Does that crunch affect performance any?

I suppose it could, but given that we're talking about minis, probably not much. Maybe on slower corners. I certainly wouldn't lose any sleep over it.

I forgot, but who made different diameter tire inserts for mini's?

ride makes some

This like many things, this is a matter of opinion and conjecture. Many of the best Mini racers I know do spend quite a bit of time to get their diffs "right". I don't believe any of them would run a "crunchy" diff. It's odd that some prefer a gear diff and others a ball diff.

My preference is for a ball diff, primarily cause it is so much easier to build "right" and gives me the diff action that fits my driving "style". I have never had a build come out "crunchy" although it is possible if improper techniques are used.

Some tips
1. Never reuse metal diff balls
2. Always sand out any grooves in the diff ring
3. Polish the diff rings
4. Use antiwar grease on the diff balls and thrust washer
5. Loctite and tighten diff screw all the way down
6. Build it exactly the way the instructions say to

Again, I am just offering this as a differing view from some others that were posted. I am also not inferring that mine is the only correct opinion.

With age comes wisdom.

I feel old. Doesn't that count?

GP's build instructions are dead on. I suppose the definition of what crunchy means is subjective. My version is barely noticeable when turning the wheels, but more pronounced when holding the diff alone.

Speaking of the ball diff, it's going back in this weekend, in place of the spool I've been running. I just want one race day with easy steering.

I have lost count of the amount of times I/we have told people -

Use a TA03 ball diff, built as per instructions except for AW grease, tighten it, and leave it...

9/10 rc-mini net cars run this and have done so for years....

i like that im the one of ten that doesnt use it LOL
But have certainly build a number of them for other people, and still recommend them

Time for a new gearset... Is the black Tamiya reinforced gearset any longer lasting/stronger than the stock tan colored gearset ? I know somewhere way back in this thread there was some discussion about this but I couldn't find it.

They are a bit stronger but I tend to break them rather than wear them out.

They are a little stronger. If you're running an m05/06, they'll work for you. If you're running an m03/04, you're best off with the old gears.

Sometimes we all forget how much we owe you for the info on your website. I for one learned a lot and much of what I do had it's basis from your site. My first efforts were built exactly as you recommended. There are differences now, but that's primarily due to the different rules we race to and some personal preferences.

If I haven't thanked you before, let me thank you now for getting me started on the right path in Mini racing. People wouldn't have some of these weird problems if they had built their cars following your guidelines. Not that I didn't have an odd problem or two and more than one WTF.

+1
i've only been racing mini for 2 seasons but i re-built my first used M03 using the guidelines on the rc-mini net site and so far i put the car down and race... no issues at all...

Who else?