+1

82 spur and 60 pinion gives a range from 94-114 with tires from 41-50 which is pretty close to where we need to be. Might start with that as it gives me some room to play with tire diameter.
Thanks ericf

EDIT: Just searched for spurs gonna need to be 81 or 83 cant seem to find an 82. Recommendations on spur brands. I can get serpent ( obvious choice being its going on a s120lt) or associated or xray and kimborough. I read somewhere about having lots of holes for the balls...???
I think i'll lash out and go the sxx, save me having to much around and charge the booster as well.

The more diff balls you can use the less you have to tighten the diff to get the same action. This results in a smoother diff that lasts longer. CRC has a new spur gear that uses a smaller diff ball to get more in the same area and it works quite well. You will have to add spacers to that side of the axle though to keep the back end centered properly. Xenon makes a spur gear now that has as many diff balls but still uses the standard 1/8th diff balls. I've tried the CRC ones and like them a lot but picked up some of the Xenon ones at the IIC to give a try as well.

If it's LRP for boosted, make sure you go with the Stock Spec, it's the only one that has enough boost for stock spec motors, not the TC, not the comp.

And I'm not sure you can fit spurs in the 80's with pinions in the 50-60's
That's why we have to run the smaller spurs when running higher roll.

I saw the xenon ones too will have a look.
Apparently the kit comes with 8 balls so the muchmore xray ones are out as they only have 6 holes it seems.
Yeah redbull WAAAAYY down south, I work only an hour from the most southern point in tasmania so the name is fitting
Thanks heaps for the advice, i've learnt more in the past 1hr then i've done the past few weeks, it all makes much more sense, now if I can just work out the rule to get an idea of rollout based on a specific track type. Maybe for every 10 meters/30 feet of straight = 30mm of rollout? or 1ft = 1mm of rollout per straight??

The Xenon gears are the best I've seen to date.

When you figure out the rollout formula for all tracks, please post it here

Haha go figure, i'll go back to the 72 spur with a 58-60 pinion then. It will be a good start and I can see if i'm winding out and go from there.

Note: I did say at my track...
Also, pinion grears are an investment. buy them all from 35-60 and you'll eventually find the right gear for where your racing. multiple sizes of spur are good to have around as well. PRS make a 82, Kimbrough spur gears go from a 76 and up by 4 teeth at a time.
E

Is it better to run a novak smart boost or a receiver pack? If a receiver pack what brand and part number. i run a tekin rs if that helps or is there a better speed controll to run in 1/12 scale ?

Hey mate, apparently running a rx pack means steadier and more reliable power to the rx throughout the race.
I have been tossing up and it seems that either you run no pack with an sxx or run a pack with the RS. Redbull above if you read the thread noted that the rs with pack is much faster with boost.
I'm going to go with the sxx no rx pack just to save the hassle of charging the rx pack.
TQ cells are meant to have the best rx packs out there for 1s http://www.tqcells.com/

I bought a spare complete diff (individual parts) for my Associatted 12r5.1 and it needs to be done up noticeably tighter to stop the diff from slipping compared to the one that came in the kit. Both diffs are built identically and I swapped a bunch of bits around and it turns out its the main axle that is causing the issue.

Is this common?

Will the Xray full Aluminium rear axle fit? Maybe with all of the Xray parts?
http://www.teamxray.com/teamxray/pro...20Axle%20Shaft

Think you will find the Xray is metric and the Associated is Imperial.

I can lend you another rear axle if you need it this weekend. I only require you to pull over and let me pass in the races lol

Can someone explain this rollout please

Thanks

As i understand it rollout is how far the car travels with one revolution of the motor.
This is important as it helps to keep the motor in its workable and useable range. This keeps temperatures down prolongs the life of the motor and should keep the power drain on the batteries uniform and not like a thirsty camel.
It also helps with getting the right amount of drive for the track you are at. No point having a zippy point to point car when you have long straights and sweeping turns and vice versa.
To calculate rollout you need to know the tire diameter, pinion gear size and spur gear size plus something else that I cant remember.
check out this site for some more explaining.
http://www.carsrcracing.co.uk/?page_id=33

So it's basically how you gear something?

Yes. But because we are using foam tyres that wear and change size. We have to change pinions as the tyres wear to keep the same rollout or gearing.