VB's on BMW's

[Gixxerthou]

So, my K1300R is a great bike, but it has one feature that is a pain in the hands, and that's Vibration. Usually it manifests itself at cruising speed (80 ish) when your 'off' the throttle in top gear.
I've been thinking about what could cause this and because of the way it manifests, I'm drawn to the Cam Chain. Under load, theres no problem but as you rolll off the throttle it instantly appears. Mines fitted with a Hydraulic Tensioner, but I'm thinking of swapping this out for an APE Manual one. I've already bought some Grip Puppies and will be filling the bars with Putty/Plasticine ASAP.Just wondering if anyone here has heard of the CC Tensioner sorting this problem out before, or is it the Shaft Drive thats doing it?

Answers on a postcard please.

[Gobert]

21 minutes ago, Gixxerthou said:

So, my K1300R is a great bike, but it has one feature that is a pain in the hands, and that's Vibration. Usually it manifests itself at cruising speed (80 ish) when your 'off' the throttle in top gear.
I've been thinking about what could cause this and because of the way it manifests, I'm drawn to the Cam Chain. Under load, theres no problem but as you rolll off the throttle it instantly appears. Mines fitted with a Hydraulic Tensioner, but I'm thinking of swapping this out for an APE Manual one. I've already bought some Grip Puppies and will be filling the bars with Putty/Plasticine ASAP.Just wondering if anyone here has heard of the CC Tensioner sorting this problem out before, or is it the Shaft Drive thats doing it?

Answers on a postcard please.

the RR/R/XR all suffer to some extent so maybe someone in BM has a sick sense of humour..........I fitted the heaviest set of bar ends I could to my RR and that improved things.

[ssray]

As it's a 4 cylinder engine it will have vibes, primary or secondary , the only way round it is a balance shaft type thing or add two more cylinders.

6 cylinders have perfect primary and secondary balance.

You could try adjusting the frequency of the vibes, adding blue tack to the inside of handlebars etc

 

[bignige]

I think you need to be filling the bars to make them heavier, I don't think plasticine will do it.

I've read people filling them with roofing lead.

[hawkati]

Take a sheet (?) of blu tac, pour a whole load of shotgun pellets onto it, roll it up & stuff into bars. 

[Gixxerthou]

Thinking about it, I've got a load of Catapult ball bearing ammo in the Gun room. Might try that.

[Gixxerthou]

Right, so I serviced the final drive unit,which made a bit of difference. Fitted Grip Puppies which are pretty awful to be honest and are now in the bin. I found out yesterday that the 2 balance shafts on the engine are adjustable from the right crankcase so I will adjust those soon and see if that sorts it out (I'm expecting it will)

[jollygiant]

If you go down the shoving stuff in the bars, fishing weights are the best bet, as you can get them in 2oz + sizes and fairly cheap too.

[TLRS]

Bathroom sealant might be another easy one.

[Gixxerthou]

5 hours ago, jollygiant said:

If you go down the shoving stuff in the bars, fishing weights are the best bet, as you can get them in 2oz + sizes and fairly cheap too.

Lost most of my Sea bombs(as I call them) in Galloway fishing for Mackerel 2 years ago on the rocks unfortunately. Bought a spinning rod last year, so just using lures nowadays... 

 

[ronenige]

I've seen a few bikes filled with bajillions of small bearing type of things , I assume it's to aid this . Is cruising speed around 4k ? Most in-line 4 cyls vibe at this speed . The balance shafts may make a slight difference but more likely in noise only as you aren't really altering the balance,  just the play between .

Edited August 2 by ronenige

[Gixxerthou]

Ah ok, well I've balanced them today so will take a ride to Suffolk  tomorrow and report back.

[Gixxerthou]

It's made a bit of difference. Helibars and cam chain tensioner next on the list.

[Gixxerthou]

Ok, actually yesterday it was worse. 

Even the Mrs on thr back had a numb hand after using the grab rail for a bit

 But I've just found out online a few others with the same symptoms... revs 6k in top gear, about 90 mph, throttle closed on Over run.

Turns out it's the  rear engine mount thats loose. Going to torque it up and see what happens.

Had a quick look and can see half a thread clear of the clamp.

[Gixxerthou]

Torqued them both up to 38nm, they weren't loose. Bugger.

I managed to jury rig a centre stand using axel stands and a Teng breaker bar through the hole in the bottom of the frame. Then seperated the final drive from the driveshaft, the splines were bone dry but luckily not rusty. Liberally coated the splines with Molly and have just got back from a test ride. 

 

It's fixed, hoorah