HP needed to go 60mph IN A STREAMLINER?

[GasSavers_Otto]

Google for keywords "Sam Whittington HPV" to get started on streamliner efficiency.

The current level ground speed record for a human powered vehicle is ~81 mph, and a very skilled rider can do maybe ~1/3 hp in a sprint. HPV sites have the particulars. Since aero drag increases exponentially with speed, 60 mph is a lot less drag than 81 mph, so less hp and thrust is needed. Maybe half as much, depending on all sorts of other variables, aero, mechanical, weather, etc..

[GasSavers_RoadWarrior]

I wonder if those HP figures are for straight over the pedals effort though, as far as I understand it the recliner style that hold most of the top speed records, allows one the back of the seat to push against. Though to some extent, record holding "upright" bikes are becoming more like forward recliners, with the athlete able to brace against the bars.

Edit: BTW I'm always busting the pawls, or splitting ball bearings in the freewheel assembly on the back hub of my bikes, does that mean I'm developing a high burst torque/HP or just that I'm getting crappy parts? I did pay $75 for one once, hoping it would last... killed it in 2 months, quicker than the one that came on my bike. (Yes, I actually can have traction issues when I set off, and can make 2 inch mountain bike tires scream for mercy, also for some reason I can pedal harder on old sit up and beg roadsters than most touring bikes, frame geometry must not work out for me or something...)

[samandw]

Originally Posted by Otto

Google for keywords "Sam Whittington HPV" to get started on streamliner efficiency.

The current level ground speed record for a human powered vehicle is ~81 mph, and a very skilled rider can do maybe ~1/3 hp in a sprint. HPV sites have the particulars. Since aero drag increases exponentially with speed, 60 mph is a lot less drag than 81 mph, so less hp and thrust is needed. Maybe half as much, depending on all sorts of other variables, aero, mechanical, weather, etc..

1/3 hp doesn't sound right. Most reasonably skilled riders can ride a 100 miles in 5 hours. . . which amounts to about 1/4 hp continuous. This link claims that Jason Queally can put out 2200 watts (2.94 hp) in a sprint:
http://www.wisil.recumbents.com/wisi...onder_Team.htm

I've peaked at over 1 hp (for a second) myself, and I'm not exactly a sprinter, though generally in good shape.

[mtkawboy]

Cross winds are why that streamiler design shown are no longer legal to run at Bonneville. That is similar to Bert Munroe's "Worlds Fastest Indian " liner who's record still stands

[VetteOwner]

Originally Posted by Big Dave

I agree with Vette owner about somebody merging into you. Motorcyclists survive on a mixture of 75% situational awareness and 25% raw acceleration. Thus bikes cannot be operated quite like cars or trucks. That's also why bikers say: "Loud pipes save lives."

.

hehe that last statement always kinda T-ees me off. i can see the point of having a somewhat loud bike, yes it does make you more aware of where it is when you hear one, BUT there is a limit. i shouldnt and DONT need to hear your bike 1/4 mile away in my house!

i could say the same thing about small cars and loud exhaust...especially with the behemoth land barges that are out nowadays

[Big Dave]

If I had $10 for every time I've seen a motorcyclist being squeegeed up and the cage driver standing there telling the cop: "I didn't see him!" I would be so wealthy that fuel prices wouldn't matter.

Well, they might not see me but by jingo they'll know I'm around.

The only other alternative is a Glock on your hip.

[VetteOwner]

yup i feel the need to shoot dumb drivers too. BUT also dumb motorcycalist. you kow the crotch rocket types who go 90 in a 55 no helmet just jeans and a tshirt, riding down the center line passing between 2 cars whiping in and out riding your butt while your in a car, etc.

[GasSavers_RoadWarrior]

I notice when cycling that it's impossible to go more than about 15mph on city streets because you just don't get seen, or if you get seen they misjudge your speed badly. Motorbikes/scooters I have the most problem with though are those that use white sidelights in daytime, through any kind of haze or spray they look like a car 4x as far off.... if it was a single or triple light I'd look twice.. even no lights under certain conditions I'd be able to discern a tall silhouette.