16/18 triples on a FE

I've got a bike that's got parts from three bikes on it.

2005 FS650

05' FE forks, shock, swingarm

FS triples, the billet adjustable ones.

Currently have them set as oem, 16mm?, the steering lock works, but not if I flip the stem around. I don't care about the lock though, I want it to turn.

Problem is, when i had the knobbs fitted I was having a hard time with the front running wide. "pushing?"

I have way more time on the 17's off road, and have way more confidence and experience on them in the dirt than with knobbies.

I want to ride tougher areas (wetter and steeper) where slicks just can't make it.




Just wondering and trying to clarify which offset does what.

I've ridden it on 17's with it both at 16 and 18, and couldn't tell too much difference.

Basically my question is should I flip it and run at 18mm offset when I put my 21/18 wheels on? More offset means more trail does it not?

It seems like I'm perfectly confused about offset vs trail, and how that relates to 17" and 21" wheels.

*A shorter wheel will by design have less trail all else being equal.
*more trail equals more stability and harder to turn.
*less trail equals sharper steering easier to turn.
*offset is 16mm with 17", and steering is perfect.
*offset at 18mm with 21" would give me more trail than if set at 16mm.

*true or false?



I'd rather not have to swap clamps every time I swap wheels. (I have 05' FE clamps as well.)

I just want it to turn better and not feel like it's slipping and running wide all the time.

I have ktm 18-20 clamps on a 01 (different frame geometry. I do a fair bit of full lock slow circles to practice control. The stock triples were just ok, the 18 setting was good, then I ran the fork tubes up in the clamps 10mm and it was better again. I got all my sag set first and then started fooling around. The bike now handles the tight single track very well with the front end planted. I think you will see a big difference with the 21/18 if you run the tubes up in the triples. Pushing could also be your fork springs too stiff. If you were using it as an sm, they might be too stiff.
Someone correct me if I'm wrong. I'm pretty new to suspension but I've been playing with the berg to try to get it manageable in the single track.

This is a great thread! After going from a 450FE to YZ 250 2st I am unhappy with my FE and the way it turns and want to alter it.
Taffy messed around with triple clamps but I can't understand his rants so gave up there. Anyone else tried KTM triple clamps in a post 04 Fe /x frame?

I've heard that if you run the sm triples with a 21" front wheel then you run the risk of the tire hitting the frame if the suspension is compressed enough. I don't personally know if this is true, but it's something you should definitely watch out for.

If the bike is on level tarmac the contact patch is always directly under the axle, in reality it moves forward a bit but not much on tarmac

offroad though the tyres sink into the dirt and the effective contact patch moves forward a lot and reduces the trail. with a bigger tyre this reduction isn't as severe.

regarding the difference, going from say 22 to 14mm offset increases trail because you are moving the tyre and its contact patch closer to the bike and away from the projected axis of the steering stem, more distance between the 2 = trail increase

if there wasn't much difference between 16 and 18 I reckon look into the suspension settings as KFS suggests, make the front a bit softer and the HSC on the rear stiffer


FWIW I just put KTM 14mm offset clamps on my 08 frame

decided I would like to have 4mm offset in the sand

the husaberg bearings can be used with the ktm stem but the right seals are hard to find, I have some spare Idle and Blunny.. send me a pm if you need some.

My berg with the factory triples (22mm offset) was super stable and really great for Dualsport riding, fast gravel roads and fire access roads. It did suffer in the tight stuff though.
From what I could gather 18-20 clamps in the 18 position really help the turning. I was considering 14mm offset on my 01 as they are more raked out than the 04 and up. I'm not sure if this would be going too far or not. I'm happy with the 18-20 on my road legal bike. The 14 would be for the Offroad bike. Any thoughts?

Idle said:

More offset means more trail does it not?

Click to expand...

No. More offset, say 22 mm vs. 18 mm, decreases trail. As far as stability, turn in, etc. there are a lot of variables affecting this in addition to trail. Some like to run lots of trail on the older chassis bikes. When I had my 05 I was always most happy with the stock 22mm clamps. The lower offset clamps seemed to make my bike sluggish to turn in and also in side to side direction changes.

That was just my personal preference on that particular bike. I know many were happy with running lots of trail by using the SM clamps, but not me.

Johns post is the best one here . .try something and see


my trail bike was being a top heavy wallowing bucket of snot today, the shock is terrible and its so hard to get far enough forward for corner entry with the fat OEM tank in the way and my shortarse arms need lower bars.

Ill machine the clamps and the bar mounts and lower the bars 15mm .. will help make turning easier.

