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Old 08-20-2010, 01:01 AM
Chalo Chalo is offline
Motorized Bicycle Senior Member
Join Date: Aug 2010
Location: Texas
Posts: 78
Default Re: Strengenthing my new cruiser

Originally Posted by Greenlake View Post
Hi there.

New to this forum and motorized bicycling.

Just bought a Huffy beach cruiser from walmart (see pic below) and ordered a 49cc 4 stroke 4g t belt engine kit.

Wondering if any of you have any advice to whether I need to strengthen my bike in anyway to handle the motor?

It has a steel frame and steel wheels.
The frame will probably not be a problem. The rear dropouts (frame ends where the wheel attaches) might be flimsy. Nothing to do there but try it out and see if it holds up.

The wheels will have reliability issues if you ride other than gently, slowly, and infrequently. If they get too beat up to tolerate, do not replace them with the same. Replace them as necessary with wheels that have aluminum rims (preferably double walled) and stainless steel spokes. Have a qualified shop condition them for heavy duty use. Do this before the rag joint sprocket is attached if they are snobs about motorized bikes.

The gentleman I ordered the engine kit from said he has the same exact set up on his bike and has never had a problem....but just wanted to make sure with you guys.
It might be that he does not have a problem, it might be that he does not acknowledge problems when he detects them (very common), and he might just be oblivious (also very common). The assessment of a typical motorized bicycle owner as to whether his bike is in good running condition is in my observation very untrustworthy.

Also, it only has one brake in the rear. Does anyone recommend an easy front brake set a disc, drum, U shape etc....
The strongest braking you can get on that bike without spending a pile of money and/or modifying the bike is a linear pull brake (V-brake) on an adapter plate like this:

The plate mounts on the bike's fork, and the brake bolts up to the plate. You could also replace the bike's fork with one that has studs, but that would probably cost more before everything was ready to ride.

The minimum safe braking to use on your bike is a good quality front caliper brake with good pads. Any rim brake is going to be crippled by a steel rim. Brake pad friction is poor on dry steel rims and almost nonexistent on wet steel rims. This is one of the primary reasons to use aluminum rims.

I would like to keep it as ol school looking as possible so a disc brake setup would probably be my least favorite.
That's OK, because you can't just put discs on a bike like yours that isn't equipped for them. At the least, you'd have to weld on a mounting tab for the caliper and switch to a disc compatible wheel.

To be frank, I'm not clear why people so often choose a coaster brake cruiser for a motorized bicycle conversion. Those bikes are heavy, weak for how heavy they are, complicated to mount things on, and crowded inside the front triangle. They usually lack hardpoints for racks and accessories. They limit the choice of drivetrain options. They usually don't come with decent rim brakes (or any at all), and then the typical motorized bicycle kit makes it likely that the builder will mess up the coaster brake.

Much, much better would be an old pre-suspension mountain bike like this one:

That frame has strong, modest diameter straight round tubing, lots of space inside the frame, lots of space between the rear wheel and seat tube, capable brakes, wide range gearing, and plenty of braze-ons and bosses to mount things upon. Good solid used examples of this sort of bike are not even expensive.

But I guess because Whizzer used a goofy heavy cruiser as the platform for their motor kit sixty years ago, that's what everybody feels like they have to use now? I don't get it. Whizzer didn't have very many suitable bikes to choose from. We do. Why don't y'all use them?

"When I see an adult on a bicycle, I do not despair for the future of the human race."
H.G. Wells
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