|Cutteridge cone kit for wires|
|50 degree cone ready to accept wire wheel|
The wheel and outer cone went on and it was all tightened up in the usual way. It all looked good and away we went. Alas, the by now familiar routine followed, once I had persuaded the guy to take the wheel off and put it on again. A typical variation from the initial 0-0 would be say 15-30. All four wheels produced similar results. Weights were moved around, different types tried, the machine switched off and on, re-calibrated and all manner of buttons pushed but to no avail.
|And outer 20 degree cone fitted which replicates the spinner|
I initially take in two wheels, first thing in the morning when hopefully the day’s pressures are minimal. The cone kit requires a spacer as before and the previously semi balanced wheel now shows 45-60. Very quickly this is adjusted with weights to 5-0, by now a more than acceptable result. Then the acid test – off and back on - 30-20 I ask the operator to check the machine with a normal wheel and surprisingly he agrees. Its a 14” alloy with brand new low profile tyre. 0-0 with around 70 grams added. Then the acid test – off and back on – now 15-20. The guy looked genuinely perturbed.
Another interesting thing is that all machines appear to have self calibration programmes, I suppose negating the requirement for an independent check. Try googling 'wheel balance calibration services' – clearly not a popular business. One of the depots even volunteered the information that their two machines always give different results!
|Fresh from the Dynamic balancing machine - looks spot on|
Then I added 3 nuts each weighing 17 grams – 51 grams in total to the rim – I barely saw it move and had a couple of mates verify the result just in case it was the previous night’s gin and tonic making me a bit cockeyed and upsetting the outcome.
|And with 50 grams added (3 x 7/16 nuts to the right)|
The point is, the machines are designed to balance a wheel to within one gram. Given that the most likely cause of vibration is wheel imbalance; naturally this should be the first thing to be ruled out for certain. If you’re trying to locate a vibration but it persists even after you've seen 0-0 on the machine and been relieved of some hard earned, it seems you still can’t be absolutely certain that it’s not a wheel balance issue that’s causing the problem.
To be fair I haven't given my 120 a run since the wheel balancing saga so I might well be crying before I'm hit. This weekend it's the big classic show at Newby Hall near Ripon which requires a drive up the A19. A section of this road was re-surfaced a few years back and it must be one of the smoothest ten miles of dual carriageway in the country so ideal for a test run. I'll let you know the outcome.
If anyone out there can throw any more light on this conundrum, add anything or just generally confirm my findings or otherwise perhaps you could email me at :
Next post beginning of August