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Old 04-23-2012, 09:38 AM   #496
SOLO LOBO OP
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Originally Posted by SOLO LOBO View Post
new skins and some serious WEIGHTS
Rode in today, some thoughts:
  • The wheel hop is gone!
  • Clearly my Ohlins out back has more sag and it set up much softer than the front.... This is causing the unbalanced feeling between the ends and is making evaluation of the front harder (the soft rear is making the front work harder).... I added 2 clicks comp and rebound to the back when I got to work and will have to add some pre-load as well
  • I took 6 clicks off both comp and rebound on the front.... the front still feels harsh over small bumps and perhaps a bit less "plush" than I would like over larger hits... first I need to bring the back end closer to the front and then will re-evaluate
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 04-23-2012, 11:30 AM   #497
hardwaregrrl
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So, some thoughts off road....

Ok folks, I feel like a real shit for not taking video. I rode quite a it off road up in N GA yesterday with Nathan Mende of Boxerworks.....If your curious to google the roads we were on were: Duncan Ridge, Cooper Gap, Grassy Gap, W Wolf Creek. A bit of mud, big rocks, and lots of downed tree limbs.

This was worth the coin IMO off road. I feel so comfortable in the corners at speed on uneven and loose surfaces. I've never felt that on this bike. I felt like I could lay on the side of the tank in the corners. I took the BMW off road course a few years back, and any time I'm off road I begin my "turn" with weighting the peg in the direction of the turn, then body to the outside after the turn has begun, and all the weight on the outside peg, elbows up and out and turn the throttle like a door knob. It works and feels planted with the WPs up front. I wish I could communicate in suspension terms how "planted" I felt. It was almost like my tires were constantly pushing into the surface and getting the most traction possible in the situation.

So a big s up for the WP conversion. I couldn't afford it at the time, but the bike is much more enjoyable to ride off road. And bonus, unless Nathan was having a slow, mellow day, it made me much faster because I was up his ass and I usually can't get near him. Better suspension does make a better rider!!!!
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Old 04-23-2012, 01:39 PM   #498
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yeah, but Nathan probably has shit for suspension......I'm just sayin'


Dang I'd like to get the DRZ out a play with you guys, hard for me to find playmates here. At least on a regular basis.
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Old 04-25-2012, 04:15 AM   #499
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Finally took the new front end for a test ride today.
Pissing down with rain and very cold- not the best testing conditions for bitumen and a bald rear and full knobby motocross front tyre

anyway, it was good fun- It was not a serious test, as things are still quite literally cobbled together- but it was just a proof of concept sort of ride as a kind of reward.

[/IMG]


Note the 'ึhlins Yellow' electrical tape holding things together After almost having to cut the last handgrip off that I slid halfway onto the new(old) throttle tube, I decided on a temporary grip- a rag wrapped around and electrical taped on

I have no headlight set up, nor front indicators so all I could do was run around my neighbourhood hitting speed bumps and testing the brakes and whatnot, hoping not to get in trouble by the 'boys in blue'

Initial thoughts are
VERY NICE.
I can't say I practiced turning much, but it hits bumps well.
With unshortened forks it is bloody tall- and I can see why people are leery of loosing any more turning circle. It is tough enough as is.

Aside from putting in new .6 kg springs, plus an Ohlins on the back sprung to my bike/weight, I haven't done any actual 'setting up' of the suspension- I haven't shortened forks (have just slid them up in the triples as far as I can) nor set front or rear sag, nor even fiddled with the reb/comp adjusters on front or rear. Hell, I haven't even changed nor checked the volume or weight of oil in the forks- there is some in there, that is about all I know.
Despite all this, and the problem described below, the suspension feels remarkably nice and if I had to I would happily take it for a ride in the dirt as is.
I couldn't hit a speed bump too fast- big hits seemed excellent. Undulations in the road seemed a little odd- more about that below.
Anyway, there is a lot to work out.

On old pads not yet bedded into this very lightly used 320mm rotor, the brakes are simply excellent. Given the knobby tyres and the wet, it probably isn't saying much, but I can lock up the front wheel with two fingers... a little too easily
I definitely won't be needing to upgrade anything brake related. I am happy.
My funky home-bungled caliper bracket(s) performed flawlessly. I did a lot of laps up and down my street hitting or riding the brakes and just watching the bracket and caliper assembly and disc the whole time and it is all solid as a rock.
I got the alignment right and by filing out the caliper bracket a little and rotating the caliper a little bit further around than stock (at more of an angle to the disc) I think I might have a teeny bit more rotor under the pads than Jenna's slick HE setup with the same disc. I'm sure it doesn't do a bit of difference though.





One thing that I am not happy with, and am a bit confused about, is around the first few inches of travel I am getting a bit of stiction. Basically around the whole area of travel from full extension- static sag- race sag and the bottom area of brake dive.
For example, If I hit the brakes I get some brake dive, then to some extent it just kind of stays down there. If I hit the throttle and lift the front a bit, then the forks extend again.
With static sag it is the same. Lock the front brake and push the bike forward and back and the suspension 'settles' in quite different spots.
Sticky stiction.
I suspect this is the primary reason that big hits feel good and small undulations in the road felt funny.
I'd expect a bit of stiction, but it just doesn't feel right.

