Actually, I quite like blogging and I've had several topics that I've *meant* to get to but putting together a comprehensive, well-written piece takes time and since fall I've been busy between moving, a pretty intense consulting job that has just finished and some bike-related projects. On that note:
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Bike Fit on a TT bike:
2010 season was a good one, I had up and down bike results which I was never able to put a finger on. All of the power data seem to indicate I was ready to rumble and some days I had a great, easy power and other days it was everything I could do to race at baseline.
I decided to make some "big" off-season changes: I had a carbon TCR road frame sitting in my shed that needed fixing and a build. Plus the TT frame I was riding was a 75degree TT frame that worked well with road drops but I was feeling quizzical about my up & down results and chalked it up to not committing to a full TT approach.
Both bikes were finished and as soon as I got the TT rig back I noticed the road bike crankset turned much more smoothly (everything was the same between the two- cranks, bb, drive train, etc.)
As it turns out the bottom bracket that had been on the TT rig was completely shot; it hardly turned relative to the fresh one on my road bike. Yikes. I felt relief that perhaps it wasn't that my form that was off, rather the BB was difficult to turn in certain conditions and maybe that explained some things, especially why I had such a tough time getting power numbers up.
As it turns out the bottom bracket that had been on the TT rig was completely shot; it hardly turned relative to the fresh one on my road bike. Yikes. I felt relief that perhaps it wasn't that my form that was off, rather the BB was difficult to turn in certain conditions and maybe that explained some things, especially why I had such a tough time getting power numbers up.
On to bike fit: I had the bikes built up at the only Triathlon shop in town and they did a decent job on both.
Figured I'd get their input on my fit; I was fitted years ago at River City and have tweaked it on my own since then, so I was a little nervous about changing things drastically as that would most certainly impact power output.
The shop suggested getting "forward" and "lower"; we spent some time trying this. I had some issues with how the fit was executed:
-Forward closed my hip angle.
-Lower did not optimize my breathing
-Instead of my glutes powering the pedal stroke it felt as if my quads were the primary driver.
Given that my bike has a 75degree STA getting more forward is not really an option; and in my opinion given the popularity of "forward" and "lower" fitting this is why STA have shifted to 78 degrees.
Along those lines here's a great video done by Dave Scott on time trial fit. This seems to validate my thoughts on "quad centric positions" vs. "glute centric". That said, I do think you can ride "glute centric" on frames with a steeper seat tube more easily but on many bikes, not so much; *and* I think this is one of the reasons I hear folks say things like:
"I was faster on my road bike with clip-ons" or "I could just never get comfortable on the TT bike"
Or why I've seen folks on TT bikes in long course triathlons sitting up on the base bar.
Closed hip angles and stiff quads, that's what happened.
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So about road bikes, TT bikes and hip angles
I've always felt strongly about not riding a TT bike for the bulk of training. When I decided to train for (with the goal of just finishing decently) an Ironman in 2005 I trained on a dedicated TT bike. It was trying to say the least, the bulk of the miles were darn annoying and I'm usually able to suffer through lots of training.
I bought a frame the next season with near exact dimensions, but road bars/clip ons and life was much better! I always wondered why. It turns out on a road bike in the drops, hoods or tops your hip angle is not drastically different and you can change it by shifting on the saddle to some degree.
On a TT bike the only position you should really be racing in are the aero bars, except when climbing steeper grades. When you sit up on the base bar or use the hand holds near the brake levers you aren't recruiting the same muscles you are down on the aero extensions.
The position is actually *too* open. Well, sitting up on a saddle like that is akin to riding a beach cruiser (I had one, hated riding it) and super duper uncomfortable if one is trying to make the bike move faster then an leisurely jaunt.
I've linked to great piece on this; definitely read it:
"Why Triathletes need a road bike"
So you may ask, do *I* eschew my TT bike?
Not at all. I quite like riding it finally in a TT set-up, but training on it regularly? Stupid. Where I ride is mostly very hilly and I'd be flogging myself to ride up those grades that I'd never see in any Tri. Most Tri bike legs are flat to rolling, a serious climb is the exception. Plus, climbing on the road bike recruits the right muscles for flat TT'ing!
I do jump on it once every week or so for trainer intervals and to make little adjustments since it's only recently been re-configured and I'm making an effort to ride Time Trial events this spring simply to get used to racing it thusly.
