Just a thought but braking performance has improved significantly in recent years. As the disc is only on one side of the wheel is this applying a twisting force to the bearing?

Power has also increased ?

Thanks Balilocks this was all I was after if anyone had same problem, like you I have even been to my engineering suplier from my time in Industry for quality bearings.

Quick update son has swopped bike I am going to record dates I replace wheel bearings. Thanks Basil for the images of pair of quality bearings with dust covers removed showing 1 was packed with grease the other bone dry. My conclusion crap manufacture.

What brand of bearing was that?

What is your technique for fitting?

How often are your wheels trued?

How tight do you do rear axle up?

Do you pressure wash after every ride?

Without stating the obvious if a change in bearing cheap vs. quality is making no difference to life then cause of prematur failure is something else?

Edited June 19, 20197 yr by nigel dabster

25 minutes ago, nigel dabster said:

What is your technique for fitting? Heat hub with hot air gun, knock bearing in with socket which is same size as the outer race.

How often are your wheels trued? Never, on any bike. Suppose this could vary bike to bike depending on how true it was out of the box.

How tight do you do rear axle up?

Probably less than I used to on the rear since GG went to Allen key spindle from 24mm spanner. It's never come loose but maybe not tight enough ?

Do you pressure wash after every ride?

Yes but have done for 20 years.

Without stating the obvious if a change in bearing cheap vs. quality is making no difference to life then cause of prematur failure is something else?

Good Points Senor Dabster, see above

Once on a sherco I fitted bearings and actually knocked them in too hard with the spacer being marginally too long. This meant the spacer was pushing the inners races outwards. If I tried to turn one bearing both turned and they were both tight. This obviously wouldn't have helped their lifespan. I ended up taking a bit off the spacer and refitted.

If the spacer isnt exactly the right length, whether it's too long or too short then axially loads are being introduced. Do you clean out the bearing seats to make sure there is no corrosion or dirt holding out the new bearings. Do you check the spacer is tight between the bearings but the bearings aren't pinched? I know a guy who installed bearings without the spacer and they didn't last a day so it has a large effect.

When was hub design changed to accomodate bearing spacers? 

Edited June 19, 20197 yr by faussy

I ride virtually every weekend including a couple S3s and all Normandales etc  -got 3 sets of wheel and maybe change bearings in each once a year or maybe twice in the wheels I use most.

I buy a bag load on flebay 12 for £20 or similar so if it cost me £20 or £30 year. I have a tool to knock out  /drift back in correctly and takes 5 mins to swap.

I run them until they are noticeably rough rather than as soon as you feel any hint of play   -  works out at  less than 50p a trial worst case so can live with that - as said above if you are going through say a set a month just riding weekends then something is probably not right. 

 

 

Anyone have any vendors and part numbers for SS bearing for the 4RT and 300RR?

Google 6004 2rs stainless.

I can state my empiric observation that there is no rule, sometimes the wheel bearing last "for ever" and sometimes the got bad after a couple of rides.

I have used OEM, Aftermarket, NoName and first class industry standard, all the same.

 

 

I've been through quite a few bearings in my Montesa 4 Ride, more so than on my previous true trials bikes, i put this down to riding more streams, and LOTS of pressure washing. I think it's always slight surface rust that has begun the degradation, that's then lead to actual play in the bearing. I've swapped to Stainless bearings, so far they've lasted longer. I wouldn't say this is conclusive tho!

Be interesting to see the cost / durability  stainless bearings - ie 3 times the price 3 times the life or just less hassle? 

I use stainless bearings and pack with water proof grease this combination seems to work well.

Rusty bearings cause a lot of the problem, which can happen if you pressure wash regularly and the bike stands a while also. stainless bearings eliminate this problem but they do wear just the same as mild steel equivalents, so its still important to keep them well lubricated for longevity.  

One thing I always do is after jet washing my bike I run it round the yard/drive to dry it off before i store it away. Getting rid of the moisture off the bike before you store it really helps.

When I was moto x riding we always ran the bikes up and around after a wash, especially the 2 strokes cause they were prone to main bearings & big ends failing if the bike had stood for a while due to moisture causing rust.