Jump to content
Sign in to follow this  

Diameter of SSS forks?

Recommended Posts

I know this info is on TT somewhere but I can't find it.  What is the diameter of SSS forks where the triple clamps tighten down on them.  I'm trying to figure out a parts combination to fit some 22.5 offset trees on my '01 with the OE forks. It  seems the aftermarket is mostly ignoring "such an old bike" and when I've found them, there spendy so my plan was to use the late 250f trees with the 22.5 offset. Thanks.

Share this post


Link to post
Share on other sites

After quick measurement on my 2010 YZ125 :

 

upper fork tube diameter at top clamp: 55.85mm

upper fork tube diameter at bottom clamp: 59.15mm

Edited by mlatour

Share this post


Link to post
Share on other sites

The year and model they came off of makes a difference. 10+ 450s and 12+ 250s 4 strokes they are narrower at the top clamp.

Share this post


Link to post
Share on other sites

I have heard of people using the newer clamps with the older forks and just machining the top clamp to fit. It is only a couple mm difference I believe.

Share this post


Link to post
Share on other sites

Since I wanted to use the '01 forks with the newer clamps, I'm kind of going the other way.  My forks are smaller at both locations than mlatour stated.  I did a quick measurement, which is very close at : top end - 54.05 mm.   Lower area - 58.40.  There may be no workable parts combination to do what I want which is 22.5 mm offset and OE '01 forks.  The funny thing about looking on ebay, the guys that strip and part out bikes quite likely don't know if the triples they are selling are aftermarket or what the offset is.

Edited by motoxvet

Share this post


Link to post
Share on other sites

According to my data:

All 2005+ 48mm KYB SSS forks have 59.0mm lower clamp.

2005-14 2 strokes: Upper 56.0mm.

2005-09 YZ450F: Upper 56.0

2005-12 YZ250F: Upper 56.0

2010-15 YZ450F: Upper 54.0.

2013-15 YZ250F: Upper 54.0

2006-2012 KX450F: Upper 54.0

  • Like 3

Share this post


Link to post
Share on other sites

Thanks for the infos numroe, could be useful one day if ever I find a spare set of forks.

Share this post


Link to post
Share on other sites

You're welcome. And in the 2016 4 strokes, maybe I heard that a clamp size changed again.

Also, I think the 2016 YZ450F went back to a 25mm offset triple. In favour of high speed stability on rough stuff, I guess.

Share this post


Link to post
Share on other sites

According to my data:

All 2005+ 48mm KYB SSS forks have 59.0mm lower clamp.

2005-14 2 strokes: Upper 56.0mm.

2005-09 YZ450F: Upper 56.0

2005-12 YZ250F: Upper 56.0

2010-15 YZ450F: Upper 54.0.

2013-15 YZ250F: Upper 54.0

2006-2012 KX450F: Upper 54.0

Thanks numroe.  I should have known you would have the spec's.  So then there is a workable parts combination....IF the 59 mm. lower clamp will effectively clamp down on a 58.4 mm fork body. Could a guy do something as primitive as inserting a shim around the body to take up some of that space...?

Share this post


Link to post
Share on other sites

You're welcome. I'm no mechanical engineer. Maybe I have ok mechanical intuition ... Are you sure you measured the 58.4 accurately? Seems odd. Anyway I think that a 59 clamp will pull down onto a 58.4mm tube just fine. I'd be very weary or reluctant to use shims unless they were precision items. You cannot have anything that acts as a tube material stress raiser on the lower clamp surfaces.

Share this post


Link to post
Share on other sites

I was miking it in a weird position but I checked it several times and it repeated that measurement with a digital mic.  As far as precision is concerned, I think either brass or stainless steel made for industrial use is quite precision.  My plan is this: Get a triple clamp set from a YZ-450f, press the stem out of mine and put the 2 stroke stem in, bolt it together and bingo - 22.5 mm offset with minimal money.  There is a question of what hoops I have to jump thru to get the '01 front wheel to fit these forks.  I believe the SSS forks have a wider c. to c. measurement but I'd like to keep these forks for now.  I have a lot of "sweat equity" in them.

 See any pitfalls in my plan?

Share this post


Link to post
Share on other sites

I should have added the triple set I'd use is a late one with the 22.5 mm offset.  They do come up pretty frequently on ebay.

Share this post


Link to post
Share on other sites

My plan is this: Get a triple clamp set from a YZ-450f, press the stem out of mine and put the 2 stroke stem in, bolt it together and bingo - 22.5 mm offset with minimal money.  There is a question of what hoops I have to jump thru to get the '01 front wheel to fit these forks.  I believe the SSS forks have a wider c. to c. measurement but I'd like to keep these forks for now.  I have a lot of "sweat equity" in them.

 See any pitfalls in my plan?

Seems OK to me.

I found that the stem in the 2011 YZ450F triples was just long enough to be used in my 2004 frame.

Regarding the wheel. I don't see the issue. 2001 forks, axle, spacer and wheel, right?

  • Like 1

Share this post


Link to post
Share on other sites

People use Coke can shims to put twin chamber Showa's on mid 90's cr250 all the time, you'll be fine.

Share this post


Link to post
Share on other sites

Thanks for all the comments and info guys.  I'm going ahead with the plan.  I'll start a new thread as the project progresses .  I don't think the actual work will take any time at all BUT the bike is actually in storage so I'm not sure when I will start it.

The worst thing that can happen is for some reason it won't work, I just have to re-sell the triple clamps.

Share this post


Link to post
Share on other sites

I hope this works out for you. If it won't remember Emig Racing will make a set of triple clamps with whatever offset you want for your bike. If I am remembering correctly they even have pricing on the web page.

  • Like 1

Share this post


Link to post
Share on other sites

Yes, I know there were probably sources for the parts, maybe more than just Emig but  the end result will be an embarrassingly low cost mod for older YZ's.  The triple clamps are already on order (a pristine set from ebay) and I snagged a front axle for the same year YZ450f just in case I need it.  

Share this post


Link to post
Share on other sites

I'm still in the middle of this project and everything is going OK.  I was worried about front wheel fitment because for some reason, I thought the SSS forks had a wider c. to c. measurement but they don't.  Same as the '01.  I'll do the build thread on specifics as soon as all the details are worked out.

Share this post


Link to post
Share on other sites

The clamps are wider. The difference was made in the fork lugs. It is minimal and usually only results in the wheel being offset 1 mm. The caliper seems to have enough clearance to still line up.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...