Bike wanders, feels heavy in turns

The bike:
2008 K1200GT, stock suspension and shocks.
30K miles (now).
Michelin PR3 tires with (now) 5K miles. Front = 38 psi, rear = 40 psi.

The situation:
Just returned from 11 day, 4.8K trip from Oklahoma to New England and Canada. Left with new (300 miles) Michelin PR3s front and rear. On the 9th day of the trip about an hour before laying up for the night, I noticed the bike start to wander a bit at highway (60-70 mph) speed. At slower speeds (20-40 mph) steering seemed very heavy, not wanting to fall easily into slow speed turns. Had this exact sensation several years ago when I lost air pressure in the front tire. Stopped and checked (tires hot) and pressure was OK. Examined both tires and could find no problems. No unusual wear, cupping, tire chatter in turns, etc. Next day, all was well until several hundred miles then same symptoms. Same problem on last day of trip, OK for first few hundred miles then symptoms recur. Again, careful tire inspection reveals no problems.

I feel that the front suspension is the problem since I can't find a tire issue. Any ideas on what may be the cause? Thanks.

"All who wander are not lost." Maybe your bike has an adventerous soul.

Bad ball joints will make the bike wonder and feel a little tippy like the front tire is V shaped. This usually is felt at slow speeds, 20 to 40 MPH, not that much over 60 MPH.
Replaced the ball joints on my wife's K1300S around 35,000 miles. My K1300S feels like it also needs this done. 40,000 miles on mine.

Had to replace the ball joints on my 08 GT this year as well at only 35000 kms. The bike was always very twitchy feeling and unstable in corners. I was ready to trade it in on a new RT when I read about the ball joint issue and discovered the looseness in mine. Changing them made the bike rock solid for the first time since I've owned it.

Worn ball joints?

I appreciate the responses. Can someone point me to information on this repair? Thanks!

Ball joint replacement ... is this a reasonable DIY job?

DrPaul said:

I appreciate the responses. Can someone point me to information on this repair? Thanks!

Click to expand...

I plan to check with my local dealer on cost for this job. The service manual suggests the need for special BMW tools. However, I generally do all my own service and would appreciate advise on whether this is worth attempting on my own. Thanks.

I did the work myself to change my ball joint, but you do need some tools for the job that would not be typically found in many home shops. Specifically you need two very large sockets or wrenches to remove the ball joints from the wheel carrier; I believe they are 50 mm and 55 mm. If you use sockets, they need to be deep ones to clear the ball joint stem, I bought a pair online through Amazon for not too much money, though one I could only get the 50 mm one in a shallow socket so I had to weld on an extension to turn it into a deep socket. The ball joints are incredibly tight in the carrier, so it takes a lot of effort to break them loose and thus a holding fixture is needed. The BMW special tool for that is basically a bar that fits in like the axle but is robust enough to be clamped in a vise. Don't even think about using the axle unless you like buying more parts. I made my own holding fixture from a large steel bar, but I have a metal lathe for just that kind of work. I also used an impact gun to break the ball joints loose which was much easier than using a long breaker bar. The hex on the ball joints is rather shallow, so getting the sockets to bite on that was difficult using a bar as it wanted to lever up off the hex. I did turn down the rim of the sockets so that there was no more relief angle in opening ensuring the maximum engagement on the hex.

Getting the wheel carrier out of the bike is a bit of work too, but a reasonably skilled DIYer should be capable of that part and no unusual tools are needed for that. If the last step of R&R of the ball joints themselves in the carrier is too daunting, that last step could be subbed out to a dealer or qualified shop.

Some threads over here...more with search of ball joints

http://www.i-bmw.com/showthread.php?t=37322

Thanks, Steve. Very useful information. Sorry about your Longhorns just now ...

DrPaul said:

Thanks, Steve. Very useful information. Sorry about your Longhorns just now ...

Click to expand...

The better game is on now...#5 vs. #9

DrPaul said:

I plan to check with my local dealer on cost for this job. .

