Never assume that a new hub is correctly adjusted

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peetee
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Never assume that a new hub is correctly adjusted

Post by peetee »

I have just had cause to inspect an XT m735a hub and found that the left hand cone and locknut were loose and the both cone surfaces are wrecked. The hub is a year old and has about 1000 miles of use and has never been worked on. Bruceys comments re adjustment of Shimano hubs from new rings true and was the reason I checked this. I wouldn't expect this issue on a cheaper hub never mind an XT. Thanks Brucey, your input is hugely beneficial. I have been in the business for a long time and never realised I knew so little and assumed so much.
Last edited by Graham on 17 Nov 2018, 6:31pm, edited 1 time in total.
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Gattonero
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Re: Never assume

Post by Gattonero »

As a rule of thumb, you never assume anything that is factory-made for mass production. Things that are meant to be adjusted are often adjusted via automatic machines or in a hurry anyway
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
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NATURAL ANKLING
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Re: Never assume

Post by NATURAL ANKLING »

Hi,
So your next new car or television your check every nut and bolt/solder joint :?:
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Gattonero
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Re: Never assume

Post by Gattonero »

NATURAL ANKLING wrote:Hi,
So your next new car or television your check every nut and bolt/solder joint :?:


Things that are meant to be adjusted...
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Never assume

Post by Brucey »

thanks for your kind words peetee.

When it comes to cup and cone bearing hubs they always need adjusting anyway (because the bearing clearance varies with both spoke loadings when the wheel is built and QR pressure once it is installed) and it only takes a few moments to

a) check that the RH cone and locknut are tight against one another and

b) to whack a load of SFG into the hub bearings

before you adjust them correctly.

With those few moments of effort IME the expected service life of the hubs (before intervention is needed or failure is encountered) goes from less than a year to 'several years', if not 'many'. There are similar benefits arising even with much cheaper hubs; many of them are basically OK, but some will clap out anyway, no matter what you do with them.

cheers
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peetee
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Re: Never assume

Post by peetee »

Indeed. I would go so far as to say without these adjustments there is no advantage to spending the extra dosh on an XT as opposed to a, say, Sora. Bit of a con really. Given the attention to detail I have seen on some expensive stock bikes I find it very hard to believe the hubs are routinely fettled when the machines are assembled.
The older I get the more I’m inclined to act my shoe size, not my age.
Brucey
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Re: Never assume

Post by Brucey »

peetee wrote:Indeed. I would go so far as to say without these adjustments there is no advantage to spending the extra dosh on an XT as opposed to a, say, Sora. Bit of a con really. Given the attention to detail I have seen on some expensive stock bikes I find it very hard to believe the hubs are routinely fettled when the machines are assembled.


well that is because (IME) they are not usually touched before the bike goes out of the door.... it is a rare factory/ bike shop that is prepared to make the effort and it is a rare customer that will appreciate it....

cheers
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thelawnet
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Re: Never assume

Post by thelawnet »

peetee wrote:Indeed. I would go so far as to say without these adjustments there is no advantage to spending the extra dosh on an XT as opposed to a, say, Sora. Bit of a con really.


Depends which model of XT, some have aluminium axles, some steel, some have 'quick engagement' (make silly whirry noise), etc. The Sora hubs (apparently the old 3500 models better than the new?) may be better than them depending on your definition of better.

AFAIK on the road side some lower end models may lack some kind of shielding, some use aluminium axles which might save 10g or so (but not necessarily a good thing), and the Dura-Ace has titanium freehub bodies to save 50g of weight, and then you might find ball retainers in the top models, as well as smaller ball bearings & stainless balls (probably not a good thing).

The most expensive one is likely not any better performing than the cheapest one if both are set up and maintained, unless you ride technical trail and need quick engagement. I somewhat like the whirry freewheel and the Tourney-level stuff is missing seals, so I try to get one (for MTB) advertising contact + labyrinth seals.
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NATURAL ANKLING
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Re: Never assume

Post by NATURAL ANKLING »

Hi,
Gattonero wrote:
NATURAL ANKLING wrote:Hi,
So your next new car or television your check every nut and bolt/solder joint :?:


Things that are meant to be adjusted...

I was probably a bit too quick and sloppy with that reply :(
Granted that I wouldn't ride a bike for the first time without checking the skewers, but they are hand done.
Its a sorry state that wheelbearings aren't just so and tight too.
Another example of what is fitted on a bicycle you would never find on a motor vehicle, weight and simplicity ruling design.
Are wheel bearing that require adjustment assembled by machine?

Did the OP have the hub built up?
I think Brucey has said in the past that on building wheels that hubs are checked over for lube and thus clearance.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
Brucey
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Re: Never assume that a new hub is correctly adjusted

Post by Brucey »

I have mentioned this before but once again; it is impossible to build hubs with angular contact bearings that will stay in perfect adjustment when

a) the wheel is built and then when
b) the QR is tightened.

If you have hubs with (deep groove) cartridge bearings then they will (under the same circumstances) have either a sliding fit for at least one of the bearings and/or an excessive (lateral) preload. The radial dimensions of the hub change when the wheel is built too; this also affects preload on catridge bearings of course.

Plenty of cars have adjustable taper roller wheel bearings, and bearing failures on those that don't are depressingly commonplace; same story BTW, preload can exceed service loads because of poor tolerances.

cheers
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NATURAL ANKLING
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Re: Never assume that a new hub is correctly adjusted

Post by NATURAL ANKLING »

Hi,
I wasn't suggesting that you build a wheel without readjusting the bearings.

Maybe hubs should come with loads of slack so the assembler needs to adjust hub bearings correctly.

Many bikes I take apart have tight bearings, which does prove your point about checking them before using them.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
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