New to motorized bycicles, have a few questions

[jeffdamann]

Im thinking about building one of these bad boys, but I have a few questions.

being 200 lbs, will I be able to build a bike that can go 60 mph on moderately level terrain? Having a decent amount of technical expertise I dont mind having to do minor fabrication and the like to make things work.

Im assuming if I want to go 60 and not wreck, I will need wider tires and a beefy suspension correct?

How much torque do most of these kits produce? Will I be able to find one that can hold a wheelie if I manually jerk the bicycle in to one?

How ideal are these kits for offroad usage? I would also like to use one of these as a semi dirtbike. I know its not going to really perform spectacularly, but at least being able to carry me through thick grasses, dirt, and rocks at a decent speed of 30-40 would be a plus.

As Ive said Im quite new and have done some reading, but I dont want to get too far into this if my goals cannot be accomplished without exorbitant financial difficulty.

 

[Tony01]

Motoped. 60 is a stretch but you can build a cruiser for about $1500 with front suspension that will do 55. Better to find a second hand motoped or brand new.

 

[LandSpeedRecord]

Yes, what he said about motoped. Your goals and expectations are way outside the performance 99 percent of these can handle. You are actually outside motoped performance and into motorcycle territory. These have a serious learning curve and first you need to get experience building them to be safe at 30 then probably be able to eventually get 40 out of a typical beach cruiser. The cruisers will be faster than the mountain bikes in almost every case given the same motor. Google image racing motorized bicycle and you will see 60mph plus bikes. They were built by people who have many many builds under their belt and cost in the multi thousands just in parts in most cases. Off road performance is a huge hurdle your only true option is the motorped or possibly with a lot of work on of the old GT or Proflex mountain bikes that will take an engine. Research that close there are a select few that work and they are complicated to build. You will also need to make big power, either a master built China girl or a KTM type motor. This forum is a great place to learn. Read read read on here before you start so you can go in the right direction.

 

[TheNecromancer13]

For your first build 60 mph is unrealistic. You will need a lot of experience and a lot of money to build a bike that can go 60, and also learn how not to kill yourself with it. I have also never seen any bike built from a kit that can do 60. Some of the really good ones can do 50, but that's after a thousand dollars worth of upgrades and hundreds of hours of work. I'm currently building one that will do 60, but I'm using a 125cc 4 speed pit bike engine, spending a few thousand dollars, and I've been working on it for over a month and I'm nowhere near done. And I am someone who has built quite a few bikes and I'd like to think that I know what I'm doing.

If you want off-road capability, consider something like this, but swap out the 79cc for a 212 since you weigh more than I do:

This is my current bike, it does about 40 on level ground, and has a good front suspension and big tires so it handles offroading pretty well. It can't do big jumps or anything like that, but I sometimes ride it on single track trails for fun and I also use it to get to work every day, and it recently hit 5,000 miles without a breakdown despite my best efforts to abuse it. You can build one similar to mine for about $1,500. Here's how: http://www.instructables.com/id/79cc-Motorized-Bicycle-From-Scratch/

Note that for a first build, this will be challenging, and it's going to take a while. But if you want something a more than a kit can offer and have the knowledge and tools, it's a good starting point. It will also help that my instructions are better than the ones that come with the kits lol.

 

[Allen_Wrench]

Experienced race builders are pretty stoked if they can build a motorized bike that can do 50 mph - and those tend to be seriously modified and customized pieces of work. Almost everything on them has to be up to the task - top notch tires that won't blow, solid rims, strong spokes, heavy-duty hubs with a hub adapter help, good wheel bearings with high-temp grease, 415 chain at least, strong frame - usually steel but not always, reliable front suspension becomes pretty important, and of course the engine is generally modified with plenty of performance parts and lots of tuning has been done, and others who have done all this could probably contribute even more tips.
This is a serious endeavor for a first-time builder of motorized cycles, even if you opt for the motoped. I would like to see you reach 60 mph, that would be cool, but I hope you are able to do it safely.

 

[DaveC]

There's an Italian company called Seven that makes a 25 horse 50cc stroke. It's a 6 speed and is used on tiny little GP bikes...they are fast...and expensive. Try around $6000 for a base model. That's about the only 50cc legal motor that has the power needed to get to those speeds. But can you imagine the road raspberry that would come from dumping a bike at 60?

 

[Cylon]

Your post was great lol, but if you want to go 60 mph I recommend buying a used motorcycle those are already made to travel the streets at that speed safely. Im 220 and my bike goes a bit over 40 maybe like 43 tops with a 41t sprocket. I can pull a wheelie if Im trail riding, preload your front suspension and it will pop up. Not easy to ride the wheelie out with a small sprocket since you gotta be going fast to hit the power band.