Recumbent - wow

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
itsajustme
10-09-08, 08:10 PM
just wow (http://www.vimeo.com/1819714) :eek:
megaman
10-09-08, 08:42 PM
That is fast. I just don't feel video does it justice. I would have had to be there to really appreciate that kind of speed.
Rogerinchrist
10-09-08, 10:54 PM
Dig that sound!!
That's a truely awesome video, thanks for posting that!
Amazing. And the record for an up right bike is 47 or 49 MPH and it has not been broken in about 20 yrs:-)
Mark
Torque1st
10-13-08, 08:54 PM
I wonder what makes that noise? Do you suppose it is the chain on the cogs? Then other bikes did it also.
Jeff Wills
10-13-08, 09:39 PM
I wonder what makes that noise? Do you suppose it is the chain on the cogs? Then other bikes did it also.
I was there.
It's the tires that make that hum. Sam goes so fast and is otherwise so smooth that the tires give off a distinctive hum. Other bikes do not sound like this, and besides, the drivetrain is completely enclosed.
That evening was absolutely perfect conditions for a record run- it was about 80 degrees and the wind was fairly calm for a couple hours beforehand. Usually it's pretty blustery until about 5:30PM, then the wind dies off. That day it was quiet most of the day.
Torque1st
10-13-08, 10:54 PM
The other bike videos on the page where this one was all have the same noise, differing frequencies tho, probably related to speed.
Jeff Wills
10-13-08, 11:53 PM
The other bike videos on the page where this one was all have the same noise, differing frequencies tho, probably related to speed.
I guess you had to be there. :D
The sound that Sam's Varna (and Freddy's, too) is distinctive. It may be that it's part of all the sensations that go with witnessing all of them go by. The sound, though, goes something like this:
Larry Lem / Tom Amick in the Goliath II : WhiiiirrrrRRRRRrrrroooo
Warren Beauchamp in the Cuda-W : WhiiiirrrrRRRRRrrrroooo
Barclay Henry in the Black Trike: Whhhiiiirrrrrrrrr
Ron Layman in the Primal: Whiiiirrrroooooorrrroooo
Aaron Williams in the Athena: WhiiiirrrrRRRRRrrrroooo
Sam Whittingham in the Diablo III: SsssssssoooOOO WHOMPP!! ooooooooo
Fred Markham in the Mephisto: SsssssssoooOOO whompp! ooooooooo
I know that Sam "only" did 1/10 the speed of sound, but there's a definite shockwave when he goes by. Maybe it's the massive intake of breath from the spectators. :thumb:
Torque1st
10-14-08, 09:07 PM
Being familiar with machines of many types the noises were all similar. I think it was chain and sprocket noise, not the tires. No matter what made it, the noise represents an energy bleed.
Jeff Wills
10-15-08, 12:44 AM
Being familiar with machines of many types the noises were all similar. I think it was chain and sprocket noise, not the tires. No matter what made it, the noise represents an energy bleed.
The pavement at Battle Mountain is pretty bad. Not chipseal bad, but well-worn bad. I know what chain and sprocket noise sounds like (heck, I spent 5 years working in a bike shop) and that's not what I hear when a Varna goes by.
I agree that the noise represents lost energy. That's why I'd like to see an alternative event held near Burns, Oregon (http://www.bentrideronline.com/messageboard/showthread.php?t=31933&page=3). Same altitude, same weather, extremely smooth pavement. Sam reported that the ride was so smooth that he was discovering all sorts of "new" problems- but they were things that he could never hear before.
Torque1st
10-15-08, 02:07 AM
Interesting... My experience does not include a bike shop. But it does include lots of chain drives under power. The rollers hitting the sprocket make a similar noise.
My bike experience is all shade tree except for 4 years in a real old fashioned "service" station where we fixed kid's bike tires for free and the kids knew it. I started the "bike service" when a kid filled his own tire like he saw us fill car tires and blew it up. The boss liked the idea of always filling them ourselves and/or with supervision so it became policy. He was an old softie and did not want to see a kid hurt. You would be surprised how many $ from regular customers that saw us fixing bikes flowed into the patch fund. We were sort of a bike "teaching hospital". The kids could watch us repair their tires and we always explained every move we made and why. Once they had seen it done a time or two they got to help... We also made adjustments and lubrication. The bike shop down the street about 5 blocks probably hated us but they charged the little kids just for looking at a bike. Parents would come in and have their cars serviced or filled and thank us. It was good advertising on our part.
gew0419
10-15-08, 07:52 AM
That blows my mind. I can't imagine 81 mph. I've gone 38 mph on my Sun EZSport...down hill. That's plenty fast enough for me.:)
BlazingPedals
10-15-08, 03:19 PM
Not to take sides, but to me it sounds like tires on rough-textured pavement. It even drowns out the normal hollow 'whoosh' that streamliners usually make.
Rogerinchrist
10-15-08, 08:59 PM
Not to take sides, but to me it sounds like tires on rough-textured pavement. It even drowns out the normal hollow 'whoosh' that streamliners usually make.
I would agree.
Open a car window & shut off the engine (while in neutral) the tires will make noise while at some speed.
