Vintage Dirt Bike Q & A

I’m looking to upgrade my ’79 CR 250 forks. I already installed new Works Performance shocks. I’m a 220 lb Vet Amateur motocrosser.

Which forks are the most popular upgrade?

I’m thinking of ’81, '82, or ’83 CR480 forks. Does this sound right? Will either of these work and be a nice upgrade?

Is there an advantage of one over the others?

Are the lengths of the forks different than my stockers? Is this a concern?

Are many modifications needed to the steering stem and triple clamps, or do they bolt right up?

Sorry for all the questions. I’ve been searching all the threads in this site and others but can’t find the answers.

Thanks in advance!!!

I like the '83 forks, either cr250r or cr480r. You'll love the double pull brakes! You can slide the forks up and down in the triple tree to fine tune the handling.

Nathan,

Thank you for the response.

Does anyone have any other comments regarding complexity of the swap, things to watch out for, or suggestions for further research on the subject?

You can fit later model forks, including those from the late 80s with disc brakes. However historic racing rules mean you are generally confined to 81 through 83.

81 Showas are 41mm and they are more difficult to find, but look the most like the works forks that were on the RC bikes of 1979. 82 forks are 43mm Kayaba and are the best stock forks, even though they have less adjustability. 83 forks are 43mm Showas with more compression adjustment but the valving worked worse than '82. However, Race Tech does emulators that replace this damping circuitry. (I have 43mm Showas with a full "make-over" from Race Tech). At 220 lbs you are going to need a spring in the .46 kg/mm range and some damping work.

The headset bearings are common from (at least) 1978-1987. However the steerer is longer on the later models, so in your case you are going to have to a) have a shop transplant your '79 steerer tube (I did) or b) use some big washers on top of the lock nut and under the top triple clamp. There are some differences in the triple clamps - rubber mounts v fixed and the method of holding the steerer. Some clamp the steerer into the lower triple clamp which makes a transplant easier, other use a clip mechanism which may force you down the washer route. Both are straight-forward.

You can use your 1979 or a later hub with these forks. Obviously the later double-leading shoe works better, but is more tricky to set up.

_________________
Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

Redrocket,

That's a very nice 480 you have for sale.

Thanks for the info. You provided a lot of answers.

Actually I have a spare set of 43mm Showas for sale, but they are only in OK condition. You would be best to find a set complete with triple clamp and the front wheel.

_________________
Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF