V20 on velodrome

[Luis Rives]

I would love to see a V20 going against the clock on a velodrome as compared with a DF bike, both using experienced riders. I would be fascinating to see just how much of an aerodynamic advantage the V20 has against the DF in a real world test? Is anyone aware of such comparison ever been made?

 

[LarryOz]

I would love to see a V20 going against the clock on a velodrome as compared with a DF bike, both using experienced riders. I would be fascinating to see just how much of an aerodynamic advantage the V20 has against the DF in a real world test? Is anyone aware of such comparison ever been made?

I know of nothing, but it would be really hard to get athletes of equality ability and fitness on each platform. Even the type of DF bike would matter and really it is a package deal. Rider + bike = CdA. A fully setup and tuned TT bike is extremely aero, but I still have never seen a TT bike with CdA lower than mine on my V20. There is also the power making ability on each type of bike. Most (although not all) would agree that it is harder to make watts laying on your back compared to an upright, and the more you lay flat, then harder it gets. I can attest to that.
But.... I would still put money on a V20 against any DF bike with riders of equal FTP strength. (caveat: Not talking short sprint, but something at least 1mile) I cannot beat the acceleration of a DF on my V20 in a sprint, but I am also no sprinter. Other's like Kyle maybe??
Not on a Velodrom, but in real life on a road course I have easily been able to out-ride groups of 10-20 strong DF riders riding as a pack in a long event. Last time was at a 100K race in SC. I beat the chase pack by 9-10 km in a solo effort.

 

[Osiris]

I would love to see a V20 going against the clock on a velodrome as compared with a DF bike, both using experienced riders. I would be fascinating to see just how much of an aerodynamic advantage the V20 has against the DF in a real world test? Is anyone aware of such comparison ever been made?

If you're comparing equipment, you'd need to put the same rider(s) on both and run multiple tests. Judging by my results, a DF wouldn't stand a chance against the V20 on a flat track. It wouldn't even be close. The problem, as Larry mentions, is that it's very unlikely that you'll find someone equally suited to racing say, a TT bike and a recumbent. It requires years for the body to adapt to each platform, and you'd have to train for both simultaneously to achieve optimal results.

 

[bladderhead]

J Perez rides both. You want Perez v Perez. How difficult would it be for him to get used to a track bike? How different is the orange Trek from a track bike? These DF bikes all look the same to me.

 

[jond]

Now Larry my wife can attest to the fact it’s easier to make what’s on your back

Especially at this age.

 

[LarryOz]

I have forgotten that I had tested an S-works upright bike (full drops, but no TT bars) against a Vendetta and an M1 on the local "velodrome". Not a "true velodrome, with high banked corners, but a nice fast 1/3 mile oval with about 6 degrees of banking. This was 2 1/2 years ago - Nov, 2015.
Here is the data:

The difference between power and speed is pretty incredible.
Vendetta took 293 watts to go 29.5mph, and S-works too 465 watts! 172 more watts for roughly the same speed!!!!
The ability to make "more" power on the upright bike is also pretty substantial. There is no way I could push 465 watts for 2 miles on a Vendetta - If I could, might break the sound barrier!

 

[Needforspeed]

Holy crap Larry, that was you on all those runs? Now we know how strong you really are, you could even be a contender an upright bike. 465 watts, 465 watts, 465 watts! (I’m thinking of Doc Brown in “Back to the Future” with his ‘1.21 gigawatts!’ quote)

 

[Gary123]

29.3 for 2 miles on df ain't shabby.

 

[Charles.Plager]

Hi Larry,

The difference between power and speed is pretty incredible.
Vendetta took 293 watts to go 29.5mph, and S-works too 465 watts! 172 more watts for roughly the same speed!!!!
The ability to make "more" power on the upright bike is also pretty substantial. There is no way I could push 465 watts for 2 miles on a Vendetta - If I could, might break the sound barrier!

I wonder if you'd make more power on an S40?

It would also be interesting to get a V20 where you could raise the seat somewhat. I'm willing to believe that a bit higher seat might be enough more power to get over the bigger drag.

And if only somebody would suggest building a socked Silvio, then we might be getting somewhere (very quickly).

 

[LarryOz]

I wonder if you'd make more power on an S40?

It would also be interesting to get a V20 where you could raise the seat somewhat. I'm willing to believe that a bit higher seat might be enough more power to get over the bigger drag.

