# There's nothing wrong with square taper



## Creakyknees (Sep 21, 2003)

Ok tech heads, here's your chance to convince me otherwise. What's so great about BB30 or any other standard?

I'll go first. Here's what's good about square taper:

- It's truly a standard (not just a marketing term); millions of bikes and BB's were built for it. I'd guess more are still on the road than all the other "modern" standards combined. 
- It's simple to work on, especially with cartridge BB's. No torque wrenches required, only 2 tools that are in every basic toolkit
- Adjustment? What adjustment? Install and pedal.
- Stiffness? You stomp on the pedals and the cranks move. I've pedaled noodly steel bikes with square taper and stiff fat alu bikes with BB30 and I see no difference in stiffness, I hear no difference in chain rub. Where's the beef? 
(Besides which, there's the whole debate over whether stiffness really matters but that's a whole other thread) 
- Cheap. Get a Shimano UN54 for $20. Not nice enough? Really, it'll last forever.. but ok, get a Dura Ace for $50.
- Ubiquitous. Walk into any LBS in the country, they will have something in stock that fits a 68mm English thread BB. Try that with your outboard bearings (assuming you even know which particular model you need)

So what's so great about these other standards, hmm?


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## rx-79g (Sep 14, 2010)

Creakyknees said:


> Ok tech heads, here's your chance to convince me otherwise. What's so great about BB30 or any other standard?
> 
> I'll go first. Here's what's good about square taper:
> 
> ...


Off the top of my head:

There are multiple square taper standards.
It is difficult to tell what spindle length you need for a given set of cranks. Also, some are asymetric.
You should use a torque wrench on square tapers. You can install other systems without one.
Sloppy chainline standards.
There are fewer standards in the new BBs than the old ones.

Like aheadsets, the new BBs are lighter, stiffer and use larger bearing. There is nothing "wrong" with square taper, just like there is nothing wrong with DT shifters, loose ball bearings, center pull brakes, quill stems, 531 frames, tubulars, nutted axles and Brooks saddles.

But if you are going to buy a lightweight frame with a carbon fork and $1500 component group, why would you combine it with older, heavy tech instead of the components it was designed for, as you suggested in the other thread?


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## Creakyknees (Sep 21, 2003)

rx-79g said:


> Off the top of my head:
> 
> There are multiple square taper standards.
> It is difficult to tell what spindle length you need for a given set of cranks. Also, some are asymetric.
> ...


These are interesting points but I think you need a bit more clarity.


There are multiple square taper standards.
- 2, right? Campy/ISO and Shimano / JIS. 
... how many different sizes and formats of splined and oversized and various outboard configs are there? 

It is difficult to tell what spindle length you need for a given set of cranks. Also, some are asymetric.
- Pshaw. For road bikes there are 2. Double and Triple. 

You should use a torque wrench on square tapers. You can install other systems without one.
- "should" - sure, I suppose, but generations of mechanics have done just fine without them. And, you "can install" square taper without one.

Sloppy chainline standards.
- not even sure what this means.

There are fewer standards in the new BBs than the old ones.
- really? BB86. BB30 press fit, BB30, Cartridge/ISIS, Conversion Kit(s), MegaExo, PowerDrive... I'm sure I'm missing a few

Like aheadsets, the new BBs are lighter, 
- this is generally true; by a factor of grams, if you exclude the weight of the crank axle. Whether it matters is a different conversation.

Stiffer
- as measured in isolation in a test rig, perhaps? On the bike, there is no noticeable or meaningful difference

And use larger bearing. 
- so? 

There is nothing "wrong" with square taper, just like there is nothing wrong with DT shifters, loose ball bearings, center pull brakes, quill stems, 531 frames, tubulars, nutted axles and Brooks saddles.

- thank you for conceding my point. 

But if you are going to buy a lightweight frame with a carbon fork and $1500 component group, why would you combine it with older, heavy tech instead of the components it was designed for, as you suggested in the other thread?
- Suppose for a moment that the designers don't really care about anything beyond selling the bike. And they know they are competing in a commodity market, where there is really no difference between the old stuff and the new stuff (as you've conceded). So, as car makers learned a long time ago, you have to invent new things that you can claim are new and improved, but really are only different.


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## dcl10 (Jul 2, 2010)

What is so great about them?!