Torque1st
10-15-08, 09:49 PM
I have ridden a bike and coasted at some speed. 35+ over rough pavement and smooth both asphalt and concrete. I have also coasted in a vehicle at high speeds. The large auto tires with a more aggressive tread and a large footprint make noise, the bike tires just make a hiss with a buzz from the freewheel. Of course vehicles with a very aggressive tread make a huge amount of road noise. Listen to one of those lifted trucks... I still think the major noise is chain noise having heard it first hand on my own bike, and machines without tires or engines, just motors. Unfortunately that noise represents an energy bleed. Has anyone ever used a belt drive for a high speed run? A belt makes a similar noise but much more subdued due to an elastomer impacting the sprocket rather than a hard steel ring.
Jeff Wills
10-16-08, 12:14 AM
I have ridden a bike and coasted at some speed. 35+ over rough pavement and smooth both asphalt and concrete. I have also coasted in a vehicle at high speeds. The large auto tires with a more aggressive tread and a large footprint make noise, the bike tires just make a hiss with a buzz from the freewheel. Of course vehicles with a very aggressive tread make a huge amount of road noise. Listen to one of those lifted trucks... I still think the major noise is chain noise having heard it first hand on my own bike, and machines without tires or engines, just motors. Unfortunately that noise represents an energy bleed. Has anyone ever used a belt drive for a high speed run? A belt makes a similar noise but much more subdued due to an elastomer impacting the sprocket rather than a hard steel ring.
The other bikes make that sibilant hiss as they roll by, too. The difference is that Sam is doing EIGHTY TWO POINT THREE MILES PER HOUR. He's also rolling on some very nice sew-up tires, which resonate differently than more usual clinchers.
If your chain is making noise when you're pedaling, it's probably worn or lacking lubrication or both. My bikes are silent when parts are new or newly lubricated, growing progressively noisier as they age and accumulate gunk.
Belt drives have been tried, most notably on Matt Weaver's Cutting Edge II:
http://www.speed101.com/images/cuttingedgeII/IMG_2337.jpg
http://www.speed101.com/images/cuttingedgeII/IMG_2306.jpg
(belt drive parts visible on the left side of the frame)
From: http://www.speed101.com/gallery/cuttingedgeII_june22.htm
Unfortunately, belt drives aren't compatible with derailleur-style gear changing, and roller chains are 90 to 95 percent efficient. It's very hard to come up with an overall better drive system than a conventional bicycle chain.
Torque1st
10-16-08, 01:44 AM
Roller chain always makes noise even new and bathed in lubricant which is why they have "silent" chain but silent chain is an entirely different device. Some of the major manufacturers also have low noise chain but it is still not silent.
Jeff Wills
10-16-08, 08:07 PM
Roller chain always makes noise even new and bathed in lubricant which is why they have "silent" chain but silent chain is an entirely different device. Some of the major manufacturers also have low noise chain but it is still not silent.
I don't know what you're doing to your chains, but my bikes are silent, particularly the single-speed and the fixie.
Torque1st
10-16-08, 10:00 PM
Roller chain ALWAYS makes noise. It is the nature of the beast, if you think it is silent you need your hearing checked.
BlazingPedals
10-17-08, 07:27 AM
Roller chain ALWAYS makes noise. It is the nature of the beast, if you think it is silent you need your hearing checked.
Yes, but his chain is enclosed inside a carbon/kevlar/foam shell. It absorbs sound very well. Chain noise, however much there was inside, would be muffled to the point of being insignificant to an observer on the outside.
EnigManiac
10-17-08, 12:43 PM
I go that fast on my urban commute ride every day on my BikeE AT...ok, maybe I'm a little slower. :D
StephenH
10-17-08, 12:43 PM
They're probably running knobby tires in case they hit a mud patch up there.
Jeff Wills
10-17-08, 11:36 PM
Here's a couple more vehicles:
The Orion trike
http://www.vimeo.com/1892372
http://www.vimeo.com/1892418
The Goliath back-to-back tandem (two drivetrains, twice as many chains)
http://www.vimeo.com/1898550
The Speedhawk
http://www.vimeo.com/1991518
DannoXYZ
11-09-08, 12:41 AM
Sew-ups definitely have a "ripping fabric" sound to them due to the supple casing. If you've ever used sew-ups, you'd recognized that sound at speed in a second. :)
What kind of gearing was he using? Does that bike have the standard drivetrain with derailleurs?
BlazingPedals
11-09-08, 09:58 AM
What kind of gearing was he using? Does that bike have the standard drivetrain with derailleurs?
I'm not sure what the final drive ratios are;, but it's only a 5-speed transmission. The cassette (or is it a freewheel?) is located at the mid-drive.
http://www.wired.com/images/slideshow/2007/03/gallery_bikerecord/orpheusguts.jpg
DannoXYZ
11-09-08, 05:06 PM
Hmmm, double-reduction gearing, interesting. So that's how you get the insanely high-gearing needed for 83mph! And front-wheel drive too, cool!!!
Allister
11-12-08, 06:30 AM
There's probably a bit of amplification of the tyre noise happening with that hard shell, too.
BlazingPedals
11-20-08, 04:42 PM
Here is a video of Fast Freddie Markham doing his run at Battle Mountain. I hear some chain noise and a lot of wind noise. See the plastic bubble being buffeted around!
http://www.youtube.com/watch?v=lPzFavvTqHk