I have a 7900 grupo and if I were to switch the crank for a **ÁGILIS Road Crank, **what issues would I have if any with the front and rear deralleur and a 7900 chain?
thanks
you will be fine
.
that is aside from the crappy shifting that comes from any gruppo when you put a different crank in the mix.
Hi Leo,
I don’t think you will have any problems with the RD but mabye some issues with the FD. This
because the distance between the small and big chainring is some 0,? mm wider than on the 7800
to prevent chain rubbing on the big ring when running 39 -11(12) and the FD is optimized for this.
This is probably just a case of some fine tuning of the FD once you’ve switched.
I haven’t tried a different crank with my group. Didn’t Cervelo Test Team try to run a Rotor crank with
the 7900 group and ended up running with the 7800 group with whatever crank they are on now? I believe
they got issues with their rotorcranks and the 7900 FD.
Hope this helps a bit but I don’t think you can go with a better crank than the DA 7900. This is where the real
improvement lies from the 7800 group.
Brg
Magnus
the crank on the 7900 is certainly not the big upgrade from 7800, 7900 is for a step down from 7800.
The Cervelo test team is using a Quarq Cinqo powermeter which is not compatible with shimano crank yet, that is why they changed it…I was looking at the weight difference between a 7900crank and a 7800crank and the its only 40g lighter.
I do have a a full 7800 groupo also that is not being used…anyways, check out this roto agilis used by team cervelo
That’s a nice crank. I would like to try the Quarq someday when I get the chance.
Okey, the weight difference there is not that much but Shimano has really stiffened up
the 7900 crank mostly through the new “sandwich” technology in the big chainring. That
is why I think this is a upgrade from the 7800 crank that was allready one of the
stiffest on the market.
That Agilis crank would work fine with the 7800 group as it does for the CTT. But I am still
uncertain with the 7900 group. Are you putting it on a TT/tri bike or on your road bike?
I would happily run the Quarq with the 7800 components on my Tri bike. But on the road bike
I think it is nice to have the integrated cables that the 7900 provide.
My friend rides with the 7800 SRM crank together with the 7900 group and it works fine for him. He’s
a continental team rider so he is dependant on good function so I gues this combination has no issues.
With this in perspective I guess it would work fine. Difficult to say, worth giving it a shot…
Brg
Magnus