I got the K100RS back on the road last week
I should add that although its a 1987 K100RS
it has a 1985 RT fairing and bars on it

I had intended to leave it laid up for while and use my trusty old CX as a
winter hack.

I've had two shortish rides on it since and not happy with it

Slow speed riding is little fun
the bike feels heavy even with RT bars and when making a slow turn
into a the next street the bars felt
as if they wanted to fall in to the turn.
I can ride the cx at walking pace with one hand on the bars if I want
but didnt want try this on the beemer
theres no wobbling as such.
the bars felt heavy, vague and a slight tendency to
lurch one way or the other and very sensitive to uneven road surfaces

It gets better as I pick up speed but my 'go for a ride' turned into
a brief ride in town traffic as I turned back home
the stiff clutch lever didnt make it any more enjoyable but thats
another job for the todo list

I checked the tyre pressures pre setting off and topped them up to
36F 42R but it felt no different to the other day at lower pressures
I can see no evidence of fork seals leaking or brakes binding


When the weather permits I shall give
it a good look over

So, any clues and tips as to what to check?
head bearings and wheel bearings are my guess to start of with

Thanks

I would strongly suspect head bearings but a question why was it laid up not a crash I trust? If so you could have bent something if no crash then I suspect head bearings and check the wheel bearings too. I trust you don't have binding brake callipers?
Regards,
K-BIKE

No, not crashed.
Just thought I'd leave it outback for a while and use the CX
I find its much more agile about the city.
I know the K is a heavier bike but even allowing for this
is just doesnt feel right.
I'll jack the front wheel off the ground soon and have a good look around

To me definitely does not sound normal but I must admit when I first started riding mine after a very long break from bikes in general I was far from comfortable at slow speed but after a "while" I got used to it and while the steering is probably not as quick as the CX (one of my all time favourite bikes) it is rock solid once up and rolling.

Steering head bearings definitely worth checking as mentioned and check the handlebar mounts as one of mine snapped the other day and they only screw through rubber mounts.

I don't know what the symptoms of fork stiction are but be worth checking they are both at the correct height, I think level with the top triple clamp, and not binding.

Might be also worth checking the back wheel and swingarm are nice and tight with no play.

Regards,

Phil

I got the same feeling when I rode my RT for the first time. The problem was the head bearing. The grease was 20 years old, and had turned into a sticky varnish. The head bearing was also way too tight.
As I was planning a complete rebuild, I just sprayed WD40 in the head bearing and re-adjusted the pressure. It made a big difference.
The K100rt is very heavy, but I can ride at slow speed with only one hand on the handle bar.
Under inflated tire or unevenly worn front tire will produce the same effect. The type of tire also affects the steering. Wide tires with a square shape will make the bike very difficult to steer.

Check your front tire size. Previous owner had a 110/90-18 on mine. Handled like a truck. Put a 100/90-18 on and it handles fine.

My bikes live outdoors and I've no garage so I have to wait till
the weather and time allows me to tinker
AT 75 thousand miles its probaby due to have the steering head bearings looking at anyway
It has BT45's fore an aft.
During some googling I found a a comment whch said
if the steering bearings are quote:
"too tight you'll feel the bike feels 'drunk' and 'staggers' around at slow speeds"
This kind of describes the symptoms
As I said before, I knew it would feel heavy after the CX but despite that I found i was conciously controlling it at low speeds
rather than 'riding' it.

I'll let you know what I find.

My 1993 K75RT has 107000 on the clock and judging by the general state, I doubt if the head bearings have been done. Bike handles fine though but not as fun as my CX650ED. Heated grips, huge fairing and ABS make up for the lack of fun though.

As Bert suggested spraying some thin lubricant like aerosol liquid grease into the bearing will thin down any dried up grease at least until you can get in there and fix the bearings properly. It will also tell you if the bearings and grease are too tight as it should loosen it up a bit by dissolving the old grease.
Regards,
K-BIKE

Right.
Today was chilly bur bright so I jacked the front of the engine to lift
the front wheel off the ground.
Grabbed the tyre at front and moved it from side to side
and was shocked how tight it was !!!
I had to push it from lock to lock and it would stop wherever I left it.
'That aint right' I says to myself

I considered stripping the front down but decided to try the
WD40 idea first.
(2 minutes to find the WD40, 15 to find that damned wee tube thingy !!)
Anyway, after liberal amounts of wd40 and working the bars, the steering freed up considerably.
Once iit was turning freely, I couldnt feel any notching especially in the centre positon so hopefully no damage to the bearings

Next a run over to another part of Bristol
What difference
I actually enjoyed riding it again !!
Whoo hoo!
The other day I felt I could easily fall off at low speed and wasnt enjoying it at all.

I still think it could be slightly better but now I'm aware of it
a repack with fresh grease and an examination of the races
is on the todo list.
Oddly enough even the clutch didnt feel so bad today
Thanks for the tips guys

I am certain that soon or later you will really enjoy you K100. It's a big bike and a bit heavy, but so easy to ride. This is due to the low center of gravity.
The solution to your problem was very simple.
I suspect that you head bearing is in fine shape.

Hi,
Now get some spray grease in there ASAP as the WD40 is not a good lubricant for ball bearings. It has freed them up but will have washed out the old dried grease but that definitely needs to be replaced.
Regards,
K-BIKE

Spray grease eh?
Good idea that, thanks

With the clutch there are a couple of spots that it is worth applying a bit of lube to. First is to the lever pivot and also the spot where the cable pivots around in the lever. Next is to do the same at the gearbox end since unless you have fitted the mudguard extension as I did recently it gets a continuous deluge of water and grit when riding in the rain. Lastly each side of the shaft which actuates the clutch push rod in response to the cable pull needs a good lube. I give each side a regular go with aerosol chain lube as that goes on very thin and then penetrates dries out and leaves a good lubricant behind.
Regards,
K-BIKE