> >With a tadpole boom, and the pedals out on the end of it, you might find >that python style steering will cause the front wheels to hit your legs, >pedals or both and put big limits on how tight you can turn. The only fix, >it to make the thing about 36" wide or wider, and even then, you still might >have wheel - leg issues. I have brought this up in the past. if the python design is reversed so the pivot point stear the rear wheel and the drive wheel is fixed to the seat very tight turns are possible without leg rub or miss-alignment with the pedals. > >> >> 6) some type of handle bars to allow the rider to induce the lean for >> the steering. > >I don't think you are going to be able to lean the trike. When turning, it >will swing up to the outside of the turn, and swing back down to center, but >it can't lean - at least the way it looks to be explained so far . . . a lean steer can be accomplished by using a simular design used by skatebords. I am assuming we are talking about the tadpole design.? > >> The purpose of this is to design is as follows: >> >> 1) A self centering trike that can be the base platform for a >velomobile. > >It will self center all right, but think about how far out to the sides the >wheels and/or wheel fairings will stick when turning, especially if they >have small wheel fairings. If you plan to enclose the front wheels in the >body of the velo, again, the front end of the fairing will need to be crazy >wide. consider having only the wheels turn like in a car. With proper design they will self center like a car. > >> 2) It will allow the use of standard bicycle parts without relying on >> special hubs for the front wheels. > >You can already use standard bike parts for the front wheels without any >special hubs. BMX front wheels come with 14mm axles which are more than >strong enough to be used on a tadpole. Myself and many others have used >them quite successfully with simple rim brakes. You can also get disc front >hubs with a 12mm axle and sealed bearings made by Formula - no machining >required. Do not forget the 4 meters of bike chain needed for the tadpole design. > >> 3) Allow higher gearing using as 26" rear wheel and using 16" or 20" >> front wheels with disk brakes. > >You can get higher gearing with just about any size rear wheel now by using >a Shimano Capreo rear hub that has a small cog of 9 teeth without having to >go for crazy 60T chainrings on 20" wheels. > >> 4) If building a velomobile the python frame joints could be built >> into the faring design for the front wheel mounts and to total encase >> the front wheels for aerodynamics. > >It's a cool idea, but honestly, for a tadpole, just build a tadpole - >they're not difficult or expensive to built. If you want to utilize the >python design, then built a python delta like some others have. It makes a >great delta, which you can still turn into a velo if you want, much simpler >steering, chainline and frame design. A whole lot lighter too. Good luck >whatever your choice though :) > Having the bike flex in the middle of the velo will require the velo to be much larger than normal to allow for the movement. Not to for get how will it be attached. If a python type bike is used having a different type of velo would be a good idea. It will look more like a bug with a thorax and a tail with a pivot in the middle. >> If someone is good with a sketchup I can try to provide further details >> if need be to help developing the plans. sketchup is an easy program to learn. It is a little buggy but usable. Just sit down with it and go. The Step by steps are great. ============================================================ This is the Python Mailinglist http://www.freelists.org/list/python Listmaster: Jürgen Mages jmages@xxxxxx To unsubscribe send an empty mail to python-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field. ============================================================