Saturday, August 15, 2009

The TitanFlex Demo Continues

Wednesday morning, I brought the bike back to Tom for a quick tune-up. Turns out the source of the shifting problem was using too wide a chain with the 9 speed cassette. A quick chain swap and derailleur adjustment and I was on my way.

I decided to do a short ride on the nearby CA-56 bike path to charge up some of the steep hills that are easy to access from the bike path. Just how stiff is the TitanFlex frame? Well, all I can say is it is more than stiff enough to handle my 185 lbs without any noticeable deflection. It is as least as stiff as my Trek Madone carbon frame, and the Trek frame has a good reputation for stiffness combined with comfort.

Speaking of comfort, how could I best evaluate the quality of the beam tube suspension? Sure, I had already ridden over normal road bumps, railroad crossings, and small potholes without a problem. For the first several I encountered, I instinctively got out of the saddle, as I do on my road bike, to take the bump with my legs, instead of forcing the frame to take the hit. It took a conscious effort for me to stay in the saddle over these bumps, and the resulting ride was surprisingly smooth.

On the larger bumps, I was expecting the boom to flex back quickly enough to lift me off the saddle, but that never happened on any of the larger bumps I rode over. My guess is that the rate of energy return from the beam is compatible with what the body can dissipate.

I wouldn't hop a curb in the saddle (well, I didn't try), but anything smaller should be no problem. One of the things I fear most on the road is hitting a large bump I can't prepare for. On a stiff frame, a big bump can throw you from the bike. On a TitanFlex, I know I would not have to worry nearly as much about that.

So, individual bumps are OK on a TitanFlex. But what about some mean, nasty, corduroy road? You know, the kind that shakes you hard and long enough to make your fillings fall out, make your hands and feet go numb, and make your vision blurry. Well, OK, I don't know of a road like that in San Diego. But I do know of a few bumpy stretches.

You know the western part of the CA-56 bike path that goes through the edge of that gated community? There are parts of the asphalt path that have cracks from tree roots that have either not been repaired, or have been only partially ground down. Staying in the seat on the TitanFlex over that stretch of path was no problem at all. The only adaptation I made was to come out of aero, since I'm still very much a newbie in that position.

For those of you who really know the CA-56 bike path and the roads near it, you will also know of a tiny stretch of extremely rough road just south of CA-56 at the Carmel Valley Road exit. When you head south from the exit, you immediately turn west onto a small road that provides access to a dog boarding facility, a plant nursery, and a couple of other small businesses.

This road takes a dip into a wide natural drainage ditch, and at the bottom of the ditch is one piece of mean road work. It's an array of cement ovals that are 2" wide, 3" long and about 2" high, that are separated by 1/2". Yes, concrete cobblestones! This stretch of nasty road is only about 100 feet long, but it is a punishing 100 feet. I call it the "Tres Petit Paris-Roubaix". Here's a photo of it:

And a closeup, with my foot included for scale:

Previously, I had only traveled this road on my hybrid bike, which has tires that are 2 inches wide that are inflated to 60 PSI. On that bike, the road provides quite a nice butt massage. I had never EVER planned to ride over this road on tires 23 mm wide inflated to 110 PSI!

So, there I was, at the top of one side of the ditch, looking across to the other, with the "Tres Petit Paris-Roubaix" at the bottom. Thought I was gonna die. I took the first pass out of the saddle at about 5 MPH, to be sure I could retain steering control. Bumpy and shaky, but no control issues at all. I climbed up the opposite side, turned around, and did the same thing in the opposite direction, this time in the saddle. Surprisingly smooth! I increased speed to about 10 MPH and did it again, still in the saddle. Though my hands felt large amounts of vigorous vibration, my butt was comfortable. For the last pass, I increased speed to about 12 MPH, and the vibration became a hard buzz in my hands, but my butt hardly felt it.

I'd say the TitanFlex primary design goal has absolutely been met: The titanium beam suspension really does its job, isolating the rider from a huge amount of road vibration and bumps.

Let's compare the TitanFlex titanium beam to other means used to reduce the vibration applied through the saddle. I'm not talking about MTB rear suspensions here, but specifically about vibration reduction systems.

First, there are gel saddles, which are available starting with a thin layer of gel (to dissipate normal seat pressure), going all the way up to about a gallon of gel (for improved vibration isolation). The larger saddles do reduce vibration, but the weight penalty is large, and these saddles make it harder to stabilize the butt while spinning. They also do little to keep you in the seat over small and moderate bumps.

