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Crank Swap
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I want to swap my stock Rotor crank for an Ultegra 6800 Di2 11 speed crank on my 2015 Cervelo Ultegra Di2 11 speed. If I understand correctly the present BB is 30 and the 6800 crank would be 24. Can someone tell me exactly what parts are required for a straight crank swap. If I want to swap out the BB what else would be required and any suggestions for a BB. Seems like most I have seen are less than $100, but I was told by a bike shop a BB would cost me almost $300. Am I not seeing the correct BB's? Thanks for any help.
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Re: Crank Swap [rebel59] [ In reply to ]
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You have (basically) two options:

1) adapters used with your current BB (it's a PF30 bottom bracket, by the way...in a BBRight "shell" - your frame) such as these

2) a new bottom bracket that installs into a BBRight shell and reduces to 24mm http://wheelsmfg.com/...no-cranks-black.html
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Re: Crank Swap [James Haycraft] [ In reply to ]
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Thanks for the help. Anything special to look for when replacing the bottom bracket?
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Re: Crank Swap [rebel59] [ In reply to ]
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To install

Option # 2 -

http://wheelsmfg.com/...m-bracket-press.html


and 2 of these http://wheelsmfg.com/...wrench-16-notch.html

Option # 1 - you'd need no tools, but you'd need to have an existing BB that is in good shape.

Replacing a bottom bracket is not really a "new DIY'er" type of job. If you do it wrong or poorly it could be either sort of expensive (mess up the BB you're installing, have to buy a new one) or really expensive (mess up the frame you're taking a BB out of, mess up a frame you're putting a new BB in...).
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Re: Crank Swap [James Haycraft] [ In reply to ]
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Thanks for the help James. My closest bike shop is a 5 hour drive, so I do a fair amount of my own maintenance. So luckily I am mechanically inclined and can do most things. The things I don't feel comfortable doing or don't want to mess with due to the complexity then I make the drive which normally ends up having to be a 2 day excursion. Most things I figure out myself or have the Internet for help. But some things, like this, I want to make sure I can start and finish because I don't want to pull it apart and then make the drive to have the BM put it back together. So given all that I really appreciate the help I get from others like yourself, you've been very helpful. I'm still deciding if this is worth tackling myself. If I had the luxury of a close bike shop it would be a no brainer.
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Re: Crank Swap [rebel59] [ In reply to ]
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If you're mechanically inclined, you can do a press fit bottom bracket swap; I just tried for the first time a few weeks ago and everything went well. Punch out the old bearing cups with a flathead punch, go slowly around and make sure it comes out evenly. My bottom bracket had been secured with loctite as per Cervelo specs at the time it was installed, so it took a few times around but then they popped right out. To press in the new bottom bracket, I used a large threaded rod from the hardware store, washers large enough to span the bearing cups, and nuts with the correct thread. Again, just go slowly and make sure everything lines up and is even. Other than that, it isn't rocket science.
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Re: Crank Swap [Vman455] [ In reply to ]
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Vman455 wrote:
If you're mechanically inclined, you can do a press fit bottom bracket swap; I just tried for the first time a few weeks ago and everything went well. Punch out the old bearing cups with a flathead punch, go slowly around and make sure it comes out evenly. My bottom bracket had been secured with loctite as per Cervelo specs at the time it was installed, so it took a few times around but then they popped right out. To press in the new bottom bracket, I used a large threaded rod from the hardware store, washers large enough to span the bearing cups, and nuts with the correct thread. Again, just go slowly and make sure everything lines up and is even. Other than that, it isn't rocket science.

Oh dear.
Please do not advise anybody to do this.
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Re: Crank Swap [lyrrad] [ In reply to ]
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Re: Crank Swap [Vman455] [ In reply to ]
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I disagree with lyarrd. The home made press is can work well. I use a homemade press like the one in the link below and it works very well.

https://www.pinkbike.com/...om-bracket-2012.html
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Re: Crank Swap [rebel59] [ In reply to ]
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I have grown to like the bbright/pf30 bottom brackets that thread into one another. I have the Manufacturing works one (... the only pain is that it does require two special bearing cup tools).

If I were to buy another BB for my cervelo, I would likely try this out (see link below). For $50 and ceramic bearings, it's worth the shot.

https://www.aliexpress.com/....13010308.0.0.zCM4B4


Last edited by: beston: Mar 25, 17 6:03
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Re: Crank Swap [beston] [ In reply to ]
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beston wrote:
I disagree with lyarrd. The home made press is can work well. I use a homemade press like the one in the link below and it works very well.

https://www.pinkbike.com/...om-bracket-2012.html

You will note in the link you posted that they did not use washers that flex and put pressure on the balls and races, they used proper molded bearing supports and they used a proper tool to punch out the bearings, not wriggle them out with a rocking motion.

Flexy washers =no
Tapping out by going around the edges with a punch=no
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Re: Crank Swap [beston] [ In reply to ]
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beston wrote:
I disagree with lyarrd. The home made press is can work well. I use a homemade press like the one in the link below and it works very well.

https://www.pinkbike.com/...om-bracket-2012.html

The Wheels Manufacturing press that James linked above is a whole $35 for working on a frame worth a couple thousand. Why bother with all thread, nuts and washers? Even with the Park Tool drifts that come with the removal tool, your method still requires pressing both Bb shells into the frame at the same time. This can easily lead to misalignment issues. Yeah it's pressed in place, but how long until it starts creaking is the question.

With the wheels mfr press universal drifts you can press one half of the BB into place at a time starting with one drift in the frame to center and align the bb half being pressed in.

That particular Park BB removal tool shown in the PB article often interferes with the BB spindle shield and probably isn't worth the investment. A standard headset removal tool or the smaller diameter version Park sells for BB90 bearing removal works very cleanly for most PF30 BB30 removals.
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Re: Crank Swap [SummitAK] [ In reply to ]
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I do agree that the headset removal tool is an easy way to get bearing cups out. I have one and that has worked.

I've only installed a couple of pf30 / bbright bottom brackets, and have always managed to do it one side at a time. For example, my Manufacturing Works BB only 'presses' in on side and then threads in the other. I will say that after taking a closer Look at the PB instructions, I suppose my method of installation varies a little bit from that and I do use tricks with washers and press-in cups. to keep it all centred.

While I do think this fear of misalignment seems exaggerated, I have to admit that, I'm using the threaded mfg. works bb on my cervelo because I don't want alignment or creeping out of the frame issues. It just seems like a better design. Even better is the version that Praxis sells (I wish they had a bbright version). I also have a standard PF30 bb on my gravel bike and will also replace it with a threaded version of these bb's when it comes time.
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Re: Crank Swap [rebel59] [ In reply to ]
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Thanks for the ideas and tips. With a little improvising the job is done. Works like new. Really happy with the results.
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