9 speed to 11 speed - new chainrings needed or crankset?
9 speed to 11 speed - new chainrings needed or crankset?
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BlueNGT

Original Poster:

708 posts

251 months

Wednesday 13th January 2016
quotequote all
I've been buying up parts secretly to convert the other half's Bianchi from 9 speed to 11 speed. I now have Fulcrum wheels, Shimano 105 derailleurs front and rear, 11-28 cassette, 105 levers, dura-ace 11 spd chain (105 brakes with Swissstop Blue too).

When she bought the bike it came with FSA chainset with 50/34 chainrings. There are no markings on the chainrings at all but I suspect they are not N10/11 FSA as the bike is fitted with Sora 9spd.

The Bike was only bought April 2014 and I understand it is has a FSA BSA Square type 110.5mm so converting to 105 chainset isn't needed really as it is not worn at all....I am not aware of any real advantage of swapping to a 105 chainset?

If I stick with the FSA set up do I need to change the chainrings to suit the 11spd chain - I understand the 9 spd and 11 spd chains are different widths to seat on the relevant chainrings but will the 11spd chain work on the original chainrings?


Matt_N

9,035 posts

231 months

Wednesday 13th January 2016
quotequote all
As far as I know it should work, the chains are narrower on 11 speed due to narrower outer plates and roll pins, the internal dimensions are the same.

10 speed chainrings work with 11 speed cassettes and chain on both Shimano and Campag, Shimano was 9/10 speed for most of it's gear so 9/11 speed should be ok.

Definitely worth a try anyway.

Worst case, a new BB and 5800 chainset will be around £75.



Edited by Matt_N on Wednesday 13th January 14:28

Matt_N

9,035 posts

231 months

BlueNGT

Original Poster:

708 posts

251 months

Wednesday 13th January 2016
quotequote all
Thanks for the link, interesting reading.

As we will be changing the whole drivetrain to 11spd that suggests the chain will be fine on the existing chainrings. If not I can pick up some chainrings and it is quick easy swap.

Black can man

31,973 posts

197 months

Wednesday 13th January 2016
quotequote all
BlueNGT said:
Thanks for the link, interesting reading.

As we will be changing the whole drivetrain to 11spd that suggests the chain will be fine on the existing chainrings. If not I can pick up some chainrings and it is quick easy swap.
Are you rebuilding it yourself ?