rear axle bearing spacer

[dlaing]

Looks Great!

New on left, old on right

[dlaing]

Old OEM on left, New Longer Alluminum Alloy one on right.

The ruler is off by about a millimeter and the camera angle is misleading.

Once I buy a proper measuring thing, I'll post some measurements.

If I am ambitious, I'll try to get measurements under torque.

I think the new one is about a half millimeter longer.

[Baldini]

...someone out there must know

...

 

I used to think that too.....but with youth went certainty, I'm only certain now that I'll never know.

 

KB

 

PS: I measured the rear wheel (4.5") I have off Goran... housing to housing = ****mm - EDIT : OH NO !! SEE NEXT POST

[jrt]

THANK YOU KB!!

That's the number I was looking for!

[jrt]

I was quoted about £16

 

 

That's great-this one is a little cheaper and a lot nicer.

 

Oh, and it's really good bread.

[Baldini]

THANK YOU KB!!

That's the number I was looking for!

57707[/snapback]

 

Jason - WAIT ON !!Thought I better check that measurement... I've just looked again & it's a bit shorter than that - sorry to p*ss you about. Vernier is hard to keep square & I wasn't allowing for shoulder on housing...

 

I'll post accurate measure later.

 

KB

[Baldini]

The wheel I got from Goran measures 112.65mm between flats of bearing housings. The spacer that came w/wheel measures 112.85mm.

 

KB

[jrt]

Well, a rough calculation from Young's modulus of compression of aluminum suggests that under about 4000 psi compression (from 100 ft/pounds torque) the change in length of the aluminum piece will be 0.02 mm. Sorry to mix English/Metric units there.

 

Found this interesting site (a calculator for Young's modulus)

http://www.allmeasures.com/Formulae/static...ngs_modulus.htm

[dlaing]

Drum roll please....David trips falls stumbles and can't figure out how to work the cheap arsed $30 caliber.

For example if I read the length of the dial guage inch side of the caliber, the new spacer is 4.44 inches, which translates to about 112.776mm....but if I read the metric side of the caliber, I get a little over 113mm.

The old OEM spacer measures 4.423 inches or 112.3442mm...on the metric side of the caliber I read it as about 112.5.

Then comes the damn gap @#$@%%@#!!!!!

First off I can't tell if the one bearing I have in there is seated or not, so I end up pulling both my bearings. So this freaking project is getting expensive!!!!!

I know the OEM spacer is too short for the gap, but I Measure the gap to be 4.42 or 112.268mm or as I read the metric side, it is about 112.4mm

I pop a new bearing back in and measure again, 4.42 inches!!!!

So maybe my original spacer was not too bad, and when I saw it as being too short, one of the original bearings may not have been seated properly.

 

Anyway the good news is that I put the axle in a vice with a series of spacers to see if torquing down on the spacer would change the length, and I could measure absolutely no change.

So, Young's modulus has been verified!!!

Interestingly I was able to crush the aluminum pipe that I had made my first spacer from, while the high grade alloy that Bob used would not deviate.

Good thing I did not over tighten the axle.

So, the new aluminum alloy spacer may have just saved my life.

A special thanks to Ratchethack for being the first to chastise me for not using tempered alloy!!!!!!!

 

For those who are still sceptical of using an aluminum alloy, keep in mind that the rear brake bracket is also made from aluminum, and it too endures the torque of the axle.

As long as the aluminum is high grade tempered alloy, it should be fine.

So, the bottom line is that the spacer dropped in nicely and was clearly long enough, but not too long.

I added a couple fat O-rings to the OD of the spacer to help center it, and when I reassembled the axle slid through pretty nicely.

 

Thank you everyone for making this possible.

Sorry I could not get better measurements.

I think Baldini is spot on!

[Baldini]

Dave, the gap is a b*td to measure! I have a good quality vernier guage but it's too big to go thru the hub - so I used the depth rod. First it's hard to be sure you're measuring parallel w/hub bore then it's a job to keep the end guage sitting on the flat face of the housing w/o it riding up on the curved section around the corner of the rebate which gives an overlong reading. There's probably a wombat w/ a tool out there'll do the job but clearly neither of us have it!

 

KB

[dlaing]

Yah, I guess the thing would be to find a flat disk about the same OD as the bearing and measure the depth rod against that.

I suppose one could measure with the bearings in place and subtract 28mm for the thickness of the bearings. If the spacer is short, the bearings will seat home, and you will get a good reading.

I thought I was getting good readings against the seated bearing, but once I converted to metric, I was clearly off.

