30-45MPH I wouldn't be that concerned, much above that with the HP you are talking about and I'm concerned....LOL!
Sounds to me like you're itching to build a death trap.......LOL, a bicycle doesn't require 10+ hp to cruise at a very nice speed and have plenty of power for using a bicycle frame to it's limits, a 6.5hp Honda clone HF engine will push a bike to 50+ mph if set up right and that would be beyond what is safe for most bike frames and the small axles.
Just giving personal opinions here, not trying to shoot you down in any way, I have three bikes that will hit around 40 mph which is good enough for me on my bikes, I also have a 150cc scooter that will run 60mph which is good enough for a small scooter, I have a 1982 inline 4 cyl. Yamaha Maxim that will go way faster than I will ever want to go, point is that a typical bicycle that will cruise 35-40 mph is what I consider a safe speed as long as all things are good and right, 10+HP engine that will put loads of torque on a bike frame........I'm out, not safe, bike frames are NOT designed for that, I know some may disagree and that's fine, but to me Motorized Bikes should be Fun but also Safe NOT Fun & potentialy Lethal from being to fast & over powered.
I wish you the very best with what ever you do, but just keep in mind, It's a little underbuilt Bicycle Frame when it comes to putting BIG HP on it.
Originally Posted by racing fan
I have a frame I really want to use but I don't think it will handle what I want to do with it, I need some advise on that aspect. Here is some info on the frame, it's a banana bike frame from the 70's made of steel with 3/4 in tubing used in construction. I was wondering if you guys think it will hold together at 30+ mph? (definitely higher than 30) Another note is the engine will be no less than 7 hp and will probability be 10 hp with a variator for a trans set up. In short it will accelerate hard and also top out at a high speed too. With that kind of power I have doubts about the frame and the forks.
sorry forgot this part:
The forks are stock and some 16+ in in length and the taper from about 3/4 of an in. to about 1/2 in and are slightly oval not round. (factory)
Do you guys think monark forks will hold up to it too?