Difference between 105 vs Ultegra cranks

Triathlon Forum
1

Looking to upgrade my fsa crankset on my Cervelo P2 and want to upgrade to a shimano crankset since everything else on the bike is shimano (ultegra fd & rd). I am noticing there is a price difference between 105 and ultegra cranksets. Curious to know what the big differences are between the two. I am assuming even if I went with the 105 that it would be an improvement in shifting compared to what I have now.

Personal note: I am a middle of the pack age grouper and race 1-2 70.3’s a year and every other year 140.6.

Any insight on which to go with would be greatly appreciated. Currently looking at either 105 (5650, 5750) or ultegra (6750).

2

We have all been there with ‘upgrade-itis’. Upgrading and building bikes is a freakin’ blast.

You won’t notice much if any difference. Ultegra is a bit lighter, shift performance probably nil. The reality is that as long as you know how to use a barrel adjuster they will all work just fine. As long as your ring teeth aren’t shot I would say again, probably won’t notice any difference IF your derailleurs are tuned and chain/cassette are not worn.

FWIW I ride a $60 SRAM S150 crank, KMC chain and 105 cassette with 3 year old Rival rear derailleur and my bike performs just like it did when I had SRAM Red hanging off it. Doesn’t look as cool and certainly weighs more though.

3

the ultegra is a little lighter and the chain rings on it are a little stiffer.

there is no rational reason to upgrade. I use 105 cranks with an aero chainring on my bike. Cheap and aero.

http://www.slip-angle.com/texas-state-tt.jpg

4

Didn’t you have an Adamo at one point? Just interested to know the why on the switch. I started with ISM…Max for life now on all my bikes. Nirvana for my bits.

5

Would using a dura ace bottom bracket help with performance of a 105 crank?

6

Would using a dura ace bottom bracket help with performance of a 105 crank?

no. there isn’t really free speed to be had from bottom brackets.

its possible the dura ace ones are more reliable, or lighter. I’m not sure. I think I have an ultegra BB. Not sure if they even make 105 BBs, the LBS didn’t have any.

7

Didn’t you have an Adamo at one point? Just interested to know the why on the switch. I started with ISM…Max for life now on all my bikes. Nirvana for my bits.

yeah, rubbed my inner thighs too much

8

eah, rubbed my inner thighs too much

That’s a bad visual.

9

I just bought my wife the same bike the OP has and it has FSA Mega EXO on the front end. She hasn’t complained about front shifting yet. Is that setup that much worse than a 105 level front end? I’ve never ridden anything FSA, only SRAM and Shimmano, and I don’t do compacts, so would have no way of telling ridding the bike myself (which I can’t anyway). On the stand it seems to work fine (it just seems to climb up slow).

10

no there is nothing wrong with the FSA cranks these days. the climbing up slow has nothing to do with the cranks =)

fsa gossamer/105 should be about ‘the same’.

in that they weigh about the same and nothing is wrong with them.

11

Silly me, thinking one question and asking another.

Are the chain rings that much different (the crank can’t really affect shifting, duh)?

12

Silly me, thinking one question and asking another.

Are the chain rings that much different (the crank can’t really affect shifting, duh)?

oh THAT kind of climbing up! haha
people say the shimano chainrings are a bit nicer in that regard. Adam at ATC suggests running dura ace chainrings on cheap cranks for a slick but affordable setup. I don’t think I’ve ever run nice shimano chainrings though so I can’t say.