Has anyone running a lock axle had there spur gear hub roll pin come out.

I have run a home made locked axle and a pre made Radtec and have had no issues.
Are you running one that you made or a pre manufactured one? I did notice on the ones I personally made the roll pin was rather loose. Maybe a dab of CA on the pin before pushing it back in will prevent further failure.

The carbon by the gear mounter on the spool axles will degrade over time. F1 cars due to the big tires are the toughest on spools. A good test is to twist the tires in opposite directions. If the tires have any give/twist (and a hub isn't loose) then your axle is going south...

So does everyone true their tires down to 41mm or less for CRC Carpet?

Yes if you want to run with our group down here. I'm usually tall at 41mm but that's where I start. Big races go to 40mm.

I run on a small black crc track with a 17.5. I turn my tires down to 42mm to start. Personally, I turn just as fast laps with 42mm as with 40mm tires and I think for most of us, that is going to be true. I race with a couple of guys that can place in the B main at national level events, and I think they turn down to 41.5mm at our track.

Tire size
 

The WIKI is fixed. Feel free to make changes as needed, updating links, adding kits, ESC's, Servos, all those good things that help people build good pan cars.

Spool chassis setup
 

Hi all,
I have read a lot about spools being used in 12th scale cars, but I haven't found many notes about how to set up your car to work with a spool.
from my own experience, I found a relatively soft side spring and tube setup seems to work. Also, the spool seems to work well only in high traction conditions.
are there any general things to consider when setting up a car with spool?
thanks in advance for your feedback

You're not far off from what most people are running right now with a spool setup. I found soft side springs, 7-10k tube lube, medium hard - medium center damper spring and standard front springs work quite wel on CRC Black carpet. However, you need to make sure your chassis settings are spot on, if not, the car will easily spin out and or be a handful to drive around the track.

Forgot to mention for CRC Black carpet - 0.2 mm to 0 mm front droop, and 0.4~ 0.8 pod droop with 0 sag.

Thanks for the feedback, Edward.
I find it interesting that you basically use a similar setup to what I run on ETS carpet.
do you have any suggestions for center shock oil? I use a crc shock. For the record: The car is a heavily modified crc Xti-WC with speedtech aluminum chassis.