"Roll Hop"

[Alex]

What is "chatter" ,"roll hop" and "bounce hop"? Can anyone explain what each one of these rear end problems mean?
Thanks

[Garry Lobaugh]

The bounce is due to an improper set up and reflects too tight of chassis set up or an untrained brake/throttle entry to the corner.

The chatter is most likely when the tires have low inflation and going through a corner at too high of entry speed the tire lays down and the rim starts to touch pavement.

Roll hop is most likely a bent axle.

I'm not sure who is providing these terms to you, but it would be best to work with a trained tuner to observe your issues. Too often drivers are forced into stating what is wrong and when pushed into a corner they give an answer. Often it is the wrong answer. Our view is the mechanic or tuner should be watching the driver and they make the decision as to what is wrong. Over time a good driver will be able to learn from this experience and provide needed feed back to produce a winning team (driver/tuner).

[Graham Odell]

Alex, it was I who asked the question below that these terms were given in.

What I have found so far is that the solution to my problem was to move my seat forward to take weight from the rear axle (about 1cm forward) and also I started using slightly higher tyre pressures. The recommended tyres pressures realy don't seem to work for me as they don't warm quick enough on a "green" track. And when too much rubber is layed down the tyre is just so soft the sidewalls are flexing too much and the tyre has no real strenght.

As regards the 3 types of hop. Its probably quite a hard thing to pin down because what you might feel is one things, might actually be another without a trained backside giving you feedback. Garrys explaination sounds good though.

[Garry Lobaugh]

Gra, thanks for your follow up. My thoughts were just early morning ideas and now what you describe better helps explain what was trying to be said.

The key remains to work with a tuner who can watch the kart.