Bottom Bracket standards to avoid?

madmacca
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Bottom Bracket standards to avoid?

Postby madmacca » Wed Sep 19, 2018 10:23 am

I'm starting to construct a long list for my next road bike. I was fortunate that my entry level roadie (when I didn't know any better) came with a Shimano threaded BB, which was largely trouble free, and I easily replaced it after 30K km with a standard toolkit.

Hoping to reduce the long list by eliminating those bikes with more trouble-prone BB's.

So advice as to which BB standards to avoid like the plague would be appreciated. Hopefully based on more than a single anecdote.

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MichaelB
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Re: Bottom Bracket standards to avoid?

Postby MichaelB » Wed Sep 19, 2018 11:06 am

Ha !! Just posted a link to a great article on BB standards !! Here

My suggestion is to also work out what crank you will be using, see if there is a good solution readily available (quality, not price).

The common consensus is to stick with a threaded BB (such as BSA or T47, but the T47 is not yet established ..), and then decide on a crank that will fit that frame.

Oh, and regular servicing too.

For my BSA frame and BB386EVO crank, the suggested BB adaptor (from a respected guy who specialises in quality bearings and does his own BB adaptors, but just not this specific one) was from Hope - the 30mm Threaded BB, but as mentioned in the article linked above, needs a special tool :roll: .

Currently, the BB & Tool are in transit from the UK.

My 5c worth.

What frame & material are you looking at ?

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Duck!
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Re: Bottom Bracket standards to avoid?

Postby Duck! » Wed Sep 19, 2018 1:56 pm

Not all BB systems are standards ("standard" is a very misused term). Avoid proprietary systems such as Trek's BB90, which is dreadful, Cervelo's BBRight etc.
I had a thought, but it got run over as it crossed my mind.

madmacca
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Re: Bottom Bracket standards to avoid?

Postby madmacca » Thu Sep 20, 2018 9:36 am

As I would be buying the bike entire rather than building it up from a frame, and unlikely to swap cranks, proprietary systems per se don't bother me too much. Unless perhaps they are really expensive/difficult to source spares for.

It is BB systems that are prone to noise or early failure, or are difficult to maintain that concern me.

Duck - if it is "dreadful", then I have just struck Trek from my list. Is your objection to BBright that it is proprietary, or that it has specific problems?

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10speedsemiracer
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Re: Bottom Bracket standards to avoid?

Postby 10speedsemiracer » Thu Sep 20, 2018 11:28 am

Having just assisted a friend thru the BS that is Trek BB90, I can only echo what Duck has said. My experience so far with both Cannondale BB30 and Treks BB90 has been less than ideal and personally I wouldn't spend any of my currency on any frame that used these standards as the issue is one of frame tolerance, not necessarily the bearings themselves although Trek have apparently shifted away from Enduro bearings, for reasons unknown.

Not knowing what sort of bike you're looking at, or the $ range, it would be difficult to provide any sort of recommendations..
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MichaelB
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Re: Bottom Bracket standards to avoid?

Postby MichaelB » Thu Sep 20, 2018 3:57 pm

Basically, the 'press fit' systems were primarily a way to reduce manufacturing cost, which then required 'marketing' to prove that it was better/stiffer/faster/saved power/etc/etc.

Whilst press fit BB's are not hard/complicated generally to service or get spares for, the noises that can come from them, and the cost to try and solve them make them a PITA. The more proprietary it is, the less options you have, and these are typically then more expensive.

BSA threaded BB is probably the key in terms of simplicity, reliability and availability.

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rkelsen
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Re: Bottom Bracket standards to avoid?

Postby rkelsen » Sun Sep 23, 2018 8:12 pm

^ I agree, but try finding a new road frame that's not designed for PF these days... it's near impossible.

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baabaa
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Re: Bottom Bracket standards to avoid?

Postby baabaa » Sun Sep 23, 2018 10:18 pm

MichaelB wrote:Basically, the 'press fit' systems were primarily a way to reduce manufacturing cost, which then required 'marketing' to prove that it was better/stiffer/faster/saved power/etc/etc.

Whilst press fit BB's are not hard/complicated generally to service or get spares for, the noises that can come from them, and the cost to try and solve them make them a PITA. The more proprietary it is, the less options you have, and these are typically then more expensive.

BSA threaded BB is probably the key in terms of simplicity, reliability and availability.


This would/could/may have helped...
https://www.bikeradar.com/news/article/ ... ems-45660/

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MichaelB
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Re: Bottom Bracket standards to avoid?

