slow non aero recumbents...Not

[Paul W]

As part of the research into "which 'bent" I've come across some Posts that
insist that unfaired recumbents have a larger frontal area than road bikes
and therefore cannot be competitive in terms of speed.

Some may; well designed 'bents have less frontal area.

My MR Swiftlet trike has 25% less frontal area than my wifes road bike (sit
up position.)
I measured the frontal areas using a calibrated backdrop and tele lens.

It's quite evident in a strong head wind that the trike has a huge
advantage. In no wind the two styles are about equally efficient. In a tail
wind the bikes are equal until speeds get up to 40 kph plus, at which point
the trike surges ahead (higher gearing and low profile.) Of course
performance depends on the riders, but I have ridden beside my wife on a
road bike, a 45 degree seat trike and a lowracer trike in all conditions -
the performances of the different designs are consistent.

In a tuck the road bike would be about the same, but the area presented to
the slipstream/wind is higher above the road for a road bike. Wind speed
varies with the wind at ground level being near zero and increasing with
height (which is why wind turbines are mounted on towers...) In addition,
the upright rider is disadvantaged by breathing restriction in the tuck
position.

High and low racers have a lot less frontal area.

I think another factor is "time on bike." An enthusiastic roadie will spend
a lot of time training. That doesn't seem to be the case for recumbent
riders..maybe it's because we're more laid back (sorry....)

So that's my opinion on record!

Paul W

 

[blazingpedals]

My MR Swiftlet trike has 25% less frontal area than my wifes road bike (sit
up position.)
I measured the frontal areas using a calibrated backdrop and tele lens.
Paul W

American 'sport' recumbents tend to be less reclined and higher than most trikes. I think you'd find if you repeated your procedure that a Burley or a RANS (except for the F5,) just to pick on two popular brands, the difference would be much less. Most first-time recumbent buyers in the US end up getting these type recumbents, not trikes, lowracers, or highracers. So, if they are expecting speed they are going to be disappointed when they don't get it. BikeE used to be terrible about that. They would tout the fact that all speed records were by recumbents, implying that their bikes, being recumbents, were fast. Then one more poster would show up on some forum, wondering why he wasn't seeing the expected roadie-roasting speeds.

Of course, if comfort, not speed, is the main concern, then it doesn't really matter.

 

[blazingpedals]

I think another factor is "time on bike." An enthusiastic roadie will spend
a lot of time training. That doesn't seem to be the case for recumbent
riders..maybe it's because we're more laid back (sorry....)
Paul W

That's true in many cases, but in at least as many cases, the pain-free aspect of recumbents actually allowed the rider to do more high-quality miles and end up being stronger than ever. The ones that never get any stronger - they're the ones roadies point to when they're asserting that recumbents are slow and wobbly. For myself, I enjoy proving they're not all that way.

 

[Johnny NoCom]

There are quite a few roadies that showed how slow and wobbly John PutPut Foltz was at roadie vs. bent race in Grayling.

Recumbents are suppose to be faster than roadies. Looks like some roadies still rule the road when slow bent riders like John Foltz show up to ride.


3 54 Norman Licht Traverse City M 46 4:18:17 23.2
4 214 Derek Prechtl Empire M 30 4:18:17 23.2
5 146 Jared Gilyard Traverse City M 20 4:18:18 23.2
6 194 Clifford Onthank Traverse City M 50 4:18:18 23.2
7 49 Charles Rennie Traverse City M 37 4:21:39 22.9
8 4 Paul Monkman Ithaca M 36 4:21:41 22.9
9 35 Bob Meikle Waterford M 47 4:22:52 22.8
10 215 Bob Kyes Traverse City M 32 4:23:57 22.7
11 167 Jimmie Colflesh Livonia M 30 4:23:57 22.7
12 72 Mike Anderson Alpena M 15 4:23:57 22.7
13 175 Matt Levasseur Midland M 29 4:23:58 22.7
14 197 Rick Oberle Lansing M 49 4:23:58 22.7
15 46 Rich Budek Kingsley M 38 4:23:58 22.7
16 143 Don Fedrigon Williamsburg M 47 4:23:58 22.7
17 198 Hal Bevier Traverse City M 42 4:23:59 22.7
18 2 Bonnie Karas Rochester Hills F 44 4:23:59 22.7
19 83 Frank Tafelsky Traverse City M 37 4:23:59 22.7
20 188 Bob Volant Gaylord M 47 4:23:59 22.7
21 98 Glenn Goodmen Bellaire M 37 4:24:00 22.7
22 73 Ron Anderson Alpena M 47 4:24:00 22.7
23 100 Tom Roberts Maybee M 36 4:24:00 22.7
24 94 Lars Welton Traverse City M 50 4:24:01 22.7
25 120 Floyd Scott Lowell M 29 4:29:55 22.2
26 5 John Foltz Haslett M 48 4:31:17 22.1

Cheers,
Johnny NoCom

That's true in many cases, but in at least as many cases, the pain-free aspect of recumbents actually allowed the rider to do more high-quality miles and end up being stronger than ever. The ones that never get any stronger - they're the ones roadies point to when they're asserting that recumbents are slow and wobbly. For myself, I enjoy proving they're not all that way.

