Fitting an Ultegra bottom bracket + crankset

[Jp]

Hi guys,

I just bought a new cannondale road frame and asked the bike shop to fit an Ultegra 6500 bottom
bracket for me (I don't have the correct shimano BB tool) to suit my shiny new ultegra crankset. I
have just spent today building up my new bike, pretty much from scratch and had no problems - except
the cranks - they are so damn tight fitting. It looks as if they should slide perfectly into the
grooves of the BB to a depth of about 8mm - i would say they are on about half that distance, and
that required some considerable effort! I would say that, looking form underneath, about 4mm of the
BB is still exposed between the edge of the bottom tube and the top of the crank arm (I hope that is
easily understood, its pretty hard to explain even after looking at the damn thing for 5 hours).

So, is it possible that the bike shop sent me the wrong BB? I don't think so. Should it be this
tight? And should I try and force it on further - if so do you have any advice on doing this? If it
isnt on far enough what effect will it have on the shifting?

I'd really appreciate any help offered! Thanks JP

---------------------
Jonny Palmer

 

[Ssomnala]

I fitted a new Ultegra bottom bracket and crankset earlier this year. I am assuming that you are
fitting the hollow axle BB. Anyway, my main worry was getting the old sealed BB unit out. But due to
my preventive maintanence (very unsual for me - lashings of GT-85 after amost every ride) it came
out very easy. With the Ultegra BB axle and cranks, the main problem to me was getting each of the
cranks to match exactly - to many notches in the cranks and the axle. The cranks do stand proud of
the cranks with out tightening. The are unlike the old four-side axles were the cranks slipped on
almost on almost al the way before tightening. But with the Ultegra once committed and tightened all
was OK. The only problem I did experience was creaking coming from the BB axle and the cranks. This
was cured by squirting GT-85 between the two mating surfaces. No more creaking.

Even though the cranks are fully tight, there is a gap of about 4mm or less between the BB shell and
the cranks on both sides. I have not measured this gap. But the cranks have been ridden for over six
months with no problems (90 miles covered yesterday)! So I suggest that you tighten them as far as
you can without straining your self or the cranks them selves. Then go for a test ride. But take
your allen key with you, just in case

Cheers

Alan

 

[Jp]

Thanks Alan - I'm glad I haven't wrecked them!

I really appreciate the advice JP

 

[Abbey Engineer]

"JP" <[email protected]> wrote in message news:[email protected]...
> Hi guys,
>
> I just bought a new cannondale road frame and asked the bike shop to fit
an
> Ultegra 6500 bottom bracket for me (I don't have the correct shimano BB tool) to suit my shiny new
> ultegra crankset. I have just spent today building up my new bike, pretty much from scratch and
> had no problems - except the cranks - they are so damn tight fitting. It looks as if they should
> slide perfectly into the grooves of the BB to a depth of about
8mm -
> i would say they are on about half that distance, and that required some considerable effort! I
> would say that, looking form underneath, about 4mm of the BB is still exposed between the edge of
> the bottom tube and the top of the crank arm (I hope that is easily understood, its pretty hard to
> explain even after looking at the damn thing for 5 hours).
>
> So, is it possible that the bike shop sent me the wrong BB? I don't think so. Should it be this
> tight? And should I try and force it on further -
if
> so do you have any advice on doing this? If it isnt on far enough what effect will it have on the
> shifting?
>
> I'd really appreciate any help offered! Thanks JP
I originally tightened my Octalink hollow BB by hand and it started clicking after several months.
Bought a torque wrench and tightened it to the specified torque and the cranks went on so much
further the front shifting was way out.

KC

 

[Pete Biggs]

JP wrote:
> I just bought a new cannondale road frame and asked the bike shop to fit an Ultegra 6500 bottom
> bracket for me (I don't have the correct shimano BB tool) to suit my shiny new ultegra crankset. I
> have just spent today building up my new bike, pretty much from scratch and had no problems -
> except the cranks - they are so damn tight fitting.

Splines should be greased and cranks should be tightened with a torque wrench to be sure of getting
them on correctly.

See: http://www.parktool.com/repair_help/Pipe_Billet_Spindle_type.shtml

~PB