Jon Kerr

iTrader: (17)

I'm always on rubbers so I never even think about roll out

DaveW

iTrader: (1)

Ok. That was why i asked. Many people ask for gear and never consider the difference tire size can make. If you are using 64 pitch, and true your tires, you can lose one tooths worth of gear. I dont know about your areas track, but here we balance and true our belted rubbers as well. Makes for a smoother car, and the gearing is more accurate. (you would be amazed at how off balance and unround molded tires are)
- Dave

Aluma

iTrader: (1)

how in the world do you true a sorex 32R tire? I can understand balancing the wheels with tires...but truing?

Jon Kerr

iTrader: (17)

I balance mine too but I have never heard of truing rubber.

adrian

jkerr0043 & Aluma you only true foam tires... i would hate to see a rubber tire been trued!

TSR6

iTrader: (5)

Not only would that make a mess, but think of the burnt rubber smell! You might be able to make a pass on it, but don't cry to me when you have a blow-out.

Grizzbob - I've run both 767's and 4499's in my monsters. I had the same problem with my 767's! I've been using 4499's in my monsters ever since. With the 767's, sometimes they would dyno & run awesome, but I had one motor that droped power dramaticly every time I rebuilt it, and dynoed it.

Funky stuff...

Jon Kerr

iTrader: (17)

DaveW,
what do you mean by "truing" your rubber tires?

DaveW

iTrader: (1)

By truing a set of rubbers, i do not mean cutting them down like you would foams. You simply make a skim cut on the tire, a little at a time as you do when you true the armature for your motor. Of course you would have to have the high quality bit on your lathe. But the idea is to take off the excess rubber... or the "high spots" of the tire. Try it on an older set of belted tires, and use sandpaper (100 grit) to gently round the edges of the sidewalls. Clean the tire with denatured alcohol and a clean rag... make sure your glue beads are tight. Wait about 5 minutes, you will see how sticky the tire is. Not from heat, for the tire will be cool. I then take a bastard cut file, and using the most agressive side of it, i run it diagonally across the face of the tire by hand. They run like scuffs on a real car, and are ALOT smoother at high speeds. With the flatter contact patch, for those of you that run rubber on carpet, you will have a tire that gives you more bite... and the rounded sidewalls give consistent sidebite compared to a squared sidewall. I actually got sight of this by a racer i know in the Maryland area many years ago... since then it is something i have played with, and get great results from. Try it on an older set of belted tires you have retired after 3 or 4 runs. I think youll be impressed. Ill also mention that the tires (24mm) i run are always mounted on inch up rims (26mm) with a firm (26mm) insert. The car is really responsive with a tire that is stretched like this, but there is less airgap between the belt and the insert and the rim. The insert plays more of a role in tire tuning, and not as much by putting a hole on the inside of your rim to allow air to escape.
- Dave

DaveW

iTrader: (1)

No one else has tried this?!
- Dave

popsracer

DaveW;

I have a Friend that made a Bastard (sorry) set of Rubbers by stretching the rubbers over some old trued down foams. He then trued them (somewhat) to give them a wider contact patch. Unfortunately they didn't work as good as he thought they would.
I have seen Guys many times 'Scuffing' a new set of rubber tires at the race track with a piece of sandpaper. Never liked the results when I've tried it.
But I like your method and am going to suggest we try it on a mounted set of Sorex's.

Thanks,

Aluma

iTrader: (1)

LOL...actually i kinda do that... 26mm wheels with sorex 24mm tires and firm inserts! I just never thought about rounding the edges more since they're so rounded already from being stretched.

Well, I've been using the medial pro insertless tires and they seem to have the same grip as the above combo...except that they do let go rather suddenly at their limits... I'm guessing from the excessively squared off side wall... maybe I'll sand these down and see what happens. thanks for the tip Dave!

Kraig

iTrader: (81)

The oval racers still do that with cap tires. A lot of times they would true their caps to remove the high spots thus providing a round tire. You just have to be careful though so you don't burn the rubber.

rod_b

You can do this this process with the new Integy tire truer. The Integy bit is similar to the carbide bit I have on my Hudy truer. I noticed that my Yokomo 138Gs needed to be "worn-in" before they started working well. Maybe I'll throw them on my truer and see if that speeds up the process.

popsracer

Using 24mm Tires/inserts on 26mm wheeels is no big deal. I think it makes the sidewalls flex/squirm a little more and the handling is less consistant than with 24mm wheels.

I've tried the Medial Pro tires and the only thing that they worked decent (not Good) on for me, was Concrete.

DaveW

iTrader: (1)

Yes, the idea is to take your time as you true... going to fast will overheat the rubber, and once it cools.. itwill be hard as a rock. Yok 138G respond well to this Rod... that was the last set of tires i did a few days ago and they worked real well. Pops... you said stretchin the tire over a wider rim made the tire squirm more? I wonder what insert you were using. I ask because a medium insert did the same for me... and going to a firmer insert solved that issue. I guess it is similar to real cars, the smaller the tire... the more air pressure it needs. Monster trucks like Bigfoot use only 5 PSI .... whereas low profile tires on BTCC cars use up to 60 PSI. I guess when you stretch a tire like that over a wider/larger diameter rim... it requires a harder insert... since the insert mimics air pressure. Dunno for sure... but just my theory. How do the insertless tires handle and wear? i have yet to try any... but the technology looked interesting. Looks like it would be a great spec tire, as far as tire/insert control goes. Who distributes them?
- Dave