Taming front wheel lift- Geometry questions

Dropping your wrists/curling your wrists is a nice easy trick to help plant the front on climbing btw. (tm Ian Potter)

nemesis – Member

Similarly a slacker head angle will relatively move your weight away from the front wheel towards the back one.

Well, yes, but in terms of wheel lift that doesn’t actually matter when you’re doing it by changing the front centre. What does is that you’re lengthening the bike and moving bike weight forward, which counter wheel lift. And also steepens the seat tube so moves your weight forward as an absolute.

(it’ll have other handling effects too o’course which are unpredictable and may not be desirable. I did exactly this on a C456 and it gave it a more planted front end while climbing but did make it slightly more wandery

But the forces act through the BB and axle.

I still don’t see how riding a bike in say 32:16 will differ to riding it in 42:21. Can anyone explain?

If the forces acted through the BB and axle then your cranks wouldn’t turn and nor would your wheel.

The forces act at the contact patch and along the top half of the chain and the anti-squat generated is as a result of those force vectors working against the force vector caused by your mass above oscillating with the pedal strokes. Any full-sus with the effective pivot point above the BB will have obviously varying anti-squat depending on chain line.

Your first sentence aside (there are already forces on both!), I kind of get it, but an explanation/diagram would be cool, I’ll google.

This is what Linkage shows for 32:16 vs 42:21.

42:21 shows much lower antisquat on this particular model (a 32t chainline optimised singlepivot suspenson system)as a result of the chain pulling the swingarm up (less than 100% is anti-anti squat/aka squat).