Technical FAQ: Tall rider bike fit

Dear Lennard,
As a tall rider (6-foot-5 and a 36-inch inseam), what recommendations do you have for selecting a road bike:

Are there some manufacturers whose frames are better suited to the tall rider?

As a Clydesdale (>200 lbs), is carbon worth the added cost?

Are there services which can evaluate your body frame and make unbiased recommendations on a bike manufacturer that would probably best fit your physique?
-Steve

Dear Steve,
I’m not sure if this is a trick question, but perhaps you are not aware that I’m your height and have been building custom frames, cranks and bikes for tall riders for 27 years (and off and on – currently on, big and tall cycling clothing, too). So I have devoted much of my life to answering your question.

First of all, I would want you to re-do that inseam measurement, because 36 inches is a very short inseam for a 6-foot-5-inch rider. Perhaps that is your pants inseam size, which runs about two inches shorter than the actual inseam measurement from crotch to floor in stocking feet; 38 inches is an average inseam for a 6-foot-5-inch rider.

Obviously, there are some manufacturers better suited to the tall rider, and I consider myself to be the one most ideally suited. Most of my customers are your height and taller, and I understand personally the problems and challenges a tall rider faces. You don’t specify if you’re looking for a road or mountain bike. On the mountain side, there are choices for XXL frames besides Zinn, like Ventana, Lenz, and maybe Turner and Niner.

I also think you will be faster, more comfortable, and happier with a longer crank (at least 180mm, but we often build cranks more like 200mm for riders your height. The frame really needs to be designed for the crank, for obvious clearance problems, however.

Carbon frames in general make no sense for a rider your size, because most of them are molded in one to three pieces. Given the expense of the molds, that investment is only undertaken for sizes that fit the large part of the bell curve of rider sizes. These frames are generally not big enough for you, and usually they would not be stiff or strong enough either, not having been designed for riders of your weight, particularly with your height. That said, you could get a custom carbon frame from a small custom carbon manufacturer who miters carbon tubes like metal tubes and wraps the joints with carbon. Calfee, Parlee, and Kirklee come to mind.

As for evaluating your body measurements to determine frame size, there are lots of fitting systems out there ranging from free to around $1,000. You can go to the Boulder Center for Sports Medicine for the gold standard fitting including X-rays and 3D analysis. Many bike shops have fitters certified by companies like SICI, Bike Fitting, Fit Kit, Wobble Naught, Bicycle Fitting, Tiemeyer Position Cycle, or  www.bodyscanningcrm.com.  Less expensively, you can use Wobble Naught’s online fitting system, or buy Bill Boston’s Personal Accufit software. I used to have a free fit calculator system on my zinncycles.com site into which you could plug three simple body measurements (the first three body measurements here) and get back suggested frame dimensions and crank length for road or mountain bikes.

However, we recently re-designed the site, and that and a cool price calculator page we had were lost in the shuffle. Hopefully we will be able to get it running again with this new site soon. But in the meantime, you can use the appendix of Zinn and the Art of Road Bike Maintenance or Zinn and the Art of Mountain Bike Maintenance, I explain taking these same three body measurements and how to do the calculations yourself to come up with frame dimensions to fit you.
-Lennard