Shimano R700 / Ultegra SL - Chainset/BB Compatible?

kmahony

Hi,

I have an R700 compact chainset and bottom bracket.
If I got an Ultegra SL compact chainset without the BB, would I be able to simply change the chainset on the existing BB? If possible, would this be a simple job?

thanks

oldwelshman

Last time I looked the R700 is a hollowtech 2 chainset with integrated bottom bracket. Maybe some one will correct me if I am wrong.
Also the ultegra SL is hollowtech2 with integrated B.

maddog 2

yes, all the HT2 BBs are interchangeable AFAIK

you can also use:

FSA
RaceFace
Acros (ceramic)
Superstar
etc.

but not the Truvativ/GXP ones

oldwelshman

Silly question, how do you remove the BB from the crank arm if it is integrated?

kmahony

oldwelshman wrote:

Silly question, how do you remove the BB from the crank arm if it is integrated?

That's what I was thinking, but then I noticed they sell them without the bottom bracket??

maddog 2

it's the crank arm and axle that is integrated (attached), not the BB cups

Steven Martin

So, FSA hollowtech type cranks and Shimano have identical diameters?
Excellent news, I was thinking of getting an FSA compact and I currently run 10 Dura Ace. That saves me hassle when swapping between the two.

Steven Martin

I just looked on the FSA website, and it suggests that FSA cups are not compatible across it's range, with specific BB cups for each.

Are they taking the mick?

maddog 2

Shimano sometimes say the same, and that's a load of cr@p

I've not tried it on roadie chainsets but for mtb c/sets the cups are interchangeable AFAIK.

oldwelshman

I assumed in OP that he asked could he keep BB which is actually integrated.
I realise you can keep the cups but thats not what I understood to be the question
So I guess he needs to use the original "cups" and fit new crank arm and rings with integrated bottom bracket

kmahony

oldwelshman wrote:

I assumed in OP that he asked could he keep BB which is actually integrated.
I realise you can keep the cups but thats not what I understood to be the question
So I guess he needs to use the original "cups" and fit new crank arm and rings with integrated bottom bracket

Yes, I think my question was probably wrong, but I think I understand now.

To confirm:
The BB Cups can be left on, but the chainset comes with the internal part of the BB attached?
Even if it's described as:
"Does not include the bottom bracket, these are purchased seperately and depend on your frame's BB threads"

If I just change the chainset (not the BB cups) , is this an easy job?

thanks

maddog 2

it's straighhtforward. Undo bolts, remove non-driveside crank arm and gently tap the old crank/axle out. Fit new crank in reverse order.

The main thing is to preload the bearings and do up the pinch bolts properly. Read the instructions. They specify a torque setting and tightening method. Stick to that and they'll be fine.