better KTM bad road handling......and others

[CATSLEDMAN1]

4 years ago when we built our first kits from scratch we had not idea where and how to make a front ski handle, and we were making our own skis and it was bad bad.

What we found was:

1. the further out we shoved the ski pedestal the worse it handled, made for heavy steering, front end washout and near unrideable on an icy snowmobile trail.

2. the further back we sucked the pedestal the better it got , less washout, tracked straighter with less effort. all this happened while we made skiis, sucked up limiter straps etc etc etc. BIGGEST difference was always how we had our pedestal mounted.

3. this fall I began riding a TS 2013 kit updated shocks, bearing, 2017 120 track on a 2013 KTM 500 xcw. So far powder and new snow every ride and been working through some issues. When I rode a 450 suzuki with one of our old kits, and Tylers 450 Honda, they both went down the road WAY WAY WAY better than my KTM 500. So back to the shop.

4. what I found was my pedestal had been put together with the bolt holding the ski on out in front of the fork axle, the measurement was:
ski mount bolt .400 in front of the fork axel. from past experience building kits that can NEVER WILL WORK, causes ski washout, very nervous trail handling, hard lots of effort to turn the bars and scarey at times.

5. Redrilled the next closest 5/6 hole to set the ski back, at the back edge of the pedestal my hole was only halfway in the aluminum, but ok for testing. Now my ski bolt was in back of the fork axle 1.4 inches. We did the same for Dan's SX, next hole on his bike put the ski axle back to 1.75 inches. Out to the snow to ride roads and trails and powder for testing. WOW, way way better. Nasty trail handling huge improvement, deep snow washout and climbing up out of old sidehill trail far better, turn around in the road far better. Great day of riding.

6. but back at the truck, out comes the drill, I had welded aluminum ears on the back of my pedestal to see how far is BAD. The next set of holes put the ski bolt back to 3" behind the fork axle. I have never run it that far back. Backout onto a darty frozen snowmobile road, BIG BIG IMPROVEMENT YET ! hmm, getting dark and we were thrilled about our improvements for the day we went home to weld up more ears. More holes more testing, who knows whats the bad setting back, its not 3".

So what I can say is this will or can or should make an improvement on a 2013 KTM sx or xcw .If you are running less than an inch of caster. For your bike, who knows. EXPERIMENT, lots of ski pedestals out there now, checking a UFO kit on a yz250 it was over 2" and it handles great, and likely could be better. The stock TS pedestal just doesn't allow enough adjustment to get towards the handling sweet spot on a KTM500xcw, l measure up your bike and see where its at, you might be able to do a lot better than what you bought.

My pictures show a square on the floor with the edge going through the center of the axle bolt and tape showing the offset, also the forward no offset that SUCKED BIG TIME. Also picture of the ears welded on and painted as I ran them.

 

[snowrydr]

That's great information. Maybe I'll be able to get this Mototrax front ski to work better with some modification.

 

[J&L Snowhawk]

Nice work I run 1" normally. Had first Moto trax ones at 2.5" w stock holes.

 

[CATSLEDMAN1]

ski attitude check

in addition to moving the ski mount back to trailing , its, importand to make sure when the front of the bike is lifted up off the ground, the rubber bumper that sits between the pedestal and ski shoe makes the ski tip always up...... tip high. The rubber ski bumper must have the taller part of the bumper in the back.

A couple of years ago on this forum when this issue was beat to death, it was pretty generally agreed that better road performance and better deep snow performance was gained by the tip high attitude. Several posts at the time about making a spacer to go under the back of the rubber bumper. A 4" x 2" .200 thick piece of plastic sheet under the back of my bumper make my tip high again and nice cushy pressure to keep it there in deep snow.

 

[dooman92]

In regard to increasing the trailing distance, much like increasing negative caster on an auto, between the axle shaft center and the ski bolt. No doubt some trailing or negative caster improves certain aspects of handling but the more the ski bolt moves rearward in relation to the axle the more the spindle becomes a lever to twist the forks rearward as opposed to compressing the forks when met with resistance like a log or rock. I think the least amount of trailing one can tolerate is potentially better for fork survival in a big hit.

 

[Selkirk72]

Great info.

Is the TS ski always mounted to saddle in center set of holes here?

What effect does moving ski fwd and back on saddle have?

Both my TS skiis had rubber installed with tall bump forward, tips down. Wrong.

Yeti ski saddle is mounted roughly 1" further fwd than TS ski. Ski rides further back on bike.
Center skag contact patch is 2" back from TS, and side skags are 6" back from TS.

Anyone play with custom skag setbacks on the TS ski?

 

[CATSLEDMAN1]

TESTING

two more days of testing and adjustments on the xcw and the sx and so far we like

1. ski bolt on the xcw seems to work real well at 2.250 inches back. I rewelded up my old holes and moved back from 3 to 2.25 to see what happens, road manners great, really didn't seem to improve washout, both of us concluded it might be a little better than 3" on crusty side hills.

