Unlimited class: bearing wheel/axle questions

[waffe7]

Hi,

I'm building an unlimited car this year for a parent race for our pack, and I have done pretty well so far using a derbydadforhire body and the razr wheels he sells with the axles for them. I have a couple quick questions regarding these. I have searched around for pictures of pro cars and it appears some of them have a brace or wire where the 4th wheel would normally be, but it seems not everybody does this. Is this just to keep the car on the track in cases where a bad bump shifts the front over, or are these just to protect the body so it doesn't bump? I'm just wondering if I should leave that side totally bare or put something on for this. Is there a term for it? Happy to read old posts I just have no idea what it's called.

Secondly, I have seen some posts saying most guys run hubs facing in on the back, and hub facing out on DFW with the bearing wheels. The rear axle I have basically fits the car body almost perfectly, meaning, where the axle goes down to the thin diameter doesn't leave much if any "thick part" to keep the hubs off the body. Do people normally use a plastic washer/sleeve to keep the bearing wheel hubs from rubbing the body? Just curious what is normal for that, if anything.

Lastly, is there a standard for how much steer to go for when using Razrs? I have seen all kinds of info out there for stock wheels (on my boys' cars we usually shoot for 1-2" for 4ft) but wasn't sure if Razrs should use more/less/same for the DFW.

Thanks for any help!

 

[DerbyDad4Hire]

The pin keeps the car from drifting off the track. This is the route you want to go.

Narrow your body so the axle protrudes. The front can be much more narrow. Flipping the wheels like that ensures the rears wheels dont hit the rail.

Razrs tend to need less steer but you need to track tune them to know for sure. It is always better safe than sorry if you cant track tune.

 

[Loud2ns]

A few years ago I thought I had the railriding method by the tail and made our cars three wheelers. In one heat my sons car tripped the lane next to him and his own lane! Moral of the story.....you need a pin or wheel in case the car wiggles.

 

[waffe7]

Ok, thanks guys. Is there something people normally use to make this pin? I was going to try to use a stock axle but my guess is it's not long enough, not sure have to check later tonight. If not i'll have to improvise, need to race Saturday.

@DerbyDad4Hire thanks a ton for the advice, makes sense. Is there anywhere I can get more of that plastic tubing that comes on the axle?

 

[Reecedad]

Ok, thanks guys. Is there something people normally use to make this pin? I was going to try to use a stock axle but my guess is it's not long enough, not sure have to check later tonight. If not i'll have to improvise, need to race Saturday.

@DerbyDad4Hire thanks a ton for the advice, makes sense. Is there anywhere I can get more of that plastic tubing that comes on the axle?

I’ve stripped 18 gauge wire and used the plastic that surrounds the wire with some success

 

[waffe7]

Great, thanks. Just for posterity it seems these things are called "guide pin". Thanks for the help I found a few threads on it. I'll try the wire insulator trick!