An Unholy Union II: Wp Extreme 50mm Conventionals on a G/S

I haven't dropped by for a while but exactly. What preload a torque spec sets all depends on thread pitch, temp, grease, cables, and the list goes on. Preload torque specs are about as gray as 'snug' for those reasons. Different bearings have different tapers. Some bikes are running sealed ball bearings. They take different preload too. Whatever is right is right. There is absolutely no concrete way to nail it down any better than that.

The pinch bolt on the stem helps transfer loads to the stem just like they do for the fork tubes. Someone said all new big bikes have that. Not even close to all new big bikes from what I can tell. Something to mind while adjusting preload but other than that preload is preload?

Someone was wanting to compare forks from one set of trees to the other to see if the trees were the cause of some stiction. Perfect trees can cause all sorts of stiction depending on how they are setup. It's not just the trees but very much tightening everything down as well (the setup).

I've taken well over a minute to consider things, what I am saying, and how to try to say it, I'd ask you do the same.
(Despite us not actually having a BMW figure to torque a top nut like the top nut we are using) Your point about thread pitch is valid, IF we were using a bmw stem with KTM bearings, however our stems are KTM stems with KTM pitch. That stem and pitch calls for 7.4 ft lbs on their KTM smaller contact angle bearings. This is a direct measurable torque designed to accurately preload a specific bearing. Increasing the contact angle of a TRB bearing to what we are using requires more torque to preload it correctly, thus the torque for our BMW bearings in this stem with this thread pitch should be at least equal to and greater than 7.4 ft lbs.
I dont know how much greater, but sitting the bearings side by side together they are fairly different and I can imagine the different torque required could be 'significant'.

Also, you now saying 7.4 ft lbs is the same as saying "snug" is a bit disingenuous and certainly goes against the last two quotes you raised to support your "snug" setting description- to me, both quotes quite clearly describe setting these bearings just to the desired point of no play- posibly a fraction further. Zero clearance. The first quote seems to make the claim that any actual preload will damage the bearing.

Snug is not preload- certainly in the descriptions used. Snug I would argue means zero play and in the real world would sit an insignificant fraction either side of zero into negative and positive clearance. If it is measurable negative clearance then it is preload. This zero clearance, it is important to repeat, will turn into positive clearance once radial and or axial loads are introduced, as will any given preload in response to a specific set of external loads.

I've tried to argue why actual real preload is desirable thing in setting up TRB's for our steering heads, and also why we should be torquing this figure up (with a KTM stem, blind nut and thread pitch) over 7.4 ft lbs.
Ive also tried to question how a reasonable preload could damage these bearings, and tried to show how an insufficient amount of preload can lead to damage and faster wear due to the loads they experience reducing the negative clearence and resulting in positive clearance.

Aside from the difference in our stem and blind nut and thread pitch , our bearings are still bmw bearings, so although they are problematic the traditional methods of setting preload by the resistance to turn the bars (fallaway or measured by a spring gauge) are still entirely valid.

As Supershaft says, Right is Right.
I've tried to set mine by this method and tested the results, and adjusted and retested.
Different to what Supershaft says, on our stems and clamps, once we have set them 'right' we now actually have a more concrete way to reproduce exactly what torque on the nut is required to correctly preload to the bearings and make it right. Set it 'right', test and adjust and decide when it is right- measure the preload.
Take everything apart, put it back together and simply reproduce that preload and it will be set right.
We no longer have most of the variables that make setting the normal BMW assembly up so.... variable.

At around 25 ft lb I suspect I've currently set mine a little on the high side, but at this torque I've experienced none of the negative handling effects of too much preload- and I am trying to run them at the highest preload setting I can before noticing any effect. 30 ft lb I could notice an effect. 20 ft lb just started to give me too rapid a bar fallaway (by my judgement).

This is not a perfect test, and I've only had it up to 80 or 90 Kmh like this and won't be testing it more in depth for a while, aside from not yet running it at high speed, variables might be that I am using old used but perfectly un-brinelled races with new bearings (I'll swap the races when I powdercoat the frame).

Nonetheless.
Preload is preload and is not snug. And we can measure it, and In this application I claim it should be over 7.4 ft lb, and that it should be as high as it can be before you notice any negative effects.


Thanks for dropping in Supershaft we haven't seen you in this thread much

OK, to clarify, with the forks all the way down in the triples I felt like I was "steering around" the front end and the balance was weird as well as the drop into corners.

On the freeway, when accelerating hard at higher speeds road bumps would unsettle the bike and give a slight headshake.

I added a bit of comp and rebound to the rear shock, as well as sliding the forks up in the triples.

