Opik
Well-Known Member
It's a human powered record. If it's the fastest rier? why not freeze the design from 1930s? no carbon fiber, no almunium, etc.
Break the 60KM/HR record
- Thread starter Enid
- Start date
It's a human powered record. If it's the fastest rier? why not freeze the design from 1930s? no carbon fiber, no almunium, etc.
Osiris
Zen MBB Master
I once asked a local racing coach (Adam Baskin of Cat 1 Racing) if he knew of any cyclists in Florida capable of holding 400 watts for an hour. He said he only knew one guy in Tallahassee who could do it. But if he's anything like me, his power output would probably drop by about a hundred watts on a recumbent.
Years ago I met a freakishly large mountain biker who was literally seven feet tall and weighed about 300 lbs. Each of his thighs had roughly the same circumference as my torso, and I wondered how much power a giant like that could produce. His enormous frame would of course create as much drag as a billboard when riding an upright, but placed horizontally on a recumbent, his cross sectional area may not increase drag that much compared to that of a normal sized rider.
Strava prohibits velomobiles from competition. You could of course upload your data without mentioning that you were riding a velomobile, but it would still be against their rules.
So is riding behind a motorcycle. Two wrongs make an upwrong.
Of course my guesstimate of how much power it might take to break 60km/h could be off a little bit one way of the other, cycling analytics claims that 0.1% of cyclists make 420 watts FTP. Of course, their dataset is also a rather select one as well.
https://www.cyclinganalytics.com/blog/2018/06/how-does-your-cycling-power-output-compare
LarryOz
Cruzeum Curator & Sigma Wrangler
A nice reminder that you just can't talk watts, you really need to be talking W/Kg.
i.e. There are lots of really big guys that would not have any trouble pushing 400+ watts for an hour. I'll be a bunch of NFL types could do it. Problem is, there weight is really hi, like 140 Kgs.
- instead of 70 or less. I believe Bradley Wiggins was sub 70 Kg when he rode his record and he was averaging 450 watts I believe. That is 6.4 W/Kg. I am lucky to be able to do 4 W/Kg now for 1 Hr. That would be 280watts.But on my Magic, I was able to average 27+mph on about 210 watts for 3 hours earlier this year for a good data point at that speed. No where near close to 37 mph though.
McWheels
Off the long run
Chris Hoy made a good point commentating on the wold championships not so long ago. He said sprinters had to balance power to frontal area. Jason Kenny is compact so it works for him, Sir Chris just got on with being massive.
We also saw similar results from Jim and Maria in the wind tunnel. Maria's drag is that much less due to her size, which translated to I think about 30 or 40W equivalent vs Jim on the same bike.
We also saw similar results from Jim and Maria in the wind tunnel. Maria's drag is that much less due to her size, which translated to I think about 30 or 40W equivalent vs Jim on the same bike.
Well, this has been interesting. Certainly explains why I am so much slower than what V20 riders report on this forum. I do not have power meters, and rely on my bike computer for power output, which makes several assumptions. Although it is probably not accurate, it is quite repeatable. So it looks like I am at about 1.7 W/Kg. So I can power a 100 watt light bulb.... One would think that somebody who ran track and cross country in high school and college would have a little more get up and go.
I am trying to get my speed up by cycling 7 miles out to a 6 mile loop which has no intersections and little traffic. There, I can focus on maintaining my goal speed. Once I make my goal, I bump up my goal by another 0.5 mile/hour. This seems to be working. I am able to hold better speed when just out cruising.
I am trying to get my speed up by cycling 7 miles out to a 6 mile loop which has no intersections and little traffic. There, I can focus on maintaining my goal speed. Once I make my goal, I bump up my goal by another 0.5 mile/hour. This seems to be working. I am able to hold better speed when just out cruising.
Osiris
Zen MBB Master
That's the first time your numbers have ever matched mine. On my M1, I also average 27+ mph on 210 watts. That explains why your 12 mile TT time in your "Summer Time Trial" thread is nearly identical to mine.
I did 27.5 mph on 218 watts average power over 10 miles, yesterday. 29.1 mph on 270 watts average for 5 miles with a touch of climb yesterday doing some sweetspot work. 29.2 mph over 10 miles on 258 watts. Just regular kit and regular helmet but good warm temps.
Osiris
Zen MBB Master
Your M5 seems to go faster than mine. IIRC, my 1 mile segment on the M5 at 27.4 mph average cost me around 235 watts. Larry and I both use the same Garmin Vector pedals, so that makes for a better comparison when it comes to power output.
It ain't the arrow, its the.....wait. Can't say that.
A lot goes into making it fast, bike might be 40% of it.
For instance, a misplaced drinking tube hanging loosely from a bladder can have a huge effect on speed, around 0.01 ^m2 additional drag or more. Where you put your Garmin, hand position, etc.