Well for one, when the bearings seize up with a square taper what happens? You can't turn the cranks anymore, but with BB30 your bb shell is conveniently turned into makeshift bearing race. This is a double bonus with BB30, because with the bearings being so exposed they fail with an almost illogical frequency. Plus these are hard times for bike manufacturers, if your bb shell last forever you'll never buy a new bike, and they would go bankrupt. Then everybody would be out of a job you heartless bastard.

BB30 is defiantly stiffer, my new bikes have BB30 and compared to my old steel trek that has square taper the difference is noticeable, and I attribute this to BB30 more than 20 years of advanced composites technology. Plus I just "feel" like they are stiffer. I mean some people were skeptical of ceramic bearings too, but I tried those and I can go maybe 2-3 mph faster with them. You are also overlooking all the independent study's that Cannondale did, which prove BB30 is stiffer.

Finally, square taper is like having sex with a prostitute. All business and no romance. I'd like to be wined and dined a little you know. I want some nice marketing videos, maybe a fancy website or two. Not to mention when was the last time square tapers marketing department paid for an elaborate and unnecessary vacation to Southern France, and showered with free gifts just so you'd write a good review? Exactly! Plus everybody's had sex with square taper, but BB30? She's young, hot, and have you seen the size of those axles? All your friends will be so jealous.


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## dwgranda (Sep 8, 2009)

There are many different spindle lengths for square taper. Are you saying the spindle length for Campy 10 double is the same as non-campy double? I just bought a square taper BB for Campy and it was 102mm while most of the other ones were 110+.

http://www.sheldonbrown.com/harris/bottombrackets.html

Nothing wrong with square taper though. I have square taper on one bike and gxp on another. gxp cups are cheap too. Only one bolt to tighten the cranks.


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## natedg200202 (Sep 2, 2008)

While we're at it, nothing wrong with toeclips either.


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## rx-79g (Sep 14, 2010)

Creakyknees said:


> - Pshaw. For road bikes there are 2. Double and Triple.


Just in a few years Shimano had spindles for double road cranks ranging from 103 to 115mm. There are at least 4 taper profiles I can think of. Spindles of the same length produced different chainlines depending on how they were centered and which cranks they were bolted to.

I really don't think you have the information to have a constructive conversation about this topic. And I don't feel like being a historian. Trust me, square tapered spindles were not the grossly simple tech you make it out to be.

I am similarly annoyed by all the current systems, but most of the confusion comes from people trying to make different brand parts work together and not reading: "Press fit 30" is not "BB30" which is not "BB90".


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## TomH (Oct 6, 2008)

Creakyknees said:


> - It's truly a standard (not just a marketing term); millions of bikes and BB's were built for it. I'd guess more are still on the road than all the other "modern" standards combined.
> - It's simple to work on, especially with cartridge BB's. No torque wrenches required, only 2 tools that are in every basic toolkit
> - Adjustment? What adjustment? Install and pedal.
> - Stiffness? You stomp on the pedals and the cranks move.
> ...


All this applies to standard outboard cranks, except they're even more available and the good ones are cheaper.


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## UrbanPrimitive (Jun 14, 2009)

dcl10 said:


> Well for one, when the bearings seize up with a square taper what happens? You can't turn the cranks anymore, but with BB30 your bb shell is conveniently turned into makeshift bearing race. . . if your bb shell last forever you'll never buy a new bike, and they would go bankrupt. Then everybody would be out of a job you heartless bastard.


You took the words right out of my mouth.



rx-79g said:


> There is nothing "wrong" with square taper, just like there is nothing wrong with DT shifters, loose ball bearings, center pull brakes, quill stems, 531 frames, tubulars, nutted axles and Brooks saddles.


You just listed half the kit on my bike.

As for larger bearings, check SKF before talking about significantly larger bearing size and improved performance.

*** Full disclosure: I'm down two glasses of port before dinner. I am, as they said, "in my cups."***


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## wim (Feb 28, 2005)

rx-79g said:


> And I don't feel like being a historian.


Aw come on, be one. I'd get to know what those four tapers are and could then rest in the certain knowledge that you do have the information to have a constructive conversation about this topic.


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## Dave Hickey (Jan 27, 2002)

rx-79g said:


> I really don't think you have the information to have a constructive conversation about this topic. And I don't feel like being a historian. Trust me, square tapered spindles were not the grossly simple tech you make it out to be.
> .


