Focus bike review and BB30

[Bustedknuckle]

Written on cyclingnews-"Speaking of the BB30 bottom bracket, this represents a change from the 2009 model, negating the need for external bearings and the potential for loss of energy generated by the rider."

Yikes.....

 

[Bobby700c]

Written on cyclingnews-"Speaking of the BB30 bottom bracket, this represents a change from the 2009 model, negating the need for external bearings and the potential for loss of energy generated by the rider."

Yikes.....

Is this your way of saying that you don't rate BB30 over other BB systems?

 

[forty four]

are external bbs bad for some reason. i have them on both my bikes a fuji team issue and a sworks tarmac sl2 that one has some cheap hybrid ceramics buttery though.

 

[ImmaculateKadence]

Yeah I'm confused here. Are you criticizing external BBs?

 

[James Huang]

If I'm reading this correctly, I believe bustedknuckle is referring to the suggestion that external bottom brackets somehow sap appreciably more energy than BB30 ones. Though there is a difference, it's been shown by others to be minimal. The real advantage is reduced weight in most cases.

In any event, I had the text updated this morning so as to prevent any confusion.

 

[karlboss]

Any idea where I can get data on BB types and losses? The increase in size of the bottom bracket region of the frame to accomodate it would also be an advantage.

 

[James Huang]

karlboss,

Velonews did a nice bench test in the print issue a few months ago though it never appeared online and I'm not sure exactly what month it was. Pretty interesting stuff, though. Basically very little differences in stiffness but fairly substantially reductions in weight.

As for the effect on frame design owing to the larger bottom bracket shell, though, I'm not sure BB30 would be all that much different from standard threaded shells right now. Both are 68mm wide and these days, most threaded bottom bracket shells are already more than spacious enough to house a BB30 system.

Greater gains are likely from the variety of wider standards now out there (like Trek's BB90 drop-in bearings and Shimano's new press-fit cups). Those would allow for wider down tubes and seat tubes and more widely spaced chain stays. That being said, though, some of the stiffest frames tested still use standard 68mm-wide threaded shells and straight, non-tapered head tubes...

 

[usedtobefast]

karlboss,

Velonews did a nice bench test in the print issue a few months ago though it never appeared online and I'm not sure exactly what month it was. Pretty interesting stuff, though. Basically very little differences in stiffness but fairly substantially reductions in weight.

As for the effect on frame design owing to the larger bottom bracket shell, though, I'm not sure BB30 would be all that much different from standard threaded shells right now. Both are 68mm wide and these days, most threaded bottom bracket shells are already more than spacious enough to house a BB30 system.

Greater gains are likely from the variety of wider standards now out there (like Trek's BB90 drop-in bearings and Shimano's new press-fit cups). Those would allow for wider down tubes and seat tubes and more widely spaced chain stays. That being said, though, some of the stiffest frames tested still use standard 68mm-wide threaded shells and straight, non-tapered head tubes...

thanks, good to know the 'older' tech is still up to date.

 

[karlboss]

I'll try to dig up velonews and look at their methodology. Stiffness of what is nearly always important. How big are the balls in bb30?

Thanks James

 

[Bustedknuckle]

Is this your way of saying that you don't rate BB30 over other BB systems?

It's my way of saying that 'energy loss due to external bearings' is silly. When CN writes things like that they lose a bit more credibility within an already pretty shallow credibility bowl.

 

[Bobby700c]

It's my way of saying that 'energy loss due to external bearings' is silly. When CN writes things like that they lose a bit more credibility within an already pretty shallow credibility bowl.

Thanks for clarifying - harsh words though!

 

[Sheltowee]

It's my way of saying that 'energy loss due to external bearings' is silly. When CN writes things like that they lose a bit more credibility within an already pretty shallow credibility bowl.

"shallow credibility bowl?" Not. I bought a set of Krysium ES wheels after a review by CN a few years ago and they have lived up to everything stated in the article and more. Now, for a shallow person? Take a peer at a mirror.

 

[Bustedknuckle]

"shallow credibility bowl?" Not. I bought a set of Krysium ES wheels after a review by CN a few years ago and they have lived up to everything stated in the article and more. Now, for a shallow person? Take a peer at a mirror.

Do ya really think you 'lose energy' when you use an external BB type crank when compared to a BB-30 one? Velonews test says no, engineers say no, marketeers say-YES!!