From square taper to outboard bearings - DISADVANTAGES?

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Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by Brucey »

some of the FSA ones are just rubbish; when the bearings go (which is often) it frequently takes the spindle out too. Not just a case of fitting new bearings, the whole shooting match has to go in the bin.

cheers
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reohn2
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Joined: 26 Jun 2009, 8:21pm

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by reohn2 »

As a derider,I go off what I read on here and what other cyclists I come in contact with tell me,and what I read and hear ain't good from a longevity POV,unless your willing to strip it down when it sees a bit of inclement weather :?

Brucey's just educated me a bit more (yet again :) ) with more OBB stories of woe.
Last edited by reohn2 on 19 Aug 2014, 6:36pm, edited 1 time in total.
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MartinC
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by MartinC »

meic wrote:............I have heard of these split axle types but not seen them in the flesh or pictures. I dont even know who makes them
I would say that is like somebody condemning Square Tapers because of a bad experience with an Octalink or even Cotterpins!..............................


Ah, I guess this a reference to Campag Ultra Torque Chainsets. They still use external bearings the same as Hollowtech II so they're directly comparable in most respects. I actually prefer the Hirth joint solution to a 2 piece crankset 'cos I think produces a more rigid and better aligned joint - which makes sense if the whole point is a stiffer crankset. They also avoid the need to set the preload when you assemble them - not a free lunch though because the preload depends on how accurately the BB shell has been faced. They're more expensive to produce and only come with the more expensive groupsets now.

As an aside to the this debate I can't understand why Shimano moved their low end groups on to Hollowtech I (Octalink) BBs from ST, it makes no sense to me. Like ISIS BBs to me they're a failed experiment and a temporary aberration best forgotten.

Another disadvantage of outboard bearing BBs is that now when anyone types EBB I don't know whether they mean an Eccentric BB (like it always used to mean) or an External BB!
Brucey
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by Brucey »

MartinC wrote: ....Another disadvantage of outboard bearing BBs is that now when anyone types EBB I don't know whether they mean an Eccentric BB (like it always used to mean) or an External BB!


indeed, I prefer 'OBB' myself

cheers
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bensonboo
Posts: 268
Joined: 29 Jun 2009, 7:28pm

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by bensonboo »

JohnW wrote:At the moment, and probably in my ignorance, the only square taper 22-32-44 (ish) square taper chainsets that I know of are the Spa ones. Bless them - they continue to provide a service to cyclists, as opposed to those who see us as cash cows and exploit us for their own benefit.

SRAM still make them, cheap and cheerful but black, one on my mtb as it happens, here's one on eBay, no affiliation btw.
http://www.ebay.co.uk/itm/like/16139108 ... 0&ff14=108
JohnW
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by JohnW »

bensonboo wrote:
JohnW wrote:At the moment, and probably in my ignorance, the only square taper 22-32-44 (ish) square taper chainsets that I know of are the Spa ones. Bless them - they continue to provide a service to cyclists, as opposed to those who see us as cash cows and exploit us for their own benefit.

SRAM still make them, cheap and cheerful but black, one on my mtb as it happens, here's one on eBay, no affiliation btw.
http://www.ebay.co.uk/itm/like/16139108 ... 0&ff14=108


The description says square taper, but the picture shows splined...........but assuming the description is right, I didn't know about them. Are they any good? They're not much cheaper than the Spa, which are Sugino, I understand, and will be decent quality.
beardy
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by beardy »

Two Acera's and one Alivio on this page

http://www.rosebikes.co.uk/products/bik ... cranksets/

but you may well have stumbled on a disadvantage of square tapers, the cranksets are no longer being made and sold commonly enough to remain easily available.
reohn2
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Joined: 26 Jun 2009, 8:21pm

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by reohn2 »

Sorry to continue the thread drift but I have this one fitted to the KONa currently on the for sale board:- http://www.rosebikes.co.uk/article/shim ... aid:667940
A great value C/set though the Q is wider than other road oriented C/sets.

As you were :) .
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squeaker
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by squeaker »

Many, many years ago I was taught that with a dual ball bearing set up (primarily radial loads), the inner bearing races should be clamped onto the shaft, and just one of the two outer races clamped to provide axial location, the other being a light interference (?) fit in the housing. AFAIK external BBs turn this on its head, which is another reason that I am not a fan ;)
"42"
Brucey
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by Brucey »

well in fairness they don't all work in the same way, and nor does the assembly see the same kinds of temperature excursions and shaft speeds that other machinery might.

I quite like the campag and shimano designs; unlike some FSA designs, they both avoid a high risk of shaft damage in the event of corrosion and/or bearing problems, because there isn't a sliding metal-on-metal fit between the bearing and the shaft.

These designs also apply a low preload via an elastically compliant interface; solid plastic in the case of shimano, and a wave washer in the case of campagnolo IIRC. I think that in both cases this is probably adequate to maintain preload for most normal service temperatures.

