Ambrosio Hub Bearings

[vorsprung]

As I went through some floods at the weekend (during an audax) I thought it might be a good idea to take the the rear hub to bits. 

It is an Ambrosio Zenith sealed bearing hub.  There are 4 sealed bearings.  The right axle one felt gritty so I replaced it.  It was a different size in this hub to the last hub I had of this type.  The left axle one still feels plush.  The two in the hub body/cassette holder were wet so I left them to dry out over night.  This morning I twiddled them and they felt rough.

I checked the records for how far this bike has gone since this hub was new.  Only 2000km and only three rides before this weekend that were even described as "damp".   i don't tend to ride this bike in really bad weather and mud.  The audax at the weekend caught me out with the worst conditions for it in years.

I have ordered some more bearings and when they are fitted there will be a lot of additional grease pumped in.  I should have done this when the hub was new I guess.  I broke the last one of these hubs I had with neglect.  But 2000km in mostly dry doesn't seem enough to expect the worse...

I need to build up the Royce hub so I can destroy use that too, so I have a spare

[Paul D]

Dunno about Ambrosio hubs, but the Royce sounds nice!

My (probably useless) tuppence worth is that back in 2006 I decided that I just CBA to strip & rebuild hubs, so I bought a pair of Hope monos for the audax bike. They were used in all weathers for most of my riding until Spring 2009, when I paid about £25 to get the rear serviced. The front is still fine.

[vorsprung]

Hope

I think eventually I will buy a Hope hub

I am adopting the US foreign policy method.  I will do the right thing.  After I have tried every other possible approach

[vorsprung]

Yesterday I ordered up a pack of ten 6901 2RS bearings

I also put the hub back together, with lots of grease.   The only bearing that now feels a bit bad is the inside cassette carrier one.  On a second look the outer cassette carrier bearing isn't too bad.   

I'm going to start building the Royce hub wheel tonight, I think.

[Polar Bear]

Threadjack - sorry.

I have one of these hubs which has done 4000 miles.   I have noticed some noises from the rear, and, a bit of play has emerged.   Can you advise me on any links for servicing, and, does the cassette carrier take the same bearings as the hub please?

[vorsprung]

Threadjack - sorry.

I have one of these hubs which has done 4000 miles.   I have noticed some noises from the rear, and, a bit of play has emerged.   Can you advise me on any links for servicing, and, does the cassette carrier take the same bearings as the hub please?

links no, the site I used is gone now.  I can furnish full instructions

bearings, there are 4 sealed bearings in the hub.  The 2 in the freehub body are 6901 as shown above
The 2 other bearings in my 2007 hub were both 6805 (not sure of the number off hand but bigger ) ISTR
The 2009 model one is 6901 and one is 6805 for the "other" bearings. So no, the cassette carrier does not take the same size

Special tools: you need two 17mm cone spanners and a pair of circlip pliers

[Polar Bear]

Ah right, that's interesting.   Thanks very much indeed.

I had in my mind but I cannot find the info that it was 6001 2RS for the hub and 6901 2RS for the cassette carrier.   I also understand that if it's a Shimano carrier then teh bearings are the same as the main hub.

I'll have to go a bearing hunting   

   

[vorsprung]

Ah right, that's interesting.   Thanks very much indeed.

I had in my mind but I cannot find the info that it was 6001 2RS for the hub and 6901 2RS for the cassette carrier.   I also understand that if it's a Shimano carrier then teh bearings are the same as the main hub.

I'll have to go a bearing hunting   

   

I might be wrong about the "other" bearing size number.  I'll try and remember to take a look tonight, I have one or two unused in the spares box

The bearing that always goes is the inner one in the freehub body and that is a 6901 2RS

If you spot any 6901 for sale that are stainless steel, let me know

[Polar Bear]

Thanks very much, and will do   

[pdm]

Speaking to my local tame wheelbuilder this afternoon about Ambrosia hubs... He seems to think they are fine and last well in his experience - very easy to replace the bearings - you can buy the sealed bearings from any bearing merchant over the counter - they are not bicycle or Ambrosia specific and thus allegedly cheap and easy to replace.
It seems only Shimano and some Campag hubs still use cone and cup bearings.
He is currently building me a new rear wheel with said Ambrosia bearing so I will report back how well it lasted when I have destroyed it. (It is to replace yet another destroyed rear wheel: rim worn, spokes breaking and a 105 hub on its 2nd rim..... He builds the wheels for the cost of the components so it is not worth me building them  )

[vorsprung]

two points

first I was wrong about the bearing number it is a  6001 as you said before, so the hub probably has 3x 6901 and one 6001

second I would disagree with pdm's wheelbuilder about how good the ambrosio hubs are.  They really have almost no resistance to water ingress.  Please read the first message in this thread

[rogerzilla]

Cartridge bearings are not normally all that good at keeping water out - the seals are really dust seals.  Better hubs have some sort of shield to deflect the worst of the water before it gets to the seals.

In practice they last a lot better than they should, and I wouldn't avoid cartridge bearings.

[MSeries]

My Ambrosio fixed hub has cartridge bearings which don't last very long. A winter or so. They are cheap, easy to find and easy to replace though. The hubs are not expensive hubs so can't really complain.

[PhilO]

Cartridge bearings are not normally all that good at keeping water out - the seals are really dust seals. 

Not true (unless you're buying 2Zs instead of 2RSs; Z denotes a dust shield), but the quality of the seal will vary between manufacturers. I'd always buy good brands (SKF, NSK, etc) and research the seal design: NSK do a triple-lip seal, for instance, for which you'll pay a premium and most suppliers will assume you don't want it unless you ask specifically...

