1150 balancing conundrum

[R Savage]

I carefully balance my 1150 using my Carbtune to give as near perfect balance as I can. Apart from the actual Carbtune reading I use mirror vibration as a guide and can get it to the point where they both vibrate a small but equal amount at high motorway speeds. This is desirable from the point of view of numb toes and fingers.

However, after about 100 miles the nearside mirror has stopped vibrating and the offside one vibrates to the extent that although I can see that it's a car coming up fast behind me, I cannot see if it is white (or silver) with a nice shiny light bar. The vibration does not get any worse.

Is it reasonable for the balance to slip like this, and so quickly?


TIA Richard

 

[Steptoe]

did you balance your mirrors at the same time, they might have gone out of syhnc

 

[Gecko]

I suspect this is caused by the inverted doppler effect (B)reacting to the changes in velocity (O) due to the drag coefficient (1) not being equal to the resonance (1O) divided by the effect of turbulence (X)caused by driving a right hand drive bike on the left.
If you add these factors up you will have the answer .

 

[(RIP) Kaister]

yes

however...

mirror reflectivity hasn't been thoroughly adopted by many manufacturers as a reliable guide to engine balance - yet.

but - plough your own furrow - go your own way...

Patent some sort of mirror reflectivity device to show perfect cylinder vacuum equilibrium.

I'll buy one of them....honest

 

[Jimb]

It does change in 3000 miles, I do mine at every 3K, the cables do stretch a bit but as the bike is getting older the stretch is getting less.

The way I do it is to set the idle speed & balance first on a warm engine then do the balance at 2k, 3k, 4k & 5k rpm shut the engine off & open the throttle fully a couple of times and check it again.

The valve clearances also make a big difference.

HTH

 

[R Savage]

It does change in 3000 miles, I do mine at every 3K, the cables do stretch a bit but as the bike is getting older the stretch is getting less.

The way I do it is to set the idle speed & balance first on a warm engine then do the balance at 2k, 3k, 4k & 5k rpm shut the engine off & open the throttle fully a couple of times and check it again.

The valve clearances also make a big difference.

HTH

Thanks for all the 'humourous' replies (have I spelt that correctly or have I missed the 'un' off?) and one sensible reply.

Seriously though, yes the valve clearances have been checked and yes I do think that the mirrors give a useful indication of engine balance at some speeds, as do feet and hands that either do or do not develope pins-and-needles or vibration white finger as the engine goes out of balance. I recall seeing lasers used at college to make non-contact measurements of component flexing.

(Some) rgds Richard

 

[Deleted account W]

I recall seeing lasers used at college to make non-contact measurements of component flexing.

(Some) rgds Richard

It all becomes a lot clearer now.

 

[Steptoe]

It all becomes a lot clearer now.

you missed the "un" off

 

[Fanum]

Get on the fekker and open her up FFS.....

Mirrors vibrating?

WTF!!!

who needs mirrors!!!!


PS Sevenoaks.....15 mins nice ride from Eynsford......see you there in a couple of weeks I hope??

 

[R Savage]

PS Sevenoaks.....15 mins nice ride from Eynsford......see you there in a couple of weeks I hope??

Even nearer, but then everyone thinks that Otford is a university city north-west of London! ;-)

Joking apart, having right hand and toes go numb is not much fun, hence the fruitless search for a balanced boxer.

Rgds Richard

 

[richie]

Mines at 51000 miles and I haven't balanced it ever...

Doh, and yes for the last 15000 my right hand goes numb on motorway streches of more than 25mins....


So Gecko or Migsel or anyone else outhere in sunny belgium. Do you fancy a visit sometime from Richie to sort out his valves and balancing....

I've even read somewhere that it also reduces the amount of noise when in neutral with the clutch out???

My bike still returns 6 litres to a 100KMS so it aint that bad...