Come on....Quit with the arrogance.. There are only two tapers that were regularly used on _most_ road bikes.... JIS and ISO...


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## rx-79g (Sep 14, 2010)

Dave Hickey said:


> Come on....Quit with the arrogance.. There are only two tapers that were regularly used on _most_ road bikes.... JIS and ISO...


And only two spindle lengths, too? Double and triple?

The OP doesn't understand what he's arguing in favor of. You can make this about my response, but that's ignoring the real point of my post - square spindles were anything but standardized.


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## frpax (Feb 13, 2010)

Wait a dang minute here...

You should use a torque wrench on square tapers??? 

I have never, ever done this. And have never, ever had anything even resembling an issue.

The only thing I dislike about square taper is that it seems to be going away...


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## wim (Feb 28, 2005)

rx-79g said:


> And only two spindle lengths, too? Double and triple?
> 
> The OP doesn't understand what he's arguing in favor of. You can make this about my response, but that's ignoring the real point of my post - square spindles were anything but standardized.


In spite of what you say, the real point of your last few posts still isn't quite clear. Ad hominem attacks and changing the subject make it appear as if you're trying to avoid having to defend a claim. Why not just put forth some credible and interesting information? If you don't have any, no big deal either.


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## Dave Hickey (Jan 27, 2002)

rx-79g said:


> And only two spindle lengths, too? Double and triple?
> 
> The OP doesn't understand what he's arguing in favor of. You can make this about my response, but that's ignoring the real point of my post - square spindles were anything but standardized.


I happen to know the OP very well....and he is extremely knowledgeable....His experience is based upon actually riding and racing...........have a nice day....


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## rx-79g (Sep 14, 2010)

wim said:


> In spite of what you say, the real point of your last few posts still isn't quite clear. Ad hominem attacks and changing the subject make it appear as if you're trying to avoid having to defend a claim. Why not just put forth some credible and interesting information?


Fine. Off the top of my head:
ISO, JIS, JIS low profile, Avocet.

I already pointed out the difference in Shimano double road cranks varied between 103 and 115.

You may find that your crank takes a 119 spindle, but is it a symetrical or asymetric?

If you're using a cartridge BB with two adjustable cups, how do you set up chainline without taking the cranks on and off?

If two spindle lengths are listed for FD clearance, at what seat tube diameter do you go up to the larger one?

What is the correct torque setting for tapered spindles? What happens when you overtorque?

Do you need different spindles for 68 vs. 70 BB shells?


It wasn't an attack. You can't have an intelligent discussion about something if one party has only cursory knowledge of the topic. When the response is "Pshaw. Double and triple," it isn't going to go uphill from there.


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## rx-79g (Sep 14, 2010)

Dave Hickey said:


> I happen to know the OP very well....and he is extremely knowledgeable....His experience is based upon actually riding and racing...........have a nice day....


Does that mean he was correct? Just double and triple? 


My knowledge comes from riding, racing and rebuilding an awful lot of BBs in and out of shops. Which really doesn't matter - it's the internet: All of this kind of crap can be looked up. I know most of it because I've dealt with it, but it's all out there for the riders and racers to read.


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## Dave Hickey (Jan 27, 2002)

rx-79g said:


> Fine. Off the top of my head:
> ISO, JIS, JIS low profile, Avocet.
> 
> I already pointed out the difference in Shimano double road cranks varied between 103 and 115.
> ...


You are making it harder than it is....it wasn't that difficult to get a BB in square taper days......

You bought at new crank, you bought the BB to go with it...

Today, you buy a new crank, you buy a new BB to go with it....that is unless you have a proprietary frame in which case, you might not be able to use certain cranks on some frames..


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## Dave Hickey (Jan 27, 2002)

frpax said:


> Wait a dang minute here...
> 
> You should use a torque wrench on square tapers???
> 
> ..



I'm still trying to figure that one out too......I've been wrenching my bikes for a long time and never had the need to use a torque wrench on square tapered BB's


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## rx-79g (Sep 14, 2010)

Dave Hickey said:


> You are making it harder than it is....it wasn't that difficult to get a BB in square taper days......
> 
> You bought at new crank, you bought the BB to go with it...
> 
> Today, you buy a new crank, you buy a new BB to go with it....that is unless you have a proprietary frame in which case, you might not be able to use certain cranks on some frames..


