Front end question

[Warthog]

Just bought a used K100LT and had it in the shop for some work (actually alot of work - another story...) Any way had new tires put on and have noticed the front end seems a little loose - mainly when going of bumps. Since I'm realively new to beemers I was wondering if this was normal. I figured that the BMW tech who test drove it would have said something if some thing was wrong. Also thought about changing the front fork oil. Any thoughts?

[GSTom]

Don,
Welcome to the forum and to the wonderful world of K-bikes. What year is your K? I ride a 1988 K100LT (brown) I also ride an airhead GS.

To help you in your search for information you might utilize the information that has alredy been posted here.

There have been several threads over the past couple of years discussing K-bike front forks, seal replacement, changing fork oil, steering head bearings, etc. You can do a search by clicking on K-Bikes Forum. Once there you will find on the right side about midway down, that you can click on "Search this Forum". Then you can enter your desired topic, say "forks" and find several different topics to look at. You may find just the answer you are looking for.

I personally have benefitted many times by the advice available here, and I think you will find these forums an invaluable resource that will enhance your experience of owning a K-bike. :thumb

[breyfogle]

Just what is "loose" ? Loose like in loose steering head bearings, loose like mayber the front wheel kicks side to side going over a bump ? Underdamped maybe ?

K bikes are not really any different from other bikes when it comes to issues of the front forks. If what your K bike is doing would not be considered "normal" on whatever other bikes you have experience with, then it is also not normal for the K.

[lorazepam]

Just bought a used K100LT and had it in the shop for some work (actually alot of work - another story...) Any way had new tires put on and have noticed the front end seems a little loose - mainly when going of bumps. Since I'm realively new to beemers I was wondering if this was normal. I figured that the BMW tech who test drove it would have said something if some thing was wrong. Also thought about changing the front fork oil. Any thoughts?

First thing to check would be the tire pressure. Get your own gauge, and use it all the time. Gas station gauges get thrown around a lot, and are not very accurate. You may be suprised at the difference in handling just by keeping your air pressure in the proper range. I personally run the max printed on the sidewall of the tire, and it makes my bikes handle so much better.

[deilenberger]

Just bought a used K100LT and had it in the shop for some work (actually alot of work - another story...) Any way had new tires put on and have noticed the front end seems a little loose - mainly when going of bumps. Since I'm realively new to beemers I was wondering if this was normal. I figured that the BMW tech who test drove it would have said something if some thing was wrong. Also thought about changing the front fork oil. Any thoughts?Define "loose".. need a better explaination before giving thoughts on it.

And the advice on checking your tire pressure is spot on - if the tires are overinflated they will loose some of their contact patch and not feel as glued to the road.

[Warthog]

I checked my tire pressure and I have 34 in the front and 36 in the rear. I have ME880 (43 psi Max cold) on the front an ME 88 (50 psi cold) on the rear. I also picked up some fork oil and plan on chaning that next week.

The dealer recommend that I run 36-38 psi in the front and 38 in the rear. Said by inflating them close to the max it will reduce cupping.

Any recommendations on tire pressure?

[Bruce_C]

I checked my tire pressure and I have 34 in the front and 36 in the rear. I have ME880 (43 psi Max cold) on the front an ME 88 (50 psi cold) on the rear. I also picked up some fork oil and plan on chaning that next week.

The dealer recommend that I run 36-38 psi in the front and 38 in the rear. Said by inflating them close to the max it will reduce cupping.

Any recommendations on tire pressure?

Don
I run a close cousin to your bike('85K100RT). I run 40psi. front and rear and have no "loose or tight" steering(oops. to much NASCAR). Tires are ME880 front and Michelin Macadam 50 rear (I like that combo).
My front suspension is a Fichtel&Sachs unit. I changed the oil to 15wht. and went 10cc over to 370cc per fork leg. This pretty much eleminated the "pogo stick" ride the stock 5wht. oil gives .
Bruce C :)

[gsmetal]

I run 40 pounds in the front and the back on my R1100GS and on my K1100LT. The bike handles better and the tires seem to last longer.

[deilenberger]

Just bought a used K100LT and had it in the shop for some work (actually alot of work - another story...) Any way had new tires put on and have noticed the front end seems a little loose - mainly when going of bumps. Since I'm realively new to beemers I was wondering if this was normal. I figured that the BMW tech who test drove it would have said something if some thing was wrong. Also thought about changing the front fork oil. Any thoughts?A few thoughts:

If you have no records of the fork-oil being changed, then it's time to do it so you know when it was done.

If you are uncertain if the steering head bearings were ever adjusted, it's time to do that also. It's worth having these checked by someone who knows what to look for - if they are neglected too long, the bearings can be damaged and will result in a loose sort of feeling (and sometimes some noise.)

Once those two items are attended to I think the only "improvement" you might consider is new fork springs. There are several aftermarket alternatives to choose from - Progressive Suspension makes progressively wound springs, Works Peformance makes dual-rate springs.

I prefer the Works, but the Progressives are generally an improvement over old stock ones.

HTH,

[Warthog]

Inflated my tires to 40 PSI both front and rear and have noticed an improvement in the handling. Next task is changing the fork oil (weekend job once I get done with the honey dos).

Also I checked my rear shock and it is leaking. I tired to find a brand name but could not see one. It has a black spring and looks like a separate reservoir attached (gold in color). Any idea as to what brand this may be and if it is rebuildable?

[dlearl476]

>It has a black spring and looks like a separate reservoir attached (gold in color).


He he he he! You MAY have an Ohlins. Is there any blue writing on it? (Black spring makes it suspect) Ohlins are rebuildable. Anything else, there is a possibility*. Gold MAY just be the color of what you need to bring to the dealer to replace it!

*Lindeman Engineering would be my first phone call. USA Tel +1 408-371-6151

[Warthog]

Dave, checked tonite and compared the rear shock to the Ohilen web page and it appears to be a 46 PRC (it does not have the have the spring preload adjuster which would give it the 46 PRCS designator). Your comment about the black spring may indicate that it is the 46 PRCW which is delivered without a spring and may sggest that the previous owner(s) opted to keep a black spring on it and reuse their old one.

Also noted the unit has the adjustable compression damping knob at the top of the piggy back reservoir.

Anyway good call. Now I just need to see if I can rebuild it or have it rebuilt with out costing me a fortune.

Just did some web research and found a site called PPS Racing that has quotes for rebuilds of Ohlin shocks:

http://ppsracing.com/bmw.html

Don :clap