The stated: "Anything over 16mph and unless there's a good tailwind I'm likely to be in the drops" isn't just Ted, it's backed up by physics. Power needed to overcome air resistance goes as the cube of the relative air velocity. So for an upright rider, the power needed to overcome air resistance at 12 mph is about 50 W. With rolling resistance you should be well below 100 W, which is comfortable to the average rider to maintain. However, at 16 mph the power needed to overcome air resistance has doubled to 100 W and now you're probably needing close to 135W to maintain that speed. Most recreational cyclists average power is somewhere right around that. However, if you assume a good crouched position you can decrease the power needed to overcome air resistance by up to half (our BOBish bikes probably aren't allowing us to achieve that, but any reduction in air resistance becomes extremely useful at this point). And of course, the second half of that statement is "unless there is a good tailwind" which is to the point of relative wind velocity. So if you had a steady 16 mph breeze at your back on level ground, you'd maintain a 32 mph speed with only needing to overcome the modest rolling resistance which grows approx. linearly, so a rather comfortable 60-70 W or so.
I prefer drops mostly for the previously discussed comfort of providing an increased number of hand positions, but for aerodynamics, they're really is no constant between drops and other bars for allowing one to comfortably and safely lower the power needed to maintain speeds above 10 mph. And due to the human body and the physics of road bikes, it just so happens that 16 mph is just about where that inflection point occurs of most of us wanting to go faster. On Thursday, May 15, 2025 at 5:21:54 PM UTC-7 John Hawrylak, Woodstown NJ wrote: > Ted stated: " Anything over 16mph and unless there's a good tailwind I'm > likely to be in the drops." > > I agree and do the same. I set the top of the bars even or slightly > above the saddle, so when I am in the drops I can see ahead without > cranning my neck. > > Currently using 44cm RH Randonuer bars > > John Hawrylak > Woodstown NJ > > On Thursday, May 15, 2025 at 1:49:18 PM UTC-4 Ted Durant wrote: > >> Jumping off The Charlie Gallop Thread, I thought I'd share some thoughts >> and data on upright vs drop bars. In that thread I made the observation >> that wind drag becomes an issue as I get into the 16-20mph range. Today I >> did a 40 mile ride at an average of 16.8mph, with a nicely low 5mph wind >> out of the southeast, and modest amounts of hills. So, a bit above that >> 16mph threshold, and trying to maintain a steady pace all the way around. I >> found myself riding on the drops for the vast majority of the ride. >> Anything over 16mph and unless there's a good tailwind I'm likely to be in >> the drops. Around 16mph I'm often on the brake levers or just behind them. >> By 12-13mph I'm almost certainly on the tops, with wind drag a non-issue >> and hill climbing benefitting from more open hip angles. >> >> So, that's anecdotal. >> >> Now for some data. From November 2016 to November 2017 I commuted to work >> on a Cheviot, with a typical Cheviot upright position (though I >> experimented a lot with bars and stems). For commuting I carried a backpack >> in a front basket. Then, in November 2017, I replaced the Cheviot with a >> Terraferma Corsa 650B (a very light tubing, very low trail frame) with >> Noodle bars (the very wide ones, to get around the backpack and basket). >> Pretty much every ride to work and home was recorded on my bike computer. >> So, I can take a year's worth of commuting rides on the Cheviot and a >> year's worth of commuting rides on the Terraferma and compare the data. >> >> I expected, just based on my internal dyno, that my average speed on the >> Terraferma would be higher than on the Cheviot. Subjectively I felt very >> slow on the Cheviot. It turns out, though, that the average of average >> speed is exactly 23.2kph (14.5 mph) for each bike. However, the max average >> speed for the Terraferma is 27.9kph (17.4mph) vs 26.0kph (16.3mph) for the >> Cheviot. The 80th percentile, i.e. the speed above which 20% of the rides >> were ridden, is 25.2kph (15.7mph) for the Terraferma vs 24.8kph (15.5) for >> the Cheviot. >> >> I think this data supports my anecdotal feel about the 16mph threshold. >> Over almost 300 rides averaging 14.5mph, the aerodynamics (and the other >> bike factors ... I might note that tires are pretty much the same on each >> bike, including studded snows during the winter) don't appear to slow me >> down, though I don't have any data to address the question of whether I was >> in fact working harder to maintain that speed. I didn't record when I >> swapped out the studded tires, so it's possible that factor confounds the >> analysis. The fact that many more of my faster rides were on the >> Terraferma, I think, demonstrates the effect of a more aerodynamic position >> at speeds above 16mph. >> >> Ted Durant >> Milwaukee, WI USA >> > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/6598c331-2ae5-4456-93a1-eb35605189b3n%40googlegroups.com.
