Front Hubs

[mantaray]

Well after a track day at Brands last sunday my n/s/f hub has destroyed it self , so i have upgraded both of em with Caterhams kit which seems to be new hubs bearings and shafts , but no instructions , i presume this upgrade is just the newer style 2003 bearings and hub .
Well they are all now fitted , but i dont know the torque setting of the main hub nut , i know FT will do but be nice to do it correct . Many thanks

Edited by mantaray on Friday 13th November 14:22

[Epimetheus]

mantaray said:

i know FT will do

It's won't actually. You tighten up until there is no play.
And I hope you pressed the bearings in properly . . .

[mantaray]

Hi , i to hope i pressed em in properly , they didnt seem to be able to go in wrong ? but i could of done , as for the setting on the 33mm nut anybody know ?

[Incorrigible]

As he said ^^^ tighten it until there is no play in the bearing, it shouldn't need to be much more than finger tight then back off to the nearest 12th of a turn and fit the split pin

[normalbloke]

Epimetheus said:

mantaray said:

i know FT will do

It's won't actually. You tighten up until there is no play.
And I hope you pressed the bearings in properly . . .

I assume you were talking about the bearing races being pressed in, the bearings themselves are not an interference fit.

Edited by normalbloke on Saturday 14th November 23:34

[David Long]

I think the 'official' pinch on a new bearing is 8nm, if you've got a torque wrench that goes that low. Check them after a few hundred miles as they will loosen up.

[BertBert]

David Long said:

I think the 'official' pinch on a new bearing is 8nm, if you've got a torque wrench that accuratelygoes that low. Check them after a few hundred miles as they will loosen up.

I wouldn't use a talk-wench on the front hubs. The nip them up and loosen to the nearest place for the splitpin through the castellated nut is the time honoured method. With the wheel back on you can afford very slight play. You cannot afford an over-tighened bearing!

Bert

[David Long]

BertBert said:

David Long said:

I think the 'official' pinch on a new bearing is 8nm, if you've got a torque wrench that accuratelygoes that low. Check them after a few hundred miles as they will loosen up.

I wouldn't use a talk-wench on the front hubs. The nip them up and loosen to the nearest place for the splitpin through the castellated nut is the time honoured method. With the wheel back on you can afford very slight play. You cannot afford an over-tighened bearing!

Bert

Don't want to start an argument here, but what you are suggesting is the traditional method that does not take full advantage of modern bearings.



To reduce loads on the bearing, and prolong it's life, you need a slight preload. If they are slack the load is not spread evenly across the rollers and the life is reduced.

[BertBert]

As I understand the method (as taught me by my Dad!) does give the pre-load, so we are in full agreement. The reason for suggesting it is that very few people at home will have a talk-wench accurate enough for that method.

BErt

[normalbloke]

BertBert said:

As I understand the method (as taught me by my Dad!) does give the pre-load, so we are in full agreement. The reason for suggesting it is that very few people at home will have a talk-wench accurate enough for that method.

BErt

Don't panic, we are used to rebuilding Jeep diffs.So a teeny torque wrench is available as we use them to set preload on the pinion shim stacks.
Also,any cycle shoip will sell torque wrenchs that go that low and usally have them on the shelf.

[Incorrigible]

What's the scale on the graph how tight is 0.1 ?

[David Long]

Incorrigible said:

What's the scale on the graph how tight is 0.1 ?

I don't know what the scale means for sure, but it is probably mm. You could work out the angle to rotate the nut from the thread pitch, but life's too short.

I think we are in agreement that we need some preload (that's a bit more than finger tight). Less preload is safer than too much. A bearing that is only finger tight will have a reduced the life - by about 25%, which may still be many years on a Caterham.

[BertBert]

Yes we are in agreement! If you do a finger tight bearing and put the wheel back on and rock it top to bottom (still in the air), you will feel a lot of play with a finger tight bearing!

Regarding the talk-wenches from bikeshops has anyone any experience in how accurate they are?

Bert

[Incorrigible]

David Long said:

Incorrigible said:

What's the scale on the graph how tight is 0.1 ?

I don't know what the scale means for sure, but it is probably mm. You could work out the angle to rotate the nut from the thread pitch, but life's too short.

I think we are in agreement that we need some preload (that's a bit more than finger tight). Less preload is safer than too much. A bearing that is only finger tight will have a reduced the life - by about 25%, which may still be many years on a Caterham.

No worries, I don't think it'll affect my life massively

Interesting non the less

And I know it's pedantic and everyone knows what they're talking about but "talk wench".... please, it's just too Colin hunt

Edited by Incorrigible on Monday 16th November 00:05

[Dave J]

I doesnt matter anyway, as you tighten up to the prescribed 9nM and then find that the thread in the nut is too coarse to maintain that preload whilst threading through the split pin, so you have to make up some shims to do the job properly.

Quite why Caterham specifid that thread is beyond me ...

[mantaray]

Thanks for the help people , well my nice new shiny hubs are now fitted , so much better than the old taper bearing style , and seem so much stronger .
It does seem odd to have a huge 33mm nut and have it really not much more than finger tight , but what do i know i build off road jeeps 33mm nuts are small

[Incorrigible]

Are the new one not a taper roller bearing then I think we all assumed that you just had the new style hubs (which are very similar to the old style apart from a more subtantial stub axle and lrger outside taper roller bearing)

[mantaray]

No they are what i would call timkin bearings , the inner or outer are not tapered , just pressed into the hubs .

[The Wookie]

Not sure exactly what bits you've replaced, but worth pointing out that some racers with about 2004/5 vintage cars who have replaced hub assemblies have noticed that the new hubs supplied by Caterham have been metric and the studs are fractionally longer. Older wheel nuts are thus not long enough, and run out of thread and bind against the inside of the cap before they've got a decent purchase on the wheel. The effect is that torquing up the nuts results in a sturdy wheel nut that isn't actually holding the wheel on properly.

Fixed with either open nuts or newer, longer items.

[BertBert]

who's colin hunt?
Bert