So, if you bought a NOS square crank without a BB, you'd know what spindle it uses? How?

Since advent of splined spindles, the number of spindle lengths as been reduced drastically. By that point, there were only two spindle lengths for Shimano: Double and triple. With the new systems the spindle is built in and you just have follow the instructions. I believe that is simpler.


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## Dave Hickey (Jan 27, 2002)

rx-79g said:


> So, if you bought a NOS square crank without a BB, you'd know what spindle it uses? How?



yep.....it's called the internet......I do it all the time.....


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## rx-79g (Sep 14, 2010)

Dave Hickey said:


> yep.....it's called the internet......I do it all the time.....


Good, then you'll be able to find information about using a torque wrench on crank bolts, too.

My first shop started doing it in '91.


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## wim (Feb 28, 2005)

rx-79g said:


> Fine. Off the top of my head: ISO, JIS, JIS low profile, Avocet.


Thanks, didn't know about JIS low profile and Avocet. But with Jobst Brandt having been in the employ of Avocet and given his many internet lectures on square taper spindles and the crank bolt torques in connection with those, that sounds intriguing. Hell, come to think of it: are you Jobst Brandt?


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## Kuma601 (Jan 22, 2004)

IME, the Shimano square tapers I bought have been excellent. As with all due care, keeping them clean and adjusted properly goes a long way in their longevity. Except for the bearings, I'm still suing a 600EX Ital and English spindle and cups on two bikes.


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## rx-79g (Sep 14, 2010)

wim said:


> Thanks, didn't know about JIS low profile and Avocet. But with Jobst Brandt having been in the employ of Avocet and given his many internet lectures on square taper spindles and the crank bolt torques in connection with those, that sounds intriguing. Hell, come to think of it: are you Jobst Brandt?


Would it matter? Good information is good information. If it's true, it doesn't matter who it comes from.

Internet "credential sharing" is annoying.


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## wooglin (Feb 22, 2002)

I ran square taper cranks with a beer can shim for about 5 years. Can't do that with any of the new stuff I don't think. Not sure you'd ever need to though, so I'm not sure which side I come down on here. Probably on the beer can shim side.


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## wim (Feb 28, 2005)

rx-79g said:


> Internet "credential sharing" is annoying.


Whatever. I was trying to be somewhat amusing and failed. Good night.


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## DIRT BOY (Aug 22, 2002)

rx-79g said:


> So, if you bought a NOS square crank without a BB, you'd know what spindle it uses? How?
> 
> Since advent of splined spindles, the number of spindle lengths as been reduced drastically. By that point, there were only two spindle lengths for Shimano: Double and triple. With the new systems the spindle is built in and you just have follow the instructions. I believe that is simpler.


And thats about the only advantage. How many people whine and moan about their new larger outboard bearings where out every few thousand miles.

Now, let talk about standards. There is the common 68/70/73mm BB shells, Italian, BB30 68 &73 sizes, BB90, PF-30, plus I think Specialized has their BB propriety size. 
Also Shimano is coming up with their new standard. I think its BB95 IIRC.

Certain brands can now only use creation brand cranks, etc.

I have had a few customers already buying cranks and then calling back saying the cranks/BB don't fit their frames. 

Come on. Many of this crap is just hype and ways for manufactures to keep making money. The ex-manager of Syntace USA brought this up when 31.8 stems where coming out. Not about stiffness, etc. Its about saving companions money. Now they make ! stem for road bikes and MTB bikes. Just flip the graphics and poof! MTB or Road stems.

I am have the Princess and the Pea syndrome. I can fell very minute changes in many things. I have a sense for things. I can detect small changes in my position on the bikes, shoes cleats, clothes, etc. Never felt anything form square to ISIS to external to BB30.
NOTHING! Same brand of cranks, same material, etc. NOTHING!!!!

Why I am still riding ISIS road and MTB cranks. Both works great, BB are durable.

The best things about external cranks/BB. Ease of maintenance and installation. Simple tools and easy removal for cleaning. BB wear aster even though they are LARGER bearings.

Hell, I think TOUR magazines had done stiffens tests relating to power loss on BB years ago and showed its miniscule.

yes, I will agree that the whole lengths with the old BB was an issue with chain lines, etc. 
But pre-10 speed bikes were not so sensitive about being off a bit. But sorry, ISO and JIS were basically the norm for most bikes.