Next are the various seatpost shock absorbers. Some are true shocks, like the front shocks on MTB bikes, with a corresponding weight penalty. Others are little more than chunks of elastomer inside a telescoping seatpost. They handle small bumps and vibration very well, though I've never seen one that can handle significant bumps without bottoming out, which makes them worse than a gel saddle in that situation!

However, none of the above are ever seen on racing bikes. For road and TT bikes, there are very few options, none of which have much market share.

Before getting into the road accessories, let's discuss the ageless war between frame stiffness and "compliance" (comfort). I used to have back spasms, so I've always tried to protect my back whenever possible. My first road bikes (mid '70's through early '80's) had CrMo frames that twanged like crazy over every bump, and vibrated over all but the smoothest roads. Very bad for my back, but that's all that was available on the market that was also lightweight. Steel frames were significantly heavier and still twanged, though only a little less than CrMo.

Then came aluminum road frames, and while the early Trek frames were still very twangy, along came the "fat downtube" Cannondale frames. For me, that frame completely redefined what comfort on a road bike could be. I still have my '85 Cannondale frame, and probably always will. I rode that frame through the early days of carbon frames, which were either twangy or fragile or both. Not until I purchased my '06 Trek Madone SL did I find a carbon frame that exceeded the stiffness of my Cannondale with equal comfort and adequate ruggedness.

But the vibration reduction, while significant, only seemed large in comparison to the torture of CrMo frames. Race accessory manufactures have not stood still, and have tried many ways to provide additional vibration reduction.

The first change was to saddle geometry. Change how the saddle applies force to the body, and you change how that force affects the body. For me, the biggest change in this area has been my Adamo road saddle. But many people can't ride this saddle, and while other innovative saddle geometries exist (such as "sling" suspension saddles), no manufacturer has yet gone to an alternative geometry saddle as the standard saddle on their race bikes. They still ship thin hard butt-killing saddles by default.

I've only found one other accessory that claims to reduce vibration on race bikes, and that is a carbon seatpost that contains a small cantilever at the top of the post. It looks like a question mark. Genius or gimmick? I can't say. Again, no manufacturer I'm aware of even offers it as an option.

So, for a standard road or TT bike, the default solution seems to be reduced tire pressure combined with a "suck it up" attitude to butt and back pain. For many of us, that answer is simply not realistic.

If race accessories aren't effective, and traditional frames have been optimized, that would seem to leave only non-traditional frames as the path to better vibration reduction. And of all such frames, few ever made it to production, and they were all "beam bikes", somewhat similar to the TitanFlex.

There have been several other makers of "beam bikes" over the years, but the TitanFlex is the only one I am aware of on the market today. Clearly, the idea was good, but making it work in the market was hard. For Tom Piszkin, this has meant being a one-stop shop with no middlemen, so he can reduce costs and overhead at all levels to their absolute minimum. As a result, despite relatively low sales volume, Tom's TitanFlex bikes are competitively priced.

So, yes, the TitanFlex beam eliminates vibration and small bumps, and the frame is more than stiff enough to climb well. That's all very nice, but I need to know about the bottom line: Will the TitanFlex bike help me go faster in my next sprint triathlon?

My next stop was Fiesta Island, for Andy Concors' Wednesday 6PM time trial. While I have ridden Fiesta Island many times, both on my own, with friends, and in TCSD club races, this was my first time at Andy's time trial event. This was also my first time doing a timed ride on a TT bike in aero position (remember, I'm STILL a newbie). I had also been riding more this week than I usually do, so I was already a bit tired before the start. And the wind was blowing at around 10 MPH. Conditions were not ideal for an exceptional performance.

I started, and right away I had more problems. I couldn't get my cleats clipped in. And I came out of aero at the first corner, simply because I wanted a better view, despite the fact that the other rider who started with me was still in sight right in front of me. When I came around the end of the island and hit the wind head-on, I had to shift to my inner chainring, and the front derailleur refused to get the chain back onto the outer chainring. Arrgh! So I had to do the rest of the race using only the inner chainring. (Note to self: TAKE A RIDE IN THE PARKING LOT AFTER ANY BIKE ADJUSTMENT!)

The only things I felt I had going for me were that I was spending more time in the aero position, and I was on a TitanFlex bike, which hopefully would reduce vibration enough to make a meaningful difference to my fatigue and discomfort levels.

According to my Garmin, I did the 3 large loops (12.35 miles) in 36:13, for an average speed of 20.4 MPH. For me, this was a PR for this distance, wind or no wind!

If I were I fresh and on my road bike using the aero bars, I expect I could do just a well, maybe better. Why? I think the main improvement was due to my being in the aero position. I believe it will take some long rides on the TitanFlex to judge any change to fatigue or discomfort.

By this time I was dead tired. No long rides tonite! Time to head home.

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