S30 and Ultegra 6800

[dummey]

Putting my new shinny Silvio together and am a bit confused about how the bottom bracket area is suppose to work out. The 6800 BB is 40mm in diameter as opposed to SRAM and Hollowtech's 44mm diameter. There is no way that the BB clamps will fit with any snugness.

Did I miss a memo somewhere about required BB dimensions =(?

 

[jond]

as i understand it ( i have fsa mega exo crankset and bb) the new shimano standard bb is as you say smaller in diameter. shimano sells an adaptor tool so that the common bb tool (sram gxp/ fsa mega exo/prev generation shimano) works with the adaptor tool. i understand if you place two tools one each side onto the bb cups then the silvio bb clamps will compress on them okay. hopefully someone will chime in here that has done exactly this. i have no direct experience doing this. back when john tolhurst the bikes designer was on the forum i contacted him directly about using a full durace build and he thought that clamping onto the tool adaptor would be okay???? your other option is to source a 5700 bb 105 or ultegra or durace with the older diamater from your local bike shop. note that the actual clamping of the bottom bracket is only pinch tight and does not need to torqued extensively.

this issue is why i did not go with a durace build. good luck and congratulations on the new shiny silvio. check out the adaptor tool for sure.

 

[dummey]

So the 6800 BB does come with a plastic tool so that you can adapt the standard BB tool to their new smaller standard. I'll post a picture of said plastic tool, but it will probably not meet the needs of being clamped on (not to also mention that it only comes with one).



I may have to just go source a BB with the older 44 dimension. Or maybe switch the build over to SRAM because I just don't know how I feel about building a Shimano bike if their long term plan is to move to a smaller BB.

 

[telephd]

I had this experience with my V20 build. You will have to find a BB6700 or BB7900 to utilize the 6800 crankset. I picked up a spare BB7900 as I was thinking of switching my S30 over to 6800 too. Decided to leave the S30 SRAM as built. Let me know if you have trouble finding a BB.

 

[Robert Holler]

The constantly changing BB "standard" is a real hassle and telephd has the good advice there.

Robert

 

[ratz]

BB "standard"

Yeah might as well have said purple unicorn.

 

[JOSEPHWEISSERT]

Putting my new shinny Silvio together and am a bit confused about how the bottom bracket area is suppose to work out. The 6800 BB is 40mm in diameter as opposed to SRAM and Hollowtech's 44mm diameter. There is no way that the BB clamps will fit with any snugness.

Did I miss a memo somewhere about required BB dimensions =(?

I have two brand new Shimano Dura Ace BB7900 bottom bracket bearings that I can't use anymore because I switched over to a SRAM crankset. I would sell both for what I paid ($25 each) plus shipping to you if you're interested.

 

[Cruzbike Chris]

I have two brand new Shimano Dura Ace BB7900 bottom bracket bearings that I can't use anymore because I switched over to a SRAM crankset. I would sell both for what I paid ($25 each) plus shipping to you if you're interested.

Sent you a PM sir.