2. sx, Dan redid back to 2", and again we both concluded it was for sure better than 1/ 1/2" and seemed to be as good as the 3" we rode for a couple of days.

3. more air pressure ( 20 psi ) in my forks and 16 more clicks of compression dampening in my xcw, was better on washout in powder/junk/crust. stiff fork, less washout.

We purposely road an extra mile or so of mealy some ice plowed road, all good, gearing was the only limiting factor for speed, very good. We are running the tri carbide center skeg, junked the half pipe a couple of years ago due to poor hard snow or road performance.

3 days of fooling with our front end, moving the ski in the saddle ( won't work), snow conditions moving target, sunny last two days, snow changing by the hour, buy still riding same trails, old crusty powder, in the tight tight trees. The setting we are using really worked and way better than where we started with no caster in the ski.

 

[J&L Snowhawk]

[so your saying that moving the ski saddle on ski in either direction from center is not good?
And your saying with your setup 2.25" setback is best in all conditions?
Thanks for all the testing you can do in your back yard.

QUOTE=CATSLEDMAN1;4044040]two more days of testing and adjustments on the xcw and the sx and so far we like

1. ski bolt on the xcw seems to work real well at 2.250 inches back. I rewelded up my old holes and moved back from 3 to 2.25 to see what happens, road manners great, really didn't seem to improve washout, both of us concluded it might be a little better than 3" on crusty side hills.

2. sx, Dan redid back to 2", and again we both concluded it was for sure better than 1/ 1/2" and seemed to be as good as the 3" we rode for a couple of days.

3. more air pressure ( 20 psi ) in my forks and 16 more clicks of compression dampening in my xcw, was better on washout in powder/junk/crust. stiff fork, less washout.

We purposely road an extra mile or so of mealy some ice plowed road, all good, gearing was the only limiting factor for speed, very good. We are running the tri carbide center skeg, junked the half pipe a couple of years ago due to poor hard snow or road performance.

3 days of fooling with our front end, moving the ski in the saddle ( won't work), snow conditions moving target, sunny last two days, snow changing by the hour, buy still riding same trails, old crusty powder, in the tight tight trees. The setting we are using really worked and way better than where we started with no caster in the ski.[/QUOTE]

 

[CATSLEDMAN1]

ski saddle

with the current edition TS ski, the raised center skeg is short and it appears that the shoe really needs to be balance directly in the middle of it. When we moved the shoe either direction from stock, the weight on the ski to the back shoots the ski tip up and you fall off the back of the ski, ditto when you move the shoe forward, you fall right off the front of the ski.

Back in the day when we were all fooling with the originally supplied SIMMONS narrow twin runner ski, you had long side runners and moving the shoe fore and aft, we tried to find better trail handling but didn't seem to severely affect the ski balance.

[so your saying that moving the ski saddle on ski in either direction from center is not good?
And your saying with your setup 2.25" setback is best in all conditions?
Thanks for all the testing you can do in your back yard.

QUOTE=CATSLEDMAN1;4044040]two more days of testing and adjustments on the xcw and the sx and so far we like

1. ski bolt on the xcw seems to work real well at 2.250 inches back. I rewelded up my old holes and moved back from 3 to 2.25 to see what happens, road manners great, really didn't seem to improve washout, both of us concluded it might be a little better than 3" on crusty side hills.

2. sx, Dan redid back to 2", and again we both concluded it was for sure better than 1/ 1/2" and seemed to be as good as the 3" we rode for a couple of days.

3. more air pressure ( 20 psi ) in my forks and 16 more clicks of compression dampening in my xcw, was better on washout in powder/junk/crust. stiff fork, less washout.

We purposely road an extra mile or so of mealy some ice plowed road, all good, gearing was the only limiting factor for speed, very good. We are running the tri carbide center skeg, junked the half pipe a couple of years ago due to poor hard snow or road performance.

3 days of fooling with our front end, moving the ski in the saddle ( won't work), snow conditions moving target, sunny last two days, snow changing by the hour, buy still riding same trails, old crusty powder, in the tight tight trees. The setting we are using really worked and way better than where we started with no caster in the ski.

[/QUOTE]

 

[Hawkster]

In regard to increasing the trailing distance, much like increasing negative caster on an auto, between the axle shaft center and the ski bolt. No doubt some trailing or negative caster improves certain aspects of handling but the more the ski bolt moves rearward in relation to the axle the more the spindle becomes a lever to twist the forks rearward as opposed to compressing the forks when met with resistance like a log or rock. I think the least amount of trailing one can tolerate is potentially better for fork survival in a big hit.

Why not just turn the tube decreasing the leverage and height of the spindle ?