Things got a little crazy when Shimano started producing too many version of Octalink and incompatibilities within cranks.

Both have their pros and cons. But square taper BB were and still are fine.


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## MR_GRUMPY (Aug 21, 2002)

Never used a torque wrench on a bottom bracket. Never used a torque wrench on the crank bolts either.
Square taper 102mm Campy bottom brackets were great (unless you let water sit in the shell).
Square taper Dura Ace and Ultegra bottom brackets were almost as good. (if you couldn't find a DA 103mm, an Ultegra 107mm would work)

Pre sealed bearing square taper bottom brackets were the suck, though.


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## rx-79g (Sep 14, 2010)

DIRT BOY said:


> And thats about the only advantage. How many people whine and moan about their new larger outboard bearings where out every few thousand miles.
> 
> Now, let talk about standards. There is the common 68/70/73mm BB shells, Italian, BB30 68 &73 sizes, BB90, PF-30, plus I think Specialized has their BB propriety size.
> Also Shimano is coming up with their new standard. I think its BB95 IIRC.
> ...


I use square on half my bikes.

The history of the BB changes where this:
Splined replaced square because the tubular spindles were lighter (Octalink road only has two lengths).
External replaced internal because the bearings on the splined BBs wore out easily because they were small.
BB30 was conceived to reduced the Q factor of external BBs AND reduce the weight of spindle by making room for an aluminum spindle.
BB90 and others were produced out of silliness. Specialized is BB30.

Really, the point has always been to make things work better while being lighter. I don't know why things should be wearing out quicker, but I suspect it is because people are putting too much pre-tension on them. That has always been a problem when cartridge bearings that are user accessible - the reason Shimano, Phil Wood and other intermal BBs don't have real "cups".

So while it may look like an unnecessary change, the new BBs are part of the all the changes that have shaved nearly a third off bike weights in the last 15 years. And people really dig that.


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## GearDaddy (Apr 1, 2004)

I played the game back in the day with older Shimano stuff, i.e. before sealed BBs, different spindle lengths, blah, blah, blah. Plus, DuraAce stuff often wasn't even compatible with other Shimano lines. You've got to be kidding me.

I finally got away from all that crap and went to Campy. They didn't fool around with a myriad of different specs and it worked great. Sure, it mattered whether you used Record/Chorus vs. Centaur/Veloce as far as having everything nice and true, but everything worked with everything else at least. Thank God I never had to deal with the debacle of Octalink!

Well, I'm fishing for something new and I decided to go the GXP with Bontrager/Truvativ crank route. I love it! It's much lighter, the tolerances are nice and tight, everything is true, and it is easy as hell to install and service. Plus, it's not expensive. I'm sold. It is truly an improvement over square taper.

Now BB30, that's another story. I don't get where there is really any value add over what I've got now. Plus, it kind of burns me that BB30 is going to obsolete all those existing frames out there for no real good reason.


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## TomH (Oct 6, 2008)

Lets be honest with ourselves.. it was and is cake to find the right spindle. Some of this stuff reads like a bad infomercial trying to make something sound 100x harder than it really is. Worst case you might have to make a short phone call or google search to find the size you need for any standard. 

Theres some good points to be made.. the outboards really dont last that long, thats a point worth making. Theres really very little confusion about finding compatible units though.


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## Pieter (Oct 17, 2005)

Yay for square taper! You have just reminded me, the BB on my 1988 Cannondale commuter requires a service.

I am going to pull the cranks off, loosen the NDS cup locknut with a hammer blow to the hooked spanner, and unscrew the cup with an old pair of long nosed pliers. 

I will wash the axle, cups and loose balls in kerosene and soap water and dry. I will inspect the cups (like the cranks, still the OE Shimano 105 after some 75,000km) and reassemble with my nice 1980s vintage white grease I re-discovered on my dad's garage shelf.

The whole heap should go back together in minutes - remember some antiseize on the square - no torque wrench required either...


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## aengbretson (Sep 17, 2009)

Speaking from a pure design perspective:

BB30 makes sense. Use a larger diameter hollow aluminium spindle and you get the same or better torsional resistance with a lighter package. Larger bearings are less sensitive to contamination, although that could also cause people to go longer without servicing them and result in premature failure.