The main flaws -as I see it- are the accuracy of initial alignment, user unfamiliarity, and the weatherproofing.

cheers
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squeaker
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by squeaker »

Brucey wrote:well in fairness they don't all work in the same way, and nor does the assembly see the same kinds of temperature excursions and shaft speeds that other machinery might.

I quite like the campag and shimano designs; unlike some FSA designs, they both avoid a high risk of shaft damage in the event of corrosion and/or bearing problems, because there isn't a sliding metal-on-metal fit between the bearing and the shaft.

These designs also apply a low preload via an elastically compliant interface; solid plastic in the case of shimano, and a wave washer in the case of campagnolo IIRC. I think that in both cases this is probably adequate to maintain preload for most normal service temperatures.

The main flaws -as I see it- are the accuracy of initial alignment, user unfamiliarity, and the weatherproofing.

cheers


Ah, hadn't examined anything other than FSA :oops: I like the idea of avoiding shaft damage (which all the FSA ones I've looked at had...).

Cheers
"42"
freeflow
Posts: 1637
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by freeflow »

With FSA carbon cranks there is no danger of damaging the spindle. The pedals fall out before you get as far as wearing out the bearings :twisted: :twisted:
Brucey
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Re: From square taper to outboard bearings - DISADVANTAGES?

Post by Brucey »

squeaker wrote: Ah, hadn't examined anything other than FSA :oops: I like the idea of avoiding shaft damage (which all the FSA ones I've looked at had...).


The shimano ones have a sliding fit where the bearings go onto the shaft, but the interface is sleeved with hard plastic. This seems to work fairly well; in theory the shaft could corrode or wear but in practice this doesn't happen often.

The campag ones have the bearings a push fit onto the shaft and a sliding fit in the cups.

With both systems if (when... :roll: ) the bearings fail, new cups and bearings usually sorts it.

cheers
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freeflow
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Joined: 29 Aug 2011, 1:54pm

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by freeflow »

The crud ingress on hollowness Ii could be easily solved with plastic tubes that fit over the BB cups. I'll go see if I can hunt out some appropriately sized silicon tubing.
freeloader
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Joined: 5 Jun 2013, 4:10am

Re: From square taper to outboard bearings - DISADVANTAGES?

Post by freeloader »

Forgive me for going off topic...but below are my observation about the current state in cycling -

1) Profit-oriented manufacturers, companies, shops, web sites and other commercial entities
a) sell or promotes products/services with prime purpose of gaining maximum profit
b) sell or promotes products/services that might not be of the best interest to consumer
c) some of their products/services are of little or no functional benefits to consumers
d) some of their products/services pose potential safety risks to consumers
e) some of their products are proprietary, therefore restricting competition and choice for consumers
f) spend a fair amount of their funds in marketing and influencing consumers to purchase their products, sometimes disregarding functionality, safety etc
g) sometimes provide false/untrue information to consumers
h) sometimes withhold useful/important information to consumers
2) Uneducated and rich consumers
a) base their purchasing decisions on the lightest/fastest/greatest/fanciest items that can fit their inflated budget
b) have no or little concern about usability, functionality, reliability and safety of the equipments they purchase
c) have limited understanding about usability, functionality, reliability and safety of the equipments they purchase
d) usually purchase the "latest and greatest" products that can fit their budget
e) easily influenced by peer pressure, marketing, vanity etc in their purchasing decisions
f) sometimes purchases product that are of little value for their intended usage
g) key target audiences for the 1st group
h) can spot them from a mile
3) Professional cyclists
a) usually have sponsorship relations with the 1st group
b) usually uses products sold/promoted by the 1st group
c) usually do not handle maintenance of equipments they use
d) base their choice of equipments on mostly on performance and sponsorship pressure
e) have little concern over the interest of the other groups except group 1
4) Uneducated and poor riders
a) base their purchasing decisions on their limited budget
b) have limited understanding about usability, functionality, reliability and safety of the equipments they purchase
5) Customer-oriented manufacturers, companies, shops, web sites and other commercial entities
a) sell or promotes products/services to the interest of consumer, at the same time gaining profit
b) sell or promotes products/services that are of value to consumers
c) do not knowingly sell/promotes products/services that pose potential safety risks to consumers
d) do not provides false/untrue information to consumers
e) do not withhold useful/important information to consumers
6) Knowledge-able and experienced riders/contributors
a) have good understanding about usability, functionality, reliability and safety of the equipments they purchase
b) makes rational decisions when purchases cycling products
c) give useful advice, feedback to fellow riders on choice of equipment
d) able to handle maintenance of their equipments
e) not easily influenced by peer pressure, marketing, vanity etc in their purchasing decisions

Unfortunately, the 1st 3 groups are overwhelming in numbers, financial power etc. I can go on and on, but i guess wiser people here already much better ideas ... :mrgreen:
Last edited by freeloader on 22 Aug 2014, 4:27am, edited 1 time in total.
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