But just by eyeballing, I could see that the OEM space is too short and Bob's spacer is perfect(just a little longer).

One way that you can be sure your spacer is too short is to finger tighten the axle nut and spin the wheel, than torque the axle nut, and spin the wheel. If it spins less easily, your spacer is too tight.

Of course the spacer may still be too short, so it is not a complete test.

For me, the wheel spun fine when tightened, but when I pulled a bearing(for the second time), I could see the spacer was too short.

(The first time the dealer changed the bearing, so I did not get a chance to check it)

I hope this is the last time I'll have to change a bearing!

EDIT FEBRUARY 2007: AFTER TWO TIRE CHANGES, THE BEARINGS AND SPACERS ARE HOLDING UP WELL. BOTH TIMES I CHANGED THE TIRE, I NOTICED THE BEARING SPACER WAS SNUG BETWEEN THE BEARINGS AND THE BEARINGS TURNED SMOOTHLY.

THANKS AGAIN, BOB, JRT, AND ALL YOU POSTERS.

[Baldini]

Yah, I guess the thing would be to find a flat disk about the same OD as the bearing and measure the depth rod against that.

 

That's what I did - it's still a b*std...but least now I've got something perfect to knock home the bearings...

 

KB

[big J]

Jrt,any of those spacers left? Back wheel bearings going again

 

Measured the spacer last time and it looked ok,but it was raining ,maybe my measuring string got wet and stretched

 

I need a new piece of string.

[Martin Barrett]

Jrt,any of those spacers left? Back wheel bearings going again

 

Measured the spacer last time and it looked ok,but it was raining ,maybe my measuring string got wet and stretched

 

I need a new piece of string.

67634[/snapback]

 

Big J, how long did it last. I think I'm going to need a new bearing next week when I change my tire. The slight audible knock has developed in to definite play. On trip home from work(26 miles round) two days ago as I used the rear brake to slow in to the road there definitely was a graunchy noise. I initially thought rear brake pad, but a quick check showed a couple on mm left. A fuller check today on the shop stand indicated the play. It seems to be the bevel box side that has the movement.

One (not sure which side)bearing race had destructed at 6000 miles when the first rear tyre was changed by the dealer, I had the 12000 one done by a little motorcycle workshop in the town. He said the bearings were fine and I'm now at 17,700 and could do with a new rear tyre and it looks like one of the bearings has gone.

 

I'm just debating on how to approach it. Do I take the whole bike to the workshop, Drop of a lose wheel for the tyre change and bearing or do the bearing myself. The last time I did a big bike tyre change myself (1988) I managed to bugger (technical term) the bead, Though having looked at my wheel today I have some spots where the paint has come off the rim but I hadn't notice before but could have been on the last tyre change. I want to keep a good rapport with the workshop for Mot test time because of my RHD headlight, hoping to get away with a £5 to mask up for test and then remove for aesthetic purposes. But last time was £315 for both tyres fitted to the bike

 

I love my bike , but she can be irksome. I suppose not to dissimilar from the wife

[belfastguzzi]

But last time was £315 for both tyres fitted to the bike

67657[/snapback]

 

WHAT! You can't be serious? But then, I know you wouldn't tell a word of a lie.....

 

Take the wheels off and leave them into a fitter. It will be half that price. Don't pay £315 for a pair of new tyres.

 

I've just had a new pair fitted: £179. Tyre prices are going up just at the moment. Oil prices and all that...

 

The hardest part about the bearings will be getting them out. Easy enough to knock in new ones with your famous giant boots. So if you're not sure you might be best letting the shop do them. But again - just give 'em the wheel, not the whole bike. And check where they're getting the bearings from. You don't want to be paying Guzzi prices. A few quid will buy two bearings and then its just the extraction/fitting labour cost. Do both bearings, not just one.

 

Get an accurate measurement of the spacer before the bearings go back. You might want to insert a 1mm shim, or at least be able to contribute to any future threads concerning the variable length of Guzzi axle spacers.

 

Don't forget to admire the rusty water that will have gathered in the needle roller bearing at the bevel box end.

 

I have some spots

67657[/snapback]

You'll need to corespond with JRT about your personal problems

 

I want to keep a good rapport with the workshop for Mot test time because of my RHD headlight, hoping to get away with a £5 to mask up for test and then remove for aesthetic purposes.

67657[/snapback]

Disgraceful. The sooner you Great Britain part of UK Johnnies have to do MOTs at proper Government Test Centres, packed to the gills with computerised machinery, the better.