Tuesday, August 07, 2012

Bike Talk: How Can I Prevent Finger/Toe Numbness on Long Distance Rides?

Jim (@DCin24 on Twitter) asks:

How can I prevent finger/toe numbness on long rides?

Before I answer Jim's question, a disclaimer. I'm not a doctor and I haven't seen Jim on a bike. There is only so much that some random guy on the internet can do to help you out with bike comfort and fit issues. That said, I do have some experience in doing rides that people tell me count as "long rides" and I'm fit-certified by Trek. I hope Jim and any of you others reading this at least find what I write here worth the time you're going to spend reading it. As always, feel free to add any insight you might have as a comment to this blog.

Having a bike that's the right size matters and any good bike shop should be able to get you on a bike that is the right size. Fit, however, deals with all the aspects of how you as a person interface with the bicycle and getting a good fit requires a lot of attention to human factors such a skeletal dimensions, musculature, flexibility, injury history and so forth. A full, professional fit with a good bike fitter may seem expensive, but many people find it to be time and money well spent. So my first advice is find a good, local fit person. Ask around, a person good at fitting will have a good reputation and happy clients.

But not everybody has a good local fit person and there are some good resources on the internet.  Peter White wrote a pretty good, no BS article on bike fit here:

http://www.peterwhitecycles.com/fitting.htm

The reason I'm talking so much about fit instead of diving right into Jim's specific question is that the problems he's asking about concern two of the three contact points on a bike, the hands and the feet. You contact the bike in three spots, your butt, your feet and your hands. You can think of those spots as vertices of a triangle. Often the pain or numbness that manifests on one vertex of the triangle is best addressed by adjusting the dimensions or orientation of the triangle. For example, a change in saddle fore/aft position can have quite an effect on how much pressure is on your hands. Raising or lowering your handlebars or changing your stem length can also have profound effects. When I did the final dial in of my Redline Flight for the Tour Divide, I changed both the stem length and the saddle position.

Now experience has taught me to be cautious of absolutes so I am wary of formulas or mechanisms that say this is the "best" spot for your feet to be on the pedals, and this is the "ideal" saddle height and here is the "exact" reach you should have to your handle bars. Do you want to make sure you're uncomfortable? Lock yourself into one position. Want to be more comfortable? Be willing and able to change things if you need to.

A couple of stories to illustrate my point. Michael Sylvester, one of the fellows who trained me in fitting, tells of a honeymoon tandem tour he took with his wife. She wound up having foot pain (or maybe it was knee pain) with her clipless pedals. Michael's fix? Flat pedals. Was his wife's foot in the "optimal" position for pedaling? Probably not. Was her pain problem solved? Yes it was.

Or take the famous stories of Eddy Merckx fiddling with his saddle height mid-race. A lot of folks take this as a "he's so in tune with his machine, he can tell when the mechanic got a dimension wrong" but I think that's the wrong take away. On any given day, Merckx was willing to tweak his position. Merckx was in tune with his body and what it needed.

I'm a big fan of Ergon grips, flat pedals and saddles and clothing with smooth seams. All these items allow me as a rider to avoid continual pressure on a single point of contact. I can slide around on my saddle, my grips have broad, flat surfaces with a several good places to grip. My feet are not locked into a single spot on the pedal and my knees and feet like it that way. Your mileage may vary. Many, many people ride many, many happy miles with their feet clipped into pedals. I'm just not one of those people these days.

I hope some of this helps.

Keep 'em rolling,

Kent "Mountain Turtle" Peterson
Issaquah WA USA
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