To lube or not to lube?

For discussions about bikes and equipment.
landsurfer
Posts: 5081
Joined: 27 Oct 2012, 9:13pm
Location: Rotherham

Re: To lube or not to lube?

Postby landsurfer » 14 Mar 2019, 7:08pm

There is an amazing replacement for the Hollowtech axle .... longevity, low cost and ease of maintenance .. I think it's called "Square Taper axle" ... so i have been told .. ... :)
The Road Goes On Forever

Brucey
Posts: 36763
Joined: 4 Jan 2012, 6:25pm

Re: To lube or not to lube?

Postby Brucey » 14 Mar 2019, 7:22pm

if conditions are right for corrosion in the bearings, then the conditions may also be right for corrosion to accelerate nucleation of a crack in the BB spindle. Once a crack starts in a part like that, it won't take long to propagate in a regularly-used bike. Thus the majority of the fracture could be clean and uncorroded, with only the oldest part of the crack -the nucleation point- manifesting much obvious corrosion.

FWIW parts that never, ever, break are probably built too heavy.....?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

peetee
Posts: 1668
Joined: 4 May 2010, 10:20pm
Location: Cornwall

Re: To lube or not to lube?

Postby peetee » 15 Mar 2019, 2:19pm

Interesting stuff. I still have the crank so i will take a closer look and see if I can find that weak spot.
Current status report:
Back on two wheels in deepest Pastyland and loving every minute. Mission: to enjoy big, bad hills again.

Ivor Tingting
Posts: 856
Joined: 10 Mar 2009, 9:57pm

Re: To lube or not to lube?

Postby Ivor Tingting » 15 Mar 2019, 4:22pm

Well if the bearings corrode through water and grit ingress then seize, how is the crank supposed to turn if the bike is still ridden, except for the spindle itself to turn within the housing of the bearing? The issue here is seized bearings and a failure of maintenance to notice this. Surely when riding you would feel that the bearing was gritty or had developed play or certainly if the whole set up was seized. Bikes need to be properly maintained. Some a lot more than others.
"Zat is ze reel prowoking qwestion Mr Paxman." - Peer Steinbruck, German Finance Minister 31/03/2009.

peetee
Posts: 1668
Joined: 4 May 2010, 10:20pm
Location: Cornwall

Re: To lube or not to lube?

Postby peetee » 15 Mar 2019, 8:47pm

Ivor Tingting wrote:Well if the bearings corrode through water and grit ingress then seize, how is the crank supposed to turn if the bike is still ridden, except for the spindle itself to turn within the housing of the bearing? The issue here is seized bearings and a failure of maintenance to notice this. Surely when riding you would feel that the bearing was gritty or had developed play or certainly if the whole set up was seized. Bikes need to be properly maintained. Some a lot more than others.


This bike is owned by a 'ordinary Joe' who only thinks of maintenance when something fails to work. He is not fine tuned to his machine and has a history of middling bike ownership where a bit of resistance when riding is expected and probably not noticed. As mentioned before, the design of this BB system means that movement between axle and seized cups represents negligible resistance to the legs. To be fair, the hollow tech set up is hardly free-running when new - certainly in comparison to the old adjustable cup set up - and it's impossible to notice that small resistance when pedalling. In practice a under lubed chain presents more drag than a hollow tech cranks axle that is spinning free within its rusted BB bearings. By the time the (noticeable) play has occured the whole crankset is lost.
Current status report:
Back on two wheels in deepest Pastyland and loving every minute. Mission: to enjoy big, bad hills again.

markjohnobrien
Posts: 176
Joined: 4 Oct 2007, 8:15pm

Re: To lube or not to lube?

Postby markjohnobrien » 18 Mar 2019, 9:13pm

landsurfer wrote:There is an amazing replacement for the Hollowtech axle .... longevity, low cost and ease of maintenance .. I think it's called "Square Taper axle" ... so i have been told .. ... :)



Agree: have square taper on most of my bikes and, as I have a proclivity to buy second hand older bikes, all are fine.

However, while I hold that Shimano hollowtech external BB are crap, I have two bikes with Hope bottom brackets which, so far, have been excellent: one has lasted 11 years and one 4 so far...

jb
Posts: 909
Joined: 6 Jan 2007, 12:17pm
Location: Clitheroe

Re: To lube or not to lube?

Postby jb » 18 Mar 2019, 10:31pm

The weakness in the cup & cone bottom bracket apart from the non existent seals, is that its always tricky to have different hardness qualities in the same lump of metal - the crank needing to be tough whilst the ball races needed to be hard. So unless the very best axles where bought it wasn't long before the races started crumbling regardless of grease quality. But being designed for a time when no one would dream of throwing a whole axle away for the sake of turning the pedals 90 degrees and a packet of new balls they were very successful for a long time.
I would bet that for the vast majority of bikes sold, most went to the scrap yard with the same axle & cone set still working so the insentive to improve it wasn't much there.
Cheers
J Bro