 

[Freewheeling]

I don't know about frontal area, but the drag coefficient for something like
a RANS V-Rex is considerably less than for an upright. It's not just
frontal area, but postion, pedal/crank position, etc. I mean, it's not even
really a contest. Ride a century on the Eastern shore on a recumbent like
the Rex and then try it on an upright. Heh.

A lot of us here in the DC area have experience with that little "natural
experiment." You can ride in a paceline, of course, to reclaim some of that
aerodynamic loss... if you just love paceline riding.

--
--Scott
"blazingpedals" <[email protected]> wrote
in message news:[email protected]...
>
> Paul W Wrote:
>>
>> My MR Swiftlet trike has 25% less frontal area than my wifes road bike
>> (sit
>> up position.)
>> I measured the frontal areas using a calibrated backdrop and tele
>> lens.
>> Paul W
> American 'sport' recumbents tend to be less reclined and higher than
> most trikes. I think you'd find if you repeated your procedure that a
> Burley or a RANS (except for the F5,) just to pick on two popular
> brands, the difference would be much less. Most first-time recumbent
> buyers in the US end up getting these type recumbents, not trikes,
> lowracers, or highracers. So, if they are expecting speed they are
> going to be disappointed when they don't get it. BikeE used to be
> terrible about that. They would tout the fact that all speed records
> were by recumbents, implying that -their- bikes, being recumbents, were
> fast. Then one more poster would show up on some forum, wondering why he
> wasn't seeing the expected roadie-roasting speeds.
>
> Of course, if comfort, not speed, is the main concern, then it doesn't
> really matter.
>
>
> --
> blazingpedals
>

 

[Mark Leuck]

"Freewheeling" <[email protected]> wrote in message
news:[email protected]...
> I don't know about frontal area, but the drag coefficient for something
like
> a RANS V-Rex is considerably less than for an upright. It's not just
> frontal area, but postion, pedal/crank position, etc.

Has that actually been measured for that particular bike?

I've been riding recumbents for a little over 2 years now and my
observations are quite different, in almost EVERY case the recumbent is
slower however in most of these the rider is middle age and not in shape
compared to many of the other DF riders. In the end the main factor is the
rider and not the bike


Would you say a rider on a BikeE would be faster than the same rider on a
carbon fiber sub 20 pound bike? I don't think so because the BikeE wasn't
designed for speed.

Could be the same for the V-Rex

> I mean, it's not even
> really a contest. Ride a century on the Eastern shore on a recumbent like
> the Rex and then try it on an upright. Heh.

You have many factors involved there although the main one would be comfort
which I'm sure the Rans wins hands down

> A lot of us here in the DC area have experience with that little "natural
> experiment." You can ride in a paceline, of course, to reclaim some of
that
> aerodynamic loss... if you just love paceline riding.

I've run pacelines at 25+ on my Baron and still get blown away by DF'ers
although they are in better shape than I am

 

[blazingpedals]

Has that actually been measured for that particular bike?
[?QUOTE]
I know I haven't. What I'm going by is my coastdowns. At speeds in the high teens, my V-Rex coasts side by side with DF riders of roughly the same weight, if they are on the drops. If I go into an 'aero slouch' I can barely pull away, but I can't pedal in that position so I can't use it as a normal riding position any more than they can keep their noses on the handlebars all the time. The implication is that when they're on the hoods I have a *teeny* aero advantage. To back up that supposition, my top flat sprint speeds are similar on both platforms.

 

[Paul W]

>Of course, if comfort, not speed, is the main concern, then it doesn't
>really matter.

Just a little postscript to this thread.

I've just ridden several hundred kilometres (Great Vic Bike Ride) on the
carbon fibre seat of the MR Swiftlet and MUCH to my suprise, I didn't get
numb bum or notice any discomfort (except neck tiredness from time to time
( 28 degrees) - but I'm an old codger...) Even the "wet back" syndrome was
minimal and I can only put this down to the thin perforated rubber cover.

The seat is an M5 and I've added a couple of lengths of soft plumbers
lagging half way up the seat, on the sides, to give lateral support.

After a hot, hard, hilly days ride on this trike, I still had enough energy
to sprint the last kilometre.

Paul W