I've goofed up a couple of times with the axle and spacers- I think I've got it right now but the stiction continues.
My front wheel came to me with the rotor side spacer that slips into the hub, but not other side spacer. I bought this separately but it seems to be the exact right fit.

here is the side with the rotor, with most of the spacer slid inside the hub


then here is the other side spacer- this is the one to replace the old speedo drive one (that originally came with this wheel but did not get sold with the wheel)


Is this how everyone elses with this wheel and axle looks?

Has anyone found the KTM tightening and torque procedure?

Whatever the case, as I have it now I am neither pushing out nor pulling in the fork tubes. The forks are sitting exactly where they want to sit with a moderate amount of torque on the axle (and after Jenna's warning, not too much torque at all on the pinch bolts). I think the wheel is spaced properly and my stiction is not caused by forcing the forks out of alignment.

Of course before jumping the gun and declaring a problem I need to go through these forks and change the oil and set the sag/preload and whatnot, maybe that alone will help, but any ideas on this stiction?

Cheers,
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Old 04-25-2012, 06:01 AM   #500
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So just thinking about your stiction problem, where is your rebound set? I have to get my welder back from Beater so I can make a tool to disassemble my other wp 50's and swipe the rebound needle. I'm just wondering if yours is bent like mine and stuck not allowing oil to flow. I've got 800cc in each leg of 7.5. I'll take some pics of my spacer set up, I know my wheel was not centered and I had to have a spacer made. Bike's lookin' good, Hans!!!
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Old 04-25-2012, 07:27 AM   #501
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Thanks Jenna,
good question.
Basically my adjusters were set 'somewhere in the middle'. I just went and put my adjuster knobs on them and clicked them both all the way out (-). While I felt the forks lighten up in the compression (at least) there was no difference in the way it settled and 'stuck' once they slowed down.

However, your questioning of the rebound adjuster setting may still be the answer. Here is what I am thinking...
When I removed my adjuster screws





and brazed in those extensions that allow my on-the-fly adjuster knobs







I had noticed that the rebound adjuster had fine ribbing on its blunt needle and seemed to be glued into something (the top of the rebound needle- or 'needle extension') with a clear loctite-like substance.
Here you can see it burned by the brazing



I never glued this back in, which would mean to my logic that the rebound needle extension is sitting right down the bottom and thus is at maximum rebound damping regardless of where I set the top adjuster screw.
I was planning to glue it back in, but just haven't gotten around to it yet, and didn't think of it until you mentioned it.

Theoretically, If there is no 'bleed shim' in the rebound shim stack then unless there was enough rebound force to flex the shims and allow oil through then it might be causing this stiction....?
Thus it feels good for me under heavy rebound but sticks up once the rebound force reduces?

at least that is my poor understanding of how I think these forks could work. I'd welcome some other thoughts from people with better suspension knowledge than me.

I'm also not quite sure if it is just settling/sticking in the position where it doesn't rebound enough- it seems to just as easily also settle and stick high as well as low.




About the oil volume- I seem to have read most write-ups talking about setting the oil as a height from the top rather than as an overall volume- I suppose this becomes particularly relevant with shortened forks. Are your forks shortened?
If we go with a volume, that works for full length forks, on shortened forks then the air cushion will be less and the suspension a little more harsh on small bumps (again, just my understanding).
I guess it doesn't matter how you get to what works, volume or height down from top- but I wonder what we should be aiming for when we read the instructions on and others advice on how much oil to put in to put in these forks? Should the volume of oil be the same regardless of fork length, or should we reduce the volume of oil along with the fork length and stick with the same air volume- or something in-between such as keep the same ratio of oil to air...

So many questions

and thanks for the compliments on the bike.
It has looked worse before, but there is much better to come and it looks pretty scrappy to me right now.
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Old 04-25-2012, 08:30 AM   #502
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Good point about oil volume with shortened forks, meaning less "headroom" for air.

Jenna's running 7.5wt and I have 10 in the comp and 15 in rebound. The choppyness or harshness over small bumps with the oil I have now is much more significant than when I had 5wt in.

I need to do some testing with the comp and rebound all the way out ride, screw one all the way in and ride the same loop, bring that one out and screw the other all the way in and determine how much adjustment and change I am seeing with the adjusters.

