Steeringhead Stiffness

[AnnapolisAirhead]

Just thought I'd post an interesting tolerance issue that I (er, my clever mechanic friend) discovered.

I recently converted my '83 R100 into an R100RT with a fairing I bought on ibmwr.org. It was a sizable job and now all together running like a top, but not without some challenges.

I had cleaned the steeringhead bearings in a heated ultrasonic bath (without removing the lower one from the stem/triple tree. Clean and shiny. Before installing the triple clamp assembly, I had installed the fairing spider frame mount, which bolts into the steeringhead tube on the frame with two specialized bolts (not 1.25 threads, finer 1.0) that I bought from the local BMW dealer. I also used a wavy washer on each as I saw in the diagrams. I then installed the triple clamp assembly, forks, etc. and onto the wiring harness mods needed for the fairing conversion.

Well, as it turns out the lower steeringhead bearing wasn't fully seated as my friend discovered. So, he checked seated it and checked the steeringhead bearing play...it was super stiff, even with the wheel off the ground. Even with the steeringhead nut backed way out.

He pulled it all apart again and discovered two notches in the steeringhead stem. they were there when I was initially assembling it, because I hadn't put the spider frame on at that point. It turns out that the fairing spider mount frame bolts need a pair of 2mm washers, not wavy washers. Without them, the bolt ends were interfering with the steeringhead stem. A problem he had never seen in all his years working at BMW and on his own.

Rides, steering and feels like a new bike now. Just thought I'd share this for anyone else considering a fairing project. The same would/will apply to an RS fairing conversion (my spring project).

[PGlaves]

Just thought I'd post an interesting tolerance issue that I (er, my clever mechanic friend) discovered.

I recently converted my '83 R100 into an R100RT with a fairing I bought on ibmwr.org. It was a sizable job and now all together running like a top, but not without some challenges.

I had cleaned the steeringhead bearings in a heated ultrasonic bath (without removing the lower one from the stem/triple tree. Clean and shiny. Before installing the triple clamp assembly, I had installed the fairing spider frame mount, which bolts into the steeringhead tube on the frame with two specialized bolts (not 1.25 threads, finer 1.0) that I bought from the local BMW dealer. I also used a wavy washer on each as I saw in the diagrams. I then installed the triple clamp assembly, forks, etc. and onto the wiring harness mods needed for the fairing conversion.

Well, as it turns out the lower steeringhead bearing wasn't fully seated as my friend discovered. So, he checked seated it and checked the steeringhead bearing play...it was super stiff, even with the wheel off the ground. Even with the steeringhead nut backed way out.

He pulled it all apart again and discovered two notches in the steeringhead stem. they were there when I was initially assembling it, because I hadn't put the spider frame on at that point. It turns out that the fairing spider mount frame bolts need a pair of 2mm washers, not wavy washers. Without them, the bolt ends were interfering with the steeringhead stem. A problem he had never seen in all his years working at BMW and on his own.

Rides, steering and feels like a new bike now. Just thought I'd share this for anyone else considering a fairing project. The same would/will apply to an RS fairing conversion (my spring project).

New supplier, different that when originals were sped'd for an '83 in '81 or so, no doubt. And marginally longer bolts. Maybe 1/2 a thread longer. Sad, but not shocking to me.

[AnnapolisAirhead]

As usual, the fix was easy. Detecting what the problem was is another story. First he thought it was my concoction of grease (I used about 70% Lucas Red Tacky #2 and 30% Lucas Heavy Duty grease). Seemed unlikely to me because I had so thoroughly cleaned the bearings in the ultrasonic cleaner--but I have a tremendous amount of respect for his knowledge and more so for his ability to figure things out (not unlike you in that regard).

So, a lesson learned. Perhaps it was a supplier change. I can't imagine that the frame thickness was thinner on an R100--its the same frame I believe.I think (can't recall) that Clymer's only showed a wavy washer, but RealOEM.com clearly indicates the need for a flat washer (p/n 07119931684) in addition to the wavy washer (p/n 07119932121), so I blew it in that sense--all over a couple of $0.40 flat washers. Incidentally, I think most of the threads on the fasteners are 1.25 pitch, but these spider mount bolts are M8X1X12 (e.g. 1.0 thread pitch).

Live and learn. Fortunately, nothing was damaged other than those two little nicks in the steering stem. As a precaution, he replaced the steeringhead bearings and races anyway. So I am good to go and will finally start planning my long trips to Birmingham (Barber Museum and Track), western NC, Austin and possibly/finally make it out to my chuck o'land in Tombstone, AZ. Waving to fellow riders along the way.

[Yarddog]

I had the same problem, as I believe I mentioned when this came up previously... I installed studs which I cut off even with the inner surfaces of the thread bosses... Discovered it when my steering was stiff and I found rub marks on the steering stem. In my opinion, studs are a better option for things like this...