Idle said:

Currently have them set as oem, 16mm?, the steering lock works, but not if I flip the stem around. I don't care about the lock though, I want it to turn.
the more trail you have the fsater it turns or as I would put it: 'flicks'

Problem is, when i had the knobbs fitted I was having a hard time with the front running wide. "pushing?"
this shouldn't have happened. more weight is more grip. more trail means less turning of the steering so it won't slide on

I have way more time on the 17's off road, and have way more confidence and experience on them in the dirt than with knobbies.

that is perehaps because the 17s were designed for SM! it sounds like a suspension set up problem. find out how much travel you're using? are you on SM forks and shock or FE?

Just wondering and trying to clarify which offset does what.

I've ridden it on 17's with it both at 16 and 18, and couldn't tell too much difference.
probably takes extreme effort (i.e racing or riding at 100%) to feel the difference. green laning can';t do that. also you need to be back-to-back when you test.

Basically my question is should I flip it and run at 18mm offset when I put my 21/18 wheels on?
18s are about right off road with 21"/18" when yoiu have the 2004-8 headstock angle of 26.5d

More offset means more trail does it not?
no. wrong sorry. the wheel touches the ground behind a focal point taken through the middle of the headstock. the tyre always site on the ground trailing this point. you can have more or less offset that takes you nearer that point. so more offset means less trail. less offset means more trail

It seems like I'm perfectly confused about offset vs trail, and how that relates to 17" and 21" wheels.
well don't listen to Bushie or you'll be right in the shiet

*A shorter wheel will by design have less trail all else being equal.
shorter? shorter! you mean smaller? like 17" is smaller than 21"???? correct you got it
*more trail equals more stability and harder to turn.
you took the words right out of my mouth. it must have been while you were kissing me...
*less trail equals sharper steering easier to turn.
not sharper no. easier yes. sharper is the wrong word. just eaisier. think of: 'this is a bike for my mum'
*offset is 16mm with 17", and steering is perfect.
*offset at 18mm with 21" would give me more trail than if set at 16mm.
no, less trail.
*true or false?

if there is a correlation between the two set ups of on and off road it would be that the 17"s want 16mm offset and the 21"s want the 18 offset but the truth isn't in exactly 2mm

I'd rather not have to swap clamps every time I swap wheels. (I have 05' FE clamps as well.)
suggest then that you keep the 16s in all the time and sink the forks out the TCs for the dirt. or you can keep the 18s with the forks out the top of the TCs and the legs at the normal height for the dirt wheels

I just want it to turn better and not feel like it's slipping and running wide all the time.
the answer is to get the suspension right. it can't really be anything else. 16s or 18s the bike shouldn't slide on on a corner. try 6-10LB front tyre pressure. give us more info on the fork set up. also a saggy rear shock will do this. you should only drop 100mm from wheels free to your fat arse being sat on it!

Click to expand...

regards

Taffy

bushmechanic said:

If the bike is on level tarmac the trail is in theory the same with a bigger or smaller wheel (provided the front and rear are raised equally) ..the contact patch is always directly under the axle, in reality it moves back a bit but not much on tarmac

Click to expand...

not true

the wheel spindle height is vastly different between the two. that means that with the 21" front that while the line from the spindle is going down and down again after the 17" hits the deck the axis line is sailing on forwards and down at 26.5 degrees.

so dirt has more trail than street. this is with the 'level up and down'.

the contact patch moves forwards slightly on most soils and a helluva lot on sand and peet.

bushmechanic said:

offroad though the tyres sink into the dirt and the effective contact patch moves back a lot and reduces the trail. with a bigger tyre this reduction isn't as severe.

Click to expand...

see above. no, the contact patch moves forwards. both ends!

bushmechanic said:

regarding the difference, going from say 22 to 14mm offset increases trail because you are moving the tyre and its contact patch closer to the bike and away from the projected axis of the steering stem, more distance between the 2 = trail increase

Click to expand...

correct although anyone running your kicked out front end and going to 14s would be as nuts as you apparently are!

bushmechanic said:

FWIW I just put KTM 14mm offset clamps on my 08 frame

Click to expand...

anon
my best advice to you is that with whatever tyre and set up you have that you go up to a roundabout and ride around it, ride some 15-20mph turns and the steering shoulf fall in the tighter the corner gets. the steering should turn tighter while you get slower.

if the steering flips to the lock and you have to straighten the lower bar a little then you have too much trail. if you have bars that simply point straight ahead whatever the turn then you don't have enough trail.

think of a coffeee trolley and the wheels OK?
you have no rake but tons of trail. lay the coffee trolley over on to the two left wheels and the wheels flick 90 degrees....nasty! this is what happens with too much trail.

by the way, you won't see this said like this anywhere else. that's because I'm still the best original thinker on this site.

I AM THE DADDY

Taffy

yes the contact patch moves forward In soft stuff, main thing a soft surface does as i explained is reduce trail, same with smaller diam wheel.

