XRAY - Model racing cars

Hello Fellow X-Ray Drivers.

Questions, I am looking over the setup sheets and notice for the rear diff a loose, medium, and tight setting. My question is if I set my diff at a loose setting, how can test this? What I currently do is grab the back end of the car and place the rear tires in my hands, with my thumb I hold the spur gear in place and twist on of my tire to check the rear diff. Currently the rear diff when I turn it in my hands does not move.

When would you want a loose diff or a medium, or a tight?

Sorry, with my Tamiya diffs I had to put them on the tight side as if they were too loose, they would melt!!!

Hi Paul! Don't worry about the XRay diffs in a loose setting. I have not melted one yet

For me loose means it is just slightly slipping at full throttle. I.e. on the edge of slipping and not slipping. This, assuming both rear wheels stay on the ground during cornering, will make the car very stable. Harder rear diff settings will make the rear less stable on corner entry, but can make the car more stable on power in those cases where the inside rear wheel DOES lose contact with the ground during cornering.

Hope this helps.

alvast bedankt Tony! Yes, I'm the crazy American living in Holland!

I understand the concept now, but can I feel it on the car when I am setting up a loose, medium, or tight diff? I want to try this out at the LRP race Friday, but I need to understand how to adjust it and feel the different before putting on the track.

Thanks for the quick reply

Hi Tony,
I'm a little confused by exactly what you are saying. Admittedly this is one area I haven't had a clue as to what to do. I hold the right rear wheel and spur gear with one hand and try to turn the left rear wheel with the other hand. I've set some entirely arbitray "ease of turning " criteria, which is totally impossible to describe to anyone else, to distinguish the range of loose to tight. In your explaination are you saying to hold both wheels and turn the spur gear (or alternatively hold the spur gear and try to turn both wheels) to distinguish the range of loose to medium and then use the method described previously for gradiations of medium to hard. Thanks for the clarification.

No, exactly like you descibed: hold the left rear wheel and the spur then try to turn the right rear wheel. The indications I gave for loose through tight are the ones I use which are off course arbitrary as well.

When the diff is tight enough that you cannot push through in the way described above (which I call medium) then you only hold the spur and turn the right or left wheel to feel how free the diff turns and go from there.

Tony,
Thanks a lot. Now I understand. Your use of the term "push through" was confusing me a tad.

The Pro Ball diff runs on another set of bearings and looks to be of
save some parts before I rip them out with my brushless set-up.