Build a Custom Wide Coaster Hub Bicycle




here are some details on making a wide rear coaster hub like the one i used on this bike.

Step 1: This Is What You Need

this assumes you understand how a coaster hub works and what it looks like inside.
you need two hub shells for a coaster brake, the complete guts for at least one of them and an additional cone nut/pad ramp thingy for another.

then go to and buy a 3/8 24 threaded rod in three feet made of G7 alloy.

bang the spoke flange off the wide side of one hub

cut the narrow side off the other, you don't want the inside part where the coaster brake cone acts to move forward , use a level to trim the wide open side cut until it is lathe straight, got it?

Step 2: Make a Wide Hub Shell

Now if you lay them side to side there is an extra wide hub with the narrow side and braking surface unchanged and the wide side from the other hub next door with the bearing surface unchanged. if you had left both hubs alone, the braking cone could not be inserted into the hub because of the duplicate narrow area

now add a section of steel pipe into the center gap to make the hub as wide as needed, mine was 6 inches added.

Weld all that together , keeping them square by laying them into a piece of angle iron and lots of checking. finished hub pictured

Step 3: Magic Happens Here

The last thing to do is weld together the left side bearing nuts with a spacer made from ½ inch steel pipe, use the threaded axle rod to make sure they are aligned properly. Grind the bearing surface off the inner one if you plan to use the caged wheel bearings, I didn't do that and laid in loose bearings.

Confused? You should now have a stack that looks like this= inner nut will now only act as the brake pad retainer, welded to ½ inch pipe spacer, then to outer nut that will now only be the bearing carrier and action arm mount.

Step 4: Finish Assembly

Reassemble the coaster hub, it may be difficult to lay in the brake pads but use sticky grease and a small screwdriver. Substitute the threaded rod for the original axle. All you have really changed is to split the function of the left side axle nut ! And a 12 inch wide hub is born.


I have actually built one and it works, but please point out anything I may have missed because it is my only brake and i'd rather not crash.

Step 5:

I'm thinking of doing a 3 speed hub next, does anyone want to see an extra wide 3 speed hub? also would be built on a car spare tire or maybe a motorcycle tire.



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    13 Discussions


    7 years ago on Introduction

    it just occurred to me that you could just weld the brake pad nut to the new axle in a fixed position which would allow for more precise bearing adjustment with the outer nut.


    5 years ago

    I would love to go and pic up those parts but sadly I am broke


    Reply 5 years ago on Introduction

    I am moving this weekend. it should cost about 20$ in parts to make this work. I still have some leftover axle rod if you want it, but you gotta get it this weekend. look for the blue Volky.


    6 years ago on Introduction

    Sweet ride. Check out my forum group:


    7 years ago on Introduction

    Hard to ride? the handling is challenging, a long raked bike like this wants to flop the front end all over and it looks exaggerated when you steer it. the large rear tire is heavy and takes lots of grunt to get moving but good gear selection takes most of the sweat out. limited top speed and you lose lots of momentum when turning 'cause the tire scrubs bad. but you get used to it all and look really cool trolling at walking speed in a car show.

    I'll post pics when I can. check out, he's the guy i got the basic bike plans from and the inspiration for this. the rear rim is from a car and the spokes are bicycle parts. got the plans from AtomicZombie again but his bike didn't have brakes and I needed them