This homebuilt beauty was a summer project in 2004, when I was unemployed and had time to build! Front wheel drive and front steering creates the ultimate in stability for all-weather riding.
Hi, have you considered just having a directly-pedaled front wheel? That would eliminate the chain, extra axis with bearings for pedals, and the extra frame sticking in front of the front wheel. You can have an internal gear hub. Might need to move the seat back some. If weight distribution isn't good enough, you can move the rear wheel farther back. The overall frame will be bigger and heavier but is there anything fundamentally wrong with this idea? The turning and its limitations should be exactly the same as far as i can tell. PS my concern is comfort for commuting, not speed. With a few gears, any bike can have enough speed for commuting. I'm not an aero or racer, but recumbants get mixed up in that category cuz the leaning back position is way better for aero so racers can get huge speed. Makes it hard to find good the type of info i want for comfort and rideability, with a focus on commuting.
I didn't consider what could be done with the gear hubs you refer to, but that would allow better rider position. The immediate problem is the gear hub though, because they are driven from a sprocket and not the central shaft. Structurally, a bike's bottom bracket shaft and bearings that support the cranks are really stout, and all that would need to be integrated into a custom gear hub. That would need a lot of advanced design and machine work. Might be worth pursuing, though. Thanks for the idea
I had a rear drive recumbent with about the same wheelbase and rode it in the winter before the snow came. When riding on ice I could spin the back wheel without having to put a foot down. Your comment along the same line was interesting.
@asayle3r5 Interesting. Another approach could be to to flip the front forks to facing to the rear. This may cause the tire to interfer with the frame to the rear, or not, depending on the bike. It is worth considering as it is very simple to do.
@RogerSarrasin I think I just pried them apart until I reached the needed width. There is one other mod that I neglected to mention.... I made the bottom bracket as close to the tire as possible, which left very little clearance between it and the tire, but then the tire did not fit between the chain stays, so I had to notch away some of the stay tubing and then weld in a U-shaped reinforcement to maintain strength.
@eukaryon thanks for watching, happy that I can get others building creatively. I have always wanted to figure out why that stability thing is contrary to the fork geometry convention; I suspect it's related to more weight on the fork. it felt like the highest spot in the system going straight, and a little rotation would lead to the weight on the front to pull the system into more and more rotation, but it could be recovered at some point.
Nice work. This is similar to the first recumbent I built about 20 years ago except I used 20" wheels. This is my favourite bicycle configuration still. Pity they are not more popular.
I made a lot of experimenting with FWD's steering fork in 1980~90th. Found; The Optimal angle to minimaize pedaling force into steering is 45 degree to horizontal
Interesting that you made the steering angle steeper. Ideally you need to change the trail as well. There is a guy on RU-vid, built a very nice 95deg steerer , though not FWD. (The steerer angle is only there to move the handle bars closer on an upright bike)
Great work! it is inspiring me to try and build one. The seat is in a pretty good location, 50/50 weight distribution. Interesting you made the fork more perpendicular for stability, usually bike stability increases with fork angle. A MTB drop frame might make a place for the seat and MTB forks are more perpendicular. But the forks are stiff and cannot fit a cassette. Front drive and pedal is supposed to be hard on knees - the knee must twist when you turn. I would like to test this myself.
Original front fork steering angle shall be around 45 degree. You shall be able to do NO HANDs Start with your FWD. I made my FWD experiments with front-fork in early1980th.
Honest Question. From someone who has been looking at doing something like this but hasn't had the means yet. @ 2:49 If you drew a straight line from the rear axle to the front fork pivot. Would the power transfer be better if the 'seat tube distance" was moved as close to the rear tire as possible. I also also wonder how well a "butt steer' version would work If the turning radius was off of the "seat tube". Of course that angle would be critical.
That looks pretty good. Does it wobble when you pedal? Since your legs are pushing against the pedals and they are on the front fork, it seems the fork would turn to the left when you push w/ your right leg and vise versa.
On road bike, passing a bump u can stand on pedals to absorb the shock with soft knees. On recumbent u can't do that, so a suspension, even on front wheel (1" travel at least), is a must, unless frame's shock-absorbing ability suffices (at risk of fatigue fracture). Yours has none. Can u ride it on rough road for a few hours non-stop w/out lower back problems? Shallow head angle prolongs trail, thus self-stabilizing. U claim opposite(?)
@sproutingman Yes, with the typical stock geometry, the bike was virtually unridable. I need to measure the head tube angle; someone else asked what it is in the video comments. I also shot a lot of footage for a better video, but have not edited it yet. I have wanted to build a "Mark II" model of this bike, because I have access to much better tools and material than I did for this bike. You might be able to get the same stability using a front wheel smaller than the back. Good Luck!
@srussert28 Thanks for taking interest in the design. With the size of wheel used here, the seat cannot be moved any farther back, unless the rider has unusually long legs. For reference, I'm about 5'11 with very average leg length. Maybe the crank bracket could be moved downward along the same radius, then the seat could move back a bit, and the riding position could be even more reclined, effectively shifting the CG rearward. Butt steer could probably be done, provided it is self-stabilizing
We are making a recumbent cycle and planning to use front wheel drive . We are also using a fairing for aerodynamic purpose. If we adopt the same technique as you have done, the pedals would hit the fairing while taking a turn. Sir do you have any other mechanism where we can keep the crank of the pedal (eventually the pedals) fixed and still use front wheel drive which would ensure that the Tyre does not get stringed with the chain ?
From the looks of it, your recumbent is awesome. I built a low racer marauder based off of atomic zombie plans. Love that bike. It's time to build another recumbent. Your seat angle looks about the right angle for comfort with decent speed. Front drive sure cleans up the drive chain. Thanks for the video
Looks like the front wheel does not turn much when you steer. It also looks like the whole drive assembly from pedals to drive wheel are fixed and the entire drive assembly pivots to steer.
How would someone like me that knows nothing about building bikes build one, or do you make them and sell them.? I would be willing to have my bike turned into one. Please please please, lol