Bearing Spacer Haters and Old Flames
I notice that on the old skate debate forum there were a couple of spirited debates about bearing spacers. Full disclosure, I use them. I use them and I machine them to 1/1000th or so of the wheel's internal webbing space (measured using calipers) minus the width of my polished tungsten speed washers. What surprised me was how several "experts" said they make no difference at all (😹 kidding me? Can you feel your feet? You even skate bro?). Personally, it's very noticeable. Let's talk physical facts for a moment. They must be sized correctly for your wheel or they may be counterproductive or dangerous. So, sure, if you use the wrong size, they will either not work at all (too small) or they will push your axle nut out past the nylock and your wheels will vibrate off (too large). Bearing spacers keep your axle straighter under load. Spacers aid in keeping the inner faces of the bearings parallel, which consequentially aid in keeping the load radially applied (rather than flexing and turning into an axial or torsional load). Radial annular bearings perform better under radial loads (duh). Performing better means more roll out, less heat/friction generation, and less potential for chatter or seizing. I also noticed one long thread where one of the more enlightened folks pointed out how she effectively could modulate wheel grip using axle nut snugness against a bearing spacer (folks ignored that excellent fact). I do this exact thing often and agree that it's an effective method. Tighten the axle nut down and you might lose a bit of roll, but you'll get a straighter wheel/axle under load and this increases the size of the contact patch since the patch/bottom stays more parallel to the ground. I just gotta wonder what the "just throw them away" crowd is thinking if it's not "I don't want the best performance from my skates. I know better than the engineers. Hold my beer."
Comments
So your spacers are being crushed? Better upgrade your spacers if you can tension and effectively change bite. I've tried everything before, never saw any change as described. But while we are on this, better build a tester that can prove it. Show data, not feelings.
Dial indicators, scales, angle plates, surface plates... etc.
Nearly all big fights on the old forum were built upon "feel". Then at least 2 people built test gear that I know of. Then the bs died a quick death. I built 2, one proved DA45 style plates if used correctly can have adjustable steering ratios under full skater load. The second one I built showed a much shallower pressure curve or ramp up as we call it of cushion pressures at high input angles. I could test almost any cushion and measure ramp up properties.
Another guy on SLF built amachine measured wheel, tire and wheel + tire deflection under load. Load could be varied ax well.
Crushed? I don't follow. If you mean binding due to too-short length, I don't believe that is the case, but I could be wrong. I measure the width the seat webbing using a caliper until it's within 1/1000th (though on crappier wheels their tolerance is higher than mine). It is a PITA... but no such thing as too much precision, with this kind of thing, IMHO. I do it at home with a drill press and a level granite block, abrasives, and test measurements with calipers. Are you saying you'd want to see data to demonstrate the increase in axle stiffness after adding spacers? Stress-strain curves in tensile testing always show thicker diameter test samples require more stress (σ), to snap. Nonetheless, I believe it'd be probably be possible to test the size of the contact patch under various loads and positions both with and without spacers. So, that might be one way to quantify the effects, but it'd take some effort.
However, another strong argument for spacers is that Roll Line and other top brands include their own bearing spacers and speed washers which are precision axle stiffening & bearing face aligning parts. Rollerbones, Riedell, and Sure Grip also offer them. Sure Grip spacers are nylon. Rollerbones are slick enamel coated metal and precise.
I use too-big Chinese aluminum crapola spacers as feedstock for my "custom" ones. In my personal opinion, they are worth using if you don't mind the fabrication step. I don't look down on or resent any one not using them, though. Skate your own skate, world.
You said there was woman that had a noticable difference when axles were tightened and tightened further. Something has to give to get anything from that kind of adjustment.
Skates long ago, nearly all had spacers. It was required to prevent skaters from crushing wheels that were available at the time. No hubbed wheels, so something had to keep skaters from sideloading their bearings/pinching the bores and divider.
Skate companies will sell whatever sells. Moxis, it's name and branding for an appeal to female and some male skaters. Figuring out what is basically the right combination of skate parts for an individual is the goal, but never is it a cheap, er inexpensive.
The bearing spacer thing has been beat on for a very long time. You can be so precise that you can kill your own traction on the extreme end of settings. Unless you just like knowing and spending lots of time doing all this, there really is no point.
