Vintage Dirt Bike Q & A

Is there anything that can be done to modify or improve the fork for 77/78 cr125's, I know there were some air caps that can be used for the early models, what about these forks? Thanks

I found out about Race Tech cartridge emulators yesterday (thanks, Greg!):

http://racetech.com/HTML_FILES/EMULATORGV.HTML

I would contact them about your 35mm CR forks. They don't list your exact year and model, but probably have a unit that will work fine. They have a set for the '80 CR125R w/37mm forks, that may be what you need.

I used air caps with a crossover tube to a central air valve for years on my CR, w/no springs. It really worked quite well and was 100% reliable, and the seals will never leak until you let the air out. I went back to springs recently hoping for less seal stiction and a more linear spring rate, but I think the action with air alone was better.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Thanks Rick

What tubes did you use for the air cups, The 77/78 have these clips on top that hold everything together. For what I read, the 73/74's had the threaded tubing.

My '74 had large threaded chrome hex-head caps, but my MR uses unthreaded cylindrical plugs and circlips, probably quite similar to your bike.

The unit I used was made by (I believe) Goki, and consisted of a brass center piece with a standard Schrader air valve, and two small stiff-plastic hoses that mated with brass threaded inserts in each fork cap. The fork caps had to be drilled and tapped for the inserts.

I Googled around a bit but couldn't find any air caps for CR125M's. If you can find one, I would definitely go with the single-air-fill setup, as it's hard enough setting the air pressure on a single-fill system; getting two forks identical with such tiny air volumes would probably be really difficult (and even then, I bet they would change after riding a short while).

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric