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wheel bearings going bad fast, why?


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I put new front wheel bearings in and put 7 hours on them and they are already starting to be a little wobbly.

they are kinda cheap bearings that I got off ebay, 10 of them for like 45$. this might have something to do with it so im not too sure..

my new rear wheel needs bearings very very bad and I dont know what I should replace them with. I dont want something expensive as im in the mud and pressure washing the bike all the time, I change the bearings often but surely gotta be able to get more than 7 hours before they start wobbling?!

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OK... I can give you two reasons your needing to replace your wheel bearings so offen....

#1- they are kinda cheap bearings that I got off ebay,

#2- I dont want something expensive as im in the mud and pressure washing the bike all the time.

No preassering washing the bearings and but GOOD bearings...

So, now...Go to a bearing house and buy good bearings. First check the hub and be sure it's not worn out....

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Like fender said, buy some good quality bearings, and STOP pressure washing your bike if you can't keep from blasting water past the seals.

It also helps if, before you install the bearings, you pull the little rubber seals off (carefully so you don't damage it) and pack the bearings as full as possible with some high quality water-proof grease. I use Bel Ray saltwater-proof marine grease. Don't forget to put the seal back in place before you install the bearing.

You should also use a torque wrench to tighten the axle. Over-torquing the axle will kill the wheel bearings very quickly. Just as in the rear, be sure your chain tension is set correctly. An over-tightened chain will eat rear wheel bearings like there's no tomorrow.

If you grease the bearings before installing them, and make sure everything is torqued and tensioned correctly, there's no reason you can't get a year out of a set of good bearings, if you'll quit blasting them with the pressure washer.

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hmm, I didnt realize they were so finicky.

I know for a fact that my seals are bad. I damaged them a long time ago and continue to run them, I figured it wont hurt. the problem is that I cant find new replacement seals for DNA rims/hubs so I just left them.

I have done the packing full of grease trick, but im not 100% sure if I have the right grease. I used castrol bearing grease that I picked up for 4$, not sure if its waterproof or not though.

and I dont spray the pressure washer directly at the seals.. not that it matters, water gets in there other ways... so basically what I need is to buy new seals and expensive bearings.. hmm... maybe its cheaper to just keep buying cheap ones and replacing them often?

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hmm, I didnt realize they were so finicky.

I know for a fact that my seals are bad. I damaged them a long time ago and continue to run them, I figured it wont hurt. the problem is that I cant find new replacement seals for DNA rims/hubs so I just left them.

I have done the packing full of grease trick, but im not 100% sure if I have the right grease. I used castrol bearing grease that I picked up for 4$, not sure if its waterproof or not though.

and I dont spray the pressure washer directly at the seals.. not that it matters, water gets in there other ways... so basically what I need is to buy new seals and expensive bearings.. hmm... maybe its cheaper to just keep buying cheap ones and replacing them often?

You don't need expensive bearings, you just need seals that actually seal. It only takes one time of getting water in the bearing to destroy it. I built two sets of wheels using cheap bearings ($4.50 a piece) and have used them for 2 years without any problems. I make sure to pack the seals with fresh grease every time I take the wheel off and I don't blast at them directly with a pressure washer.

As for the seals for DNA wheels, they should be a standard size seal that any bearing shop could get for you. DNA also offers replacement parts on their website, and I believe that they take the same bearings and seals as Talon hubs.

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You don't need expensive bearings, you just need seals that actually seal. It only takes one time of getting water in the bearing to destroy it. I built two sets of wheels using cheap bearings ($4.50 a piece) and have used them for 2 years without any problems. I make sure to pack the seals with fresh grease every time I take the wheel off and I don't blast at them directly with a pressure washer.

As for the seals for DNA wheels, they should be a standard size seal that any bearing shop could get for you. DNA also offers replacement parts on their website, and I believe that they take the same bearings and seals as Talon hubs.

hmm that is interesting.

one thing I would like to clear up though... the word "destroyed bearing"?? to me, that means exploded, or wont spin anymore, or very very rough and wobbly. my bearings never seize, but they sure get wobbly fast. obviously it starts out with a small wobble, now the rear has gotten bad to the point where it almost feels like a flat tire in soft terrain!! I cant imagine if I kept using it much more. its time to buy new bearing and with what KJ said, I think its time to order some new seals and another 10 pack of bearings!

thanks.

the bearings should have seals in them

no not those seals, the hub seals that the spacer slides into.

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arent those shields? THey dont fit tight enough to do much

youre right. the bearing ones are called shields (I forgot)

and the hub things are called seals!

I dont think the shields are quite waterproof, I assume thats why you want them packed full of water proof grease. the hub seals + spacer should seal almost damn near perfect so normal riding water shouldnt get in... but if you blast at it with a pressure washer it will get past, I think.

either way, I dont think its water that is causing me to get wobbly bearings... I took it on like 2-3 rides and the wobble has already started again! its not the hub either. I think it might be the axle, I also think it might be my forks (long story/problem)

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I thought it was the oposite

on the bearing itself there's a seal

on the hub there's a dust shield, it's not water proof or dust proof, it's just to keep the majority of dirt from having full access to the bearing

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hmm that is interesting.

one thing I would like to clear up though... the word "destroyed bearing"?? to me, that means exploded, or wont spin anymore, or very very rough and wobbly.

I consider a bearing to be destroyed when it no longer works as designed. Having significant play would be considered destroyed in my book. If your seals are bad then dirt gets into the bearings when water goes in. This dirt grinds away at the balls and the races until there is significant play in the bearing. It doesn't take much wear to the balls and races to cause a fair amount of play in the wheel.

I thought it was the oposite

on the bearing itself there's a seal

on the hub there's a dust shield, it's not water proof or dust proof, it's just to keep the majority of dirt from having full access to the bearing

Nope, the rubber part that presses into the hub outside of the bearings is the wheel seal. Many bikes come with open bearings from the factory, so this is the only thing preventing water and dirt from getting in the bearings. There are also "sealed" bearings, and "shielded" bearings, which are very similar to eachother. Neither of these are a perfect seal around the bearing, but a "sealed" bearing along with a good wheel seal make the best combo.

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hmm, so it seems like those seals are actually a big deal!! I figured they were pretty chintzy and didnt do anything or they wore out in 2 rides but maybe theyre actually pretty useful pieces! it doesnt help the bearings either when I damaged the seals while installing them back into the hub and they werent perfectly flat a few months ago.

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Is the spacer that goes between the bearings in good shape? If the ends of the spacer are mushroomed even the slightest bit, you will get thrust pressure on the bearings and destroy them.

yes im pretty sure both ends are nice and flat, not mushroomed at all.

and I checked, the spacer is definitely in the right side... its almost impossible to mix them up.

also, the inside piece that goes in between the 2 bearings inside of the hub im pretty sure is in the proper way... if it was the other way the front rotor would be like an inch off of the brake caliper.

I think it might be the horribly damaged seals + theres no grease in them that causes them to fail so fast.

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Not to try to insult anyone's intelligence but proper installation is important too. When tapping any bearing into place you have to remember to only drive on the part of the bearing where it seats into the hub. In this case the outer race. If you hammer it in using the inner race you have definitely shortened it's life.

Many automotive front wheel bearings rely on the bearing seals alone and last a very long time, like 150K miles or more.

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Many automotive front wheel bearings rely on the bearing seals alone and last a very long time, like 150K miles or more.

Yes, but they don't see mud and water like a dirtbike, let alone direct blasts from pressure washers...

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If you hammer it in using the inner race you have definitely shortened it's life.

guilty

Yes, but they don't see mud and water like a dirtbike, let alone direct blasts from pressure washers...

yeah but what about wintertime (some people on TT dont get that...) but insane amounts of salt + snow/slush/water 24/7 for 5 months of the year is the same, or more than a few mud puddles in the bike isnt it?

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I've been fussin with MC wheel bearings since the sixties and my advice for long life is:

The factory hub "seals" or "shields" are a placebo, and most OEM bearings are not sealed.

Proper installation is important for life. Bearings will be damaged if any sharp or high pressure is applied to the the inner race to remove or install the bearing.

There are many grades and quality levels for small metric bearings and OEM bearings are the most expensive and lowest quality.

Buy sealed bearings from an industrial bearing house, they are in almost all metro areas. I've paid as low as $2.50 and as high a $7 for sealed bearings and the cheap Indian bearings have lasted as long as the more expensive ones. The more expensive bearings are usually closer tolerance and/or for high speeds, not required for wheel bearings. Absent too much chain tension, dirt or lack of lube is what usually kills wheel bearing, which is why you buy sealed bearings.The counter guy at the bearing house can advise you on the suitabilty of the different bearings for your application.

Standard metric bearings have a 4 digit code for their size, i.e. 6001, 6203, etc. here are some of common codes used on MCs:

# ID OD TH

6001 12 28 8

6201 12 32 10

16101 12 32 8

6301 12 37 12

16002 15 32 8

6002 15 32 9

6202 15 35 11

6302 15 42 13

6003 17 35 10

16003 17 35 8

6203 17 40 12

6303 17 47 14

6004 20 42 12

6204 20 47 14

6304 20 52 15

6006 30 55 13

If you leave the OEM hub seals in place they will help protect sealed bearings from pressure washer water, also use a cheap electric pressure washer because of its lower pressure.

Hope this helps.

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