And if only somebody would suggest building a socked Silvio, then we might be getting somewhere (very quickly).

Charles, I did extensive testing on my S30 against my first Vendetta back about 3 1/3 years ago. Yes, I am a testing nutcase?
I could make 361 watts for 5 minutes on the S30, but the speed was only 25.4mph
Same test, same fitness, same power meter, same track with Vendetta - The absolute best I could do was 265 watts for same 5 minutes, but it got me 25.9mph.
As you can see from my data below, I tested all ranges of wattage from 100watts up to the max I could do 25 watt increments!
This was way before I did any aero streamlining on the Vendetta with stubby handlebars, aero wheels, etc.

Since then I think I have acclimated to the Vendetta 20 degree seat angle, so I am now able to do that same 265watts for nearly an hour. (not sure what it would be on a Silvio 30 or 40 now)

But, having said all that "above" - the extra watts I can make on the Silvio (extra 10 degrees) was not enough to overcome the aero-disadvantage. Similarly, I believe the same would be the case for the S40, but more pronounced.
Caveat: I do think there would be a significant benefit of the extra power making ability on an S40 for steeper climbs where speed is so low that the aero-disadvantage would be negligible. This is were an adjustable seat position would really come in handy I think. Where you could change the seat on the fly, kind of like with a level on an office chair height adjustment.

 

[Osiris]

It's interesting that before you did all the extra aero streamlining on the Vendetta, your power numbers at ~26 mph were very close to what mine are right now. I'm riding on a set of aluminum wheels and haven't made any aero mods aside from installing a longer chainstay.

Your greater power numbers with a more upright seat also seem to match my own experience. My first pedal stroke when I'm trying to get the V20 rolling from a dead stop is done sitting up as far as I can. I've found that from this upright position, I can produce so much power that it results in tire slip if I'm not careful. I don't think I could produce that much power when lying all the way back in the seat. No way to know for sure until I put the V20 on a trainer, though.

 

[paco1961]

In the FWIW category - I'm new to CB after years of building and racing DFs including Ti, carbon, al , Singlespeed's etc. None super aero but most reasonably so. Just built an S40 and still learning but can easily tell that at 20+mph I'm at much lower watts on the S40 than on any of my DFs. 29.5mph on my best DF took every bit of 415 watts. While I haven't been to that speed yet (still a bit too unsteady at speed) it seems clear that I'll be considerably more efficient on the S40 at that speed. No side by side comp needed or me!

 

[DavidCH]

I built a DF for the task. My brother is always complaining that he can't keep up with me. It's like the Vendetta and scary fast. It's all carbon, it's minimal and it's aero. It won't win in an endurance but will keep up in a social. It might win a crit race but the V could never. It's fixed gear and weighs 5 kilos with a 56t up front and a 12t sprocket at the back but I usually run it with a 17t. It has a brake on the front to make it street legal. It has a redshift shockstock stem that's brilliant at reducing vibration through the arms. Its low maintenance too.


But this is what it's up against


(Warning. Speed kills. If you fall off the V you have a significantly better survival rate. I love all forms of cycling)

 

[bladderhead]

That fixie looks awesome, but that saddle is so high and the bars are so low... Glad I gave up DF.

The challenge is to design a crit-winning 'bent.

 

[Osiris]

The challenge is to design a crit-winning 'bent.

 

[Osiris]

It might win a crit race but the V could never. It's fixed gear and weighs 5 kilos with a 56t up front and a 12t sprocket at the back but I usually run it with a 17t.

A fixie is no good in a crit race; you'll always be in the wrong gear.

 

[LarryOz]

The challenge is to design a crit-winning 'bent.

Thing is - no Crit race director will ever let a recumbent race with uprights - for obvious reason! haha

 

[Osiris]

Thing is - no Crit race director will ever let a recumbent race with uprights - for obvious reason! haha

I actually saw a race like that on Youtube. There was only one racer on a recumbent, and he lapped the entire field!

 

[Zzzorse]

I actually saw a race like that on Youtube. There was only one racer on a recumbent, and he lapped the entire field!

Oooooh. Do you think you could find it? I'd like to watch.

 

[Osiris]

Oooooh. Do you think you could find it? I'd like to watch.

I've looked for it, but I can't find it now. It was filmed by the guy racing the recumbent, and he has a very unusual last name. If I can remember what it was, I'll be able to do a search for it.