hub breaks?

I have recently ordered a bicycle engine kit. I have looked at several bicycles with engines on them and they all have hand breaks. My bike is a single speed 26" cruiser with hub breaks. And as I looked at it I started to get a little nervous. Can someone please give me a step by step procedure on how to mount the sprocket on the wheel with this type of breaks. It's the arm that attaches to the frame that is troubling me. Will it get in the way?....Thanks

You probably have coaster brakes they are not good enough for the speeds you can attain.
Do you have a front drum brake if so all is ok , otherwise add a front drum brake quick

Ginny's Old School BMX-Hubs
look at #30 or #31 front drum brake hub
$25.00 plus installation

If you use the bolt's that came with your kit, you will have to bend the coaster brake arm to clear the mounting bolt's for the sprocket; This is best done in a vise. You could use flat head bolts that you can pick up at any hardware store and you might not have to bend the coaster arm at all, or very little.
The pic show's flat head bolts and countersunk into the sprocket which I believe will give you enough clearence. The choice is your's on which way you would like to do it.

Personally I havent had that many problems with the coaster brake on my bike, its more than strong enough to lock the back wheel under braking on dry roads from full speed...

That said relying on one alone is not the way to go - I have uprated the front brakes to use kevlar based pads which were not cheap but they stop on a dime, and they dont fade in the wet which was what made the rim brakes downright lethal before...

There is also the option of fitting up a jackshaft so that you dont need to worry about the clearance for the coaster - also there is the advantage that if you have a hub you would have a geared transmission then...

Jemma xx

billyjoebigdaddy said:

I have recently ordered a bicycle engine kit. I have looked at several bicycles with engines on them and they all have hand breaks. My bike is a single speed 26" cruiser with hub breaks. And as I looked at it I started to get a little nervous. Can someone please give me a step by step procedure on how to mount the sprocket on the wheel with this type of breaks. It's the arm that attaches to the frame that is troubling me. Will it get in the way?....Thanks

Click to expand...

As fairracing stated you can use flat head bolts. I chose to grind the head at an angle on each of the bolts after I got the sprocket mounted. I still had to bend the brake arm a bit.


You may also have to grind down the dust cover- don't just eliminate it...grind off the outter flange and check fit until it will just go inside the sprocket hole. Some enlarge the sprocket hole to fit the dust cover. The choice is yours.

As fairracing stated you can use flat head bolts. I chose to grind the head at an angle on each of the bolts after I got the sprocket mounted. I still had to bend the brake arm a bit.

I have run coaster brakes only on all three of my builds.
Retro fitting front brakes is cheap and easy if you go with a regular set of cable pull brakes.

Step - 1- take the arm off before attempting to mount the sprocket.

Then what those guys said about the arm upon reassembly.

I have a similar setup- coaster brake, cruiser bike. When you put the sprocket on, you will swear that there is no way that the sprocket could be tightened enough to actually seat around the hub- but if you do it right, it will and I think that is a must. That way you know the sprocket is centered on the wheel.

Also, center the bolts between the spokes, not rotated so a bolt touches a spoke. If you tighten the sprocket correctly, the rubber spaces will grip the spokes and the bolt will never touch the spokes- if the bolt rests against the spoke, there is undue stress on the spoke at that point.

Remember- from the outside- it's sprocket- rubber spacer- spokes- rubber spacer- metal plates nuts (lock washers, loctitie, etc. of course). I don't mean to be basic- but I have seen every combination of the components- even some wrong directions on vendor websites. I would suggest replacing the original sprocket bolts with good quality bolts of the same size from the hardware store- the originals stretch and break too easily.

It is not easy to get the sprocket centered so it will surround the hub, but tighten the bolts a little at a time and stagger the sequence. What I do is take a Sharpie marker and number the bolts 1-9. I then tighten in this pattern, a little at a time: 1-5, 2-6, 3-7, 4-8, 5-9, 1-6, 2-7....lather, rinse, repeat. Make sure that as you tighten, the sprocket is staying centered and not moving off to one side. If it does, loosen, center it, the keep at it. I top out at 12-13 ft. lbs, but other will say 15- whatever works.

You will have to deal with the dust cover for the coaster brake in some way. Some say grind the sprocket hole to clear it- if you have the machine tools to make sure the hole remains centered, fine. I say, grnd the edge off the dust cover so it just barely clears the hole in the sprocket- it will still seat over the hub assembly and keep the schmutz out and because the sprocket hole was not ground off center- it still will accurately remain in the exactcenter of the sprocket and the sprocket will have nowhere to go, but stay centered on the wheel.

Good luck!

Thanks to all that answered. The install went ok. It took me about a day and a half to get it done and to adjust everything. The funny thing was that the coaster(hub) breaks were not near as much trouble as the carb. There was not enough room in the frame to mount the carb on the intake pipe. So I went down to my friendly Low's home improvement warehouse and picked up some heavy duty 1/2 inch hose. I used about 6 inches to extend the intake out under the seat and used heavy duty cable ties to secure it. Worked like a charm. I have took it out on several rides. All is working great. I love the looks I get(motorized bicycles are rare here) when people realize there is an engine on the bike. And when I zip by other bicycles with ease. I think I found a new passion....billy

Right on, right on.