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25 Jul 2010Thanks for making my job easy!Honestly, I don’t understand mainstream bicycle manufacturers. Almost every road bike we’ve ever done, the customer has shown us his current bike and the seat has been slammed all the way back on it’s rails, and yet manufacturers still think a 73 degree seat angle is still a good mean.
This is Cadel Evan and George Hincapies bikes, courtesy of the journalistic geniuses at cyclingnews.com (btw fellas, these aren’t the same frame). See the saddles? Slammed all the way back on the most layback seatpost I’ve ever seen. Now with tube based designs, there is a limit obviously to how far you can layback the seat tube angle, and how short you can have the stays, before the tyre crashes into the seat tube, but with carbon? No such excuse. And the short chainstay myth? With any given material, through wall thickness and shape optimisation, you can make any length chainstay as stiff or as flexible as you like. Length has almost no bearing on stiffness, so any designer really can create any length chainstay they like and still have it stiff. All this boils down to then is simply the inertia of a paradigm devoid of meaning, from companies that are so scared to do the right thing that they will only be as different from one another as they dare. In the process, they bring along the baggage of a time when bicycle design is more about cost optimisation than anything meaningful like real world ergonomics and individuality. So thanks BMC and all you other Tupperware manufacturers for keeping this nice point of differentiation between yourselves and us custom guys. It makes the job just that little bit more rewarding.
Posted by warwick @ 1:12 am 5 Responses to “Thanks for making my job easy!”Leave a Reply |
October 29th, 2010 at 1:31 am
It this because of the KOPS bike fitting rule? I noticed the bike fitter doing this when I was being sized up for my frame. I am guessing that KOPS will always result in an individual’s optimal ‘virtual seat tube angle’ for a given saddle height and saddle shape / model. I noticed that my Thylacine’s seat tube angle is relatively slack, almost hybrid-like.
October 29th, 2010 at 1:49 am
KOPS is really just a ballpark Kelvin. It doesn’t really have much biomechanical basis, but we’re stuck with it as a baseline. In a perfect world your body would be scanned and your Centre of Gravity plotted so you could have weight distribution optimised between in the saddle riding, out of the saddle riding, and riding with your hands in various positions. From there you’d turn on the power meter and see which positions you naturally generate more power in. You could imagine not too many people would want to pay as much for a fitting as the bike itself!
Essentially what I’m trying to do with the fit, is get you centred on the bike with a neutral pedal, that’s not so layed back that you can’t get your back flat(ish) or have trouble getting out of the saddle. It’s a big balancing act, basically.
As a generally horrible stereotype, most riders are sitting too far forward because they can’t actually get the seat back far enough, or the bike is too long, or they lack the flexibility for the reach of the bike.
You see guys out there with a 73 degree seat tubed bike and a straight seatpost all the time. It’s beyond wrong.
October 29th, 2010 at 5:07 am
I was wondering about the CoG thing. Coming from a motorcycling background, I am surprised that less attention is paid to CoG in general bicycling compared with motorcycling. I figured that you can get correct bike fit on a wide range of off-the-rack bicycles simply by moving the handlebars and saddle in relation to the bottom bracket, but no one ever mentions the position of the front and rear wheels (or the steering head) once the rider is in their optimal comfort zone. In comparison, motorcycle designers seem to lose sleep over whether they should move the engine block 5 or 10 mm closer to the front wheel.
October 29th, 2010 at 6:26 am
Just a bit more googling in my spare time reveals this PubMed reference:
http://www.ncbi.nlm.nih.gov/pubmed/9293416
Looks like the ‘in vitro’ research results don’t necessarily translate to ‘in vivo’ practice, as shown in your TdF spy photos.
October 29th, 2010 at 9:58 pm
Yeah I’m familiar with that document. Thankfully they didn’t have to attempt to climb any hills or go around any corners with a 80 degree STA. It’s tough to generate more power when you’re on the floor and your bike is in the gutter! No mention of efficiency over time either. Its one thing to sit in a lab, it’s another to be on your bike for 3 weeks through the Alps. What about the impact on recovery times? What about the ability to transition from seated to standing position? And as mentioned before, nothing about how position actually effects your ability to….oh, I dunno….actually ride the bike!