The weird steering feeling is gone, and so far no issues on the freeway...

Well, I didn't have any head shake problems except when I couldn't get that top bearing to seat in the race.

So if you want a steel stem, they're $180 I think I paid $125 for the KTM stem turned down from Guy.

I changed a few of those bearings......

....for pics of how y'all are routing your clutch cable. As I had everything apart, I forgot my routing....and my new bars and hand guards have changed everything. thx

ANybody???

no pics, but mine run obviously down the right hand frame tube. It dives in the right hand side of hte steering neck, yeah ?hell, I've got two clutch cables in there, now, I should know.

thx, in front of the steering head, or behind? Talk me from the clutch lever down.

mine goes down in front, in between triple, right hand side of steering neck... ... lets see...








best pics I can find. Pretty sure it finds its way inbetween the neck and the gusset.

THanks....big help!

Rode in to work again today, hitting every hole I could find.... each time I ride the front end does feel better.

Added one more click of comp. to the rear Ohlins... looking forward to the ride home.

LOL, just checked my tires and the front was at 20 (now 35) and the rear at 25 (not 37). Also added on click of damping and one of rebound.

Hi,

it's been some days since my last posting.

I tried to find the reason for the stiction of my forks. Since I thought the problem could be the fork legs, I got a second set from ebay:



So, guess it. That didn't work. Although it got much better when I used the followed procedure:
1. Tightening the screws at the upper clamp.
2. Putting the bike from the main stand and compress the forks without the brake (using a piece of wood at the floor and pushing the bike against it).
3. Tightening the screws at the lower clamp.
4. Tightening the axle and the screws at the axle.

Then the forks got much better, but it wasn't still possible to compress the forks while jumping up & down at the footpegs.

After that I used the same procedure with the first set of forks. But they got stuck after tightening the screws at the upper clamp. The next steps didn't change that.

To test the clamps I dismounted the upper one and pushed the forks all the way up. Then I screwed the forks at this place and pushed the upper clamp the whole way from top down. That worked without any resistance, lso turning them up-side-down didn't change it.
Then I put the upper clamps under the lower clamp and pushed the forks though. Also did work. So I think, the clamps should be ok.

I tried to dismount the second set of forks, but they didn't want. I couldn't open the cap at the top, even with a long lever.

That was the point where I gave up.
I have now 1.5 weeks left to my trip to Iceland, not enough time for games with this stuff.
So I put the original forks back and I hope, they don't get stuck like the WP forks.

After the trip I try to find the mistake, although I still don't have a idea.

This sucks. Half a year working in the garage seems to be still not enough.

Regards,
Richard

This is starting to sound like one of those horror prison diaries or something
I really feel for you- I hate going around in circles like this.

I think I imagined what you did here, but I can't be sure. You seem to have proven that the bores in the clamps for the fork tubes are alligned. But if I am imagining you doing what you did correctly, then you probably didn't have the wheel in and the axle done up tight... so you might be back to axle spacing being incorrect?

So this means that these new forks have not been cleaned, and by the top being stuck that badly, may not been cleaned in a long time?
Mine stuck terribly before I cleaned them out. Maybe a little heat (being careful not to cook the big Oring up the top... or just take the forks into a mechanics who has a rattle gun and a socket to suit. Maybe after a clean they will be just fine....

Have a great trip. What a hassle. I hope you figure this out when you get back.
I really don't get what is going on here.

Here's more follow-up on my earlier posts about front brake pad coverage on the rotor... I have a 300mm front rotor (stock to the 1999 640 Adventures), a 640 Adventure caliper and caliper hanger.... I sourced Galfer green pads from cyclebrakes.com. Look's like I am getting coverage of about 2/3rd of the rotor.

I just emailed cyclebrakes to ask if these are the right pads as KTM lists seperate pad part numbers for the smaller cc models running the 240mm rotor and the big bore's running the 300mm one

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There's room in there for more pad I think
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how much should the WP50s be shortened to suit the geometry of a 100GS paralever bike?

it is as simple as replicating the OEM fork length or is there more thought behind this?

I would have said you have the wrong adapter bracket for the size of rotor. Like the caliper is too far out from the leg.
The inboard part is not touched.. do you have a groove in the pad at the rotors outer limit?
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J

The rotor runs right nearly touching the caliper between the pads.. I have a question on the orange forum and another 640 Adventure owner says his looks exavtly like my pix.

I had mine shortened by 85mm using a spacer. I then push them through the top clamp about 20mm.
I also have a shortened torque arm/paralever strut to hoik the back up a bit.
Just trying to get the "attitude" right

Some get the stanchion shortened, but that's not un-doable if its wrong.