38 replies to this topic

[GHILL28 TT Gold Member]

I'm running a lowering link on my YZ300, and it corners pretty damn nicely with the -2 offset from the E-axle.  I went back to the normal axle just to try it and the cornering was horrendous (with and without lowering link).

I'm wondering how hard it would be to adapt some 18/20 adjustable KTM clamps just to experiment with.  I had these on my old KTM 380 and had no complaints about the front end behavior from slow speed woods stuff to highspeed desert.

Has anyone experimented with offsets less than 22mm or so?  What were the results?  I'm hoping any instability issues would be addressed with the lowered bike and the more relaxed steering angle but the decrease in offset will still have snappy steering on corner entries.

Thoughts?


Setup:

'06 YZ300
3 gal tank, 18" rear wheel, guards on everything
'09 450 swingarm/linkage
Yamalink for '09 450 (lowers 1")
Ohlins TTX (stock length)
Ohlins fork inserts
5.3kg rear spring, 0.46kg front spring, 180lbs w/o gear on, ~200lbs geared up w/pack
100-105mm rear sag, 45-50mm front sag
Forks set about 1-2mm below 1st line
Tires:  120 width Kenda Parker DT rear, 90 width Kenda Washougal Sticky front

The bike has lately been getting used for everything from Erzberg type of trails to highspeed desert to MX tracks.  Stability is #1, won't sacrifice that much for cornering behavior, but want to have both.

[RCannon]

Zip ty racign had some 17mm, I think, clamps.  I'm not remembering the exact spec, but less than 22.  I coudl see them being more stable, which I dont think this bike needs.

[jar944 TT Gold Member]

The KTM clamps are not close to working. fork dia between the KYB and WP uppers is very different.

[rtv TT Bronze Member]

Jordan Ashburn, A GNCC xc1 class racer uses a 17mm offset(Zip-TY) setup  on his YZ 250.

[GHILL28 TT Gold Member]

I think that's the same one I saw in one of the recent magazines.  Someone had a fairly stock looking YZ set up for enduro races with 17mm or 18mm clamps they made a point of.  Really curious how that would handle.

[ECEAracer TT Bronze Member]

I think Brad Bakken was also using them on his YZ for both GNCC and the National Enduros.  With both Ashburn and Bakken using them they must work pretty well.  Thats just an expensive experiment to test since they run $500 for the upper and lower clamp.

[GHILL28 TT Gold Member]

So at what point does a reduced offset start causing problems?  And what are those problems exactly?  So far I can't see much benefit to an increased offset.  I think it might do a bit better in sand, but even that I'm not sure about.

[aled TT Bronze Member]

i just put on 22mm offset yzf 2010 clamps on my 2 stroke tonight! felt an immediated difference ! i think yz 250's corner horrendously a standard on hard packed ground especially!

[GHILL28 TT Gold Member]

That was another (cheaper) route I was considering.  How hard was that to do?

[aled TT Bronze Member]

Easy . Press your original stem into the yzf clamps! no other issues! cost me £65 posted for the clamps off ebay!

[motomanp58 TT Bronze Member]

I bought 2010 450 clamps to try 22, however the bottom clamp fit with my forks and the top would not. My bike is an 07 yz250, any thoughts? Sorry to steal the thread.

[GHILL28 TT Gold Member]

No problem, I'm curious about it as well.  It wouldn't fit the fork legs or it wouldn't fit the YZ250 steerer?

[rusky TT Platinum Member]

Have 22.5mm on my 06. Makes cornering super responsive, just have to be more careful. Excessive oversteer in the dunes though.

[aled TT Bronze Member]

hmm not sure why it wouldnt fit, my bike is a 2011 are they same diameter as 2007 forks? note you have to use the yz 2t stem! just saying incase you missed it!

[RCannon]

Its VERY difficult to predict what happens when offset changes.  Sure, you KNOW what its supposed to do based on geometry only, but the move also moves weight around.

Going to 22.5 offset actually improves stability.  BUT, it takes some looking to find it since it moved weigh on to the front wheel, makign the steering feel faster.   This is especially true at low speeds.  I had to revalve my forks to really love the 22.5 offset.    In sand, the stock forks and 22.5 were tough to deal with due to oversteer...massive tucking constantly. The problem is there in the stock forks, but 22.5 makes it worse.

Is it worth doign? Maybe.  How much?  At rg3's triple clamp prices?  Probably not. At 65.00 why not?

[GHILL28 TT Gold Member]

That's basically where I'm at with it.  Not interested in dropping hundreds on experimenting.  Not to mention changing around the clamps makes re-spacing the Scotts damper a royal PITA each time.

I know how 22-23mm feels (whatever -2mm is with the E-axle).  I was curious about real world results with offsets less than that.  I guess I could find out fairly easily with the 2010 450 clamps and the E-axle to try out 20mm.

Keep in mind I'm also running a lowered rear end which keeps that weight off the front.  I didn't run into any diving issues up front with that link and the proper springrates front and rear when running less offset.

[jeffro667 TT Bronze Member]

Sorry to bring back this thread, but I would like to try the 2010-12 450 clamps on my 06 YZ250. What year forks will fit directly in the 450 top clamp? I have the 06 forks, and also a set of 09 450 forks that I plan to use. Does anyone know for sure if the 09 forks will work with the 10-12 clamp, or could the top clamp be bored slighly to fit the forks?

[kenpowell TT Bronze Member]

I'll give you guys something else to think about...  2003 YZ265-WR with Eric Gorr low-to-mid porting; terrain is Eastern single track with lots of rocks and roots.  I also wanted quicker steering (but NOT KTM quick) so I did the following:
1.  moved the forks up in the clamps until they hit the handlebars
2.  put in a 1/2" travel limiter into the forks  (performed on both my Slavens '05 forks and my '08 test forks; I do not miss the 1/2" travel in the terrain that I ride; not recommended for you desert guys!)
---  this nets to 1.125" lowered front
The bike definitely steers quicker but does not understeer.  Great improvement!  I'm a 170 lb 'B' rider running .42 fork springs and 5.0 rear spring which seem perfect for my weight and riding conditions.  Oh yeah, I'm not sure it matters but I'm also running a '07 rear relay arm in the rear linkage.  Incidentally, a ridng buddy who weighs 240 lbs did complain about oversteer but the springs are so far off for his weight that I don't thing this counts.
This thing steers GREAT.  I really love these old steel frame bikes, especially the '03 and '04 models.

[RCannon]

You can also get some handling changes, as pointed out by Grayracer, from moving the handlebars for and aft.  Offset changes, even small numbers, are drastic changes.  Bars, fork height, rear ride height, are subtle changes.  There is no reason to change offset just for fun, or even chancing an improvement you cannot define.

Before trying to make something "better"  try to define "better" for you or your situation.  Since triple clamps are expensive and do some very specific things, I cannot tel you what better is for you.  I wanted my front end stuck to the ground like glue without losing stability.  22.5's gave me that.  But, without fork tuning the front end would tuck. Especially in sand.  No biggie as I rarely ride sand.  But a fork revalve gave me the feel I needed and wanted.

[kenpowell TT Bronze Member]

Yes, I have also worked on the valving for both my '08 forks and even my '05 Slavens forks to work with my lowered front end.  The YZ250's are so flexible that they can be tuned to work for anyone.