Monday, October 23, 2017

Beware the Jabberwock, my son!

As I mentioned recently, I ended up replacing my last frame with a Vassago Jabberwocky. I love this frame! Long top tube, reasonably short chainstays, burly steel construction, moderate geometry that is not "yeah brah, enduro!" slack but not dirt roadie XC. modern features like a fat seat tube, 44mm head tube to accommodate a tapered fork, and room for really fat tires.



This is kind of ironic because a bought an older version of the "small" size Jabber in spring of 2013 and sold it after a few short months. For some reason, I crashed on that bike more than I have ever crashed. I suspect it was my error in setting up the suspension fork, but I am happy with the way it played out. I now have a stout, steel, singlespeed XC bike with geometry that suits me, now that I have spent months agonizing over why my back hurts and every "medium" bike I have tried feels cramped.

I am definitely digging this bike. It feels much better under me than anything I have ridden. It could be lighter, that's my only real complaint. If I really wanted a lighter frame, I would probably have had to shell out 3 times as much cash on a titanium frame or get customer steel for even more than that. I can't justify that kind of spending, but I can dream.

In the meanwhile, the weight disappears under you when you're on a bike that fits and handles as if it was made for you.

Sunday, October 22, 2017

bike fittings are not all the same

I purchased a Vassago Jabberwocky from the rad folks at Cycle Progression. Ask me how I arrived at this decision!

I might have ruined this past season of riding for myself if I had not been so stubborn. I spent a considerable amount of money on a chiropractor, a bike fit, and a new frame. In the meanwhile, I worked out and rode through the pain when I could. I am much happier now.

No doubt, my body was out of whack this spring and the chiro helped with that a ton. No matter how perfectly a bike "fits" you, if your body is not fit enough for the kind of demands that cycling, or any physical activity, puts on it, you're going to be miserable. Once I had my back in recovery mode and learned to strengthen more core muscles to support my body while riding, I decided to visit an expert for advice on tweaking my bike.

Every bike fit starts with the right frame dimensions, and mountain bikes only come in a few distinct sizes (not enough increments, if you ask me) for each model, so experience -- yours or that of a knowledgeable advisor -- will be the best guide as to what works for you. In my case, I am learning the hard way.

I visited two fitters over the past few months. One was somewhat useful and the other was worth much, much more than I paid him.


Bike fitting #1

The first fitter charged me $100 and gave me advice that was $25% useful and 75% a sales pitch to sell me some special insoles and more fitting services. He asked me some relevant questions, took a few basic measurements, and watched me ride my bike in a trainer for a while. He made a few valid observations:
  • My handlebar was too close to my hips and too high. This position was painfully scrunching my back, as I was well aware. The compact handling made me very "on top of" the bike instead of "in" the bike. Also, the taller my handlebar was, the more effort was required for me to stand up, and standing enlivens the handling on a mountain bike ten-fold.
  • My saddle was a tad low, which made for poor pedaling efficiency and contributed to the aforementioned resistance to standing up.
  • The fitter thought the cleats under my shoes were in a sub-optimal position and he moved them. This was rubbish advice. More on that later.
When I was done with the fitting session, my saddle moved up about 2.5 centimeters and my handlebar went out 2 and down 4 centimeters by way of replacing my stem with a longer, much lower one. In case you're not familiar with bike fit fiddling, that an astronomical amount of change!

A few weird parts of this fit:

The fitter moved my cleats waaaaay forward, like under my toes. I thought he might be onto something, but he seemed to be moving the cleats that wasy to get my knees plumb over the center of my pedals, using the old KOPS method. As I have said before, KOPS works for some kinds of bikes for some riders. For modern mountain bikes, it's generally nonsense. That put up several big red flag for me: 
  1. If you're going to fit a bike by KOPS, you do it by moving the saddle fore/aft, not by moving the cleats around. He didn't change the saddle position at all.
  2. My frame had an eccentric bottom bracket, meaning he could have rotated the BB forward and gotten the same knee/ankle position without putting my cleats under my toes
  3. Most riders in every cycling discipline are trying to find ways to push cleats and shoe positions back, closer to center on the pedal for a more balanced foot position. He did the opposite, putting a lot of strain on my calves. He also rotated my cleat to accommodate for the "duck-footed" right leg that tends to twist toe-out, which is also medical nonsense.
Most bike fitters are not medical professionals and even the ones with medical bona fides have to admit that there's a little voodoo involved in the process. But I rode the bike with the new fit once on my local trails and found that, while the saddle height and handlebar position made the bike fit much more naturally under me, the handling was awkward. Worse yet, I had to stop and move my cleats back to their old position after my numb toes and cramping calves forced me to stop.

I asked the bike fitter at the shop about this and he told me that I would have to buy some $30 insoles from him to be sure that my foot is level. If that didn't solve the problem, I should come back for a $250 fit session on top of the $100 I already paid.

Instead, I put my cleats back into a rational position and kept riding.

On a more general note, I question his wisdom in "slamming" a negative-stem and putting such a long stem on an AM hardtail with a 30-inch wide handlebar. I know he was trying to work with what I have, but I explicitly told him that I wanted to know if I should buy a few frame that fits me better but make what I have work in the meantime. What he did with the reach was probably the best thing for me on that frame, but he insisted that there was no reason to even consider a different frame.

There's some controversy among the mountain bike community about this, but generally, a stem determines how the bike handles with the fork and handlebar, not how it fits. That can work differently for different riders, but putting a long stem on a bike that was designed with s short one in mind is kind of like buying shoes that are a size too small and cutting a hole in the front so your toes can stick out and calling it good.

Bike fitting #2

I visited Frank at ATX Bikes after he had read about my consternation at my first fit and invited me to come in for a free consultation. Frank has an amazing fit studio with an automated fit bike. Basically, you put your own handlebar, saddle, and pedals on a werid-looking stationary bike, and the fitter plugs some numbers into a computer and viola! the bike moves around to simulate the frame dimensions, saddle position, and handlebar position that he types in.

Next, he put velcro dots on my joints and stuck a wired sensor to it. A camera captured my movements in three dimensions and created an animation on the screen. I felt like Andy Serkis acting out a really boring role where he pedals a bike for the whole movie. The program analyzes the data and saves it for future use.

I had Frank plug in the dimensions of a medium Vassago Jabberwocky, since I had my eye on the frame as a replacement for the ROS 9. We were able to determine that the Jabber would be a good fit for me from a sit-and-pedal position at least, and that was enough to know that it would be a good choice. I now have a printout of the bike geometry that made me feel comfortable and fast. The next step was to acquire that new frame and start riding conscientiously to see what works.

Vassago was very far ahead of the trend, designing frames almost a decade ago with long top tubes and slack headtube angles. The "wet cat" theory was a revelation to many and I hope it will be for me. More will follow on my experience riding the Jabberwocky.