Question about 250R forks on a 350X...

[Dirtcrasher]

I read a couple of posts about using liquid 250R forks on a 350X for some more travel and I believe it is 4mm larger diameter also.

Can the 250R's neck outer bearing race be pressed into an 350X neck?

Or do I have to snag a DADS 250R bearing set and press those parts into the 350X neck in order to run the 250R steering stem?

I read that pressing the 350X stem into the R lower triple let ya use the 350X ballbearings in your 350X. HOWEVER, this person claimed to have to "OPEN" the bore on the lower 250R triple clamp for the 350X stem to press in. Does this mean "I hacked out the bore with a file and sandpaper" so the stem would fit. Confused yet??............

Are the 250R steering stops completely different than the 350X?? I'd imagine so......

[NOS_350X]

I have a 350x in my shop right now with 250r forks and tripples. the rake is completly diffrent. If you search for pics of my bikes you might see the and you can see the rake. BUT i belive it was just berrings and the R tripples and everything sliped right into the 350x stem. You cannont press out the shaft on the tripples without jacking up the tripples. Its pressed in there with a circle clip inside, it aint comin out.

Yes the stops are complteely diffrent. The one in the shop the stops is the gastank and forks.

[Derrick Adams]

I did this swap on my 350X. To do this correctly you need to swap out the stems. The 250R stem has a smaller base diameter by about .010, so you will need to hone the lower triple to be able to press the 350X stem in.

The 350X runs a ball bearing set-up on the lower triple, where as the 250R runs tapered bearings.

It will appear as if the rake is changed dramatically, however it's an optical illusion from changing the leading axle to a trailing axle.

I still have a set of triples already set-up if your interested.

[Derrick Adams]

Here's a couple pics of mine.

[Dirtcrasher]

Nice.... Thanks for the pics and info. I have a couple sets of tripples and a machine shop so I'll dink around with mine. You must have fabbed up some steering stops too??

Here's the deal, I'm looking to improve my suspension.

The R front is fatter and has about 2" more travel, but do I lose the handling that I had? Or is it barely noticeable and well worth the effort?? Still turn on a dime?? and the wheelbase looks a bit longer so I'd assume high speed runs feel tighter?

I'm also looking to add a 450R swinger and different shock to the rear end.

The 350X is just too heavy to not have better suspension.....

[NOS_350X]

The forks are raked out more, and it dose affect the handleing. My friend owned the trike, and when he was riding it all the time he didnt like riding mine he liked his set up better. He got used to it and liked it.

[Dirtcrasher]

WOW, this is kinda screwey....

Sounds like there is NO WAY that the stock outer races from a 250R can be pressed into a 350X neck. Please confirm that!! Because I was gonna post that I wanted a set of outer bearing races from an 85/86 250R and thought I could press the in the X neck. OR I was gonna order a new 250R All Balls kit from DADS but sounds like it won't work......

I though the majority of the big Honda necks were all the same length and inside bore dimension but that must be wrong.......

So the options are use the 350X stem in the 250R triple (which requires opening the 350X bore about ten thousandths...) or bore out the 350X triple clamps the 4MM total or 2MM from each wall to accept the 250R tubes. I have a mill so maybe thats a better option because I'll retain 350X rake and steering stops.

[Derrick Adams]

The downfall to using the 350X triples is that you will have to run your 250R forks leading axle. Which will put your brake caliper in front of the fork. I would stay with the 350X bearings and use the 250R triples.

You will notice a change in feel compared to stock. Nothing 10 minutes of ride time won't fix. I personally thought it made the bike feel more stable. I think when Jason and I measured it, it changed the axle location by 1/2".

[Jason Hall]

When I first got 3 leggeddog's 350x, It had 250r tripples & 250r forks. I did notice a difference In handling between It & a stocker. It was'nt that hard to get used to. I would think It would be alot easier to weld some steering stops to the R tripples then to modify the X tripples. If you run the R forks on the X tripples with the axle trailing, you will not like how It turns I can just about be certain. I would use the R tripples with the trailing axle of the R forks. I have Inverted forks on my 450 (350x frame) with a leading axle & no rake (Like stock 350x) and It turns great. If I were to build a new set of tripples though, I would build about 3-degree's of rake Into them. The stock 86R has about 6 degree's of rake built Into them.

Dirtcrasher, If you have a degree finder you could figure out about where your front axle would be without removing anything. Measure the length from the top of a 250r fork to the center of the axle ( I believe thats about 32-33 Inches), then factor In the 6-deg of rake & allow for the trailing axle about 1" behind center of the fork tube and thats where the axle will sit.

When we built Derrick's Tri-z 450, we built 3 degree's of rake Into his tripples with a leading axle. This kept the front wheel In the same place as the stock rake (around 6 deg) with a trailing axle of the stock Z setup..

[Dirtcrasher]

Thanks guys, it's amazing how just a couple inches of wheelbase and a different rake affect a bikes handling. I want better suspension but don't want to screw up the handling.


The only way we have talked about using the R triples is by opening up the 250R lower triple and using the 350X stem. Is this the only way it can be done??

Nobody answered but I'm assuming the 250R outer tapered race CANNOT be used in the 350X neck. And there is no way the stock 250R stem can be used in the 350X neck, correct??

Thanks for the help!!

[Jason Hall]

Nobody answered but I'm assuming the 250R outer tapered race CANNOT be used in the 350X neck. And there is no way the stock 250R stem can be used in the 350X neck, correct??

Thanks for the help!![/QUOTE]

Thants correct. The 350x frame Is not able to use the tapered bearing & races from the 250r. So you will have to fit the stem Into the R tripples. The handling It not changed that much, but Is for sure a little different.

[Tri-Z Pilot]

I just had a set of tapered bearings and races put in my 86 200x, moose is the one that makes the set. I think they work for the 350 also, not pos. though.

[Dirtcrasher]

Old thread, took forever but I'm ready to begin.

250R Forks are now rebuilt (last week), 450R rear end is ready; Just need some odds and ends..........

2"s more travel in the forks alone!! :beer

Pics soon :D