I put a couple of Freudian slips in there to entice old taff out of retirement LOL, good to see i can still fire the old geezer up a bit

Rake / trail is not rocket science but can be hard to explain



my frame with the 14s is not kicked out by any significant amount. it works very well with 14s but not as good as my custom frame which is kicked out by 100mm at the front. to get anywhere close to that amount of trail the 08 frame needs zero or negative offset triples.

one thing that isn't very clear initially is that increasing trail by fitting less offset triples changes the weight distribution. less offset = more weight on the front wheel. the front wheel already has 52% of the weight and increasing that is not a good thing for rough off road with rocking chassis movements (big braking bumps) the 70 deg bikes have 48% weight on the front.

more trail is more stable at speed but if you increase trail the front wheel has more leverage over your hands .. the wheel has a longer lever with more trail so if it does catch a rut or a rock you have a harder time hanging on to it

if you don't have enough trail the front wheel has less lever length to fight against your hands and is easily bullied (so called easy to turn) but is unstable or "head shakey" at speed and in soft stuff it digs in easier moving the contact patch forward of projected stem axis and in this situation rips the bars out of your hands as well.

somewhere in between there is a nice compromise

main thing about handling etc is that no 2 people will be happy with the same setup so changing things around and experimenting is a must. the answers are not on the net they are in the bike

seating position and handlebar height are equally if not more important than rake/trail especially if you can only change the trail by 2 or even 4mm... changing it by 10mm makes a reasonable difference, i made 11 different sub frames and seat positions for my 700 but only one headstock.

everyone who knows bergs and has ridden my 700 says it handles like a 250, personally i think that is an exaggeration, it handles slightly better than a stock jap 450 mx bike. no surprise really as the rake trail and weight distribution are almost the same as a 2010 rmz450.

Thanks for the help guys, I think I've gotit now.

My suspension is all out of whack currently.

*FE full length forks w/5,0 springs...revalved for bad dirt roads and goatpave on 17's primarily.

I've never used the last 40-50mm of travel assuming the dust seal leaves around 10mm on bottoming out.

They work great, and have great feel and don't dive a lot like the FE and even FS stockers did. This, when braking hard on the kart track or on the road.

Great feel and planted when cranked right over in 3rd or 4th gear on bad tarmac. They love bumps and potholes at any speed.

They are due for an oil change, so I was considering sucking out a little oil beforehand to see if I can get a little more travel out of them.

Currently have them pushed up a half mile in the clamps. About 50mm, to balance the bike out.

The shock's's...Where to begin..
Well, my FE shock I had resprung and revalved at the same time as the forks.
It was incredibly slow to return to full length on rebound on the sidestand or held level.
With the 260-98 spring my sag was spot on IF I had helmet, boots, leathers and my pack loaded up and tools on the tail.

Preload was ~2mm/hand tight collar.

It worked great on pavement, all sorts...washboarded uphills on the dirt roads it required standing or it would pack up.

Then the rebound screw became stuck, maybe the guy dinnit put any grease or aunti-seize on the rebound screw?

So ran with my FS shock for a while, with the 98 spring. It had lost it's charge long ago I believe. It was ok untill it warmed up then pogo-pogo from then on.

I bought a shock on the bay, even though they wouldn't answer my question about whether FS or FE, nor would give me an eye to eye measurement.

It's an 04 FS shock in good shape so far.
It works ok, but my 98 spring was gone, I sold it to sgomes when I sold my other bike.
Has an 88 in it, cranked down preload...and am "adjusting" my riding to accommodate it's shortcomings.

My original FS shock is finished but haven't picked it up yet, I had a shop remove the spacer and serviced it with heavier oil. They left the valving alone.

Which brings me to spring shopping now. I think a 92 or 94 would be good. I am 200£, or 90kg with pajamas on. 230-240£/105-110kg fully kitted.

Really looking forward to get back to full length suspension.

It won't blow over in the wind anymore, and I'll be able to keep up with the youngsters again. No more "grounding out" with my boots also.

I'll probably run the short 04 FS shock with the 88 for knobbies on really difficult trails with the forks pushed up. I like being able to find the ground in the rocks.

Then the "new" shock for 17's and the easier dirt work.

*also shopping around for a tire groover as my favorite tire ever Avon Pro Extreme Rain 120/70-17 is unobtanium here now. I cried a little when I took the last one off. I had 4 fronts, and 2 rears.. Awesome for dirt roads.


Knobbies: i have a 21" Pirelli scorpion MXMH, and I think I'm going to get another MT43 rear or maybe something more aggressive.

Sorry about the essay^^ (｀_´)ゞ

awesome Idle

I remember a thread on KTM talk where someone was using an "E" axle to compensate for the change in trail between wheelsets



or if you had exactly the right offset on some custom fork lugs (axle clamps) you could rotate the lower fork legs when doing the wheel swap, brake caliper would need 2 mounts.

love the £ sign for pounds Idle!

even the Brits don't use it like that!

we put 'LB' as I believe the ANZACS do.

Taffy