Weighted wheels?

Jonnys_Speed_Shop Sunday, 10/3/2021

Anyone tried adding weight to the wheels before? I'm thinking of giving it a go. If you can keep them well balanced, I feel like it would help keep the momentum up after turns. 

I would love to hear your thoughts on this. If I try it I will add some pictures of the the results.



I'd be intrigued to know what happens with your experiments.  Generally, the fastest wheels are the lightest ones, so going against the grain is interesting.

This might work on a road course with multiple turns. Most tracks I've seen have their turns level with the only downhill parts being the straight sections. Level means you aren't accelerating (i.e. slowing down) and are relying on your intertia to keep going until it can accelerate again. I seriously doubt it would have any positive effect on straight line drag racing. 

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redlinederby 10/3/21
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When I got into racing I knew a guy that added the weighted putty into his wheels and his cars flew. Of course, there's lots of other factors but I think it's worth trying out to see how it goes.

I'm sure there's some sort of rotational force of weight or something that plays a part...I'm not a scientist, but I play one on TV. And I'm sure that weight works different heading down the hill vs along the flats.

Found this when Googling the internet: "A heavy wheel stores more kinetic energy than a lighter one. It takes longer to spin it up and longer to spin it down. That's why cars with heavy wheels are slower getting to the bottom of the ramp. As we already know, a slower can win a race. The reason they win is different. Some people think that cars with heavy wheels keep the "slower" speed for a longer distance. So, overall the car's average speed is faster."

Lookup pinewood derby science and it's pretty much the same.

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SpyDude 10/3/21

Well, I am about to give this theory a test. I have a vehicle with weighted wheels headed to the Rust Belt Rat Rod Rodeo (10/20 at the Rust Belt), and a second one headed to the Ram Rod 400 over at Monster Motorsports. I used different materials to pack the wheels and make them solid - let's see how they both work.

  • Nice! I will be sending a car into the Ram Rod race as well. — Jonnys_Speed_Shop
  • May I ask what you used? For the Ram Rod car, since the rear wheels were so huge (Crate Racer truck), I used bb’s and good old-fashioned Elmer’s glue. For the Rust Belt race, I used SlickSteel (JB Weld) on all four wheels. — SpyDude
  • I haven’t done anything yet, but I was considering small fishing weights and JB weld. Bb’s seem like a great idea tho…. — Jonnys_Speed_Shop
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DRM_64 10/4/21

Hi! I will give my perspective about this:

Considering you have a weight goal to reach, or setting the weight of the car to some value, each gram you put on the wheels, is a gram less pressing the axle against the bushing or hole of the wheel. I mean, you're adding inertia (or keeping it to a value) without increasing the weight applied to the axle/bushing friction. So I would say it should work pretty good.

I thought a lot about "how to tune the cars better" or "kill all kind of friction" and adding weight to wheels was something I considered a lot. Since I never send any car to race, I just did some things to be happy with the way my cars rolled after modifying them. So not much racing experience to give lol.

About momentum and etc. that was said before, I will let this self-explanatory video. The shape of the wheel itself rather than its weight or material is really important! If the race is ran in an entire downhill track, a hollow wheel will be a disadvantage, for example:


  • Nothing like a practical experimental demonstration of something counterintuitive to blow your mind! — TheMakersBox
  • Thanks for sharing the physics video. It's great! I have been thinking about this topic myself. I am NOT a scientist, but I'd like to add my two cents/limited understanding of the concept. The video is a great demonstration of moment of inertia. The moment of inertia is essentially where the mass of an object is concentrated in relation to an object's point of rotation. In the video the hollow cylinder is slower than the solid cylinder because it has a LARGE moment of inertia - meaning it's mass is concentrated/located towards the outside of the object, or away from the point of rotation. The solid cylinder is faster because it has a SMALLER moment of inertia. It's mass is concentrated closer to the point of rotation. It seems that adding or subtracting weight form a wheel for racing will only be helpful if it results in a smaller moment of inertia (more mass concentrated towards the point of rotation... the axel!). If adding weight distributes mass towards the outside of the wheel (away from the point of rotation... the axel!) it will result in a larger moment of inertia and the physics will not be in your favor. This is a really interesting topic and experiment. I don't think it is enough to only consider weight. Based on the demonstration in the video, we should consider how adding or subtracting weight from a wheel effects it's moment of inertia (where it's mass is concentrated). — Healer_Racing
  • Exactly, most important thing is the shape of the wheel. If there is no air resistance, density of materials and weight of the cars would play no role in all this stuff — DRM_64
  • You need to build a car once in a while and send it in for a drag or a road course. Trust me, it's worth it. — SpyDude
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Numbskull 10/6/21

I'd rather be lucky than good.

Lefty Gomez 1930's.

I believe that there are 2 reasons that weighted wheels are faster.

1. as stated above they hold less speed but long enough to average out and maybe pass given a long enough track.

2. Yes it takes longer to get to the bottom of the hill, but does it? consider the following: a bowling ball and a golf ball are dropped from the exact same height and the exact same time which one hits the bottom first? answer is they hit @ the same time. same for hotwhhels. now for the why. bc the object with the larger mass takes longer to begin acceleration but bc the outside force acting on the object is the same (gravity) the larger mass has a greater max speed @ the bottom meaning that it will catch up and the time it had previously lost has now been made up and gained upon.

In conclusion weighted wheels ARE faster sometimes. You need to consider to a few things.

1. Length of track. If the track is to short it can't catch up. If the track is to long yes the car will maintain speed for longer but once the car gets to a certain speed the weight will stop the car sooner. Without running a few tests I don't know where the "sweet spot" is.

2. Weight limits. If you plan on running weighted wheels you DEFINITELY DO NOT want more weight in the 4 wheels combine than the body of the car. bc if the wheels are too heavy just forget everything i just said because you ALWAYS want the body of your car "pulling" the wheels, NOT your wheels "pusing" the body of your car. the car with the heaviest wheels won't win UNLESS those wheels are doing less work than the other cars wheels.

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RAGTAG_JIM 10/13/21

I have done it before on 2 cars...... One didn't do to well cause it didnt have graphite.... And one that has one had test runs....

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