 

[J&L Snowhawk]

well that would be just too easy to do! just make new spindles to accommodate that rotation. would make sense

Why not just turn the tube decreasing the leverage and height of the spindle ?

 

[CATSLEDMAN1]

gottta eat crow on that one

ooops, thought I would delete a double post, but I zero'd my whole mistake.............

 

[CATSLEDMAN1]

good or perfection

so the much better handling of my front end was a big step up for a TS kit. And several of my riding group have also found out how much better their bikes can handle.

So coming out of the hills the other nite bashing the chit out of the moguls , I had to ask everyone how their bikes were working. Mine would go straight and in and out of sled tracks and powder on the edge of the trail... it was working great, but now the back end was kicking. One of the riders commented that on his 17 ts kit, the stiffest dialed setting was the best for out of the hills road ride .

I rebuilt my shocks a couple of weeks ago, so my issue was not old fluid or just tired shocks. I went to the shop and redid my shocks with QUITE A BIT MORE compression and especially rebound dampening. I am running stiffer springs with less preload than stock setting so it also would figure that more rebound for sure would be in order.

My shocks were original setup for 2013 year. I recall that the couple of years following TS was bragging up more stiffer better shock setting.

So far, it appears that quite a bit stiffer valving going both directions is a can't miss. Snow conditions of course always screw with your mind and good cross over comparison, but I really liked it. If anyone is interested, I will post the shim stacks I used.

 

[hughesfoundation]

I have a 2013 ST on 04KTM 450, put springs(58) in forks and Tri carbide on center keel. Still not good on road, setback is apron 1.5". My forks are close to flush at top and fixed strut is as short as it will go, this puts my track close to level on ground. I am not sure if this is the correct strut or what difference sucking the forks up in the front will do. Will the .75" on the ski mount make that much difference?

 

[CATSLEDMAN1]

better and better

if you can manage to move the ski mount back into the 2" range, try it, it should be a little more improvement.

shims under the rubber bumper make it work better in and out of tracks and fluff on the edge, but down an icy road you won't see anything.

stiffer forks always seem to be better. this year I went with air rather than heavy fork springs so I could play with stiffer being better or ?
Too stiff for a comfortable ride for sure handles all conditions better, on my KTM I have gone back and forth between 15 psi ok comfy, 20-24 psi too stiff for mogul comfort but working great boonedocking and powder off road.



sliding your forks down in the triple clamps might help, for sure having them shorter will likely not be a plus..........same as weak spring almost.

Make sure your steering head bearing are tight and require some effort to move your forks side to side, takes a little more of the busy out of your front end.

rod adjustement to a flat track on the garage floor is usually a good setting. But out on a road, stop and shorten the rod ( if its adjustable ). a 1/4" shorter often improves road manners without too much loss of traction.

 

[hughesfoundation]

Can't wait for next testing, I have welded on the spindle to allow for more setback. Also cut and tapped the strut so I can shorten it up a bit. Was really surprised to find the strut had right hand threads on both ends not allowing adjustment while installed on bike.WTH? Again thanks for all the assistance. One more question, do you run regular carbides on the outside or the new channel type?

 

[CATSLEDMAN1]

carbides

I am running the triple lip carbide in the center, and straight carbide on the outside, If I wasn't so cheap I would try the triple lip on the outside also. We try, like all bikers, to skip the icy roads so I am not sure more viscious carbide on the outside would help where we ride, maybe bigger host bar on the outside for more keel........might have to try something there.


I way screwed up my old post on the rubber bumpers and how shiming them tight seems to always be an improvement. We are considering CAD'N out a couple of complete front mounts with more swing back to front and a different profile on the aluminum block that rubs on the rubber bumper, trying to make the bumper tighter.

I think those bumpers are an annual throw away anyway, they do get squished out after a year or so.

 

[CATSLEDMAN1]

shock rebuild

after more testing riding and rebuilding the shocks on several bikes, you can't miss on the older fox shocks on the 13-15 TS vintage for sure, when rebuiding adding A LOT MORE COMPRESSION DAMPENING AND A LOT MORE REBOUND DAMPENING, good riding feedback from several riders. Yeah, it goes down the road Way Way better, but the real nice kicker is a lot better powder riding and riding new powder on an old wooped trail, side hilling in windblown powder and across old tracks..............hugely better.

One of those rare mods that make you smile.

16 kit, watched one coming down beat out trail, for sure we are going to add a bunch of rebound, the rear is trying to launch him over the bars when riding in 5th and hitting old water bars etc.
And we have expereinced far better ride off trail, more suttle change, but a change for the better.

 

[hughesfoundation]

Well I had a great day on the snow with the updates. This thing handles great in the snow and better on the road but still don't think the wife could manage on a hard packed groomed road. It runs great on the straight but is tough on the corners. Still thinking about a new track, still a bit confused on what would be the best route and what is required as far as drive shaft.