Possible fix to BB issues (t47 standard)

[Scar556]

http://www.bicycling.com/bikes-gear/previews/first-look-new-t47-bottom-bracket-standard

[RS VR6]

Unfortunately...you need a frame that supports that bottom bracket.

BSA for me. Cheap and easy to work on.

[Scar556]

I believe if u have a metal bb30 bracket frame, it can be threaded to receive the t47 ...  maybe manufacturers will move towards using it in the future?

[RS VR6]

I saw that too. I wonder how many people out there have a metal PF30 frame? Most of the creaking complaints come from carbon frames with PF/BB30 bottom brackets. I think some carbon frames have an aluminum insert. Not sure if those can be tapped.

[cmh]

Chris King fixed everything with the ISIS bottom bracket standard. All the things. Fixed them. A couple years back.

 

Hah, funny, I didn't know about ISIS OverDrive.

I haven't come across a BB standard that I've found to be tremendously creaky, but then again I've got the tools to pull and clean everything on a regular basis. If T47 catches on, then cool.

[SportingGoods]

Agreed. Let's set one BB as a standard and forget all the others. And pick this standard to be threaded (no press-fit).

I have never had any BB issue but my setup is an overkill: BB30 pressfit frame (aluminum insert) with BB30to24 threaded bearings so I can use my old XT cranks. When I ordered my frame I picked BB30 as I thought I would then move to a 30 mm axle crankset but I love so much my XT that I keep it (pretty light too, 608 g w/o rings).

[Carbon_Dude]

Both my carbon frames have BSA bottom brackets, so far no issues.  I take them apart about once a year, clean and re-grease.  Seems to me there is nothing wrong with the old BSA, threaded, standard so I'm at a bit of a loss as to why the other standards were developed other than bike companies wanted to market something new and said it was better than BSA.

[cmh]

Agreed. Let's set one BB as a standard and forget all the others. And pick this standard to be threaded (no press-fit).

 

[Carbon_Dude]

Yep, that about sums it all up.

[Vipassana]

I've been completely happy with the BB30 setup.  I have not had near the issues others seem to have. 

I chased creaking for months and rebuilt the BB like 6 times using every trick I could find.  I would have bet my paycheck it was the BB making the noise.  I was 100% confident as was everyone else who heard/rode it.  In the end, it was the rear hub/axle/dropouts making the noise.  A coating of grease and it hasn't made noise since (the bare aluminum on aluminum was very creaky). Carbon amplifies and obscures sound. 

I have no doubt some have BB creak, but I bet a lot of it is misplaced diagnosis coupled with internet lore/speculation.


That said, I'm all for a lightweight threaded solution with true oversized bearings.  One standard to use all crank/spindle types would be sick.  Make the bearings in the threaded cups replaceable to reduce cost and weight.  Then make them the same bearings we use on the headset!  Ok, ok, maybe that's a bit optimistic. 

[Carbon_Dude]

Why not thread the outside of the bearing itself, and provide some notches to thread the bearing into the frame?  Sound crazy?  Then again, I guess that's basically what BSA is today.

[cmh]

Why not thread the outside of the bearing itself, and provide some notches to thread the bearing into the frame?  Sound crazy?  Then again, I guess that's basically what BSA is today.

The big problem there is working with the steel they use in the bearings - machining in threads and notches for the tool would probably be cost prohibitive, and would likely make the bearing heavier.

That's my guess, at least. Been a long time since I've looked at materials stuff. 

I agree with Vipassana *COMPLETELY* - I've seen several instances where a creak that absolutely, positively had to be coming from the bottom bracket -- was coming from a seat post, a rear wheel, a headset...