An admitted shoe geek waxes philosophical about running, triathlon, and life in general.
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Monday, April 23, 2012

The sadly common misconceptions of 650 wheels...

I'll admit up front that I'm a fan of 650 wheels. I've got four-and-a-half bikes that use 650's (one is a funny bike that uses a 650 front and a 700 rear). I prefer 650s on tri bike and track bikes for different, but extremely important reasons. And this is especially important on a tri bike where stability is a concern -- unless you're tall enough to merit a front center of 68cm or more, you pretty much need the 650 wheels in order to get the chainstays short enough to get your weight off the front wheel.

But I keep hearing all these arguments against them. Many times from supposedly knowledgeable people. And every one of them is absolute bunk. Horse puckey. Doodoo.

I had a very specific case this past weekend, and I'm going to leave out names to protect the guilty.

A lady came into the shop with a Lightspeed that had been absolutely TRASHED. Left bullhorn snapped off, both aero extensions rotated upward at bad angles, front wheel twisted and taco'd, rear brake locked on the back wheel and twisted. I was told that nothing could be done to the bike other than have measurements taken, as it was evidence in a court case (a lady crossed the center line into a group of 8 riders, and had done the same thing a mile before to a lone rider). In any case, this Lightspeed had 650 wheels.

She was wanting to look at the bikes offered by this shop, and so was getting put on an Argon 18 (the shop carries this brand, which does NOT use 650s even on the small size frames). And she was a bit nervous about a change over to 700 wheels.

And then all the BS came out. My tongue was bleeding for me biting it so as not to contradict the shop owner in front of the customer, but seriously, it was getting deep.

* 650 wheels are hard to come by, and you can't get as good of wheels in that size.
* Aerodynamically, 700 wheels are better.
* The geometry doesn't matter, as long as you fit on the bike.
* The industry is moving away from 650s.

And then there was the guy who frequents the shop squatting behind be as I was making an adjustment to the saddle height...
"The perfomance of 650 wheels..." I just looked over my shoulder and said, "Don't start."

About the only thing I could tell the customer's husband about the bike is that with the long front center, it would help the bike's stability.

Now I can understand a shop wanting to sell what they have. But arguing about availability of 650 wheels to some one who ALREADY HAS THEM?

What I find is that 650's have been vilified by shops who don't want to stock another size. And the industry responds to what sells. And then the BS comes out to convince customers of all the excuses shops give, when the REAL reason is just that they don't wanna...

Performance differences? 650's accelerate quicker due to the lower moment of inertia.

Geometry? Road bikes are more stable because they put 55-58% of your weight on the back wheel. Rotate yourself forward over the same geometry and that puts WAY more of your weight on the front wheel. You have to move the wheels forward to compensate. Chainstays can only get so short with 700 wheels... And that doesn't even get into aggressive positions on small frames.

Aerodynamically speaking, it's a wash. The smaller wheel will use a longer head tube, so frontal area really isn't affected.

Please, people, don't give in to the drivel dished out by shops regarding 650's. If you have a preference, or if your frame size merits the smaller wheel, by all means go there. Likely you'll be glad you did.

And when the good deals on tires and tubes roll around, stock up.

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