Fender Test

Prozach2

Workshop Leader
Jan 11, 2019
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Charlotte
My two boys each ran a car this year. We did our best to make them identical, but on one we didn't use fenders and on the other we did the Gee Diamond Fenders and trailing fenders.

Of course, there were slight differences. Fenders change the weight distribution quite a bit. I was having a hard time pushing the axles in on the one with fenders so those wheel gaps were a little too wide IMO. Due to the tight axle issue, the raised front wheel on the car with fenders was loose and the other was pinned against the side of the car (as it should be IMO). So, point being, other than the fenders, I feel like the non-fender car was put together a little better. Both cars were ladder bodies, rail runners, three wheels touching, drilled with silver bullet, 3 degree cant in back, 3 degree bend in axle of FDW, and ran on a best track.

The car with fenders ran an average time of 3.1822. The car without fenders ran an average time of 3.2324. That was about exactly one car length, so a pretty significant difference.

I've been a little intimidated to try fenders b/c I've heard they can be difficult. These were very easy to install. We just glued them right on with extra thick super glue.

Curious, have you guys had similar gains with fenders? Have any of you tested different fenders against each other? Are there any that you prefer?
 
Fenders always make a car faster as long as they don’t rub on the wheels. However, they’ve never gotten a car length for me. Probably 0.01-0.012 faster in speed (if done well). Most pro racers will make there own so that they fit better to the wheels. My guess as to why your car with fenders was that much faster is that you could’ve had better wheels, axles, and maybe your alignment is slightly off in you car without fenders.
 
Fenders always make a car faster as long as they don’t rub on the wheels. However, they’ve never gotten a car length for me. Probably 0.01-0.012 faster in speed (if done well). Most pro racers will make there own so that they fit better to the wheels. My guess as to why your car with fenders was that much faster is that you could’ve had better wheels, axles, and maybe your alignment is slightly off in you car without fenders.
Are the pros using balsa or 3D printing typically?
 
My two boys each ran a car this year. We did our best to make them identical, but on one we didn't use fenders and on the other we did the Gee Diamond Fenders and trailing fenders.

Of course, there were slight differences. Fenders change the weight distribution quite a bit. I was having a hard time pushing the axles in on the one with fenders so those wheel gaps were a little too wide IMO. Due to the tight axle issue, the raised front wheel on the car with fenders was loose and the other was pinned against the side of the car (as it should be IMO). So, point being, other than the fenders, I feel like the non-fender car was put together a little better. Both cars were ladder bodies, rail runners, three wheels touching, drilled with silver bullet, 3 degree cant in back, 3 degree bend in axle of FDW, and ran on a best track.

The car with fenders ran an average time of 3.1822. The car without fenders ran an average time of 3.2324. That was about exactly one car length, so a pretty significant difference.

I've been a little intimidated to try fenders b/c I've heard they can be difficult. These were very easy to install. We just glued them right on with extra thick super glue.

Curious, have you guys had similar gains with fenders? Have any of you tested different fenders against each other? Are there any that you prefer?

It kinda seems like you answered your own questions about your conclusion with fenders. Fenders are faster, but when they are done right. I have seen a lot of fender cars out there, where the car would probably be faster without them. My best advise to you on fenders is this.. Go to our racing league site and look at some pictures of the top guys running fenders to see what they look like. Then make a trip to Hobby Lobby or whatever you can buy some balsa wood and start making some fenders cars. If you screw up, break off and start over, but you can't learn unless you start. It's my favorite part in making a SS style car. Good luck and remember try the search, because there are crap loads of info about fenders already on this site.
 
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It kinda seems like you answered your own questions about your conclusion with fenders. Fenders are faster, but when they are done right. I have seen a lot of fender cars out there, where the car would probably be faster without them. My best advise to you on fenders is this.. Go to our racing league site and look at some pictures of the top guys running fenders to see what they look like. Then make a trip to Hobby Lobby or whatever you can buy some balsa wood and start making some fenders cars. If you screw up, break off and start over, but you can't learn unless you start. It's my favorite part in making a SS style car. Good luck and remember try the search, because there are crap loads of info about fenders already on this site.

Yes, it seems like all the pros prefer balsa fenders. I've searched the fender question a few times. I think I was just in a bit of denial about that b/c I imagined that 3D printed fenders would be so much easier and lighter. I watched the Bulldog Racing video last night on making balsa fenders, and I'm a little excited that I was wrong though. They look like they're going to be a lot of fun to make.
 
Bulldog's video is great, and a good place to start. I don't cut my fenders like he does, but everybody has their own way of doing it and I'm sure you'll get it figured out and have your own way too. I only use balsa, so I can't comment on the new 3D printed ones. I have used those old Gee fenders years ago, and I'm not sure if DD4H still sales them? I only use balsa because of the weight and I'm just not a huge fan of the 3D printed ones. I'm sure just to be able to glue them on would be a very enticing. Your right, I think you may really enjoy making them. The satisfaction of making them and then racing your car is a lot of the fun! Good luck!
 
Bulldog's video is great, and a good place to start. I don't cut my fenders like he does, but everybody has their own way of doing it and I'm sure you'll get it figured out and have your own way too. I only use balsa, so I can't comment on the new 3D printed ones. I have used those old Gee fenders years ago, and I'm not sure if DD4H still sales them? I only use balsa because of the weight and I'm just not a huge fan of the 3D printed ones. I'm sure just to be able to glue them on would be a very enticing. Your right, I think you may really enjoy making them. The satisfaction of making them and then racing your car is a lot of the fun! Good luck!

He still sells them. I bought them this year. Based on my experience, I'd still highly recommend them to anyone that doesn't have the tools/skills to make balsa fenders, especially if they're competing at the cub scout level.