Atc 200x fork swap

[Keith Salyer]

I got a set of 83-84 250R forks to put on my 200X and I have taken the clamps and a fork to 2 different machine shops to have them bored 2mm to fit the bigger forks. buth hem hawed around and didn't want to do it without charging me 300+ dollars to do it. Will the clamps off the 83-84 250 R fit the 200X stock or can I repress the stems out and in and make the conversion work. I think I can get some 250 clamps for way less than 300 bucks. Any ideas?

[oeduardo67]

I am not 100% sure but i believe that the 250r stems are a bit bigger. i have seen triple trees work with smaller stems when they use a bushing and then press on the stem. There are members on here that do boring services and they might give you a better price as well.

[oldskool83]

the 83-84 250R stem uses tapered bearings, 200X using ball bearings. $300 to bore tripples? thats weak. IM having a set bored for me shortly. I had tapered bearings once n my 200x and the kit didnt work the greatest. find a small mom and pop machine shop drop $50 off and a bottle of jack. most people should be able to do it for that.

If you cross part numbers Im sure the stem is the same dia and the just litterly pop off when you loosen the bolt. R tripples are $30 all day long on ebay. 83-84 that is. Forks are a dif story.

[deathman53]

use a 350x triple clamp, if you get a 85, its a direct fit. 86 uses tapered bearings.

[Dirtcrasher]

^ Glad someone chimed in.

Setting up a set of CAST upper and lower fork clamps is no simple process. I'd rather start with 1" billet aluminum. Then the head of the mill does the work.

People don't seem to understand what a MILL or LATHE and the procedures involved to do what a customer wants and it is expensive.

[oldskool83]

350x has no rake in the tripples, 83/84 R tripples do. FYI

[Keith Salyer]

Are the 350X forks the same diameter as the 250's. Also what do you mean by no rake?

[Keith Salyer]

The bottom clamp has machined flat/square surface on which to clamp up secure but the top clamp has no good way of finding the center of the bore and holding it that way requires a jig. The article on it was posted by dcreel in another post with all the vintage magazine clips.

[Keith Salyer]

Thanks Deathman, I found some 85 model 350 X clamps. We will see if it's a bolt on or not...:)

[oldskool83]

your gonna change geometrey. 350X forks have no rake like i said. means the do not have build it off set to put the forks out farther. 200x and 250R tripples have rake built it prob 10 degrees of so by looking at it off set from the steering stem. 350x forks have no rake because the 350x used a leading axle in front of the forks). 200x and 250r used trailing (behind the forks)

your bike will have a shorter wheel abse prob by at least and inch is you use 350x tripples and r forks. it wouldnt really change if you used 350x forks.

[Hurricane635]

Hey, Keith your 200x and the 83-84 250r lower tripples are not a press fit stem, they use a pinch bolt. The lower race presses on the stem, loosen the pinch bolt and push the stem out the bottom and measure the 2 stems to find out any difference. The top diameter is the same (I think). I have done alot of fork stem mods, would gladly help you out with any machining, if you need it, but it might be as simple as trading stems. PM me if need any help.

[oldskool83]

some quick info i got on the 200x stems vs the 2nd gen 250R stems. The top threaded nut that bolts the top tripple on is same part number so that means the top threads are the same. Everything else lists different part numbers. I cross reffed part number allballs bearings kits to see by chance if the tapered bearing kit they offer for a 200x was the same for 83-84 250r. its not. My guess is swaping the stem will work. I can veryfy this in a few days, i bought a cheap top 250R tripple also because i knew maching it could be a PITA due to the rake in the trees. Gimme a week or so.

[jb2wheels]

use a 350x triple clamp, if you get a 85, its a direct fit. 86 uses tapered bearings.

Wrong. Both use ball bearings. The 86 has them in a retainer.

And it doesn't matter tapered vs ball bearings anyway as long as you use the right races. Races are removable/replaceable.

What matters is:
stem diameter for inner race of tapered bearings or stem mounted race for ball bearings
stearing head diameter for outer race of tapered bearings or head mounted race for ball bearings
stem length so you can bolt it all up

I don't know any of that for 200X vs 350X vs 250R, though.

[Scootertrash]

When I do my swaps I'm changing out the ball bearings for tapered bearings anyways, I already did it to my 200S. Why wouldn't you? It's an easy swap and they are better than the ball bearings.

[oldskool83]

last tapered bearing kit i didnt in my 200x didnt even work like it should of.

[Scootertrash]

What happened?

[Keith Salyer]

Ok I wand the geometry to stay the same so I got the 84 250R triples on the way. In the pics look like ball bearings instead of tapered bearings. Guess I will know next week. I already have the forks so I am commited to that.

[oldskool83]

couldse get top dust cap on. seems the race didntoffer enought area. Im just going to use ball bearings because I am not dealing with it anymore. Ive bought so many ATC parts which are labeled to work only to not be worth their weight of the postage stamp. Just hand another buzzkill tonight. Alot of engineering is PISS POOR I will say.

My bored tripples might be done tomorrow, I had some word today thay prob would be started tonight or tomorrow so maybe I wont use my R tripples.

[Keith Salyer]

Did you find a set of forks recently Oldschool. I would like to know how it works out for you. Where I work has a massive machine shop but there isn't any wheeler parts getting fixed in there :(

[oldskool83]

so take you tripples in give somone $50 and a coke and get them done. HRE does all my work, I've had him do some crazy junk for me already, anothing so hard he has not been able to do for me. Just check out my build.

I bought 84 forks off a member last weekend so go with my slick 83R rear shock i got on. Ill prob have some updates tomorrow. I normaly do after i hang out there afterwork on a friday when I go over.

[Keith Salyer]

Is HRE there in PA.

[oldskool83]

Yes I was there tonight for 2 hours or so. He is doing my tripples so I have them by next weekend. We were messing around with powder coat and trying to get a 1 peice brake pedel for my 200x finaly figured out.

He can find center of the bore then bore to desired MM. Ill post pics of mine when done so you can see.