Id rather spend $6 on a new spur than a $100 gear diff. What FDR are you running?

It's EASY to stop the advance of technology---it's called RULES!! That is one major reason why pan cars have T bars in them!!! We developed a complete 4 link independant suspension car clear back in 1985 for 1/12 scale. There were NO rules against it back then. The car worked GREAT!! BUT, the powers that be that ran the organization making the rules ADDED a rule that there had to be a "solid link" between the motor and a solid live axle. Outlawing I.S. suspensions effectively--because we realize the COST of building those cars would have made the price of racing go up dramatically. 1/12 scale today in both IFMAR and ROAR still uses that rule set!! It was put in to limit the cost of racing. We DON'T need a race to the deepest pockets in racing to have a LOT of FUN and still have plenty of things for manufacturers to make for a profit. It's healthier for the sport!

Red RC ? RC Car News » Tamiya F104 ProII with 2017-type body shell

The real star of that kit is the body IMO.

And rear wing!

The more diff balls the better. I think Kawada or Arrowmax may have 18 ball gears.

Any idea what size pins?

traxxas 4685

We run on CRC black carpet. What is the best adjustment to eliminate traction rolling? Car is great, it starts to traction roll later in the day

I saw the Fenix gear diff to be an hot topic....

Mean while you may want to have a look at the setting videos

https://www.youtube.com/channel/UCDZ...2EaI7qHCMjUcjQ

As usual, comments are welcome

Glue sidewalls on front tire. Other things I tried...more caster, more camber, softer front spring, softer side spring. Less sauce on front tire. Move motor farther back with smaller spur (keep same ratio). Aluminum chassis helps tremendously too.

Whats the setup advice for using these? I'm going to see if local hobby shop can carry them.

Well since you let the cat out of the bag, you can put Traxxas slipper pegs in the inner row of the diff gear. This is lighter than the gear diff by a large margin. I have been doing this for about a year now. A good friend used to make spools for sedans this way in the foam tire days before spools were commonly available, and suggested it to me.

The peg must be cut precisely. I made a jig that helps me cut them. 3.05mm works on most spurs I have. IT also pays to only lube the diff balls, but not the rings. The ring needs a clean path for the peg to make friction.

The other thing is that most 1/12 style axles need to have the thread pinned to the axle, other wise the thread portion can pull out of the axle under high tension. You may not always run the diff that tight, but once you pop the threads, its usually over for the axle. A small drill bit matched to something like.055 music wire, is good. The music wire is glued in and then cut off carefully, and sanded flush. This is not necessary for Tamiya axles, which have a one piece steel thread, or any similar design.

The other thing is that this works better with a true thrust bearing, like Hudy or slapmaster. Again, if you run it tight, it will eat standard 1/4" bearings.

So the outer ring of holes is diff balls, and the inner ring of holes is pegs, the number of which can be varied to your liking.

This goes a long way toward preventing diffing out. Too tight can kill mid corner rotation. It will also make the car undriveable on low traction or green tracks. This is not useful on asphalt in my opinion.

I've actually found that more caster (due to the mechanical weight jacking effect) will make traction rolling worse. The rest of the above list is consistent with my experiences.

Something that often goes unmentioned when it comes to reducing traction rolling is to 'roll' the steering inputs in more smoothly. I know that's easier said than done...but it really helps.