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Hi.

I have 2 x bottom brackets and crank sets and I want to fit the best one to my best bike.

One BB has Splined Crank arms (And a Truvative crank set) and the other has Square Crank Arms (And a Suntour Duro Crank set)

I'm guessing that the Truvative is best but which is the best Bottom Bracket, in terms of strength and availability of replacement crank sets for the future? And how do I tell what make the BB's are?

Thanks

Fraz
 

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the catalan connection
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be squared

I´d pick square over splined any time. Splined have a stiffer feel (if you notice these things)but they turn on smaller bearings becouse they need more room for the larger diameter spindle, hence develop play much sooner than square ones.
 

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ISIS bbs are notorious for short bearing life, like what&son said: cramming a bigger spindle in the same BB shell means the bearings have the same OD but a much larger ID, so the balls (or whatever other element) are much smaller.

That said, there aren't a whole lot of high quality ST cranks these days, and anything Suntour (at least in the last 10 or so years) isn't one of them.

if it were me, I'd use the truvativ until either the rings or BB wear out, and keep an eye out for a deal on a Hollowtech 2 or some other integrated crank/bb - new stuff is coming out, SLX is replacing Hone and LX, so I bet there are or soon will be good deals on those cranks. The trick is keeping an eye out for deals before something wears out and you need a replacement immediately.
 

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What's "social pace?"
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Not a lot of good square cranks? What about Middleburn or White Industries? Toss one of those on a Phil Wood bottom bracket and you're set!
 

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I think splined spindles are progress backwards. The older square taper BB's are less expensive, last longer, and seem less prone to developing loose cranks. To address some of the problems of the larger spindles mfrs went to outboard bearings, pushing the cranks farther outboard and creating a host of new problems.

Watching the developements in BB's with their new problems, and solutions reminds me of the old lady who swallowed a fly. Like in that case I don't know why.

Just because folks are retro grouches doesn't mean that the new stuff isn't lousy.
 

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dinoadventures said:
Not a lot of good square cranks? What about Middleburn or White Industries? Toss one of those on a Phil Wood bottom bracket and you're set!
check on the difference between "not a lot" and "none." You might be surprised :rolleyes:

From the OPs wording, it sounded like budget was a concern. That being the case Middleburn and White cranks, and Phil Wood BBs are probably out (no one that owns that setup would even consider using a suntour crank and unknown BB even if it was free). For $100 you can't do better than an LX hollowtech 2, IMO.
 

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FBinNY said:
I think splined spindles are progress backwards. The older square taper BB's are less expensive, last longer, and seem less prone to developing loose cranks. To address some of the problems of the larger spindles mfrs went to outboard bearings, pushing the cranks farther outboard and creating a host of new problems.

Watching the developements in BB's with their new problems, and solutions reminds me of the old lady who swallowed a fly. Like in that case I don't know why.

Just because folks are retro grouches doesn't mean that the new stuff isn't lousy.
what problems did the outboard bearings produce? are you talking about the q factor? i never noticed the difference.
 

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Joules said:
check on the difference between "not a lot" and "none." You might be surprised :rolleyes:
I LOL'ed
 

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I Love my Rize
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I have the Deore hollowtech 1 m510 cranks in square tape matched to a UN 73 BB. In my opinion they are the toughest and longest lasting setups going. I stacked up on UN 73 BB while they still could be had. I have 2 new ones on ice for the future but I may never need them by the way my current BB is holding up (5 years old with about 10,000 miles on it) and still feels like brand new. The steel middle and granny rings on the m510 last a loooong time and are as cheap as they come and shift like a dream.
 

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FBinNY said:
I think splined spindles are progress backwards. The older square taper BB's are less expensive, last longer, and seem less prone to developing loose cranks. To address some of the problems of the larger spindles mfrs went to outboard bearings, pushing the cranks farther outboard and creating a host of new problems.

Watching the developements in BB's with their new problems, and solutions reminds me of the old lady who swallowed a fly. Like in that case I don't know why.

Just because folks are retro grouches doesn't mean that the new stuff isn't lousy.
Because square taper cranks are prone to loosening and gaulling. Once it happens, the cranks are done for. Some people disagree, but not everyone is large enough or strong enough to make this happen consistently. I will NEVER choose a square taper BB over a spline or external.

BTW the Octalink (Shimano spline) stuff I had never failed. This is for a 280# guy.
 

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brake jack said:
what problems did the outboard bearings produce?
Sorry for the slow answer, been away. The Q-factor is only a minor factor, though it's interesting to note that only a few years ago low Q-factors were discussed as being of critical importance.

The real issue is that the current outboard designs lack sufficient rigidity and are also very vulnerable to thread tolerance issues. Both factors cause excessive wear and contribute to difficult to diagnose and cure creaking in the BBs. Any qualified bike mechanic with more than 20 years of experience will concur that modern BBs are far more problematic than their predecessors

It's ironic that with all this progress, BBs which 20 years ago were cheap and tended to outlast the bike (or come damn close to it), are now expensive and are among the shortest lived components. Yes, they are lighter, but if this progress, it hasn't come without a cost.
 

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Never trust a fart
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I run a square taper on my hardtail and an external bearing setup on my full squish. Zero problems with either.

But I make sure that everything is checked and tight before my rides.
 

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frdfandc said:
I run a square taper on my hardtail and an external bearing setup on my full squish. Zero problems with either.

But I make sure that everything is checked and tight before my rides.
Do you make sure your lug nuts are tight every time before driving your car? Nothing wrong with checking, I'm just worrying if our standards are too low for reliability.
 

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willtsmith_nwi said:
Because square taper cranks are prone to loosening and gaulling. Once it happens, the cranks are done for. Some people disagree, but not everyone is large enough or strong enough to make this happen consistently. I will NEVER choose a square taper BB over a spline or external.

BTW the Octalink (Shimano spline) stuff I had never failed. This is for a 280# guy.
Neither design is immune to failure, but take it from someone whose been around bikes for longer than I'm willing to admit - on the numbers, the problem rate of the square tapers are far fewer than those of the current splined systems. Not being a retro grouch here, but the tapered square spindle has been a phenomaly reliable system that didn't need "improvement"

The reason for the shift to the current system was to accomodate oversize hollow spindles and their weight savings, not to improve reliability.
 
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