Reducing car vibration and wobble
The topic of reducing car and wheel vibration came up on old topic about wheels and axles. I thought it was some great points and insight into some modding techniques so I'm migrating some of that info here since it's kind of buried up on the other thread.
Some content taken from Axles and wheels modding posted by Go_Time.
Vibration and wobble is a speed killer. That we know.
Member Chrisw asked about what he can do to reduce the vibration that always seems to come along when you fix the axles in your car. No matter whether you're doing a straight wheel swap or if you're using axle tubes, sometimes the wheels always wobble, causing vibration.
I always notice the loudness of cars, or lack there of. I've learned that the quieter the car, the faster it is. And I knew that meant it had better wheels/axles but didn't really think to hard what I could do to fix that problem. I always just wrote it off as "that's the way it is" and I just pulled from a bad car. Of course, I also felt that I could test a ton of cars looking for quiet wheels and would never find them. It was nirvana. And call me lazy, but I don't have the patience (or desire) to go through car after car looking for them.
But a few members, including League of Speed, had some insight on what creates the vibrations and how to go about trying to reduce it.
From League of Speed:
The diameter of the axle is usually not the issue. Now there can be a bur near the axle head sometimes that will inhibit good wheel spin and light sanding can help, but be careful if there nickel platted though - don't sand off the platting - but 99.9% of the time it's the inner wheel hub after production. It can be egg shaped, oval shaped and that causes crappy wheel spin aka wobble or vibration. Also, when the axle is set in the chassis it usually intensifies the hub flaw, and all it takes is one bad wheel out of 4 to effect speed and perfomance.
It's one of those obvious things that you don't think about until you start chasing the dragon. I've gone down the route of (trying to) de-bur the axle and even sanding the wheels, but it never struck me to consider the wheel hub (wheel hole) as the bigger culprit...but of course!
The wheels are mass produced like everything else on the car so that hole isn't going to be the same every time...probably never, actually.
And then in my case where I glue down the axles as a general practice, that can end up making that wobble worse...so maybe since I'm not diligent enough with my wheel holes, I shouldn't be fixing my axles at all? Hmmmm...
Share your tactics and trials with improving your wheels and axles to reduce vibration. Do you drill out the wheel holes so you feel they're all uniform and likely more round? Do you try to sand that tiny hole?
I've done my fair share of axle tubing but I kind gave that up because I never felt I did a good job and ended up being more trouble for me. Instead I kind of do what you do and just sift through my cars until I find a axle/wheel set that fits naturally.
Although, now that I have a reliable axle jig, maybe using the tubes will be less of an issue. However, since tubes have to be fixed, if I don't solve the wheel hole problem then it doesn't matter much.
I might do some experimenting with unfixed axles and see what happens.
- That's what I refer to as the "Riddle of Speed"...solve the the riddle and find the speed — LeagueofSpeed
- Great article, thought provoking, combining with my (at this stage) small experiences. I was going to ask the question...So to potentially limit your issues, one is better off trying to find the correct size axle/wheel como, than axle tube or fix in your wheels... — CutRock_R_Marc_D
working with .030" -.032" so far .030" no wobble for me but still vibration. Test one a fail. Test two tomorrow .
- Making your own axles from wire? — redlinederby
- Remember that piano wire is made to sense vibration...piano wires vibrate and when they do...sound aka music...food for thought. — LeagueofSpeed
- #17 sewing pins are nickel platted...have a axel head already and are mainline axel size in diameter — LeagueofSpeed
- Interesting. Just seems like making that wire straight would be a chore. — redlinederby
- Los have you ever tried music wire ? For me if you have the right stuff listen..............zoom zoom zoom blew my fastest Ferrari F40 out the water everything stock . Different strokes for different folks . But I used to wonder what was that familiar tune as it was blowing that Ferrari F40 down the a straight line. — Chrisw
- I've seen mention of #17 sewing pins in some of these threads. My question:Does that violate the "Retail Axles only" rule many RLD races have? — Peter_Bee
Just a couple of things for this thread...I think you are always best off to start with wheels that run true...yes, you can make corrections, like LoS was saying, but, it's just easier to find wheels that don't wobble...and, they don't have to be fte's, as long as you are running good axles.
Next, I did a whole series on installing axle tubes here...
The thing with axle tubes is that they lower tge car just a little, and you can control the width of the car very precusely. If you only ever run on orange track, you don't have to worry too much about the width, but if you are running on Drag Track or on an open track, you might want those wheels out a little wider...if the body is rubbing the track side, you are scrubbing speed, if it's the wheel, you are losing a lot less speed.
Just my 2 cents :)
Does anyone still bend the axle to give a subtle camber to reduce the wheel/ground contact surface area? Or was that just a 70's/80's kind of thing? Haven't tried it since I was a kid and can't remember if it ever made a difference back then or not either - way too long ago for that.
- People do, sure. Although personally I think it's better to focus on straight wheels and weight. I find it difficult to camber nicely but that's just me. — redlinederby
- People do...but I don't...what RLD said...Run Silent...Run Straight — LeagueofSpeed
- There is an alternative way to run your cars with angled wheels. Check out this topic I wrote a few months back. It also addresses the wobble problem. Hope this helps! www.redlinederby.com/topic/cone-shaped-wheels/3989#comment-48446 — Ralph_Technology97 — Ralph_Technology97
- Sure. My kids step on cars all the time and bend the axles. LOL. It hasn't every made any of them faster though :) — SpoolHeadsRacing
So I've got a set of wheels that spin quietly but not for long as bone stock. Is that good or bad?
- It's a good start, polish the axles where the wheels run and retest. — Redline_Salvage_Inc
- Thanks — MadMike
Malformed heads and axles that aren't round would be my guess for the wobble. Sadly these are the norm and not the exception. Can you see the fold in the metal when the rod was manufactured?
- Good point. I may try #17 pins... — G_ForceRacing
I Wheel Farm....sometimes you get lucky and all 4 wheels are decent to good....sometimes very good, then they need to be sanded(many techniques on that as well)...back on point...so once I know my axel length and wheel size...I start finding would be/could be donors and I start spinning the wheels...and when I find a good set...what I refer to as a "package"....FTE package...CS package...GMS package, then the wheels get sanded....axels polished...axels set in chassis (see RLD Axel Jig)....Car properly weighted for said race and then the wheels are graphited(at least 3 times....graphite and then 3 runs...repeat 2 more times). I do use Mainline packages...contrary to popular belief and I've had the most luck with 5Dot wheels and axels.