuttle. Of course the driver could not understand why I was bringing a bike instead of skis..............

Tom had me bring my bike, and he set it up on a computrainer. The first thing he did was measure my bike and body, and then while seated on my bike in the cycling position, he had these plates that came up from the bottom until they touched my feet. This let him measure what my on the bike LLD is. Then he had me do a series of pedaling exercises where he used a video camera to record details of my pedal stroke (i.e. measuring knee angles, heel drop, things like that). He also measured the power output of each leg.

Based on the data he collected, we discussed my options. He recommended the dropped pedal system as the best solution to my problem. The fitting fee alone if I recall was ~$200, and to take the next step and have him build me a custom system using all the data he collected was ~$1500-1700. That included the pedals, and first going through riding with a more adjustable system while he tweaked out the details. The adjustable system had the dropped pedal, but it was heavier than my final system, and let me adjust vary the angles of the crank arms rel. to each other as we explored 'timing.' I don't remember how long it took to arrive, but it was less than one month. I rode with this system ~1-2 months as he designed experiments for me to do. He would have me ride a certain way, and then ask me questions and have me make adjustments based on the answers (so we had frequent phone chats). Once my set up was tweaked, he started working on my final system, which took another 1-2 months to build, although I could keep riding the temporary system until it was finished.

However, my bike was stolen with the temporary system on there, so I had to go another month off the bike ......... and of course I owed Tom for another system. At that point I had him build me two so I would never be without.

Yes, it was a lot of money, but without Tom and his system, I wouldn't be riding today, and cycling is simply too important to me to let that happen.

At Tom's urging I also worked on getting better shoe lifts, and today I am essentially pain free. Yeh, extreme cold still inflames my injuries a tad, but this has nothing to do with cycling, just an aging injured body.

p.s. I am a little uncomf. about posting prices, since I think it may depend on your individual situation. He made my systems back in 2005 so prices may have gone up, and the specifics matter, what kind of pedals, chain rings, etc. Also, remember that Tom talks to you on the phone a lot during the adjustment period, and I am sure some of that is what you are paying for too. Perhaps you could try it in steps. Go visit with him, get measured, and discuss your options. If the cost seems more than you can afford right now, perhaps you could pay for the fitting and dropped pedal, and ask whether he can build it so it will be compatble with both your current crank set up, and later be re-worked into a custom set up if that doesn't take care of the problem. I will be curious to see how it goes. I often wondered about this myself after the fact, although I have to say that I absolutely love my custom systems, and have no regrets whatsoever about the cost.