When I took the tires and bearomgs off of my ATB I saw some bushings in the center of the tire. The wheel doesn't rotate on it, and its smaller than the inside diameter of the center of the wheel, so I don't really know what its purpose is. Can anyone tell me?

The reason I ask is I want to be able to switch between hard 8 inch PU (smooth pavement) wheels and 8 inch tires (the beach or rougher surfaces). I have all the wheels and bearings I need, but not the bushings. It would not seem difficult to make some but I'd rather avoid the effort if possible.

these are spacers that sit between the bearings..actual purpose?? keep things straight, stuff out?? buggys have them between their bearings as well...i dont think i'd not want a set between my wheels so yea, make some up or you can purchase another set to make the switch fast...i know at least one of my ATB's set up it's aluminum not SS or anything

A machinist could certainly correct me here, but I always assumed they were to keep the bearings from getting pressed too far into the rims. Some bolt set ups allow for a lot of squeezing force to be set up across the bearings and these little buggers I bet act as a resistance to that force. "Spacers" as abkayak is saying.

Thanks, that was what I thought as well, though when I look at the wheels the bearings can only be pushed in so far, so it seems like they would be redundant. Does not seem like it would be hard to make up a set of them, so I'll probably do that.

Quote: Originally posted by Randy

Thanks, that was what I thought as well, though when I look at the wheels the bearings can only be pushed in so far, so it seems like they would be redundant. Does not seem like it would be hard to make up a set of them, so I'll probably do that.

The final thing I'd say on this is that the spacer would contact the bearing cartridge in the middle of the cartridge, while the pressure would be on the outside edge of the cartridge if the spacer wasn't in place. This might set up the wrong sort of forces across the bearings or even increase friction somehow. Something. This standard must have a simple important job to do, otherwise they wouldn't be so universal.

In skateboards/longboards and inline skates (much rarer to see spacer's), the primary purpose is to stabalize the bearing through high-torsional loads. IE reducing excessive movement on sharp turns/curves, or on the board, when most the weight is on an edge. Basically you can ride without spacers (doubly so when there's a built in stop - which not every wheel has...), but it may shorten bearing life/be more likely to cause potential issues of the bearing eating into the wheel. This isn't really a problem on skateboards/longboard or inline skates, as we toss our wheel and buy new ones often... On your mountainboard you don't want the potential issue of having to replace the hub from the bearing having destroyed/eaten into it's seat (the other main reason we almost always use spacers). Basically spacers help with the bit of play in the wheel, and to help make sure to maintain the bearing seat (along with providing a better tunnel for the axle were the bearing to fail). I'll ride an inline skate without them (speed/vert), but I prefer my boards with them. Given side-loads in a buggy, I can't imagine what stabilizing it might be like without them.

EDIT: I just realized I assumed board wheels/hubs made of plastic. I might consider running spacer-less (if I simply lacked on for a day or something) on a metal hub for the board. I once destroyed some cheap 12" scooter wheels (under $5 each) because they didn't have bearing spacers and the bearings migrated, enough it looked like the wheel hub had been drilled out.

Thanks volock. Sounds like I need to either find some more of them, or move them to whatever wheel/tire I will be using.

As described above they are bearing spacers and volock provided an excellent description of their utility. I run them in all my skateboards and longboards. I have three ATBs and none of them have them because they didn't come with them and I can't be bothered to machine them. My oldest set of hubs is from 2006 and still my most used GI Crossairs. They have been ridden and slid hard and have held up well. I'd say use them if you have or can get them but in my experience, on my hubs (Crossairs, Vegas and Tri-Spokes), they have proven unnecessary.

That being said, I think it is something the ATB hub makers should supply with their wheel sets. I put way more sustained side pressure on my ATBs then I do my longboards and I like to slide both (a lot).

B-Roc is right about if it didn't come with them, you're probably okay to get away without them... Funny enough my MBS board did come with them.

Quote: Originally posted by Randy

Thanks volock. Sounds like I need to either find some more of them, or move them to whatever wheel/tire I will be using.

Most skate shops carry a large range/can order what you need. The super cheap spacers can be made DIY, by finding the right round stock and using a chop saw to get a PERFECT 90 degree cut on the sides. The slightly better quality ones (used in motorcycle wheels or better skateboard ones) get made out of solid tube stock and machined out... More mentioning if you decide to go that route than suggesting to go that route

Quote: Originally posted by volock

Most skate shops carry a large range/can order what you need.

That is true but modern skate wheels utilize 8mm axels and I think the spacers are 10mm long whereas channel longboard trucks are 12mm and you'd need a set of calipers to measure the accurate length.

My ATB (a low end MBS) did come with the bushings, as did the 8 inch PU wheels I have. Only problem is the spacers for the PU wheels were designed for a smaller axle. I managed to get bearings that will fit the PU wheels and the axle, but not bushing. These plastic wheels and the MBS tire wheels both are designed so that you can only push the bearings in far enough to be flush with the outside of the wheel, but they did include bushing with both and one has to assume they did so for a reason. The picture shows the shape of the wheel w/o the bushing. BTW - the big PU wheels were salvaged from a scooter called a Slider, which is propelled by pushing the two rear wheel sideways, so the bushing was probably necessary for that.

some wheel sets don't have spacers, the lighter the wheel material make up needs the support, in general it is good practice to have them .... if the wheels are good they really can go without

easy hack around,

copper tubing, pipe cutter + 10min ...measure, start a fraction long, grind to perfection. get one right and the rest are easy.

i have numerous sets of crossairs and they don't have them. those kinda things really pile up! so if you need spares let me know

flexboardz board 9" has them, trampa has them , GI terrantulas had them ....vegas did not(really didnot matter any way).

the spacers offer better performance , but in my case they are hassle prone the get locked on axle and have to be wrenched or beat from the axle, usually powder sand and rust locks them on , so on a field repair or fresh bearing swap it can go hassle heavy sometimes, esp when trying get a session in but bearing failed on start.

