# Please help me convert pf BB86 crank to Ultegra 6800 compact chainset



## Goldberm (Feb 26, 2015)

I just purchased a 2014 Fuji Fondo 1.3 The drivetrain is full ultegra Di2 except for the cranks. The cranks are Oval 720 with a pressfit BB86. 

Does anyone know exactly what I'll need to convert to this Ultegra 6800 Compact 11 Speed Chainset?

Thank you very much!!

-Berm

BTW, first post on RBR.com  , been on MTBR for a little while


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## DrSmile (Jul 22, 2006)

Shimano makes a bottom bracket for your frame that is OEM.

Shimano Ultegra 6800 PressFit Bottom Bracket


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## PJ352 (Dec 5, 2007)

Another member may be able to verify this, but I don't believe the Oval 720 crankset is BB30, so if you have a Shimano pressfit BB86 installed, you can install the Ultegra cranks without further modifications.


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## bikerector (Oct 31, 2012)

As long as the oval crank doesn't use the sram type bearing size (one is smaller and one is larger) then it will work with shimano. I know shimano and FSA use the same BB specs and are interchangeable.

Sram is the only one I'm aware of that uses a 24mm size on the driveside and 22mm on the non-driveside.

An easy test would be to take the crank off and see if the crank spindle/axle will fit the other bearing, making them the same size. On a sram GXP-type, only the tip will fit, not the whole spindle. This also means GXP-type need to be pressed in correctly or you'll be pressing the darn things right back out and flipping them around... I wish I only did that once.

You should also make sure that teh BB is a BB86 as there are a few different pressfit BB's and the BB86 is pretty uncommon. It's basically a pressfit BSA standard that will only accept the BSA standard crank (24mm as opposed to 30mm for BB30 cranks).


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## bikerector (Oct 31, 2012)

According to the 3rd post in this thread: http://forums.roadbikereview.com/components-wrenching/crankset-pf86-bb-313656.html

the spindle is a gxp type so you would need a new BB and you just need to get a BB86 for shimano which should be pretty easy to find from an aftermarket BB supplier like praxis, VCRCbike, Wheelsmfg, Chris King, etc. Apparently shimano also makes one according to the 2nd poster above.

I've been told the BB86 is mostly a Trek bike standard so if you're looking to get one from a bike shop, they would be the most likely to have one. Make sure you talk to someone competent, my local trek dealer knew nothing about the standard. I've never heard such a string of misleading information from a bike shop, especially since the specialized dealer told me to go to the trek shop since it's a more common for trek to use the standard. I know the trek crocket uses it.


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## Goldberm (Feb 26, 2015)

PJ352 said:


> Another member may be able to verify this, but I don't believe the Oval 720 crankset is BB30, so if you have a Shimano pressfit BB86 installed, you can install the Ultegra cranks without further modifications.


My Oval crank is a pf BB86. That's why I need to modify.


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## Goldberm (Feb 26, 2015)

DrSmile said:


> Shimano makes a bottom bracket for your frame that is OEM.
> 
> Shimano Ultegra 6800 PressFit Bottom Bracket



Awesome. Thanks.


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## Mr. Scary (Dec 7, 2005)

bikerector said:


> According to the 3rd post in this thread: http://forums.roadbikereview.com/components-wrenching/crankset-pf86-bb-313656.html
> 
> the spindle is a gxp type so you would need a new BB and you just need to get a BB86 for shimano which should be pretty easy to find from an aftermarket BB supplier like praxis, VCRCbike, Wheelsmfg, Chris King, etc. Apparently shimano also makes one according to the 2nd poster above.
> 
> I've been told the BB86 is mostly a Trek bike standard so if you're looking to get one from a bike shop, they would be the most likely to have one. Make sure you talk to someone competent, my local trek dealer knew nothing about the standard. I've never heard such a string of misleading information from a bike shop, especially since the specialized dealer told me to go to the trek shop since it's a more common for trek to use the standard. I know the trek crocket uses it.


BB86 is a Giant/Shimano standard. Trek uses BB90 which is probably why a guy in a Trek bike shop didn't know...


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## BikeLayne (Apr 4, 2014)

I have no experience with it but I googled this up. 

Shimano BB86 Bottom Bracket | Competitive Cyclist

and this

http://www.amazon.com/Wheels-Manufacturing-Bracket-Ceramic-Bearings/dp/B00GSOBFQK


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## bikerector (Oct 31, 2012)

Mr. Scary said:


> BB86 is a Giant/Shimano standard. Trek uses BB90 which is probably why a guy in a Trek bike shop didn't know...


Fair enough, I was told by other shops, a specialized and norco dealer, that it was a trek thing. They do use the standard but sounds like it's not their design.


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## bikerector (Oct 31, 2012)

Goldberm said:


> My Oval crank is a pf BB86. That's why I need to modify.


Technically, the BB is BB86, the crank is 24mm/ GXP-type standard. At this point you, for the most part, only have two crank types, those with 30mm spindles and those with 24mm spindles. What PJ meant was that your crank shouldn't be the 30mm spindle standard, which it can't be and still fit into the BB86 design since it will only accept a 24mm spindle design. This is just FYI since you've already seen that shimano makes a BB for your purpose.


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## Goldberm (Feb 26, 2015)

bikerector said:


> Technically, the BB is BB86, the crank is 24mm/ GXP-type standard. At this point you, for the most part, only have two crank types, those with 30mm spindles and those with 24mm spindles. What PJ meant was that your crank shouldn't be the 30mm spindle standard, which it can't be and still fit into the BB86 design since it will only accept a 24mm spindle design. This is just FYI since you've already seen that shimano makes a BB for your purpose.


Thank you for the clarification/education. I did mean to type that my crank "has a pf BB86" and not "is a pf BB86", but the info you provided was needed, and greatly appreciated.

Part of my confusion stemmed from the response to the same question that I posted on the CRC website where I linked the crankset above. Their answer was ANY standard shimano pressfit BB would work, and they specifically stated the BB91 or the BB71 would work. Consequently, CRC doesn't sell shimanos BB86.


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## TJay74 (Sep 9, 2012)

Shimano only makes 2 BB I believe in the BB86, I have ran both with no issues. I have the Wheels Mfg ceramic BB86 in my bike now and it is a really nice BB.

That being said if the current BB is BB86 then you should be able to stick the new Ultegra 6800 crank in with no other mods needed.


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