Also, people often suggest popping the seals out and adding more grease... DON'T. Or, if you must, only disturb one seal, and mount the bearing with that seal facing inwards (ie, away from the muck). It's nigh-on impossible to remove a seal without damaging it.


<----- Formerly employed as an Engineer at NSK.

[Polar Bear]

The play in the wheel has noticeably increased, as have the accompanying noises.   I have ordered a pair of 6001 2RS stainless bearings from an ebay seller for £2.45 each plus 80p postage.   Will be fettling later in the week.

Without stripping it down I diagnose (risk I know) that it must be the bearing in the main body as the wheel has developed play.  If it was the bearings in the cassette carrier then in my mind the wheel would not have play in it.   

[Polar Bear]

Not as difficult a job as I imagined that it might be.   

Whipped wheel off, removed cassette.

Undid small grub (2mm ak) screws found on the dust seals each end, then they simply screw off.

Pulled off cassette carrier.

Pushed axle through from drive side to non-drive side taking the non-drive axle bearing with it.

Removed non-drive side bearing from axle (simply pulled off) then used axle to drift out drive side bearing - soft-faced mallet and gentle taps.

Positioned replacement drive side bearing and carefully drifted in with a socket and washer.   The washer covered edge to edge of the bearing so that the pressure was evenly spread.   This took a few patient minutes of gentle(ish) tapping.

Pushed axle back through from non-drive side, slid replacement non-drive side bearing over axle and pressed firmly by hand into hub body.

Cleaned and re-greased cassette carrier and ratchet pawls, pushed back on and screwed on dust cover.

Screwed on non-drive side dust cover.   

Replaced grub screws.

Replaced cassette.

All done and working just dandy.   

[vorsprung]

Not as difficult a job as I imagined that it might be.   

Whipped wheel off, removed cassette.

Undid small grub (2mm ak) screws found on the dust seals each end, then they simply screw off.

Pulled off cassette carrier.

Pushed axle through from drive side to non-drive side taking the non-drive axle bearing with it.

Removed non-drive side bearing from axle (simply pulled off) then used axle to drift out drive side bearing - soft-faced mallet and gentle taps.

Positioned replacement drive side bearing and carefully drifted in with a socket and washer.   The washer covered edge to edge of the bearing so that the pressure was evenly spread.   This took a few patient minutes of gentle(ish) tapping.

Pushed axle back through from non-drive side, slid replacement non-drive side bearing over axle and pressed firmly by hand into hub body.

Cleaned and re-greased cassette carrier and ratchet pawls, pushed back on and screwed on dust cover.

Screwed on non-drive side dust cover.   

Replaced grub screws.

Replaced cassette.

All done and working just dandy.   

Sounds like they've altered the design

The two hubs I replaced bearings on (2007 and 2009) did not have grub screws holding in a dust cover
The non drive side bearing does not "simply pull off" an allen key needs to be inserted in the end of the axle to undo the bit that holds it in place

Also in your description you only seem to replace 2 bearings, the zeniths I have have 4.  Two 6001 and two smaller ones inside the freehub body

[Polar Bear]

My hub is probably a 2006 model though externally it looks like the latest images.   It too has four bearings, two in the hub and two in the cassette carrier.   I have only replaced the hub bearings so far.     

[Polar Bear]

I went for a spin on said bike today - the transformation was astounding.

The irritating noises have gone - hurrah!!!   

The bike seems to flow so much better.   These stainless bearings roll right good.   

Also, and oddly, my rear shifting behaved completely today for the first time proper in years.   I'm wondering if the wheel always had play in it causing some issues with shifting accuracy.   Maybe Campag isn't so shitty after all.    

[Paul Smith SRCC]

For anyone struggling to get spares, the UK distributor is Rsi Cycles & Motors. 69 Manor Park Road London NW10 4JX , Tel: 020 8965 2510, www.ambrosio.co.uk.

Paul_Smith
www.corridori.co.uk

[Graeme]

Not as difficult a job as I imagined that it might be.   

Whipped wheel off, removed cassette.

Undid small grub (2mm ak) screws found on the dust seals each end, then they simply screw off.

Pulled off cassette carrier.

Pushed axle through from drive side to non-drive side taking the non-drive axle bearing with it.

Removed non-drive side bearing from axle (simply pulled off) then used axle to drift out drive side bearing - soft-faced mallet and gentle taps.

Positioned replacement drive side bearing and carefully drifted in with a socket and washer.   The washer covered edge to edge of the bearing so that the pressure was evenly spread.   This took a few patient minutes of gentle(ish) tapping.

Pushed axle back through from non-drive side, slid replacement non-drive side bearing over axle and pressed firmly by hand into hub body.

Cleaned and re-greased cassette carrier and ratchet pawls, pushed back on and screwed on dust cover.

Screwed on non-drive side dust cover.   

Replaced grub screws.

Replaced cassette.

All done and working just dandy.   

Sounds like they've altered the design

The two hubs I replaced bearings on (2007 and 2009) did not have grub screws holding in a dust cover
The non drive side bearing does not "simply pull off" an allen key needs to be inserted in the end of the axle to undo the bit that holds it in place

Also in your description you only seem to replace 2 bearings, the zeniths I have have 4.  Two 6001 and two smaller ones inside the freehub body

Do you still have a link to instructions... I'm coming to this for the first time and struggling to remove the drive side 'things that screw on'. I've noticed that a 5mm Allen key fits inside the axel but I'm not sure which way to turn the 'thing that screws on' to remove it. The 'thing that screws on' has a couple if flats and a 17mm cone spanner fits beautifully.

I'm a bit of a novice at replacing sealed bearings.