I am starting to think a re-valve is in order, but want to "test" more
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 04-25-2012, 08:32 AM   #503
Airhead Wrangler
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Quote:
Originally Posted by ontic View Post
If we go with a volume, that works for full length forks, on shortened forks then the air cushion will be less and the suspension a little more harsh on small bumps (again, just my understanding).
Mmmm, I'd disagree, but then I'm no expert either. Small bump harshness is a matter of your fast compression damping being too high. This can be solved by modifying your shim stack, oil weight, or more likely both. A decreased air volume will lead to more progressive spring rate. The more the fork gets compressed the higher the air pressure and thereby the higher the effective spring rate. The smaller the air volume, the more pronounced this effect will be. This is both good and bad. You will use less of your travel, but it will give you greater bottoming resistance. For casual riders taking it slow and conservative a larger air volume will give you a more comfortable ride as you'll have more of your travel available to use. More aggressive riders might want a smaller air volume for the increased bottom-out resistance they'd need for bigger hits. (same as you, this is just my understanding, so please don't take it as fact)
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Old 04-25-2012, 09:05 AM   #504
SOLO LOBO OP
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Quote:
Originally Posted by Airhead Wrangler View Post
Mmmm, I'd disagree, but then I'm no expert either. Small bump harshness is a matter of your fast compression damping being too high. This can be solved by modifying your shim stack, oil weight, or more likely both. A decreased air volume will lead to more progressive spring rate. The more the fork gets compressed the higher the air pressure and thereby the higher the effective spring rate. The smaller the air volume, the more pronounced this effect will be. This is both good and bad. You will use less of your travel, but it will give you greater bottoming resistance. For casual riders taking it slow and conservative a larger air volume will give you a more comfortable ride as you'll have more of your travel available to use. More aggressive riders might want a smaller air volume for the increased bottom-out resistance they'd need for bigger hits. (same as you, this is just my understanding, so please don't take it as fact)
So, for small bumps, the air volume may play a very small role in fork preformance/action?
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 04-25-2012, 09:12 AM   #505
Airhead Wrangler
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Quote:
Originally Posted by SOLO LOBO View Post
So, for small bumps, the air volume may play a very small role in fork preformance/action?
Yes. Unless of course the oil level is VERY high in which case you'd hydrolock the fork before you made it through the travel. Excessive stiction can also cause small bump harshness. There's also the phenomenon of when hitting a small sharp bump it bends the fork legs backward and loads the bushings extra hard creating a momentary increase in friction. The racetech suspension bible has a great graphic depicting this. If you haven't seen that book I'd highly recommend it. Buy, beg, borrow, or steal a copy if you can.
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Old 04-25-2012, 02:47 PM   #506
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Quote:
Originally Posted by Airhead Wrangler View Post
Small bump harshness is a matter of your fast compression damping being too high.
Your right, I guess I sort of agree with that- that it is a matter for your shim stack primarily (and that it is due to the base, largest shims that deflect the easiest, and/or bleed shims). Maybe 'small bumps' was the wrong word.
It gets a bit tricky trying to describe suspension stuff.
There is something (claimed within a lot of the reading I have done- not experience) about increasing the air volume increasing the 'plushness' of forks. Fork subtanks claim to be able to do this (increase plushness') while at the same time keeping your ability to not bottom out and take large hits (due to keeping a larger oil volume as well). That is sort of what I mean,
but I gotta run to work,
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Old 04-27-2012, 11:23 AM   #507
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Brakes on

Got my brake parts today so its all a step nearer the first road test.
Went for a Venhill flexi all the way to the caliper. The tube is anchored to the leg by a couple of stainless clamps and "P" clips. Used a 75 degree banjo at the caliper end.



The line is anchored at the top triple with another "P" clip. Had to drill and tap the triple. This gives a good amount for the flex of the suspension.



Got to strip it down a good way though as I have forgotten to set the head races

Still, its forecast to be a shite, wet day on Saturday and it will give me something to do between MotoGP practice sessions...
Still waiting to hear from the suspension man...

John
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Old 04-28-2012, 01:15 PM   #508
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  • Bumped the WP's up 7mm in the triples
  • Re-set the steering head bearing pre-load as it was too little
  • Re-set my Ohlins to Dan Kyle's baseline as below. My spring length is 210mm as opposed to Dan's 213mm spec below
Quote:
No measurement on the amount of threads, the measurement is the amount the spring is compressed.

In this case the freelenght of the spring is 230MM and it should be 213MM on the shock. 17MM of preload

Comp should be 15 clicks out

Rebound should be 23 clicks out
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Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
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Old 04-28-2012, 02:44 PM   #509
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Just got home from a nice ride up in the mountains. I ran the bike through the paces, and every gnarly road I could think of. The main one I wanted to run was Flatland....that was the road that ate 2 head pipes. One of mine, and one of Brads. It prompted him to make those crazy 3lb bash plates!

It handled it like a champ soaking up every stinkin' rock I hit! But now my head bearings are toast, well they're very loose.! I cannot load them any more, I've whacked the shit out of my top clamp and they aren't getting any better. So looks like I'll be taking things apart tomorrow and regreasing and preloading tomorrow. I hope that's all it takes. Anybody got an ideas????

My method is loosen all top clamp pinch bolts (6), remove blind nut, and a dead blow "tap" on the top clamp. Nope, no better.
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Old 04-28-2012, 02:53 PM   #510
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my experience is that the head bearings take a good while to stop moving after you take them apart. Lots of adjusting till they settle.

YOu dont really think they are shot, they are new with the fork swap, right?

Otherwise, of course you are not bottoming out anywhere or anything...
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