Thank you to the guys on this forum...Now sharing a secret

[Stan Pope]

Stan,

If those rear wheels are tracking together and staying off the rail, and the DFW stays on the rail, you will probably be ahead of 99% of the Tigers. It was our personal experience that on the long tracks we raced on that the DFW toe could be less aggressive (with our setup) than the toe stated by many others on this forum. Good luck on your races!

Well, it took more like 30 minutes cuz I was teaching and explaining ... but the guys with good eyes said that the inside edge of the rear wheel behind the DFW rode the 0.15" line regardless of which rear wheel was dominant! (Any more, I can't tell unless the area is really lit up brightly!) Son did the axle tweaking (for dog-trot alignment) and both watched the DFW-side rear wheel. When successive runs (one with each rear wheel dominant) with no required adjustment, we called the rears "good to race". Then set the toe-in for about 1.5" drift and squirt a final dose of graphite in.

Then spent a few minutes helping Grandson learn how to stage for best take-off!

Dunno if they will remember it all, but they are off to a good start. Dunno if it will beat the best racers, but he shouldn't be looking at their taillights!

[againstthegrain]

He already won!

He got to spend 1/2 hour with his grandpa.

The trophies will fall apart, but the love that he certainly sensed will last into eternity.

[againstthegrain]

Stan, how did the races go?

[Stan Pope]

Stan, how did the races go?

I've been ill and missed first grandson's races in a long, long time.

Report was "Fastest tiger in pack, A few older Cubs faster."

They decided on lead ballast and a kind of bulky design. Daddy was more comfortable with lead, I think. It yields to his hammer!

CM conservative.

Toe-in not "track tested", but we will do that prior to districts. Probably too much toe-in for the weight distribution. Team had an opportunity to tweak the toe-in on the pack track but Daddy wasn't very confident about changing anything! He liked the way it ran! We'll get him an attitude adjustment by next year! (Is "good" good enough?) Toe-in about the same as for Andrew's car with 1/2 oz on the DFW... William's had about 7/8 oz on the DFW!.

I failed to get a pic! I'll try to correct that oversight tomorrow.

[againstthegrain]

I hope you are feeling better. I'll be praying for you. Good to hear he made it to Districts.

[Stan Pope]

I hope you are feeling better. I'll be praying for you. Good to hear he made it to Districts.

Just cold/flu... an annual event, it seems. My family missed one district derby ... Son's first try at building.

[Gregg H]

Attaching the cubes and plates with a squishy type material that absorbs shock also helps to deaden the blows. It also allows you to remove the cubes for next year's car.

I appreciate your posting pics and explaining your methods. My cub and I are beginning to build our cars this year and these are helping me visual how to make some modifications for better speed. I am interested in what "Squishy" material it is that you use to keep the cubes in place? We are using a combination of cubes and plates this year also. And do you put a cover underneath so that the cubes don't fall out? How thick are your cars? 1/4 inch?

Cheers,
Gregg

[againstthegrain]

The material that you use to attach the cubes might be a gel or caulk type material. Our rules state that the weight must be firmly attached to avoid the weight shifting during the run giving an advantage from the affect of the weight moving. Our rules also state that the axles must not ride on any type of shock etc. You can imagine the advantage shocks would have in minimizing the effect of bumps. Since the shock absorbing can not come between the axles and the car, we figured possibly cushioning between the tungsten and the car body might help. A question to ask might be: Where should the weight be attached to the block to maximize the cushioning effect on the weight? Should it be simply super-glued to the top and sides of the weight pocket? Would suspending the weight be allowed by your rules? Would only attaching the weights only to the bottom "covering" material be advantageous? Would the possible additional height of the cushioned weight be worth the effect? When you ask how thick are cars were, I will in all honesty say it depended a great deal on how we attached the weights on a particular car, and also how much of the "thickness" was under or over the axle plane. Sorry for the evasive answers but these are the questions that you will want to consider with your son. The process of figuring it out is far more important than the results of the races...

[Stan Pope]

Stan, how did the races go?

I've been ill and missed first grandson's races in a long, long time.

Report was "Fastest tiger in pack, A few older Cubs faster."