Click to expand...

I paid $800 parts and labor on my wife's bike.
4.9 hours labor.

Lee said:

I paid $800 parts and labor on my wife's bike.
4.9 hours labor.

Click to expand...

Lee, was your labor cost for the entire job including removal and installation of the wheel carrier? I'm thinking I might remove the wheel carrier and take it in to the dealer for the ball joint replacement. I hate the thought of knackering the very expensive wheel carrier. Thanks for your information!

henzilla said:

The better game is on now...#5 vs. #9

Click to expand...

And what a game it was!

DrPaul said:

Lee, was your labor cost for the entire job !

Click to expand...

Yes, the 4.9 hours was the complete job.

Checking air pressures on hot tires is essentially meaningless as tire temperatures vary for several reasons (type of riding ranging from stop and go to triple digit touring, ambient temperatures, tire composition, load, etc.). Also, in diagnosing the problem, it helps to know approximately how many miles are on the tires.

I agree that if the onset of handling issues isn't immediate, the problem may not originate with the tires. However, it's easier and much less expensive to ensure the tires are properly inflated at the start of the day. It may be there's a slow leak that only shows up after extended riding. Only when the tires can definitely ruled out would I investigate the front suspension.

As a starting point, try 38 PSI in the front and 42 PSI in the back. Check the pressure at the end of the day, after the tires have had time to cool; at least a couple of hours after parking the bike.

As I've found too often, after spending time and money on hard, expensive procedures, it's the simple, inexpensive procedures that get the job done.

RBEmerson said:

Checking air pressures on hot tires is essentially meaningless as tire temperatures vary for several reasons (type of riding ranging from stop and go to triple digit touring, ambient temperatures, tire composition, load, etc.). Also, in diagnosing the problem, it helps to know approximately how many miles are on the tires.

I agree that if the onset of handling issues isn't immediate, the problem may not originate with the tires. However, it's easier and much less expensive to ensure the tires are properly inflated at the start of the day. It may be there's a slow leak that only shows up after extended riding. Only when the tires can definitely ruled out would I investigate the front suspension.

As a starting point, try 38 PSI in the front and 42 PSI in the back. Check the pressure at the end of the day, after the tires have had time to cool; at least a couple of hours after parking the bike.

As I've found too often, after spending time and money on hard, expensive procedures, it's the simple, inexpensive procedures that get the job done.

Click to expand...

Agreed - sort of. Specified "cold" tire pressures are for a tire at 20 degrees Celcius. That equates to 68 degrees Fahrenheit. That is air at 68F inside the tire. If you have a TPMS that displayes internal tire temperature you can mentally adjust, or if you have a TPMS such as the Smartire brand that displays temperature corrected pressure you can adjust. Otherwise ..... good luck.

I'm not sure if the OP has verified his ball joints are worn for sure or not. It is easy to do; just jack the front end to get the weight off the tire, then see if there is any play in the suspension. In my case, the play in the lower ball joint was easy to feel by moving the wheel carrier.

Sent from my Nexus 7 using Tapatalk

Slight derail.

I rode a 13GT with my older sister hanging on several hours today...it was wandering all over the place


Had a front blow thru this morning and was gusting 30 all day, no bad ball joint, just dang killer side blasts. The GT seems to really catch wind to me, I think our S' s handle better in the wind.
I have ridden several models in some crazy wind and just wasn't feeling in control at all on the GT. My sister has been on back before on other bikes in similar conditions and she even commented on the handling or lack of

New tires with recommended two up pressures and ESA set for two ( I tried several settings)

Very common issue. I got a crashed 2008 GT with 44 000 mi last summer. Did take apart and upgraded the bike before I rode. The ball joint were worn out for sure. You need about 150 $ investment in socked wrenches before you start.

I'm sure this is not the case, but just in case...
This sounds a bit like the symptoms described by BMW for the damaged rear wheel hub. Just a thought...