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Just want to make sure before I buy some forks. I have a Z50 KO. Does all years of the z50 forks set up work on it? Im doing a very cheap build for a family member and just want to get a ebay set for cheap anything will do. Hes just going to beat the hell out of it anyway :rolleyes:





also would the crf forks fit?
 

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As Tim said above, I think the hardtail steering stems are longer than the softtail and the XR/CRF ones.
 

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Oh yes. Def. different. The hardtail stems are longer. You can use internals to update the forks to newer crf stuff inside, but must use hardtail forks.
 

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There are a few other points to be aware of too. One, the roll pin that attaches the fork's sliding lower part to the fork spring is oriented differently between hardtail Z50s and later bikes, like the Z50R and ones that came after that. One goes front-to-back and the other goes side-to-side. I'm not sure when the switch took place. You could always redrill the fork lowers if you find yourself with later fork legs and hardtail fork uppers; I have a set someone gave me that's been drilled so it could be used in either style of fork and this wouldn't be hard to do, especially with a drill press.



You can also relocate a clearance notch at the top of the fork uppers, where the top bolt goes into the top spring retainer, and just rotate the whole spring and fork lower, but I've never heard of anyone else doing it and haven't actually field-tested it myself yet. I've done it to a bike that still isn't finished. I can provide photographic evidence if you aren't sure where I mean.



Two...the steering stem bearings also differ between hardtail and softtail. Hardtails have smaller-diameter races that are a light press fit in a steering stem tube that's one constant diameter. Later Zs have a steering stem tube that's swelled out somewhat where the races go in and the diameters are all larger. I discovered this when I ordered some tapered roller bearings for a Z50 steering head and realized they were way off for my hardtail but worked in a Z50R or Z50A softtail.
 

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Yella is correct. If you replace all the "guts" you won't have an issue. But mixing and matching as Yella says you will have alignment issues.
 

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CrawlerD said:
Yella is correct. If you replace all the "guts" you won't have an issue. But mixing and matching as Yella says you will have alignment issues.


Yeah, whoops, good point. I neglected to mention that in my case I was trying to put a Z50R fork leg in a set of hardtail uppers, to replace a bent leg on this set of hardtail forks. I was using the later Z50R fork lower with the earlier Z50A hardtail fork spring and retainers, thus the mismatch. Had I put the entire Z50R guts in I think it would've worked without drilling, but I didn't have the Z50R's springs and retainers at the time...
 

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Here are photos of steering stems for comparison; first a CT70H-K0 against a '79 Z50R...the CT stem is quite a bit longer. Then two photos of the same CT70H-K0 stem against a Z50A-K2 hardtail stem. The length difference is slight, but the threaded length is much longer on the Z than the CT.
 

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The main reason I edited it was it occurred to me that I'd also need to make a tubular spacer to cover and support the exposed steering stem above the steering head adjusting nut, since the top triple clamp will be well above the nut once it's adjusted and all bolted together. But the more I think about this, it seems doable...wouldn't be any weaker than a Z50R front end, I don't think, as long as the spacer tube was thick-walled enough and cut square and accurately.
 

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Would you be interested in trading your 68 K0 frame for a 69 frame and fork?



It pains me to think about a 68 K0 getting "beat to hell" lol
 

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I agree, - the most collectible of all years " beat to hell" - beat a z50r to hell, it will last longer.



The z50r 1980 and later lower forks use a horizontal pin, The z50A uses a front to back pin ( you can always drill new holes tho)



The K0 , K1- to K3 have interchangeable forks. The bearing races are different too.



Sorry if all this was previously mentioned.
 
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