Fitting SSS forks off a Yamaha

[Marty Moose]

I know there are several SSS forks threads they are huge and have lots of great information and lots of for want of a Beta word Bullsh**t. I thought I would make a thread about my journey thus far on this topic I hope it will de-clutter and help a few people.I don't really like writing but it also reinforces my learning so its a self serving thread I'll include pictures for those who prefer them I find it easier to look at them.

The two biggest issues that I see are the fork lug offset and the upper clamping surface on the fork outers. The Beta forks have a 35mm offset most of the SSS forks have a 32MM offset. I don't want to mess with the geometry of my bike its one the plus points of the Beta so am going with SSS with a 35mm offset. These forks are only off the 06 and 07 YZ's and YZF's and the later model WR450F's with the EFI 5 valve engine. They do vary in length from bike to bike by a small amount, I don't see this as an issue just adjust the height to suit. There are other issues like brakes and spacers but I will get to that as needed.

Below is a picture of the older style 35mm off set SSS forks. In some threads this is referred to as the "raw" lugs.



The next picture is from the 2014 Yz250f these are the later 32mm lugs, from 2010 on from what I can see they are anodised this colour the 2008-9 bikes they are the same design but bare aluminium in colour notice I didn't say "raw: Its easy to spot the difference with a picture.



The next major issue is the 56mm upper fork land on the pre 2010 bikes, the Beta is 54mm. I'm unsure if the WRF forks are 54 or 56mm upper maybe someone who has measured them can pipe up. I'm going to machine mine down to 54mm pictures to follow.

I can also post up my valving and spring and preload specs if people are interested but there are some HUGE threads on this on TT mine are nothing special a simple traditional starting point slightly adapted from the valving I changed in my 2014 YZ250f (sons now).

MM

[Hammer]

The WR450 went SSS in 2012 and have the 56mm uppers and as said have 35mm offset.

[Marty Moose]

Well things are moving along 56mm upper now 54mm to suit the Beta clamps next is shim stacks, springs and preload. Should have a dummy fit buy the end of the week have wheel spacers ready to go.



Heaps of meat left just like the 54mm upper SSS.



Stacks I'm going to use are pretty traditional not sure how they are going to feel on the Beta. Feel free to comment I thought it was pretty std stuff. This is with a 0.48kgmm spring and no bleed stack.

Comp
32x0.11 (16)
26x0.11
30
28
26
24
22
20
18
16
14x0.25
14x0.25

Mid
20x0.11 (3)
18
16
14
12
10x0,2
11x0.25
15x0.3
17x0.3
0.3mm float.

Reb
20x0.12 (3)
11
20
18
14
13x0.15
12x0.15
11x0.2

[Marty Moose]

The WR450 went SSS in 2012 and have the 56mm uppers and as said have 35mm offset.

Cheers Hammer thought I had read that somewhere but was not sure.

MM

[gasyz]

Looking to do the same conversion to my 300.seen some 06 yzf 250 forks.Ive got access to a machine shop,which should help a bit.what spindle do I use yzf or Beta?.

[Marty Moose]

Got most of the bits I need now will post up next week with pics. By spindle do you mean axle ? If so the YZ one with custom spacers to suit the Beta wheel.

MM

[katoom400]

I'm following this conversion, I'm doing the same but with Husky TC KYB's which should slide right in and keep the 35mm offset. I will be using the Husky brembo caliper and bracket so hopefully this will be a simple conversion. The Husky KYB's are harder to find and as mentioned, there seems to be much confusion about which Yamaha SSS forks are 35mm offset and the correct top clamping diameter.

seems like machining down the top tubes is a simple fix for the top diameter, but what about the cap? is that machined to match the tubes?

years ago I did this conversion on my ktm using 2012 Yamaha 250f forks but the offset was way off, I then used a set of 22mm clamps to get it back in the ball park. one other consideration on the yamaha forks is the lugs: the the newer (brown) lugs are cast and chip and crack easily if you ride in a rocky area. I believe the older (natural finish) lugs are forged and much stronger.......However Enduro Engineering now makes some nice billet guards to solve that problem.

another option I've read of is honda crf 450r forks from 09-12, which supposedly have the correct 35mm offset and slide right into Beta clamps. I'm not sure on the overall length, axle, spacers and brake setup.....but this seems to be a good option if it works. They are also not as plentiful as the Yamaha KYB's but there are a few pairs on ebay right now.

keep up the good work and thanks for documenting it!

[Marty Moose]

It would be better to just keep this thread on task and that being fitting Yamaha KYB SSS forks to a Beta. I know other forks fit but they need their own thread or we just end up with a confusing mess like some of the other threads on this topic. There is some great info on this forum about this but you have to wade through some garbage to get the correct information, I was hoping this thread would be straight to the point and easy to follow.

The lugs off the 2008-2009 model yamaha's are natural colour not anodised but are 32mm offset, this is an area of confusion and one that caught me out with measuring. The pics I have above are the only 35mm offset Yamaha lowers all the others are 32mm.

Yes you need to machine the upper fork and the inner cartridge cap together as the cap is just a small amount larger, I didn't do this but they can still be fitted pretty easy. Building my son's Yz250f top end today if I get time I'll fit the forks to the Beta and post up the pics I have all the parts I need now.

MM

[Marty Moose]

All fitted up still not happy with the wheel spacers. Used a POW13 braking adapter as per other threads don't think there is enough room to mount the speedo sensor bit of a pain as I like it in Enduro's for distance. May make a bracket for it in the future. Still need to make the brake line clamp bracket that will me tomorrows job. Its not really that hard to do this hope it rides well now.









MM

[Marty Moose]

The spacers are still a little rough. Was told there are two axle lengths for the SSS forks anyone know about this ? I know in 2014 they went to a bigger axle.



Brake line clamp off a 2014 Yz250f that has been turned around and modified. Easy fix just drill two holes in the cable clamp side and put to countersunk bolts back through the clamp and tighten to the fork guard. I used self vulcanising tape to bulk up the brake hose to the correct size.



Got to ride the bike today in very deep soft dry sand they felt like a good starting point. I tried many slap down landings and ran the front wheel into as many logs as I could find they felt nice and controlled with comp on 10 and rebound on 12. I'm sure on hardpack these settings will be backed off a bit. Will post up when I get on that sort of ground as its more what we race on over here.

MM