Getting a good plain set of bearings is easy, finding the perfect set of wheels is where skating gains are made. There are variables even from set to set, wheels must match the skate surface. Lots of skaters carry several sets of wheels to accommodate the venues or surfaces they go to. Way more to gain testing wheels than bearings. Bearing are much more precise in construction than any wheel ever produced.
Unless your spacers are interference fit, still not precise, still more precise than the perfect set of wheel. You find the holy grail of wheels(Scotts), you will be good to go.
Sure, wheels & cushions are a lot more influential over someone's ability to do a specific trick or motion. If skating is an equation, those are bigger coefficients. I just like testing bearings and spacers because it relates to other hobbies of mine and to my job. I agree that getting a good set of bearings is easier than matching wheels to the surface and needs/style of the skater (ie... Jam vs Rhythm vs Artistic vs XYZ). However, I'd still urge folks who care about speed and roll out to experiment with them. I have had good results and I don't think it's just "feel". I think it's due to the changing size and shape of the contact patch as the axle is stiffer with spacers, but I'm not willing to build a test rig to argue it. I get paid for stuff like that.
It's rather dramatic for example on my Sure Grip Zombie wheels where I've done the most work on precision for the spacers. I know some say they do nothing, but I still disagree and agree with the engineers who insist on shipping them with high-end rigs. I don't think it's marketing, or old-timer nostalgia for the pre-nylock nut days etc.. but *shrug*. I think it does what the engineers intend: keeps the axle stiffer and the bearing faces aligned.
You would be surprised at how much this industry is "feel".
I don't see any need to add weight to wheels by installing spacers, the hubs are an interference fit for the bearings and i for one can't see spacers making any difference at all. You can build any test rig you like and generate data to "prove" your point, but a test rig isn't reality and i doubt anyone puts enough load through their feet to need spacers to keep axles from distorting!
I'll also add that you're talking about 8mm axles with nylon nuts, what about clip (7mm) axles? my wheels click and clack as they move side to side on the axle, the inner bearing race against either the clip or the truck body. This is typical equipment of track and road speed skaters and they will generate much more load through their skates than a regular session skater.
Oh, and Boen always were and always will be the best plates available, regardless of whether they're readily available or not.😁
IMO, it's a waste of time. You would probably need to create a spacer for EACH WHEEL that you use and that spacer would be mated to a specific wheel.
There probably isn't enough of a difference in performance to require spacers. This is opinion and as previously stated, would require real testing to prove.
Indoor Inline: Pinnacle Full Customs | Junk Fury 4x110 | TLTF/Simmons Wheels | NMB
Outdoor Inline: Simmons Full Customs | Junk Fury 4x110 | Junk Wheels | NMB
Quads: Reidell 911 | Roll-Line Giotto | Corey Super-Ds/JG Hubs/B-Skater 71mm Outdoor | Bones Swiss/NMB
I like using spacers so I don't have to waste time adjusting the bolts on my wheels. I tighten them down and still get a free spin. I skate to the park in soft trash wheels and switch to _Team Bones 101a_ wheels when I get there. Less hassle for me so I do it.
Here, too, there is an empty-headed person who says that there is no need for a spacer.
If you say you don't need a spacer, why do you care about bearing performance and wheel performance?
Isn't it okay to just put on wooden wheels and ride a roller?
Spacers are a must.
Still haven't proved what the spacer did to improve performance...
The snowman is correct....
Would you also need proof that kingpins angles affect edging performance or that wheels roll with radially distributed loads?🤓 Would you need proof that wheels with a lower coefficient of friction slide more or that metal plates are more rigid than nylon? Those are all assertions I doubt you've seen "proven" with data or math, yet they are just as true as saying that fitted bearing spacers align the inner faces of the races, stiffen the axle (thus lowers vibration and increasing grip), and aid in maximum efficient use of the bearing seat. It's why they are called “annular” bearings. If the balls fail to roll in that rounded annular seat, the bearing efficiency goes down precipitously. That can happen to the upper or lower race. It’s why ISO 492 specifies that measurement of radial loads on annular bearings has to be done with the faces of both top and bottom races completely aligned. Cropduster, you do understand the alignment wheel webbing is doing, but you aren't seeing that’s only on the outer race, and doesn’t help with a torsional or axial load on the smaller, inner-race. Having both aligned is more ideal for radial loads.
