More like clarifications of statements to see if they are true…
If you walk outside and let’s say it is 100% calm…not a drop of wind…and you left on a ride and the conditions remained the same the whole time…would you be experiencing 0 deg yaw?
If the answer to the above is no, I’m dumbfounded…so I’m going to assume it’s yes…leading to my next questions…
Let’s say you show up to a local TT with two bikes…out and back course. You bring (this is just as an example because they were tested side by side) a Shiv Tri and a Shiv TT. The Shiv Tri which has shown to perform better at higher yaw ~>5deg and <-5deg’s and the TT which is better closer to 0 or in between the 5 deg and -5 deg range. You make your choice based on the conditions of the day. Would it be correct to use the TT if the wind was parallel to the course or if the day was totally calm…and better to use the Tri if the wind was perpendicular to the course or swirling?
Also, would you take into consideration where you ride and what the conditions normally are when buying a bike…for example, you ride and race in an area that tends to be very calm rather than you ride and race in an area that tends to be very windy?
Yes you should take that into account when buying a bike. The p4. Is most likely not the fastest for people who experience a lot of has or ride slower. Picking the best bike should include most seen yaw conditions the same as when you choose what wheels set to use.
Awesome, thanks Jack. That’s all I needed
You bring (this is just as an example because they were tested side by side) a Shiv Tri and a Shiv TT.
anyone who has this problem is winning in life!
seriously, though…yes. your interpretation of 0 yaw is correct.
faster riders (and shorter courses that allow for faster riding) generally mean lower yaw. slower riders (and longer courses that tend toward slower speeds) have higher yaw. stiff cross-winds (eg a race up and down the coast) could effect even those riding very fast on a short course, but a faster rider will still experience lower yaw than a slower one in that instance.
for most practical purposes, it seems the shiv TT and shiv tri are pretty darn close in terms of frame drag.
practically speaking, even on calm days yaw will vary. it’s rare for there to truly be no wind.
local wind conditions can be very hard to predict over the course of a full route. even supplied wind-station data is not measured at ground/bike level, generally speaking.
So Eric,
Do you think it would almost be impossible to show up to a TT and pick the right bike with any amount of certainty? Unless the conditions were extreme…ie, dead calm or a serious cross wind. If the conditions were just “normal”…you know, slight breeze, nice day…seems like either bike would be the choice…
Just trying to figure out how practical it would be to have condition specific equipment when you get to the highest level of bike. Or, do you just do your best to have the best setup based on where you normally race.
Do you think it would almost be impossible to show up to a TT and pick the right bike with any amount of certainty? Unless the conditions were extreme…ie, dead calm or a serious cross wind. If the conditions were just “normal”…you know, slight breeze, nice day…seems like either bike would be the choice…
Just trying to figure out how practical it would be to have condition specific equipment when you get to the highest level of bike. Or, do you just do your best to have the best setup based on where you normally race.
i think it would be possible. would it be practical for an individual? i don’t think so, not generally.
for shooter courses and out-and-backs, it would get a bit easier to make such a decision. the longer the course, the more variety in wind speed and direction. if you’re talking about triathlons…well…you have the issue of needing to make a prediction in advance in order to check in your bike, do your swim, etc. prevailing winds at 6am may not be prevailing winds at 9am.
to my eye, the differences look pretty darn close. i’m not saying that small differences are not relevant; i think they are. however, without some serious assistance i think it would be a pretty big headache that might turn out to give the answer “it’s a toss-up” anyway.
my bet would be that the bigger variable would be to think about the length of course and one’s own assessment of their ability on that day (am i gonna ride this fast like a prologue at the tour de france, or am i doing an ironman bike leg?) and go with the right bike based on that. that said…under most circumstances i’d say the bikes probably produce REALLY close results.
pretty interesting to think about, though.
obviously, the above reflects my opinion and interpretation of some aero charts and what i think the key issues would be in performing this analysis on race day. how often do you need one more thing to do (or in this case, about 10!) before your races? i’m usually pressed for time.
it would take an enormous amount of work to do the analysis and have a 75% chance of getting the right answer to save yourself 8 seconds when you did get it right.
=)
like you would need to lay out all possible wind directions, speed at the ground at all points on course, and have a spreadsheet macro set up to give you the answer based on conditions minutes before your leave the ramp =)
So Eric,
Do you think it would almost be impossible to show up to a TT and pick the right bike with any amount of certainty? Unless the conditions were extreme…ie, dead calm or a serious cross wind. If the conditions were just “normal”…you know, slight breeze, nice day…seems like either bike would be the choice…
Just trying to figure out how practical it would be to have condition specific equipment when you get to the highest level of bike. Or, do you just do your best to have the best setup based on where you normally race.
So both of these responses lead me to believe it simply isn’t practical.
The best you can really do is try for the best “all around” setup based on the most common conditions you would face coupled with an assessment of your own abilities…
yes, and don’t sweat it too much. just get a good bike and try to keep pizza boxes and barrels of water off it. =)
So both of these responses lead me to believe it simply isn’t practical.
The best you can really do is try for the best “all around” setup based on the most common conditions you would face coupled with an assessment of your own abilities…