However, hearing people talk about Q-factor of BB30 as a huge improvement... look up the numbers, Cannondale's SISL (144mm) is something like 3mm less than DA7800 and 1mm less than 10spd Campy UT. Sram Red BB30 is 145mm too.

I'll admit to a little bit of vanity and excess spending to put a hollowgram crank on my cannondale, but I can't really tell the difference in performance when comparing it to the Ultegra 6600 crank the bike came with. The weight savings, however, were more significant.

Now for the other "standards" like BB86 and BB90, they improve the stiffness of the frame's BB area but do nothing for the crank. I'd love to see a comparison between crank and BB deflection, to know which one is more significant. Cervelo's BBRight is essentially applying this BB86/BB90 principle of maximizing the frame BB area to the BB30 standard. I'll be interested to see where it goes...

EDIT: But, to get pack to the original point of everything, of course there's nothing wrong with square taper. It gets the job done just as well as newer offerings, has a narrow Q-factor, and only suffers a little bit in the weight department.


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## DIRT BOY (Aug 22, 2002)

aengbretson said:


> However, hearing people talk about Q-factor of BB30 as a huge improvement... look up the numbers, Cannondale's SISL (144mm) is something like 3mm less than DA7800 and 1mm less than 10spd Campy UT. Sram Red BB30 is 145mm too.
> .


But not everyone needs/wants such a low q-factor. This is always blown way out of proportion. I have wide hips for a guys and hate having such a low q-fator.


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## kiroskka (Mar 9, 2008)

dcl10 said:


> What is so great about them?!
> 
> Well for one, when the bearings seize up with a square taper what happens? You can't turn the cranks anymore, but with BB30 your bb shell is conveniently turned into makeshift bearing race. This is a double bonus with BB30, because with the bearings being so exposed they fail with an almost illogical frequency. Plus these are hard times for bike manufacturers, if your bb shell last forever you'll never buy a new bike, and they would go bankrupt. Then everybody would be out of a job you heartless bastard.
> 
> ...




Dude, she's only 15. Some obviously think its worth 20, though


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## aengbretson (Sep 17, 2009)

DIRT BOY said:


> But not everyone needs/wants such a low q-factor. This is always blown way out of proportion. I have wide hips for a guys and hate having such a low q-fator.


Agreed that a narrow q-factor isn't always best.

I'm a "one foot in front of the other" kind of walker and runner so I prefer a narrow stance on the bike. However I don't really notice the 3mm difference between my old 6600 and new SISL cranks.

That being said, you can always use longer pedal spindles or shims to move pedals out. It's not as easy to go the other way. However longer spindles produce a greater moment about the crank arm and can provide more deflection (although the forces necessary to bend them exceed the capabilities of nearly all of us)...

Anyway, I'm all for innovation as long as it isn't too factious, in that it produces too many competing "standards". The greater degree of integration is creating that (see: BB30, BB86, BB90, Wilier's press fit, etc.). If every manufacturer uses their own standard for BBs we as consumers suffer.


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## MR_GRUMPY (Aug 21, 2002)

Octalink is my favorite. 
Yes, if you were ham-fisted, you could destroy your crank
Yes, many people couldn't wrap their minds around the DA BB.
Yes, some people tried to put a Road crank on a MTN BB.

My TT bike still has the original DA BB. Smooth as day 1.


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## rx-79g (Sep 14, 2010)

TomH said:


> Lets be honest with ourselves.. it was and is cake to find the right spindle. Some of this stuff reads like a bad infomercial trying to make something sound 100x harder than it really is. Worst case you might have to make a short phone call or google search to find the size you need for any standard.
> 
> Theres some good points to be made.. the outboards really dont last that long, thats a point worth making. Theres really very little confusion about finding compatible units though.


Tom, the origin of this thread was the suggestion that someone with a brand new BB30 frame would be better off using an adapter and installing a square taper BB - three generations of technology earlier.

Square is fine, but it isn't actually better, and it certainly is heavier. They have their own compatibility problems - which I have personally experienced. The point is that square taper cranks aren't a solution to anything - the good old days weren't any better. They are proven old tech, but using adapters to turn a modern BB system into a square taper is not simplifying anything.

Personally, the newest BB I have is an Octalink, because I love Ritchey cranks. When a friend wanted to go to compact cranks, the Rival cranks and GXP BB I installed was impressively simple and smooth to put together. And I didn't use a torque wrench.