These facts aren't controversial just because some folks have had bad experiences. Bad experiences can come from badly measured spacers or many other implementation-errors. Yes, sometimes you definitely do need to adjust your spacers for an exact fit to each wheel. Rollerbones and Sure Grip sell exact spacers, but few others do and often include mis-matched spacers that won’t fit and will kill performance if you use them (so pay attention!). Sure Grip wheels are often inconsistent outside of the Zombie line. So, yes I have, in many cases, had to take Aluminum spacers (generic ones that come with skateboard wheels) and grind them down to within a thousandth or so of the measurement of the inner webbing of the wheel. Yes, that's right, Snowman, if you want maximum performance and durability, you need to be as precise as possible and that might mean hassling with it wheel-by-wheel. I use a drill press and mill-file to adjust mine. Too much trouble? Okay, maybe that’s fair. However, it only takes me about 20 minutes or so to make a whole set of eight and double check them with a digital caliper, but I can see how it’d be a pain for most folks. You want that last bit of performance or not? It might take work, right? Don't good things always take work?
I’m unsure why it’s so difficult to believe that skate features designed by mechanical engineers (who are also very often skaters, too) to aid or improve skate performance, in fact, do increase skate performance when used properly? In other words: bearing spacers have specific effects. If you cannot feel those effects, do not like them, or lack the ability to use them properly then fine. If you say the effects don’t exist, that’s okay, too, I guess, since folks have given zero evidence that bearing spacers are bunk-engineering or scams, either. Readers can judge for themselves, I suppose.
My personal experience with using and making bearing spacers has been rewarding. A noticeable increase in grip and edging stability as well as overall skate precision was the result for me. Yes, even more so on 7mm axles than 8mm ones (big difference). I have both Roll Line and Synder plates with 7mm axles but several plates with 8mm, too.
It’s certainly clear that others dislike spacers. I suspect I know why, but it’s not that important. Those seeking maximum skate performance will do their own experimentation and come to their own conclusions. There will always be people who act like you're crazy for wanting to improve your skate performance with small measures. I'm definitely not one of them.
By the way Fierocious1 you mentioned that folks built a bunch of test gear but exactly none of the gear you described would be very helpful with measuring bearing roll-out or performance. You got off talking about cushion performance and other unrelated tripe. What about bearings, bruh? You ain't pasted links, data, or proof involving "Dial indicators, scales, angle plates, surface plates... etc." from you what-so-ever, dude. So, while you are busy asking for proof that parts included with almost everyone's skates are fantasy/bunk/not-worth-it and unneeded, shouldn't it be you showing proof? I mean the state-of-the-art is that we use them; I'm not arguing for non-existent parts, here. The American Bearing Manufacturers Association definitely agrees with me when it comes to aligning bearing faces, in fact they require it for proper testing. Section 5.3 of ISO 492 which is the specification for radial bearings also agrees on that point. So, if you're going to throw the bullshit flag on bearing spacers, okay, where is your proof they do NOT work, eh? You going to dazzle us with your science showing they don't work? I'll be waiting...
As a rule of thumb, if you’ve got a larger diameter or softer durometer, or if you ride looser trucks, getting skateboard riser pads is a good idea to prevent wheel bites. It’s a must-have actually.
Bearing rollout and performance huh? Lol Specs on bearings are redily stated if you look up the data. To perfectly fit spacers you have to overcome the looser specs of bearing bores in wheels. Thats already been stated. If you believe in spending a day fitting spacers instead of enjoying skating, go ahead. As for any difference in performance, it would be so slight of a gain that a change of wheels would way overcome or easily exceed the gains if there were any from a spacer fitting day. Bearings are the most precise part of any skate. Even crappy bearings are more precise than all the skate parts. You can wait all you want... and spend days fitting for your "gains". I don't need to disprove bearing manufacturers specs, it's how you apply their products in the real world. It's really very basic, the application has nothing to do with their specs. If you have better gear to test bearings than the manufacturers, trot it out. It's all about application, not the bearings themselves. Everbody knows if you put a pair of bearings on a close fitting shaft, the bearings are aligned.... sideloads are brought on by pinching, or too narrow of a spacer, causing side loading in the races, ruining the bearing. Too wide of spacer is better than too tight. Most bearing move slightly in the bores anyway. So you going to glue them in to stop that imperfection too?