[AnnapolisAirhead]

I had the same problem, as I believe I mentioned when this came up previously... I installed studs which I cut off even with the inner surfaces of the thread bosses... Discovered it when my steering was stiff and I found rub marks on the steering stem. In my opinion, studs are a better option for things like this...

Well, putting a stud in as an alternative to the OEM bolts, I probably would have suspected I'd miscalculated, but these were OEM bolts. The failure turns out was mine, omitting the proper spec'd washer. C'est la Vie.

[Yarddog]

Well, putting a stud in as an alternative to the OEM bolts, I probably would have suspected I'd miscalculated, but these were OEM bolts. The failure turns out was mine, omitting the proper spec'd washer. C'est la Vie.

Ya know, if the tolerances are that close it's...once again...suspect engineering in my minor little opinion...that's the stuff that simply drives me wild about these machines...VERY well built...not so well engineered...

[AnnapolisAirhead]

Ya know, if the tolerances are that close it's...once again...suspect engineering in my minor little opinion...that's the stuff that simply drives me wild about these machines...VERY well built...not so well engineered...

I disagree, but I'll give ya $10.00 for your poorly engineered Airhead. You don't wanna git a rep for riding something like that around town, heh.

[Yarddog]

I disagree, but I'll give ya $10.00 for your poorly engineered Airhead. You don't wanna git a rep for riding something like that around town, heh.

Naw, here's what I mean...there's no doubt that they are VERY well built...but the difficulty in changing the oil filter, a routine task, is not good engineering in that this should be an easy job, both on and off...Frankly, it is not...yeah, one gets used to it, but my '78 was built in a time when even the Harley oil filters were easy to change...all they had to do was bulb out the engine case a little bit so the housing doesn't interfere with the frame and exhaust...

That's just one example...there's tons more...so that's what I mean...other examples are not using captive nuts or threading the engine case for the diode mounts...instead, you have to pull the air cleaner housing, starter housing, starter, yadayadayada to get to the nuts...not good engineering, in my opinion. Needing to pull the tranny every year and lube the clutch splines...not good engineering... Having to block the crankshaft when you remove the flywheel...what other engine requires you to do that? Oughta be a locating surface that prevents fore and aft travel...not well thought out engineering...

Even this steering head situation is bad engineering...many American automotive uses specify a shoulder bolt that prevents any possibility of leaving out a vital washer...why not use something like that to prevent what you and I have gone thru...or, specify a special stud for that...or simply use a blind hole that prevents the end of the fastener from poking thru and locking up your steering stem...now, that's an IMPORTANT thang, in my book!!!

So, Tony, that's what this old Amurican junk mechanic is a-talkin' about...there's no doubt that these German machines are high mile, somewhat dependable things...I say somewhat because from reading all these threads, hey, there seems to be as many problems with vintage Beemers as vintage Harleys, Chevys, Fords, what have you...and that's part of their charm, but there are a lotta things that the engineers could have done to minimize wrenching time, and maximize road time, more than they did!!!

Not tryin' to annoy anybody or hijack the thread, or rain on anybody's parade...I'm just sayin', is all...

[97077]

Could you post some pictures? Thanks Kevin

[Yarddog]

Could you post some pictures? Thanks Kevin

What of? The stud installation? Or how Tony solved his problem? I don't think I took any pictures of this particular issue during my project, I just cut a coupla studs and installed them with red Loctite...

[jforgo]

Naw, here's what I mean...there's no doubt that they are VERY well built...but the difficulty in changing the oil filter, a routine task, is not good engineering in that this should be an easy job, both on and off...Frankly, it is not...yeah, one gets used to it, but my '78 was built in a time when even the Harley oil filters were easy to change...all they had to do was bulb out the engine case a little bit so the housing doesn't interfere with the frame and exhaust...
.

The oil filter really is the worst thing about an Airhead - especially if you are running an oil cooler.
As I curse it while I mess with it, I always remind myself this design was one step removed from slinger rings! Beats messing with those!

[PGlaves]

The oil filter really is the worst thing about an Airhead - especially if you are running an oil cooler.
As I curse it while I mess with it, I always remind myself this design was one step removed from slinger rings! Beats messing with those!

The oil filter issue on Airheads isn't really an engineering fault - it is the result of design creep or feature creep. It was very soundly designed for the 1970 Rxx/5 bikes. Easy to access, plenty of clearance. Later they upsized the cylinders and eventually added the oil cooler. Now it gets a little crowded but who wants the expense to totally redesign the block casting, and internal lubrication scheme? Next they add the RT fairing with lowers. Now it is really crowded, but who wants the expense/cost/price of redesigning the block casting? Nobody! So what was an excellent original design only became complicated as stuff got added over the years.

When they eventually did redesign the block casting they used an externally mounted, protected, spin-on oil filter, but they redesigned the rest of the bike too, and introduced it as the R1100RS.

[AnnapolisAirhead]

...another reason to love the ole /5ers.

I still love my R100, its not an RT (more or less) and I really don't mind the oil filter changing. No oil cooler helps though.