There is no reason to villify any system - they all work reasonably well. And the care required to get the right parts is the same care required to get any BB system to work correctly. It is easy to make any mechanical system sound daunting, but the new systems are no more or less complicated than the old ones. There is a weird expectation of cross compatibility between brands and systems that causes half the problems.


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## Mel Erickson (Feb 3, 2004)

Cottered cranks, that's where it's at! Don't need no steenking torque wrench.


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## LC (Jan 28, 2004)

Usually this problem did not happen during the initial install, but when replacing or servicing the bottom bracket.

If you tighten the square taper crank too tight it would split. If you did not tighten the crank bolt enough the square taper would wiggle enough to deform the taper and the crank would loosen. So you would tighten the crank bolt after every ride till the crank splits or the taper is deformed so bad it won't tighten any more. 

Still have a box full of ruined cranks in storage...mostly to remind myself why square taper sucks!


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## MR_GRUMPY (Aug 21, 2002)

LC said:


> Usually this problem did not happen during the initial install, but when replacing or servicing the bottom bracket.
> 
> If you tighten the square taper crank too tight it would split. If you did not tighten the crank bolt enough the square taper would wiggle enough to deform the taper and the crank would loosen. So you would tighten the crank bolt after every ride till the crank splits or the taper is deformed so bad it won't tighten any more.
> 
> Still have a box full of ruined cranks in storage...mostly to remind myself why square taper sucks!



You must have had the old Campy record cranks. They were notorious for cracking there.
Shimano never did that.


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## rubbersoul (Mar 1, 2010)

rx-79g said:


> Tom, the origin of this thread was the suggestion that someone with a brand new BB30 frame would be better off using an adapter and installing a square taper BB - three generations of technology earlier.
> 
> Square is fine, but it isn't actually better, and it certainly is heavier. They have their own compatibility problems - which I have personally experienced. The point is that square taper cranks aren't a solution to anything - the good old days weren't any better. They are proven old tech, but using adapters to turn a modern BB system into a square taper is not simplifying anything.
> 
> ...


I for one believe rx-79g makes a cogent arguement


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## atpjunkie (Mar 23, 2002)

*go to the cx forum*

and hear all the stories of BB30 and such. freezing, seizing, needing replacement multiple times a season
I, an admitted luddite just chuckle at how well my $20 multiple year old UN BBs are. When they die I'll get Woods


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## kiroskka (Mar 9, 2008)

On the grounds of reliability and durability combined, external and press/slip fit system fall quite short in one way or another.

Of course, I'm using the following as a reference.









Please spare me any weigth weenieism and/or stiffness crap; it's redundant, among other things.


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## tihsepa (Nov 27, 2008)

Yah, my old Sugino crank on a Phil BB works good.


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## atpjunkie (Mar 23, 2002)

*as I said in my post*



kiroskka said:


> On the grounds of reliability and durability combined, external and press/slip fit system fall quite short in one way or another.
> 
> Of course, I'm using the following as a reference.
> 
> ...


when my UNs die I will replace with these

pretty much done at that point


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## nigglenoo (Jun 4, 2015)

atpjunkie said:


> when my UNs die I will replace with these
> 
> pretty much done at that point


Have the UNs died yet


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## mambo (Jul 29, 2012)

rx-79g said:


> I am similarly annoyed by all the current systems, but most of the confusion comes from people trying to make different brand parts work together and not reading: "Press fit 30" is not "BB30" which is not "BB90".


...and frame manufacturer tolerances not being what they should be resulting in creaking!


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## mambo (Jul 29, 2012)

aengbretson said:


> Agreed that a narrow q-factor isn't always best.
> 
> I'm a "one foot in front of the other" kind of walker and runner .


That definitely sounds a bit camp!


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## nigglenoo (Jun 4, 2015)

mambo said:


> That definitely sounds a bit camp!


Try not putting one foot in front of the other when walking or running....


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## mambo (Jul 29, 2012)

I was thinking more of this:

https://www.youtube.com/watch?v=ol5Dfs7jqFI


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## cxwrench (Nov 9, 2004)

Friday's thread dredge brought to you by:

nigglenoo and mambo. Thanks guys.


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## mambo (Jul 29, 2012)

CX - one likes to please....


