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

[ontic]

just a quick note before I head to work.
No news from Roadsacallin yet.

To anyone with the short threaded blind nut as it came to us new- I highly recommend trying either an older long threaded one, or making yourself a steel one like I did (very easily) out of a olde swing arm pivot thing.
One day in the future I'll probably be sending something to Solo (you still want that airbox?) so I could easily include a heap of these steel blind nuts (I have three more on hand I could make and can cheaply or freely get more from my parts guy).
With more thread in that stem and particularly with the steel blind nut, you really can torque it up properly.
Secondly I'd say if you are redoing the stem torque on the centerstand with the front end hanging, do it the way I theorised, cause it works well. Loosen the top triple stem pinch bolts only- then loosen the lower triple fork pinch bolts- then the top triple is supporting the weight of the front end and you torque the blind nut which is only pulling the lower triple up and loading the bearings.
I agree with Jenna that this stem and system is not ideal, but I agree with Solo that if you torque it up and preload the bearings correctly, then clamp down all the pinch bolts, it shouldn't be going anywhere.
Saying this, Jenna seems to be the only one who has heavily tested it. I certainly haven't.
I had numerous things going on with mine, but after sanding and polishing steps out of my stem (upper and lower bearings had nocked ridges in the stem) which has by the way reduced my 'interference fit', and using a long thread steel blind nut, I can get a very smooth linear increase in bearing preload as I torque up the stem- I couldn't get this before. I can now very easily way over-torque the head bearings without it feeling like I am about to strip the stem thread. I couldn't do this before.


cheers,
Gotta run.

[SOLO LOBO]

Originally Posted by ontic

One day in the future I'll probably be sending something to Solo (you still want that airbox?) so I could easily include a heap of these steel blind nuts

yes, please! I believe I have the longer bolt on there now but steel sounds better.

BTW, I just sent an email to a former local BMW rider who was the/a sales manager at Scuderia a while back, asking if he could reach out to whoever he thought was the most knowledgeable tech for these older fork and see if we can get a definitive set of instructions on pre-loading from someone who know best.

[Airhead Wrangler]

Originally Posted by SOLO LOBO

see if we can get a definitive set of instructions on pre-loading from someone who know best.

The problem is that the optimal preload depends on what bearings you're using and more specifically the contact angles on the races and the taper of the rollers. What worked on KTM bearings is not ideal for bmw bearings. What would work best is to take the torque spec for the original GS stem, figure out what from thread diameter and pitch what compressive load that torque exerted on the races and then figure out how much torque it would take to achieve that same load with the bolt that we're now using.

[SOLO LOBO]

Originally Posted by Airhead Wrangler

The problem is that the optimal preload depends on what bearings you're using and more specifically the contact angles on the races and the taper of the rollers. What worked on KTM bearings is not ideal for bmw bearings. What would work best is to take the torque spec for the original GS stem, figure out what from thread diameter and pitch what compressive load that torque exerted on the races and then figure out how much torque it would take to achieve that same load with the bolt that we're now using.

Gottcha, what I hope to get is the definitive way KTM tech's pre-loaded these bearings. I understand this may not work for our BMW's, but it is valuable info right?


Here is the BMW spec - the torque for the slotted nut is specified as "tightened without play"

[hardwaregrrl]

Originally Posted by SOLO LOBO

Gottcha, what I hope to get is the definitive way KTM tech's pre-loaded these bearings. I understand this may not work for our BMW's, but it is valuable info right?

Remember what you sent me from their manual???

http://www.advrider.com/forums/showp...&postcount=316

[SOLO LOBO]

Originally Posted by hardwaregrrl

Remember what you sent me from their manual???

http://www.advrider.com/forums/showp...&postcount=316

Yeah, I'm doing the sanity check to see if the most respect dealership has a process that works better than what's in the manual... fingers crossed at least.

[Beater]

Ahhh ... just the tube. Got it. Thanks.

[One Less Harley]

Jenna, if you decide you want to try the threaded swing arm pivot thingy let me know and I'll look to see if I still have it.

[hardwaregrrl]

Originally Posted by SOLO LOBO

Yeah, I'm doing the sanity check to see if the most respect dealership has a process that works better than what's in the manual... fingers crossed at least.

Sorry, just rubbing it in!

Guess we should have had some more R&D reasearch done before we had Guy poop them out. It's a bummer Rdubb never chimmed back in with one of his projects. And Marcus if you're out there.....let us know whats up with your head bearings. I'm certain I've not encountered anything near a Siberian road.

[SOLO LOBO]

Originally Posted by hardwaregrrl

Sorry, just rubbing it in!

Guess we should have had some more R&D reasearch done before we had Guy poop them out. It's a bummer Rdubb never chimmed back in with one of his projects. And Marcus if you're out there.....let us know whats up with your head bearings. I'm certain I've not encountered anything near a Siberian road.

There are at least a handful of folks from the first run who have been riding... too bad none have chimed in here.

I may go back to the original thread and see if I can get any to come on over.

Since this design worked for KTM's of every size and shape (including PD racers and 950's) I am still hopefull it will work out fine, my triples have no slop right now.

I am worried about the main wiring harness routing between the fender and lower triple... need to find a better way to route it.

[hardwaregrrl]

Originally Posted by SOLO LOBO

I am worried about the main wiring harness routing between the fender and lower triple... need to find a better way to route it.

Yeah, I hated that design as well and re-routed it between the triples.

[hardwaregrrl]

Here's what I'm doing with the bike.



Sorry about the quality.

[Stagehand]

Originally Posted by hardwaregrrl

Here's what I'm doing with the bike.



Sorry about the quality.

Great video!@ I would LOVE to ride that road

[hardwaregrrl]

Originally Posted by Stagehand

Great video!@ I would LOVE to ride that road

Thanks....never had a gopro. Not sure how to get better quality without taking 2 hours to download. Come on down and ride with us!!!!!

[One Less Harley]

YEAH, what she said, LBL 200 mountain bike single track open to bikes!!!

I'll find out if it's wide BMW friendly. I plan on taking the DRZ this year.