For all the time you take trying to prove some very slight advantage, it is diminishing returns. Ill simply change wheels in 5 minutes and blow away any gain you think you can prove up.
Wheel duro/grip varies performance tremendously, a lot more than any slight perceived gain for hours of work.
Very basic
Fierocious1, you still haven't explained why you know better than the engineers at Roll Line, Sure Grip, or Rollerbones who recommend the use of bearing spacers and supply them directly themselves, often including them with the wheels themselves. You also completely ignore the fact that all three of those companies will simply supply bearing spacers which are already perfectly sized for their bearing seat: precisely. Other threads in this forum list the exact measurements. Nobody needs to sit and make custom spacers unless they want to. Nobody needs to "test" your cockamamie denials of reality. We can simply just believe the manufacturer's own engineers and ignore you & yours as some guy who apparently doesn't care to get some performance from his/her setup and appears to be crusading for some ignorant idea that nobody should use spacers because you say they aren't worth it.. Go buy you some Impala skates. They agree that you don't need spacers, and are hella cheap, lol. Like someone said earlier, if engineering is so irrelevant and you know so much better I'll look forward to seeing you at nationals with a strap on set of skates with metal or wooden wheels. No problem right? What do those stupid engineers know?
Honestly, the bearing spacer thing is something I learned back in my BMX days. When you get a bottom bracket (the part the cranks go through in the frame) it comes with 2 bearings and a spacer. I always tossed those and tightened the bolts to where it “felt” smooth. I would then have to constantly adjust the bolts because they would back out. If I tightened them all the way they cranks wouldn’t spin or would spin poorly. I never put it together that the reason for this was lack of spacer! The exact same logic applies to skate wheels, if you don’t run a spacer between the bearings and you tighten the nuts all the way you will create excessive side load on the bearings and you will cause them to bind. If you have the correct spacer you can generally tighten the axle nuts as much as you like and the wheel will still spin freely. Take out the spacer and tighten the wheel the same amount and you will see that it doesn’t spin too well. The spacer gives the inner race of the bearing a stop to press against when the nut is tightened, it prevents side load and binding. I can’t speak to the axle stiffness aspect but for proper bearing performance spacers are absolutely essential.
Nice, chiliphil1 that is a great perspective. I used to do BMX also and I would also completely agree with your assertions. I think BMX axles do not have to worry about bending much because, as you point out, they have a nut on both sides of the axles holding the forks down. Skates have the additional challenge of unsupported axles which flex a lot due to being secured only on the plate-side. Race-binding and lack of bearing face alignment creates torsional, axial, or other non-radial stress on the balls and can slightly or greatly decouple balls from the rolling faces in the annulus. As you also point out, this reduces bearing performance fairly noticeably for most elite skaters. So, in skates, my guess is that keeping the axle straight is even more challenging than on a bike and thus the need for spacers being paramount for ideal performance. Bearing spacers help in both cases from an engineering perspective.
I don't over tighten axle nuts, i use flips.... lol spacer that...
Having had a wheel come off my quads rolling Kryptonics 78A 70mm wheels twice this year (still have pain from the first fall, the 2nd time I was just lucky I was standing still on grass), I realized I need to do something to keep the nylock nuts from coming off. The nuts on the left side of your quads can work off if there's friction against the spinning bearings. If I can lock down the nylocks (which I hear you can do IF YOU USE SPACERS), that should solve wheel-coming-off-problem. I just ordered spacers. Meantime I'm using thread locking compound to keep the nuts on solidly. chiliphil1's explanation above seems to explain it well enough.
My other accident this year was due to king pin shearing off at my Sure Grip Jogger plate, the front wheels hurtling ahead of me and my crashing to asphalt. Still working on recovering from the finger sprain. Figure I better swap my king pins more frequently
Watched a video today that explains spacers pretty much the same way chiliphil1 did, and solidly demonstrates the ins and outs. It's by a skateboarder, but would seem to apply to quads, well worth the watch:
Skateboard Bearing Spacers - What's the point?
https://www.youtube.com/watch?v=M5oV7q3u9so&t=205s
Never had a nyloc come off. Did find them loose from time to time but replaced them before skating. Love my flips