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'93 K75RT Steering Head Bearings question...

Hello -- I have a new-to-me 93 K75RT. The previous owner was pretty conscientious in servicing the bike and overall I've enjoyed it for the several hundred miles I've put on in the past week or so.

But I noticed "loose" feeling in the steering, particularly while counter-steering to the right at moderate speeds. It seems to be unnerving at most -- despite how it feels, I don't think the bike is going to slip out from under me. Everything else seems good -- the bike doesn't wander at all. In fact, all but right sweepers feel great. At various points, I thought it was just all in my head.

In checking various things out, from the Progressive rear shock (fairly new) to the tires (also fairly new, have tried various pressures), I managed to finally discover a "notch" dead center in the steering with the front tire off the ground. According to what I've read, that means the steering head bearings need to be replaced. It wasn't my first thought as the previous owner had them replaced in somewhat recent history.

I was planning on taking the bike for a few thousand miles -- nothing too strenuous but a bit of riding before it turns cold -- maybe a total of 70 to 80 pounds besides me (175 pounds). Looking at the shop manual, replacing those bearings could well make my head explode.

My question -- with a definite "notch" with the front wheel off the ground, can anyone provide guidance as to the risk level? Looking at the schematics of the assembly, I can't imagine how a catastrophic failure could occur but perhaps my imagination is too limited.

I would seriously appreciate any ballpark input.

Thanks!

Mitch
 
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Welcome to the forum, and to BMW, Mitch! The K75s are pretty nice bikes. I'm sure some experts will be along shortly with some insight on your concerns.
 
Welcome to the forum, and to BMW, Mitch! The K75s are pretty nice bikes. I'm sure some experts will be along shortly with some insight on your concerns.

Thank you for the welcome! I loved the bike from the first two miles. It was a 170 mile ride home from the seller, through NYC traffic and along farms -- and it was literally some of the most I've enjoyed being on a bike in 40 years of riding. I didn't notice the "loose" feeling with freeway riding (really gnarly, bumpy freeways around the city). But started to on the twisty country roads here in NJ.

Some expert input would certainly be welcome! I'm definitely not afraid to admit I'm an idiot when it comes to steering bearings.
 
K75 Steering Head Bearings Question...

An addendum....

With the front wheel off the ground, while turning the handlebars, it doesn't sproing off the end stops at all. There doesn't seem to be play in the steering nor in the forks. In fact, it doesn't feel loose at all. It feels like what I would consider a good amount of friction -- not too much, not too little. Well damped.

But it definitely has a notch dead center. And it does have an occasional "loose" feeling while counter-steering, especially to the right. It's certainly manageable but I don't know jack about steering head bearings.

Again, thank you for any input.

Mitch
 
Mitch -

Drawing on what I've observed in the Airheads, it sounds like the bearing tightness is not really an issue...the fact that there's some tension in the handlebars as they move off center to the stops is a good thing. If they quickly turned to the stops, that would be too loose.

As for the notch, I think it will be an annoyance and likely to cause the steering to "hunt" going down a straight road. The bearings get caught in the notch momentarily and they jump out of it. You correct slightly and then it does it again. Plus there will be an unsure feeling when tipping into turns at slow speeds.

I can't help with replacing the bearings, but I'm sure there are others that can help.
 
Thank you again, Kurt!

The bike is like it's on rails going straight, or even slight curves. It feels perfect to me. I can't feel the "notch" while riding. I only noticed it with the front wheel off the ground. I could find no play in the forks at all.

Where it seems to hunt is on moderate and sharper curves. It is somewhat unnerving but I think I've ridden long enough to know the bike isn't going to go out under me. I'm not sure yet if 70 or so pounds of camping gear will impact that or not, although basic physics says it certainly could. It has a new-ish Progressive shock on it -- set as high as it goes (I'm tempted to drop it a notch or two to see if that helps).

I'll take it out on some curvy roads tomorrow but I like the term, "annoyance." Are there catastrophic steering head bearing failures? I have no idea. I've ridden some pretty crap bikes and this one, despite the age, isn't one of them.

Thanks. I appreciate it.
 
Here comes some experience based conjecture. It sounds to me as if the bearing(s) got loose and pounded a little bit making a dent or notch in the outer race(s). Since then the bearings have been tightened. The looseness is gone but at least one outer race is notched. It is entirely possible that a previous owner did install new roller bearings with the inner races but left at least one of the outer races in place.
 
