Re: Dirtbike forks..

• Author: Reveeen (---.pppoe-dynamic.nb.aliant.n)
• Verified User: reveeen
• Date Posted: 07-02-09 07:06

I’m in the middle of doing this.
You want a fork from a smaller type of dirt bike, say 80cc-125cc. Measure the fork length, from say the lower steering head bearing, to the axle, to get an idea. When removing the motorcycle forks snag the frame side bearing cups (along with everything else) with some luck they will fit your moped frame (or can be machined to fit). Measure the steering head tube on the donor motorcycle (length and width) you want to replicate these dimensions (if you can) on your moped. From here on in it is just “fitting”.

The trouble you are going to have is this: many of these little bikes use a dumb size front wheel (12”, or 14”). Finding a street tire is going to be a challenge, there are plenty of off-road tires available in these sizes, but not street type tires. You are either going to have to lace up a new rim to the disk brake hub, or run some dumb looking tire (like a Cheng Shin C109 2.50-2.75/14, though it is rated for 92mph). Lacing up a rim will present it’s own challenges (I haven’t done one in over 20 years) the spokes will be special order (because they are heavier than bicycle spokes, but lighter than motorcycle spokes) and the assembly will have to be trued up.

You could move the steering head tube from the motorcycle to the moped. This will require getting it done by a professional welder, being the most important (critical) welded joint(s) on your entire moped, and will change the serial number of your moped to that of the motorcycle, because this is where the serial number is to be found. I wouldn’t go here unless I HAD to.

I’m fitting a set of forks off of a Chinese 125cc pit bike to a Jawa frame.