Postby MichaelB » Mon Sep 24, 2018 8:26 am

baabaa wrote:
This would/could/may have helped...
https://www.bikeradar.com/news/article/ ... ems-45660/


in what way ?

Just really a different sized BSA. It is indeed better than the basic pressfit solution, but then misses the point of reduced manufacturing costs. Hasn't been widely adopted yet, so may still not survive.

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ldrcycles
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Re: Bottom Bracket standards to avoid?

Postby ldrcycles » Mon Sep 24, 2018 8:31 am

BB standards to avoid? Any that are unthreaded.
"I must be rather keen on cycling"- Sir Hubert Opperman.

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baabaa
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Re: Bottom Bracket standards to avoid?

Postby baabaa » Mon Sep 24, 2018 8:49 am

MichaelB wrote:in what way ?

Sorry was vague, should have noted in terms of press fit bb squeaking only.

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find_bruce
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Re: Bottom Bracket standards to avoid?

Postby find_bruce » Mon Sep 24, 2018 2:38 pm

ldrcycles wrote:BB standards to avoid? Any that are unthreaded.

Especially rocking horse dung ones like megatech ? :D

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Re: Bottom Bracket standards to avoid?

Postby march83 » Mon Sep 24, 2018 3:13 pm

One of my roadies had a few creaks from the BB30 which was solved with green loctite. Hardly something you want to have to do, but it was a solution that worked so I'm not complaining. This frame has 30000km on it and it doesn't make a sound and it spins nicely so I guess I got lucky.

My cross bike also was BB30 with a SRAM adaptor to bring it down to 24mm. No issues except for occasionally needing new bearings because it saw so much bad weather and water. Again, I guess I was lucky.

My Cervelo roadie with BBRight makes the odd click and crack as I roll up the driveway but then shuts up completely. Other than that I have no issue with it. About 10000km so far.

I have PF30s in my mountain bikes, 1 has an EBB in it and the other has a praxisworks -> 24mm adaptor in it and both have been fine for around 5000km each.

My commuter has a standard 24mm threaded and has had 10000km on a shimano bb with no issue, then I swapped it out for a 30mm BSA30 so I could run a quarq and it has had about the same, again with no issue.

I'm currently building 2 bikes at the moment. A new commuter frame to replace the one I'm using now which I don't really like, and a new cross frame to replace a frame I broke. I think it's an indication of the market - both are BSA bottom brackets. I didn't chase these standards specifically, but I'm reasonably happy that I've got them.
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ldrcycles
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Re: Bottom Bracket standards to avoid?

Postby ldrcycles » Mon Sep 24, 2018 3:16 pm

find_bruce wrote:
ldrcycles wrote:BB standards to avoid? Any that are unthreaded.

Especially rocking horse dung ones like megatech ? :D


VERY especially! :lol:
"I must be rather keen on cycling"- Sir Hubert Opperman.

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Duck!
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Re: Bottom Bracket standards to avoid?

Postby Duck! » Mon Sep 24, 2018 9:49 pm

madmacca wrote:Duck - (snip) Is your objection to BBright that it is proprietary, or that it has specific problems?

My beef is that it's a proprietary system, moreso than any built-in flaws it may have, which afflict Trek's BB90. As a mechanic in a non-Cervelo (or Trek for that matter) shop, it means I can't just grab a standard - in the correct sense of the word - bottom bracket off the shelf and chuck it in. I have to find a (usually) third-party supplier who has a compatible unit in their range and order it in, which extends the time the bike is in the shop.

10speedsemiracer wrote:...... Trek have apparently shifted away from Enduro bearings, for reasons unknown.

Changing bearing supplier won't fix a thing with BB90. The problems lie with the tooling the frames are made off, and changing bearing supplier won't fix anything. If Trek haven't made new, properly-sized BB shell tooling plugs, the system is still f*%^ed regardless of what bearings are in it.
I had a thought, but it got run over as it crossed my mind.

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10speedsemiracer
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Re: Bottom Bracket standards to avoid?

Postby 10speedsemiracer » Mon Sep 24, 2018 10:30 pm

Duck! wrote:......Changing bearing supplier won't fix a thing with BB90. The problems lie with the tooling the frames are made off, and changing bearing supplier won't fix anything. If Trek haven't made new, properly-sized BB shell tooling plugs, the system is still f*%^ed regardless of what bearings are in it.


agree entirely, if the shell inside diameter is off, different bearings won't make any difference. Just thought it was interesting is all and wondering if it's a case of deflection or misdirection on Trek's part (it's not us it's the bearings). Maybe they should be including an industrial-sized bottle of Loctite blue with each Trek frame sold...
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