That is entirely possible, Paul. Thank you for the input.

I would say that the chances are very good that he only installed new bearings, leaving the races. We discussed it but not to that level of detail.

My hope is that this is something I can work around until I can re-work it all at later this year. I would really like to take this bike for a bit of a ride. Overall, it feels more solid than a Concours I bought new several years ago. This bike is pretty far from new. Hearing the voice of experience is invaluable. But in the end, my decisions, my responsibility, of course.

Again, thank you.
 
Notched bearings

I remember one particular trip over a week on an R100RS with notched bearings. Although i survived the trip I concluded that I never want to do that again! So I'd want to change both upper and lower bearings, including races before too long.
My extra two cents is that I would replace BOTH upper and lower bearings as a set, rather than doing a half a** job!
 
Working around

Working around your problem? Is that like working around a tire with minimum tread in "expectation" of making it through the trip without seeing air through the tread?
 
I tried the "working around" method with notched bearings on my K1100RS with sidecar, until one day in a left turn I almost couldn't straighten the bars. This is on an "alternative" front end that is basically a forward facing swingarm and the bearings only have steering load on them. I figured the bearings would last forever with the much reduced load.

I would suggest changing the bearings, top and bottom.

Also the outer race on my lower bearing wouldn't budge. I had always heard if you run a weld bead on the inside of the race it would loosen it. It works, fired up the MIG ran a bead around the inside, while I was getting my bearing puller the race fell out on the floor.
 
Mitch,

Welcome to the Forum!

Here, in the Flying Brick section of the Forum, we request that when you start a thread, you include the year and model of the bike in question in the title of the thread. This helps in many ways, from getting more specific responces to your individual issues to ease of searching the Forum for specific issues from the past.

I've added this info to the title of your thread.

With the condition of todays roads (not always the best), it is not uncommon to feel a SLIGHT notch in the headstock bearings under NO LOAD in the straight ahead position. If it's more than slight, you should consider replacing the bearings and races.

I would also check the preload on your swing arm bearings to see if that might be the source of your issue. Also you might loosen the pinch bolts on the front axle and retorque the axle preload bolt before retightening the pinch bolts.







:dance:dance:dance
 
Thank you, Lee!

I tried to use the "advanced edit" feature to change the title but it didn't fly.

I think you might be on to something with the "notch." I spoke with the previous owner who said there was maybe 10K miles on the bearings (he's a good guy and took great care of the bike). The roads in the NE certainly aren't always the best. I didn't notice the notch until the front tire was in the air. Gotta think there are a ton of bikes riding around with something similar.

My problem is this: I don't know how the bike is supposed to perform. I've been riding for a lot of years and think it should probably be a little tighter on turns but it doesn't feel dangerous. I do think it could be better so will have new bearings and races put in. But for the moment, I'm pretty comfortable riding it until they can be replaced.

I'll take a look at all of what you suggested. Thank you again!

Mitch
 
I've always found that the original equipment Metzler tire up front, steered to quick to the point of being twitchy. I put a set of Avon's on mine and the difference is like night and day. The Avon's transformed the handling for me. I found the same on my r100r Mystic with the original Metzlers. What tires are on the bike?
 
Nope. Almost new Michelin Pilot Activs -- non-radial.
Very good choice, I've run those on lots of old beemers, including airheads. Can you ride another k75 to see what it's like as compared to yours? It might give you some direction to look on yours.
 
Apologies Chunk -- that was responding to Lee.

I've always loved Metzler tires. I've had them on several bikes and have never been unhappy with them.

I'm not aware of anyone around here with a K75 but plan to join the local BMW group next month -- would be nice to get a chance then. By then the steering bearings should be replaced on my bike, too.
 
Thought I'd finish out the thread....

In riding and looking at it, the "notch" in the steering was pretty noticeable. The handlebars would easily settle into it. While it likely wasn't dangerous, it made low speed turns unpleasant, and counter-steering on the freeway (along with pothole avoidance at speed) quite unpleasant. Basically, it should have been more fun to ride the bike.

I've had motorcycles for most of my life but decided that my first project on my first BMW would not be steering bearings (plus, I don't have a MIG welder for the bottom race!). So, I handed over the cash to have a somewhat local BMW shop handle it. A few days later it was done...and the experience of riding it was vastly improved.

Thanks again to all who weighed in on my question!
 
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