Phreerider, out of curiosity why do you say it doesn't matter that Vegas didn't have them? I'm still running an old pair of Vegas, never had a problem but i'm wondering if i'm in for a doozy.

Sorry for the threadjack

Quote: Originally posted by PHREERIDER

some wheel sets don't have spacers, the lighter the wheel material make up needs the support, in general it is good practice to have them .... if the wheels are good they really can go without easy hack around, copper tubing, pipe cutter + 10min ...measure, start a fraction long, grind to perfection. get one right and the rest are easy. i have numerous sets of crossairs and they don't have them. those kinda things really pile up! so if you need spares let me know flexboardz board 9" has them, trampa has them , GI terrantulas had them ....vegas did not(really didnot matter any way). the spacers offer better performance , but in my case they are hassle prone the get locked on axle and have to be wrenched or beat from the axle, usually powder sand and rust locks them on , so on a field repair or fresh bearing swap it can go hassle heavy sometimes, esp when trying get a session in but bearing failed on start.

I disassemble enough, and ride in dry environment 90% of the time (or more), that I've usually lucked out on the corrosion issue. I'd have thought aluminum over copper pipe (I prefer aluminum over steel for the rust reasons). I've never thought of making them with a pipe cutter, I've been too concerned about them being square....

I spaced on the axle size difference... been a while since I've needed new mountain board spacers, as MBS threw me some extras the last time I talked to someone there and ordered something.

Quote: Originally posted by MotoFoo86

Phreerider, out of curiosity why do you say it doesn't matter that Vegas didn't have them? I'm still running an old pair of Vegas, never had a problem but i'm wondering if i'm in for a doozy. Sorry for the threadjack

vegas are for downhill. lateral pressure in kiting wears the attachment of the lateral spokes that connect at wheel drum very quickly. they get a little rattle to them in about 10-20 hours if not immediately and then break, never had any survive that were used. the wheel switch of vegas failure was like this...you stop because one breaks, to start again you must first replace WHICH is a mountain of suck!

and the look ? heres a shot of said issue, the crew down at Jekyll on a N wind ..go to 1:35 and see. before i can ride i need to fix . only a swap out.

https://vimeo.com/33264538

the little hub makes for interesting traction on the move makes a propeller sound at sketchy speed.

Quote: Originally posted by volock

Quote: Originally posted by PHREERIDER   some wheel sets don't have spacers, the lighter the wheel material make up needs the support, in general it is good practice to have them .... if the wheels are good they really can go without easy hack around, copper tubing, pipe cutter + 10min ...measure, start a fraction long, grind to perfection. get one right and the rest are easy. i have numerous sets of crossairs and they don't have them. those kinda things really pile up! so if you need spares let me know flexboardz board 9" has them, trampa has them , GI terrantulas had them ....vegas did not(really didnot matter any way). the spacers offer better performance , but in my case they are hassle prone the get locked on axle and have to be wrenched or beat from the axle, usually powder sand and rust locks them on , so on a field repair or fresh bearing swap it can go hassle heavy sometimes, esp when trying get a session in but bearing failed on start. I disassemble enough, and ride in dry environment 90% of the time (or more), that I've usually lucked out on the corrosion issue. I'd have thought aluminum over copper pipe (I prefer aluminum over steel for the rust reasons). I've never thought of making them with a pipe cutter, I've been too concerned about them being square.... I spaced on the axle size difference... been a while since I've needed new mountain board spacers, as MBS threw me some extras the last time I talked to someone there and ordered something.

everything on the axle is disposable in my eyes , it goes on and goes to failure in about 3-4months (bearing specifically) there is no handling in between . i have mountain of ready to go spares and harvest mountain of dead ones that gets reworked when needed. the GI crossairs go without spacers and they have been the best . even though i flush with fresh water after EVERY ride and lube once the grease is gone they can still get locked on. all my stuff is in a continous state of almost dry or recently wet with salt water.

Quote: Originally posted by volock

Quote: Originally posted by PHREERIDER   some wheel sets don't have spacers, the lighter the wheel material make up needs the support, in general it is good practice to have them .... if the wheels are good they really can go without easy hack around, copper tubing, pipe cutter + 10min ...measure, start a fraction long, grind to perfection. get one right and the rest are easy. i have numerous sets of crossairs and they don't have them. those kinda things really pile up! so if you need spares let me know flexboardz board 9" has them, trampa has them , GI terrantulas had them ....vegas did not(really didnot matter any way). the spacers offer better performance , but in my case they are hassle prone the get locked on axle and have to be wrenched or beat from the axle, usually powder sand and rust locks them on , so on a field repair or fresh bearing swap it can go hassle heavy sometimes, esp when trying get a session in but bearing failed on start. I disassemble enough, and ride in dry environment 90% of the time (or more), that I've usually lucked out on the corrosion issue. I'd have thought aluminum over copper pipe (I prefer aluminum over steel for the rust reasons). I've never thought of making them with a pipe cutter, I've been too concerned about them being square.... I spaced on the axle size difference... been a while since I've needed new mountain board spacers, as MBS threw me some extras the last time I talked to someone there and ordered something.

everything on the axle is disposable in my eyes , it goes on and goes to failure in about 3-4months (bearing specifically) there is no handling in between . i have mountain of ready to go spares and harvest mountain of dead ones that gets reworked when needed. the GI crossairs go without spacers and they have been the best . even though i flush with fresh water after EVERY ride and lube once the grease is gone they can still get lock on. all my stuff is in a continous state of almost dry or recently wet with salt water.

cant believe how much good info is in a thread just about spacers