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## nigglenoo (Jun 4, 2015)

cxwrench said:


> Friday's thread dredge brought to you by:
> 
> nigglenoo and mambo. Thanks guys.


Thread necromancy more like, but I really do want to know if atpjunkie's UN square taper BBs have failed yet.

I mistakenly thought the UN55 in my touring bike had gone, removed it and out poured a cup of water from the BB shell (after a week of commuting in heavy rain a month previously), the outside of the BB unit had a tide mark but it was running as smooth as ever, the rough running turned out to be a pedal.

Meanwhile on my road bike the Hollowtech II bearings have failed four times since I bought it in 2011, first failure I replaced with the same Sora/Tiagra bearings, second time some allegedly superior Enduro bearings, then third time some Ultegra/DA bearings which lasted a couple of months longer than the others. My road bike has mudguards and sees much less rain than the tourer.

This time seeing as the chain rings are worn as well I have just fitted a square taper 'XD2' Stronglight Impact copy chain set from Spa Cycles (£35) and Shimano UN54 BB (£10). I promise to report back when that one fails :wink:


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## cxwrench (Nov 9, 2004)

nigglenoo said:


> Thread necromancy more like, *but I really do want to know if atpjunkie's UN square taper BBs have failed yet.*
> 
> I mistakenly thought the UN55 in my touring bike had gone, removed it and out poured a cup of water from the BB shell (after a week of commuting in heavy rain a month previously), the outside of the BB unit had a tide mark but it was running as smooth as ever, the rough running turned out to be a pedal.
> 
> ...


Send him a PM and ask...:idea:


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## atpjunkie (Mar 23, 2002)

cxwrench said:


> Send him a PM and ask...:idea:


nope. I replaced one when I swapped the crank out last year (figured new crank, new BB) and yes I went Square Taper. I figured 1997 to 2014 was a pretty good life. I kept the BB as a keep sake, it still spins. I'm sure with a little TLC I could drop it in a bike and no one would ever know its age.
So that is a cx bike converted to a Rando Commuter (1997). (Fenders, front rack, bag)
2 dedicated cx bikes, both square taper (1998, 1999). 1 Race Face and 1 White Industries Cranksets. 
Road Bikes (2005) 1 Campy Square Taper (right now disassembled for paint) 1 Dura Ace Octalink
Track Bike (age unknown bought used, I'm guessing mid 2000s & not a street fixie, I live near a velodrome) Dura Ace Octalink
MTB 2002, XTR Octalink
all of them doing just fine.

yes I am a Luddite and proud

all are steel except 1 road and the MTB which are Aluminum. I own one CF fork which I will swap for steel ( I have the fork, it needs paint)


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## atpjunkie (Mar 23, 2002)

nigglenoo said:


> Have the UNs died yet


hell no. Heck I don't think I've serviced one of the cx ones since I posted this
I may switch one of my road bikes to a compact. In that case I'll get a White Industries 50/34 or 50/36 crank and a White Industries Square Taper BB.


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## atpjunkie (Mar 23, 2002)

geez, I thought this would fire up after my last comment


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## junior1210 (May 2, 2013)

Guess I'm a cheapskate. I couldn't see myself spending $100 for a square taper BB. For any BB for that matter, but definitely not for square taper JIS. Hell, I flinched when I spent $30 for my IRL BB.


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## atpjunkie (Mar 23, 2002)

junior1210 said:


> Guess I'm a cheapskate. I couldn't see myself spending $100 for a square taper BB. For any BB for that matter, but definitely not for square taper JIS. Hell, I flinched when I spent $30 for my IRL BB.


it would be the last BB you ever buy

so $100 amortized over 25 years is $4 a year

My guess is you'll go through a dozen plus $30 BBs in the same amount of time


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## junior1210 (May 2, 2013)

You might be right. I'm into my 2nd year with the IRL and so far so good.


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## DrSmile (Jul 22, 2006)

Regarding bigger bearing size... is there info on bearing size vs... ball (ahem...) size? Seems to me that the ST balls are bigger than the EB ones. Does this affect the life of the bearings? I would think that the smaller the balls, the shorter the life? I suppose the material that the bearing is made of affects this as well, but as a general rule...

I will say that my Centaur ST BB bracket is still working great after 10 years, although I did have to replace a rusty DS bearing on it with a sealed one.


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