Motorcycle wheel alignment

**koba** · 11th November 2014, 21:56

I've managed to procure a covert photo of this crazy machine.

**fixer** · 12th November 2014, 09:18

That "bloody great big measuring caliper" would have been quite handy. Though the measuring was complicated by the fact that the ends of the axle and swingarm pivot are not the same distance from the centreline of the bike. They're about 20mm offset on one side of the bike and about 10mm offset on the other. But I made a caliper out of a piece of 1/2in steel rod, a couple of Bark Buster handlebar brackets and some bits of threaded rod that I cut to different lengths. So I'm reasonably confident that the rear axle was incorrectly adjusted before and is now somewhere near right.

But while everything looks to approximately line up now, the bike still pulls distinctly to the right. As an experiment, I thought I would quantify this, so I slung a small pack 0.5m to the left of the centreline of my bike (using the aforementioned piece of 1/2in rod attached to my packframe) and weighted the pack with plastic bottles of water. 5 litres of water wasn't enough, but 6 litres of water was about right to balance the bike to the point where I could easily take my hands off the bars and the bike would maintain a straight line. If you've carried two 3-litre bottles of water in a supermarket bag lately, you'll know that that's a fair chunk of weight. Especially if you try holding it 0.5m away from your body.

I've done some rough calculations based on the weight of the standard exhaust system (about 11 or 12kg) and the distance of it's c-of-g from the centreline of the bike (about 150mm), and I reckon that it should take about 3.5kg to balance the exhaust, not 6.5kg. And this assumes that Triumph have done nothing to balance the exhaust themselves.

So the saga continues for the moment. For your amusement, I've attached a photo of my bike with a 6.5kg weight slung on the side of it.