Kx80 fork adapting

Looking for advice on how you did yours. It's going on a fantic sprinter frame so not tryna hack off the head tube. Was thinking about getting the frame remade with more modern head tube to take newer dirt bike forks but wanted to see what came up before I do that. Thanks

IMG_20191013_201616.jpg

Re: Kx80 fork adapting

I have all the bearings off the forks

Re: Kx80 fork adapting

Maitland Of the Loin /

they bolt onto Motobecane frames but using regular crappy moped headset bearings

i hear there is secret tech coming down the pipeline that will let you use proper kx80 headset bearings

TBD

Re: Kx80 fork adapting

SO MUCH SECRET TECH IN THE WORKS

I used standard moped headset hardware to mount a pair up to a magnum frame no problemo, but shortened the springs and added spacers to that they weren't so dern tall

Re: Kx80 fork adapting

TOP GUN™ ANDY ⚔ (LSLB) ⚔ /

My bike that has KX80 forks I cut the head tube off and welded one on that was lathed out to fit the conical bearings. Super helpful advice, especially given that you expressly said that's what you didn't want to do!

Re: Kx80 fork adapting

Dirty30 Dillon /

I was able to mix and match standard ball bearing cup/cones and it fit my hobbit with like no fuss

Re: Kx80 fork adapting

whats the problem? the head tube in the triple is too short?

on the pw80 forks i pressed it out and pressed in a tomos head tube, bingo.

Re: Kx80 fork adapting

just replace the bottom race with a moped one of the correct diameter?

Re: Kx80 fork adapting

> Graham Motzing Wrote:

> -------------------------------------------------------

> whats the problem? the head tube in the triple is too short?

>

> on the pw80 forks i pressed it out and pressed in a tomos head tube,

> bingo.

Majority of people on here do not have access to machinery or necessary skill to accomplish this. It's easier said than done.

Re: Kx80 fork adapting

I've done this a few times. If the headtube length works, you're just swapping out the races with moped ones. you can even use bicycle shit. Are your KX80's the conical needle bearing timkin style? Is that the problem? Old ones were balls I and then it's usually just finding the right size balls or cage.

But if it's the timkins yeah you just gotta knock the race off the bottom of the steertube basically like you were pulling bearings off a crank - like i always just tryn get a narrow chisel under it or whatever, pry it up. then you need a regular ball bearing race like from a moped headset to go in place of it that has the same ID. Be aware that usually the bottom race is flared out a little oversize and not the same diameter as the rest of the steer tube. (ex: moby bottom race is 26.5mm ID on a 26mm diameter steertube, maxi is 27.3mm race ID on a 27mm steer tube) if you're being cheap you can adapt an oversized bottom race and fill in the difference with coke can shims or whatever. i can hear the haters now but it's fine. it works.

Then hopefully the threading on the steertube is standard and you just use your regular moped top race and tighten it down as usual. if not, you can get another bottom race of proper size as an unthreaded top race and use the original KX headset nut to tighten it down. Or again if you're stupid and cheap you can dremel the threads out of a threaded one til it's the right ID and just press that down with the original hardware from the new forks. This set does it that way, 2 bottom races so your top is an unthreaded race : https://www.treatland.tv/tomos-magnum-headset-bearings-p/tomos-headset-bearings.htm

After that it's just matching your new races to the right cups. if ythey don't match the bearings you have, swap the cups wit hwhater does fit. I mean you can probably just buy that set from treats and be good to go, i'd measure the steertube OD tho. especially because usually it's flared at the bottom so the two races have to have different ID's

If the steer tube is too long, you can go with the unthreaded top race and just add spacers under the nut you're tightening it all down with. you can make up a ton of difference that way. If the steer tube is too short, you can press in a longer one, or just cut down the headtube on the frame. usually won't need much, and there's almost always a lil extra, cut it shorter and press the cups back in.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account