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Q How can I leave a weave behind?
Although in most respects my Yamaha XSR900 is a great bike with a terrific motor, the handling gets a bit interesting when you really push on. The bike weaves and shakes its head when things get hot. What happens is that, at speeds above 90mph, the bike starts to weave and, particularly if the road is at all uneven, the bars start to shake and give the impression that if I don’t back off I’ll get a proper tankslapper. I don’t take a pillion and I weigh around 12-and-a-half stone. I should say that I have clicked the rebound damping right back to soften the ride, but the problem was obvious before I did that. Grant Naismith, email
Answered by Gareth A Evans, Reactive Suspension A wobble is the steered mass (forks and front wheel assembly) oscillating around the steering pivot (headstock). But, as you say, you’ve got a weave which is the rest of the chassis oscillating around the steering pivot. A wobble is normally a fast oscillation at low speed. A weave is a slower oscillation at higher speeds. I would imagine it’s being caused by what you might diplomatically call a less than satisfactory shock performance. Here’s a link to a Dunlop ‘educational’ film from the archives that shows the difference, and how rider weight and riding position can make a difference: https://youtu. BE/Z3OQTUke2s.
In the first instance, you need to go back up on the rebound to tighten up the shock’s response. Sometimes jacking up the preload on the back end can get rid of a weave. If it’s sitting low at the rear that has the effect of giving more trail so there’s excessive selfcentring which sets up a weave. In the end, you are going to need a better-performing shock.
Tightening up XSR900’S rear shock response is first step