ATC250SX fork tube replacements

[Lanix]

I recently acquired an ATC250SX for parts, when I noticed the fork tubes were bent I did some searching and found very little info related to replacing them besides the usual 200x (or similar) swap, which is easy enough for some, but not so for others. So I started looking to see if there was any sort of replacement for the fork tubes and while I'm sure there is someone that will make them, I wasn't able to find any good information online. other than the diameter of the tube (33mm) so I went with it. Eventually, I found that a few other motorcycles used 32mm forks, including the Honda Rebel 250. I wasn't able to find the length of the tube anywhere online, but I figured what the heck and bought a pair of used Rebel forks.

After a little fighting, I finally got the forks disassembled and besides some mostly minor differences, most of it was basically the same.

https://www.partzilla.com/catalog/honda/motorcycle/2002/cmx250c-a-rebel/front-fork
#6 in above link is not present on the SX forks and to get the rebel tubes to fit it in the SX housing it needs to be removed
Also the dampening rod #13 is slightly longer.

SX fork diagram for reference: https://www.partzilla.com/catalog/honda/atv/1985/atc250sx-a/front-fork

I reassembled the SX fork with the rebel tube and dampening rod temporarily just to see how it all went together...
(LEFT is original SX fork, no changes. RIGHT is the fork with the Rebel tube)
https://i.imgur.com/vSaeX3X.jpg?1
As you may be able to see, the fork is now only slightly longer.

Here are the same 2 forks next to a slightly disassembled rebel fork:
left:SX, middle:combo, right:Rebel
https://i.imgur.com/W0GgwGO.jpg?1

I swapped out the Rebel dampening rod with the SX rod (only swapped part now is the tube itself) and the forks are virtually the same hight, maybe 1-2 mm shorter than the original SX fork. (Becuase the Rebel tube is just that much shorter.)

I am no fork expert, so I have no idea how viable this solution is but I figured I would give it a shot...

[wonderboy]

Darn, that's a really cool find! I hadn't heard of this swap. Without the spring in there, but everything else bolted together can you compare the slider travel? See if the Rebel setup gives you any more travel than the stock 250sx setup. With the extra length, you can just run the tube that much higher in the triples and keep the front end at the exact same ride height (or adjust as desired). Looks really cool!

[ps2fixer]

Interesting find thanks for sharing. I also wonder if the travel would be effected by this, but I have a feeling it's the same as stock, just the tube is longer.

[ctk]

awesome info. Thank you.

[oldskool83]

if you want 100% new copies contact for forking by frank. i had gotten new tubes for a tecate once from him. nice stuff. no real point in bending these old pitted forks back in place.

[Lanix]

Darn, that's a really cool find! I hadn't heard of this swap. Without the spring in there, but everything else bolted together can you compare the slider travel? See if the Rebel setup gives you any more travel than the stock 250sx setup. With the extra length, you can just run the tube that much higher in the triples and keep the front end at the exact same ride height (or adjust as desired). Looks really cool!

compressed height (no sping) is the same. as the original fork

and just so nobody goes around like I did and buys some used forks, rebel 250 fork tubes can be gotten from ebay (https://www.ebay.com/itm/Honda-Rebel-250-85-16-Front-Suspension-Fork-Tubes-Set-51410-KR3-003/152818037652?fits=Model%3ARebel+250%7CMake%3AHonda&epid=239100660&hash=item2394aa3394:g:NC4AAOSwzDFcGAHZ:sc:UPSGroun d!29445!US!-1)brand new.

[ps2fixer]

Yea I figured the forks would be available new xD. Could probably buy just the tubes from a dealer.

https://www.partzilla.com/product/honda/51410-KR3-003

The ebay listing is for reproductions, for a part still in production. Hard to say if similar quality or not to OEM Honda, but the listing leads you to believe it should be great quality.

Also, for the compressed height stock vs rebel tube, is that the total length when compressed, or the travel distance? Since the rebel tube is longer, if both are the same length compressed, that would mean more travel possible with the rebel tube. Not exactly a fork expert so just trying to get the details defined =).

[Shep1970]

Well I’m going give this rebel fork tube swap a try....33mm same size (diameter) as 250sx
The electric bike I’m trying to finish- has 85 200x forks (one fork has a slight bend to it) usable but it’s bothering me.
Picked up a set of cheap emgo rebel tubes (under $50) dollars
The actual quality of the emgo tubes look to be great but only time will tell.
The 85 fork caps I have screwed in great. I’ll know the length difference tomorrow, I know these (rebel) tubes are an inch shorter than 86/87 200x but I’m pretty sure 83-85 200x’s are 3/4” shorter than 86/87’s.

The tubes look to be identical (Except length) I’m hoping for a easy swap, just have to find an open store where I can get some fork oil in the am. Tranny fluid maybe my only choice (have that) I think an auto parts store near me has fork oil I think.
Anyway I’ll update when done.
https://uploads.tapatalk-cdn.com/20200512/ab9d4d36ee14ecd57cd681dbfd956428.jpg
https://uploads.tapatalk-cdn.com/20200512/40a568affd7ede61814332092938d324.jpg
https://uploads.tapatalk-cdn.com/20200512/350ca061bf576d14b12d77a8fd5d87c5.jpg
Shep


Sent from my iPhone using Tapatalk

[Dirtcrasher]

Geez, never even heard of EMGO :lol:

Shep, bring that tube by and I'll straighten it, I've unbent about 25 sets just this year alone...

I am always afraid that things that are chromed now-a-days are not nearly as good as chrome from 40 years ago.

[Shep1970]

I was really just curios if they’d fit-
Turns out they are “not” a direct replacement for the 200x anyway.
The lower (smaller) tube bushing area on the rebel forks are too big, bushing area is over 1mm too big so as u can see in the pic the bushing stays open (tried the old bushing)
My neighbor is turning that area down on his lathe to mimic the stock tubes as i write this.
Thank you for the offer Steve and depending how the rest goes I just may take u up on that.....
https://uploads.tapatalk-cdn.com/20200513/ee6fc95696162413f4098afc1f58c55a.jpg

Shep

[Shep1970]

Forks done and installed-
All went great except for bushing area size but after they were turned down fit was perfect. guess I’ll see how long the Chrome holds up.

End story......
https://uploads.tapatalk-cdn.com/20200514/6377a3ce22c4d00823233beb65f6b835.jpg
https://uploads.tapatalk-cdn.com/20200514/69084717e9f287e7595ccd092ddecb1b.jpg
Shep


Sent from my iPhone using Tapatalk

[Dirtcrasher]

^ FANTASTIC!!

I'm curious to see how long they hold up too!!