What bottom bracket standard is best and why is it 68 iso square

The Hollowtech II style.

Easy to work on with no crank puller required, and if you replace the tension bolt (or get cranks with a hex bolt) then you only need some allen keys to remove them. Wider and larger outboard bearings for strength and longevity. Quite a lot of component options due to being compatible with most other 24mm axle 2 piece cranks and bottom brackets. And lastly, the one thing I hate most about square taper, there's no need to worry about getting the right axle length.

>>959241
This tbqhfam
With bsa68 threading of course

>>959241
I agree. There's also no risk of the BB coming unscrewed on its own.

>>959237
I strongly prefer shimano hollowtech II

Cheap, easy

With the cartridge type I have to buy 3 of them and choose the overall spindle length that happens to work best with my crank, chain ring and wheel of choice

Swapping to a different brand of crank could mean a new bb and a bigger task than needed.

Shimano hollow tech ii compatible cranks 105 5800 and above now feature the no BCD feature so I can buy any chain ring I want as well


All these benefits at roughly a 50% reduction in retail price

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>tfw Hollowtech II on a gaspipe steel road bike

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>>959262
>tfw press fit square taper

>>959262
The designed the hollow tech 2 to fit any Italian or English threaded bike so it's not surprising

>>959237
>Why do people use other "standards"? Why does the industry come out with so many other "standards" ?

As a business, what marketing edge do you have when your uber neato muh grams sweet dear lord mega innovative racing components are exactly like your competitors? Businesses exist to make money, not to unify their super powers to form Voltron.

>>959241
>Wider and larger outboard bearings for strength and longevity

Bullshit. A UN72 will outlast even the best HT BB by thousands of miles.

>there's no need to worry about getting the right axle length.

This isn't a good thing. It means you have no way to adjust the chainline properly if you wish to mix a MTB cranck with road equipments (e.g for a touring bike).

>>959322
Wrong

>Why do people use other "standards"?
because they fell in love with a crank that uses some bullshitformat
>Why does the industry come out with so many other "standards" ?
how else do you keep the people entertainend?

>>959250
That reminds me of another advantage, most bottom brackets can go in 68mm or 73mm shells with the addition or removal of spacers. Also external bearings give the option of BB mounted chain guides, tensioners, and derailers.

>>959322
>A UN72 will outlast even the best HT BB by thousands of miles.
On a road bike, I'll take your word for that and let someone else correct you if it's false. For heavy use it doesn't matter how long the bearings last if the axle bends or the axle to crank arm interface gets fucked up.

>This isn't a good thing. It means you have no way to adjust the chainline properly if you wish to mix a MTB cranck with road equipment
Don't all HT II cranks have the same chainline, regardless of being road of MTB? If they are different you can adjust it with chainring spacers and BB shims. That said even if it is off it's not going to cause major issues, where as a too short square taper axle can mean it's completely unusable.

It's not that hard to measure the spindle length on a ST BB, get a $0.50 plastic caliper and measure it.

Square tapers suck ass though. I've had multiple crank arms fall off and the bearings don't last. I have play on a UN72 on a bike I barely even ride. The bearings are mounted too far inboard which puts too much stress on them especially if you stand up and mash a lot.

Meanwhile the $10 HT BB on my MTB lasts almost a year under horrible conditions almost every day.

>>959350
>It's not that hard to measure the spindle length on a ST BB, get a $0.50 plastic caliper and measure it.
That's alright if you have a BB that already fits.

>>959251
>I agree. There's also no risk of the BB coming unscrewed on its own.
as opposed to which system?
genuine questhin btw

>>959363
Both won't that poster is full of shit.

Only Italian threaded bikes will come in done and cartridge bottom brackets will unscrew it as easily as outboard bearings

>>959363
I'm guessing he's referring to those that don't have reverse threaded cups (NDS I think, can never remember).

Either that or it's theoretically possible for an internal bearing bottom bracket to unthread whilst the crank arms are still attached (would take a shit load of vibration and probably severely worn threads though) where as most external systems have the bearings sandwiched by the crank arms.


>>959371
English mother fucker.

>>959376
You stupid shit English threaded is reverse on the ds

>>959378
I know, hence why I said those that aren't reverse threaded (Italian going by your previous post).

>>959237
>iso

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>>959376
>>959378
>>959381
>>959371
>replying to siegshit

It's funny because he said the exact opposite thing before
>>956086

If you like square taper, SKF makes some DAMN nice ones.

I like Shimano's Hollowtech II a lot - a larger, stiffer, lighter spindle, outboard bearings are a more stable positioning, and it works fine with any old frame.

Of course, if you're moving the bearings further out, the temptation to framebuilders is to make the BB shell a larger diameter and push shell all the way around the bearings. Then you've got a whole lot more width and bond area to for carbon chainstays... And that's where all the new BB "standards" are coming from.

Unfortunately, as nice as two-piece cranksets are, it sucks that you can't play with spindle length anymore, and Q-factor is non-adjustable. They're no where near as mix&matchable. For example, try sticking a modern shimano compact double on a bike with a 73mm wide BB... the Q-factor is too narrow to clear the chainstays, and the spindle isn't even long enough to properly install the NDS crank. Boooo.

>>959472

Er, why would you be putting a road crank on a 73mm bottom bracket bike anyway? Your chainline will be fucked.

I mean, I've done it. I put a compact double crank on my MTB and it worked fine. But I was running it as a 1x.

>>959363
Every other system where the BB isn't sandwiched by the crank arms. Every single one of my friends who ride steel road bikes with square taper BBs, be them English or Italian threaded, have the same issue. Of course if you tighten it properly and grease the threads and whatnot it shouldn't happen, yet it still COULD. With Hollowtech II it's a non-issue.

>>959509
You answered your own question. Yes, the chainline would be bad, unless you were doing something non-standard with it.

One of the downsides of Hollowtech II and similar integrated-spindle/crankarm systems is that they're a lot less adaptable and mix&match-able. It's the price to pay for a lighter and stronger system...

>>959509
>>959535
>chainline would be bad
>implying a 73mm shell doesn't have 135mm dropouts
what

>>959472
>Unfortunately, as nice as two-piece cranksets are, it sucks that you can't play with spindle length anymore, and Q-factor is non-adjustable.

Yep. This is the one advantage to hollowtech

Q factor already went too far when hollowtech became the new thing. Now I assume it's stupidly wide. I stick with my square taper when I can

Here's an awestistic FAQ on narrowing Q on an XT hollowtech crank tho

http://faqload.com/faqs/bicycle-components/drivetrain/xt-m760-761-cranks-shrinking-the-q-factor