True WRT power measurements. They all have to be taken with a grain of salt, especially the Garmin pedals if they are not precisely torqued. To be honest, I was surprised how much power it took Magic to go 27 mph but it aligned with the laps Larry was doing somewhere on it (it was a youtube video). My next power meter will likely be a power2max on the Rotor 3D+ spider. Nonetheless, these are all accurate meters and would not expect more than a few percentage difference. When estimating CdA, you also have to estimate powertrain losses. 2-3% is typically used if measuring at the pedals/crank and 0% if at the hub, so, location of measurement isn't or should not be that big of a deal. The only way I can be confident myself in my measurements is the Chung technique on a calm day or many, many days on the same route and averaging.
I think I said it before, you and Larry have the two fastest bents that I know of.
Osiris
Zen MBB Master
The old ones yes, the newest ones aren't that finicky. I've done countless runs where the results look almost identical, the most recent being a difference of only 1 watt over a four mile segment. In my testing it's not so much accuracy as consistency that matters, and when comparing the M5 to the M1, the results are always that the M5 clocks in at just under 2 mph slower than the M1 at around 200 watts. No way I'll ever match your 30 mph 10 mile TT results on either one, though.
When I first got the M1, I took a close look at Larry's test results on his, and was pretty surprised by what I saw. His power/speed ratio even on the V20 looked better in one case. That didn't make any sense to me at all, considering that my V20 wasn't even in the same league as the M1 in terms of aerodynamic efficiency. I was very relieved to find that I'm doing much better on mine, with performance numbers comparable to the Magic. Now if I just had a better engine...
His Frankie V20 bike is very fast but still slower than the John Mircilago one...Arrowhead. I think it has a 650 front wheel. he did like an 18 minute 10 mile TT, he had to take the wide line constantly to pass slow riders but his speed and power numbers are plain as day. IRRC, WRT to his Frankie, it has some subtle changes to my eye and the speed results are there.
DavidCH
In thought; expanding the paradigm of traversity
Eh? Knees are more important .... don't do it
benphyr
Guru-me-not
Agreed.
Is 80-90 pedal rpm low enough to bother knees or high enough to avoid knee issues? It is the forces on the joints when starting from stopped that bugs me most.
Knees are more sensitive to torque or peak pedal forces than cadence per se, assuming proper leg extension/fit. Metabolic efficiency at recreational speeds is generally best at a cadence of 60-70 rpm. Peak efficiency at higher power levels comes at higher cadences. I am omitting crank length, but that is a factor.
This is what I have found works for me and I use 175 mm cranks currently. On long rides at modest power (say 90-140 watts), my cadence is around 70-72 average. As power requirements increase, my cadence will increase. For instance, I time trial at 88-92 rpm at 300-310 watts. If the cadence dips a little low because there is a small rise, I just put a little more coal on the fire. If one takes the time to evaluate Tour de France power files as I have, you will see that when they are sitting in the pack resting, they might "only" be making 200-220 watts but their cadence is relatively low (below 80). When they are on the front working hard, the power might be 400-500 watts with a higher cadence.
Spinning at 120 rpm at low power levels is very inefficient. I don't have time to find the studies.....I have to go fix the brakes on my old Land Cruiser.
This is what I have found works for me and I use 175 mm cranks currently. On long rides at modest power (say 90-140 watts), my cadence is around 70-72 average. As power requirements increase, my cadence will increase. For instance, I time trial at 88-92 rpm at 300-310 watts. If the cadence dips a little low because there is a small rise, I just put a little more coal on the fire. If one takes the time to evaluate Tour de France power files as I have, you will see that when they are sitting in the pack resting, they might "only" be making 200-220 watts but their cadence is relatively low (below 80). When they are on the front working hard, the power might be 400-500 watts with a higher cadence.
Spinning at 120 rpm at low power levels is very inefficient. I don't have time to find the studies.....I have to go fix the brakes on my old Land Cruiser.
That is when the peak forces are highest on the joints.
Do you use an easy gear to start? Maybe start a little "easier" and not push so hard? BTW....this is when I feel my knees, too. My "solution" was working on balancing so that I could just crawl from a start.
super slim
Zen MBB Master
Larry puts his huge power through 140 mm cranks, as he sits on 100 cadence, AND does it for hours.
I have long legs (46" X seam), but use 153 mm Cruzbike cranks, to nearly eliminate knee pain compared to 175 mm cranks, on 6+ hr rides, when I am putting out a HUGE 100 w according to Strava!
I have long legs (46" X seam), but use 153 mm Cruzbike cranks, to nearly eliminate knee pain compared to 175 mm cranks, on 6+ hr rides, when I am putting out a HUGE 100 w according to Strava!
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What doesn't quite satisfy me with several of these studies is focus only on cadence and no thought about crank arm length or the associated torques. Having experimented with very, very long crank arms and soon to try shorter ones, I tend just go with what feels right to me. Interestingly, the "right feel" cadence on a recumbent is a little higher than on an upright.....for me anyways. I do have to chuckle though seeing someone spin like crazy at 100+ at low power, just a total waste of energy.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367161/
https://www.cyclingweekly.com/fitness/why-amateurs-shouldnt-try-to-pedal-like-chris-froome-191779
