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Old 06-17-2015, 01:43 AM   #1 (permalink)
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Recumbent Racer, Ecomodder?

Recumbent Racer, Ecomodder?
http://thekneeslider.com/homebuilt-r...ctioned-event/

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Old 06-20-2015, 04:38 AM   #2 (permalink)
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I have been considering this design.

Recumbent seating position's lower frontal area is superior to upright position for bicycles and motorcycles and cars.

The seating position is more dangerous in a crash compared to conventional ejection (leap of faith) design. There is no escape from a crash when you are inside the vehicle therefore it requires a (heavy) roll cage.

The weight of the bike can be less than stock vehicle as has been demonstrated by Rohorn.

Handling corners does not seen to be an issue for Rohorn however I wonder if the design has the potential to keep up with upright riders in the turns.

My current thinking is that a reverse trike with recumbent seating position would be the best compromise between safety, light weight and frontal area. It also allows for better streamlining.

I would like to add that the virtual hub center steering is a bit to complicated and turns me off this design. It could be very difficult to get such an unconventional design past an engineer.

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Old 06-20-2015, 11:27 PM   #3 (permalink)
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Robert did a similar FFE (funny front end) on a Harley-engined sport bike, so he has experience with it and seems satisfied with the performance.

Motorcycle Builders Bob Horn

Something suitable for the race track is not necessarily suitable for the street. Lighter than stock streetbike is pretty easy to accomplish for a racer, as you jettison all the street stuff that isn't needed.

Quote:
the potential to keep up with upright riders in the turns
That all depends on the rider, doesn't it? You could put me on a MotoGP bike and a top club racer on a stock 20 year-old bike and I'd still come in a distant second. To my mind the issue is more of comparing apples to apples -- will Joe/Jane Rider, of middle levels of skill, do better with a conventional bike or an FF? One configuration that has an ultimately higher level of performance, but that requires an ace rider to reach it, may give slower lap times with the mediocre rider who finds the alternative configuration less intimidating.

Arthur Middleton has a lightly-modified Kawasaki EX400/500 FF track day bike. He's let a fairly fast (much faster than he is) club rider take his bike out and the fast guy not only enjoyed it, but thought there was some potential in the concept (not to mention that optimizing suspension/engine/tires/brakes would knock seconds off the lap times).



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Old 06-21-2015, 11:16 PM   #4 (permalink)
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Quote:
Originally Posted by Michael Moore View Post
That all depends on the rider, doesn't it?
There are not many masters of Robert's Recumbent motorcycle. If someone spent 10 years racing the recumbent motorcycle I wonder if Robert's recumbent motorcycle would be objectively better on the straights and on the corners.

That is what I mean.
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Old 06-22-2015, 12:51 AM   #5 (permalink)
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The long wheelbase FF is probably not going to be as good in tighter turns. A 125 with a short WB seems to be able to easily change line to go around bigger/longer bikes in a corner, though some of that is probably due to very light weight. A low center of gravity FF will have to lean a little more for a given corner and speed than a higher CG bike will. Modern RR is a very physical sport, and the recumbent won't lend itself to the rider moving around the way a conventional bike will.

It might end up being a horses for courses kind of a deal, where the high speed large radius-corner track works better for the low FF and a tight track works better for the conventional bike.

The problem is that unless you can get a top rider interested in the concept and willing to work with a builder to develop a bike away from the races we'll never know. Winning in modern RR is a matter of minute evolutionary changes and no one is going to start with a clean sheet and try to race against the bikes with years of development, and even if they decided to do so they'd probably better have a big fortune of their own to spend because they will probably have a hard time convincing sponsors to pony up megabucks.

There are a few riders who are decently fast club racers that have built conventional bikes with FFEs and they are finding that a tire that works fine with a telefork is very hard to get up to temperature with the FFE. So you need to get a tire manufacturer to build a tire optimized for that. The Elfs had support for special tires from Michelin back in the old 500cc GP days for their FFEs, but I think some of that may have been due to it being a French team running French tires.

Don't get me wrong, I've got a mildly sporting FF with FFE project "resting" in the garage, and if I ever get it running it will see some track days and I'll be happy to loan it to any fast riders (I'm not) who want to try it to get feedback. I think it is possible that a 50th percentile or lower rider might go just as fast on the FF, or maybe feel more comfortable and go a little faster. The Gurney Alligators are reported to be able to be hustled along at a pretty good clip, but then if it is Eddie Lawson on his 'gator it is hard to say if it is the rider or the vehicle that is the determining factor.

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Michael
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Old 06-22-2015, 03:41 AM   #6 (permalink)
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I've always wanted to build something like that.

Too bad I'm almost completely mechanically inept.
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Old 06-22-2015, 10:15 AM   #7 (permalink)
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Certainly a very well done project and would show some aero improvements, but I don't think it would be a good design for street use.

Riding in that position your view of the road would not be very good, and you would not be easy to see in traffic - both of which would increase the chances of a crash. In the event of a crash, with that design, I do not think the rider would fare well.

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