They decided on lead ballast and a kind of bulky design. Daddy was more comfortable with lead, I think. It yields to his hammer!

CM conservative.

...

I failed to get a pic! I'll try to correct that oversight tomorrow.

Here are specs on car
WB: 5.35"
Weights:
FL- 0
FR- 0.89
RL- 2.51
RR- 1.58
Resulting in CM 15/16"

(Walked son through the Planning Weight Additions web page to show how using 12 1/4" cubes behind axle (2 ounces at -3/8") and 12 mre ahead of axle (2 ounces at 3/8") plus a car body/wheels (1 ounce at 3") would yield a more aggressive CM!)





After measuring the run-out on the rear wheels inside edge vs outside edge, mutual decision to run with rear wheels reversed so that the car rolled on the better edge.

[againstthegrain]

It's kind of funny that you post about mounting your wheels inside-out. That suggestion was my very first post on this forum years ago. And now I have retired from racing. I still remember when the idea of rail-riding was first discussed on this forum, we immediately jumped on board, and I don't believe anyone at Districts and perhaps only one other Father-son team at Council tried it that first year. There are still hidden gems of insight for slight modifications that can gain you the slightest edge hidden in posts on this forum that others overlook. No single hint, or trick, or mod will yield a championship. You can only be as fast as your weakest component.

[Stan Pope]

The usual reason for running inside out is to be on the firm edge of highly machined wheels, e.g. 0.9 g. Not our case ... the inner edge is plenty firm, just not as true as the outer edge. I offered him some other wheels, but he wanted Red!

[DerbyAddicted]

The usual reason for running inside out is to be on the firm edge of highly machined wheels, e.g. 0.9 g. Not our case ... the inner edge is plenty firm, just not as true as the outer edge. I offered him some other wheels, but he wanted Red!

Although the inner edge is probably more true due to it being firmer.

[Stan Pope]

The usual reason for running inside out is to be on the firm edge of highly machined wheels, e.g. 0.9 g. Not our case ... the inner edge is plenty firm, just not as true as the outer edge. I offered him some other wheels, but he wanted Red!

Although the inner edge is probably more true due to it being firmer.

The "usual reason" has nil to do with being true or not ... it has to do with "tread flex" that occurs in highly machined wheels. That tread flex allows energy to be diverted (temporarily) into compressing the wheel tread instead of contributing directly to speed. The phenomenon is most noticeable on short radius tracks.

[Stan Pope]

I've been ill and missed first grandson's races in a long, long time.

Report was "Fastest tiger in pack, A few older Cubs faster."

They decided on lead ballast and a kind of bulky design. Daddy was more comfortable with lead, I think. It yields to his hammer!

CM conservative.

...

I failed to get a pic! I'll try to correct that oversight tomorrow.

Here are specs on car
WB: 5.35"
Weights:
FL- 0
FR- 0.89
RL- 2.51
RR- 1.58
Resulting in CM 15/16"

(Walked son through the Planning Weight Additions web page to show how using 12 1/4" cubes behind axle (2 ounces at -3/8") and 12 mre ahead of axle (2 ounces at 3/8") plus a car body/wheels (1 ounce at 3") would yield a more aggressive CM!)





After measuring the run-out on the rear wheels inside edge vs outside edge, mutual decision to run with rear wheels reversed so that the car rolled on the better edge.

We relieved a lot of the drift, cutting it back to less than 1/2" in 3'. Car gathered in a bunch more speed. Was narrowly bested to finish 2nd among the district Tigers, delighting Daddy, Grandma, Grandpa! Haven't heard from Mama yet. For short track (28-30' start to finish), the very conservative CM seems to give up a lot, but not as much as I thought it would!

For Grandpa, it was a looooooooooooooonnnnnggg day, but a good one. Got to see a lot of smiles, and to help clear away some tears when a car broke, and even got to see Grandson's car run a few times though not up close.

[davet]

ATG,
we have a Council race coming up on a 56' BestTrack. Right now we are running 11/16 COM centered in the car with cubes and 4" of drift. This was good enough for 1st in Districts on a 46' track but just barely. When you say you can run a less aggressive drift are you talking 2"-3" or less? I want to try moving some weight like you mention. How did you know it was even on both rear wheels?