HELP! FORKS, RIMS, & SPROCKET CONVERSION FOR '81 CBX...

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BayArchitect
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Location: Los Gatos, CA
Location: Los Gatos, CA

HELP! FORKS, RIMS, & SPROCKET CONVERSION FOR '81 CBX...

Post by BayArchitect »

I'd like to install 1000RR rims on my '81 CBX. I'm familiar with FasterSpider's conversion, using 600RR rims, but the 1000RR rims are much lighter and slightly wider. The problem is the 1000RR rims have much wider hubs, requiring the fork tubes to be set wider apart than OEM. At least a new triple tree will be needed, and possibly new forks. The 1000RR OEM fork tubes are about 8cm shorter than the CBX tubes, so they cannot be used, because they will lower the front end too much, and leave no room for the clip-ons. I'd be happy to use my existing OEM 39mm fork tubes, but equally happy to use new tubes, if they come with a set. Upside-down tubes are OK. The existing OEM CBX Euro bars are comfortable--the correct height and width for me--so the new bars should sit in a similar position. Can anyone suggest a source for new triple, or fork assembly that would accommodate the 1000RR rims, or similar rims, but use the existing or similar clip-ons? I expect to have to machine the necessary caliper adapters. Also, due to the wider rear hub, alignment of the drive chain sprockets will need to be addressed. High-quality solutions wanted. Before I design it and machine it, I'd rather buy it. Everything must look good and work well! Eager to hear from those who know!
Thanks and warm regards,
Leon

EMS
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Post by EMS »

Hi Leon!

I am not not familiar at all with the CBR1000RR rims and what the needs would be as far as a matching fork. It seems it will require some luck to find a set-up that will fit, if you don't want to use the RR tubes and triple tree. It is very likely, that you will have to use the CBX steering stem and have it pressed into a triple tree that you want to use. A triple tree that provides you with the necessary distance between the fork legs, may be one for USD forks only. Most USD forks are shorter than the old CBX front ends. The other dilemma you may run into are the handlebars and the position you want to retain if you go USD. The raised clip-ons as you have, are mostly for conventional forks. You may have to convert to a "superbike" handlebar.

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