but they would rub my pretty anodized cranks... :cry:
but they would rub my pretty anodized cranks... :cry:
What do you think about the dosnoventa Houston frame for racing and training ?
It's got a road front end (slack head tube) and a track rear (steep seat tube and high bottom bracket). Pretty bike, but probably not the first pick for a velodrome.
2) This "aero" seatpost on the Houston frame is round...just like any other round seatpost. So, it's thicker and no more round than a standard 27.2 post which actually makes it less aero...if aero seatposts were a real factor in aerodynamics :D
3) Integrated Seat Posts (ISP) create an obvious problem: Once you cut it, you can't un-cut it. So, if you cut it too short, you are sh*t out of luck. You can't even hover the cap over the post on this bike because the cap sits inside of the mast of the ISP. When you train/race, you'll adjust your seatpost a lot for various reasons (drop vs aerobars, new saddle setback, adjusting pedaling style, adjusting leg reach). So, when you buy this bike you can't do any of that. You get one chance and that's it. This is reason enough to avoid this bike, for track or street use.
4) This is a bad bike with a nice paint job.
Then that should apply to the whole back of the bike, correct?
It doesn't because that assumption isn't valid though on face value it looks like it could be. You shape flow and attach dirty air as much as possible to stop turbulence in the first place or reduce/remove it when you can, which is what an aero post does, just like shaped seat stays, chain stays, and a disc rear wheel, all of which sit behind that same dirty air.
Watch some smoke tests some time when they put a foil behind something creating turbulence. You get less turbulence. Same thing happens with an aero seat post in smoke tests.
How much of a benefit an "aero" seat post is depends on the rider, length of post, and a bunch of other variables and is a case by case number. A watt is a watt, two watts is two watts, Etc.
The rest of the objections to integrated or proprietary posts, some quite valid (though not the one about cutting it too short unless you go completely insane...most ISP have several cm of usable shim stack under the clamp), are part of a cost/benefit analysis of what that number is worth. Especially if you can use an aero post like Burrows designed.
If you really want to clean up the dirty air created by the legs, you can remove the top tube. That's what Mr. Tiemeyer told me was the reason that his team did that on this bike:
For some vintage comments on seatposts there is an interview with John Cobb (on the 'new' compact frame designs).
The summary is that for skinny posts round is better but thicker posts work better with a tail - all of this with a rider. The thicker post is supposed to help keep air out from between the legs.
My guess is that with a skinny post the air off the legs is coming in at a high angle so the airfoil is getting a side wind and stalling where round is the same for all the angles.
As far as integrated posts I like the idea on the Felt TK1 with a removable/replaceable integrated like post so it will not slip like most non integrated aero posts yet does not require a new frame when you get a different seat. I have not tried one so this is all theory where anything works.
I am with Vance on the innovation side and my hope that the UCI starts embracing change.
Too bad Tiemeyer retired. I'm having a heck of a time finding someone to build an aero tandem.
My buddy is Cobb's data recorder. John's a mad scientist and not someone who gets locked into dogma. His seatpost theories dovetail with some of his bottle tests where he ran an aero bottle vs. a round bottle. Some folks were faster with one, others with the other. That goes back to my long post above about the aero stuff being interactive.
Shot of me on the old track bike at A & M with Cobb...and some wheel tests.
And as Robbie Ketchell's (now the Garmin aero guru) bike model ;)
I live in Portland, who would you recommend for a quality bike fit?
Also check with Bike Central: http://www.bike-central.com/service_menu.html
A bike fit usually runs $75-100. It's definitely worth it if you can afford it, especially for a new rider.
If you don't go with one of them, at least try to get a bike fitter that is familiar with track racing. In track racing the races are only a few minutes long as opposed to a 30 minute criterium or a 2+ hour road race. Most beginner track races are 5-15 minutes. So, a more aggressive (and less comfortable) position will work.
I've only been in Portland about a year so I don't know that many resources. Maybe Brian can chime in.
Russell Cree at Upper Echelon did my bike fit a few years ago. He knows his stuff. Basically, unless you are complaining about back issues (or something is really out of whack), he doesn't really do much with the upper body; he is more about the leg motion. He is not a trackie, but he is up to date on racing cyclist biomechanics. He's got a fancy motion tracking machine. I recommend him primarily because when I went in, I had already been racing a few years; thought my position was pretty good (until I started getting some niggling injuries). He looked at me with that motion tracking machine, raised my saddle like a full inch, and all my troubles literally went away. Goes to show the limits of a self-fit.
At Bike Central, Dean will fit you by eye, watching you as you ride. He's not a fit specialist per se, but he does know what a good fit looks like and a lot of guys swear by him. Just ask. He might bite your head off, but only if you deserve it ;).
Those are the only two I know about personally. Russell will put you back a C note or two. Good fits are not cheap. Don't know what Dean charges.
Thanks to both of you for the suggestions, I had Russell do my road bike fit, didn't know if there was someone that specialized in track bikes. Will go back to Russell, liked what he did. Looking forward to learning about and trying track when Alpenrose starts their classes. .