for clarification i am not claiming to be the fastest and non of you read the title well enough it say "on going project" i am also using this to get to school thats why it is the way it is now. second off i am going to replace almost every thing the engine will have a be around 10k rpm 20 hp and a fuel injection system about 450 bucks ( maybe even with a turbo). i am going to buy or make a new frame . and switch the drive train i know right now i am not the fastest and i never said i was i said it was a project to get there. "on going" i just was sharing pics of the make so far. also the reason that frame doesn't have peddles is cuz i am using that frame to make a full road legal motorcycle ( or try at least).
It literally says you are planning to be the fastest, so I am just making sure you understand what "fastest" means, even though you did mention ongoing project. Some of what was pictured is downright dangerous, and I would rather let you know in case you were unaware before you started throwing more power at it. We see people post new builds all the time with terrible part selections or unrealistic goals and would rather give a reality check then see another failed build 3 months from now or even worse, a rider down.
Again, just giving safety tips. Use moped or motorcycle forks and add rake to the head tube using a trail calculator and the current wheelbase. If you can't weld aluminum to mod the frame, get a new one because no bicycle frame except for maybe those custom Imperial Cycles frames has anywhere near the proper rake for highway speeds. Less than a month ago a guy on a gas frame with CDH fork punctured a lung and almost killed himself when the poor geometry coupled with weak flexing bicycle forks caused headshake at 70+mph that threw him off the bike. If he didn't have a motorcycle helmet he would be dead right now. He had much stronger wheels and moped tires as well, would be worse with those brittle 10pt mags and less stable on bicycle tires.
Don't worry about the EFI, totally not worth it unless you actually are going forced induction. I've only seen one completed FI bike and it was Kurts all custom 212 build - frame, forks, wheels, turbo kit, etc was all totally custom. No store bought parts available for that kind of build.
Super sure, it's simply math dude. Less moving parts with twice the power strokes will allways allow a more powerful 2 stroke to fit in a given space. If a big bad super fast 4 stroke could be put on a bicycle, then a more powerful lighter bigger displacement 2 stroke will always fit.
Bit of an OT ramble but this is honestly not that cut and dry.
My 4stroke will be the quickest(AKA acceleration) motorized bicycle and likely fastest in top speed as well if I cared enough about that to swap gearing, even with a big weight penalty. It might have already been close for the acceleration part but I didn't bother testing it. To get the idea of the difference between a high end 4stroke and a high end 2stroke TQ, a theoretical 70cc big bore AM6 that makes 60% MORE HP then my motor pre-internal mods would still just make a whopping 9ftlbs of TQ. That 60% more HP is nice, but still a huge difference in pulling power when you have more than double the TQ. To be fair, there is an insane displacement difference as well so yea in things like HP:LB or the useless HP:L its not as "efficient" a platform if you care about that.
The answer to this problem for most vehicles is just "gear them better" but until someone comes up with a bolt-on transmission we can't. With our single speed bikes (shifter jackshafts can't hold big power so will never hold a speed record), the TQ benefit allows 4stroke overall gearing to be used that a 2stroke would only hope to achieve to get more mph per RPM. That negates some of the RPM advantage due to the 20:82 (22:80? I forget) internal reduction on a chinagirl. IE: You can gear a basically stock 212 to do ~60mph super easy with a 44t sprocket and 14/10 jackshaft and still have great acceleration compared to a properly ported chinagirl that can do the same exact speed but needs a 32t rear, makes a fraction of the TQ, and won't accelerate half as quickly. Yea on paper they are both the same speed bike, but one is a lot more fun to ride and gets there much quicker.
Two very different versions of High Performance...in general the 2stroke will have higher top speed but slower acceleration than a similar class engine, but when you can go bigger much easier on the 4stroke, and you are not limited to the same engine size, the 4stroke becomes much more appealing.
