Front end RS 250 Swap?

[atlimann]

Hi, im new to the forum.
My name is Atli and i am from Iceland but i live in Germany. (for now)
I just bought a 78 XS400 yesterday. (pictured)
i have been reading on the forum about front end swaps and from what i gather most of the guys are swapping the stock front end with the Aprilia RS 125 and i did a search on it and i did not find anything about RS 250 front end swap here on the forum, correct me if i'm wrong.
The reason i am asking is i have the opportunity to get a full front end from a 250 that has everything on it (pictured), brakes, rims, etc. (and the rear rims and brakes

) and i was wondering if that would fit my bike like the 125´s do?

 

[rshutchinson]

Check here and see if they share the same bearings

http://www.allballsracing.com/index.php/forkconversion

Then it's just a matter of seeing if the triple tree stem is the same length and if it is it should be a bolt on the same as a RS125.

 

[Wolfe_11B]

The bearings will be different, just get the proper size. Stem will be too long 'I think'. As long as you have the ability to swap stems or modify the original 250 (cut to length, thread with die) you are golden. You'll be happier with the 250 front end than the 125, it's a little more 'right' for the geometry. Plus the 250's internals can be upgraded and modified to some nice parts if you so choose.

 

[atlimann]

Check here and see if they share the same bearings

http://www.allballsracing.com/index.php/forkconversion

Then it's just a matter of seeing if the triple tree stem is the same length and if it is it should be a bolt on the same as a RS125.

i get no results if i select 78 Yamaha xs400 & maxim.
But if i select xs 500 then i get a big list of results, but i´m not sure if the 400 and 500 share the same frame

 

[atlimann]

The bearings will be different, just get the proper size. Stem will be too long 'I think'. As long as you have the ability to swap stems or modify the original 250 (cut to length, thread with die) you are golden. You'll be happier with the 250 front end than the 125, it's a little more 'right' for the geometry. Plus the 250's internals can be upgraded and modified to some nice parts if you so choose.

i will most likely have to buy this unseen or just from photos since the guy is 4 hours drive from me.
hope this will work, because i think it is a good deal with the calipers and everything, then i would just need a mastercyl.

 

[Wolfe_11B]

You can technically make any front end fit on any bike, so don't worry. You just have to put in the time and fabrication to get it all to work.

As for bearings, just wait until you get all the pieces then measure everything. Bearings come in all sizes so don't worry about that yet. Get the forks and see what you need to do with the stem first.

 

[16VGTIDave]

'78 and Maxim don't work. Your bike isn't a Maxim...

 

[atlimann]

'78 and Maxim don't work. Your bike isn't a Maxim...

i know that, but on the allballsracing website the dropdown menu only show the xs400 & Maxim as the same option. and there are no results for that. How ever if i select xs 500 i get a lot of hits, but like i said i am not sure if the 400 shares the same frame as the 500

 

[rshutchinson]

I searched for a 2000 Rs250 and it listed the XS400 as compatible. Check it out yourself, it's near the very bottom of the list. Oddly enough, it did not list the Rs125 though. It may not have any info on the 125 so that could be why.

 

[atlimann]

I searched for a 2000 Rs250 and it listed the XS400 as compatible. Check it out yourself, it's near the very bottom of the list. Oddly enough, it did not list the Rs125 though. It may not have any info on the 125 so that could be why.

i check this out and vice versa and it seems to fit. I also checked out the xs500 and xs650 share the same bearing as the xs 400, so this should probably fit those frame too.

 

[Wolfe_11B]

Just to give you a heads up as well- you won't be able to use the RS250 rear rim on the XS (noticed you mentioned it in the first post).

The rim itself is wider than even the clown shoes people put on. The sprocket will be too far offset to work. But none of that will mater anyway, since the swingarm is too small to even accept the rim

 

[atlimann]

Just to give you a heads up as well- you won't be able to use the RS250 rear rim on the XS (noticed you mentioned it in the first post).

The rim itself is wider than even the clown shoes people put on. The sprocket will be too far offset to work. But none of that will mater anyway, since the swingarm is too small to even accept the rim

ok good to know,
i really wasn't looking for a rear wheel but it is included in the deal. (which i have yet to close )