Wednesday, July 31, 2013

A unique highway lowracer

A big wheel forkless lowracer


Even though my bike building has come to a bit of a halt this year, that doesn't mean I’m not coming up with new ideas on a daily basis.  A few times a day, I like to find a quiet place to relax with a notebook and sketch up new project ideas. I have really missed my Marauder. I think it may be time to make another long wheelbase lowracer so I can get out once in awhile to feel that burn as I push both machine and engine to the limits. The terrain out here is not the same as the city, so my lowracer will need to have suspension to take me down the gravel road out to the highway. There isn't much traffic on the paved highway around here and the ride would certainly be challenging thanks to hills and tight corners.

Another option is to transport it to a nice stretch of country road about 15 minutes from here where there is very little traffic and fairly smooth straight terrain. There are many cyclists using this stretch. I can just see myself eating roadies up once again as I slip under the wind and pass them one by one!


Some forkless bike examples


This time though, I want a very unique lowracer that has 700cc or 26 inch wheels on the front and back, a rear suspension, over seat steering, and no front forks. Yep, you read that right, no front forks! I have two designs for a forkless bike: one with a hinged triangle and the other with a wrap around frame that allows the front wheel to pivot much like the front wheels of a quad or tadpole trike.

Having no fork over the front wheel would mean that a larger wheel could be used without obstructing the pilot’s view. This will also smooth out the ride, so it would be a decent chassis for an aerodynamic fairing, allowing the rear suspension and long frame take up the bumps. Suspension is a must on a faired lowracer since these things can easily reach automobile speeds, making the smallest bump feel like a pothole. The forkless design and long wheelbase configuration also keep the front of the fairing low so that you can see the road ahead rather than having to peer around the body. This type of streamliner would not be all that great for pack racing on a track, but out on the open road, it would be a real blast!


A crazy pivot fork bike


The easiest forkless design is shown in my sketch and in these cool examples, where the hub pivots on a kingpin held in place by a single tube that wraps around the wheel, leaving space for the turn. I would run a connecting rod up to a control arm just behind the front wheel and then use dual cable steering to get around the curved tube so that there would be less flex in the system and tighter side tolerances for a fitting into a full fairing.

My other version involves a hinged triangle with the pivot very low behind the wheel to keep the tiller effect minimal. I have tried this in the past on this crazy ride called "Tour De Hell", but the result was a bike that had serious bad attitude and took a lot of practice to ride smoothly.

Of course, having a short wheelbase and a huge amount of tiller, this bike steered like a front end loader, swinging from side to side and causing serious steering feedback. I think this system would work out on a long wheelbase recumbent if the pivot had more caster and was placed much lower to get it closer to the axle. I am not sure if I will actually try the pivot fork design since the other method would defiantly work as expected.

Perhaps this winter I may cut some tubing and lay out my new forkless highway lowracer. I always wanted to build a long wheelbase lowracer and then go all the way on a fiberglass fairing so I can get out and push the limits of what is considered possible under human power. I certainly won't be heading to Battle Mountain to race with the big boys of speed, but I would certainly have fun smoking past road bikes doing 50 MPH on a faired lowracer down our country roads!

~ Brad