Does it matter if you use a 105 4iiii left Crank power meter with a right side ultegra crank

Just wondering, if you used a 105 4iiii left Crank with an ultegra right , is there any performance loss through power or in pedalling technique or any loss in performance at all.

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NO as long as they are the same length


I doubt it very much. The Ultegra one will be slightly lighter but it is attached to the drive train so I doubt you would notice the difference.

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I had two different cranks but they were same length…that is the important part and I noticed no difference.

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I’ve been using a 105 and Ultegra 4iiii power meter on Tiagra, 105, Ultegra and Dura ace chainsets with no problems at all. Don’t over think it, they’re great power meters.


As above, no issues whatsoever as long as the RHS HT2 crank is the same length. Theoretically you could even swap it with mtb cranks

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I have a 105 4iiii left crank on a 2005 Dura-Ace right, and have previously had the same 4iiii crank on a 2006 Ultegra right. Zero problems with either setup. So not only do I have mixed 105 / [Ultegra/Dura-Ace], my mix spans 13 years of models.

As long as your right is HollowTech II, you’re set.

The biggest problem I have is that the 4iiii crank is black, and my Dura-Ace/Ultegra rights are silver. So perhaps I look dorky. I can live with that.

Only to people who can see both sides of your bike at the same time :+1:


I use my 4iiii 105 crank with Tiagra on two different bikes with no issues at all.

Just make sure same length!

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And of course your cadence will be so high only a blur will be showing !!!

Thanks for all the help

I use the 4iiii 105 5800 left crank with a full Sora groupset. I could use a dura-ace or an ultegra one but for 299€ i have the same data

My exact same setup! :smiley:

I have 105 4iii left and dura-ace right. Works fine

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No it doesn’t matter at all!

I have Dura-ace 4iiii left with a 105 Crankset. Dura-ace was on special at the time.
105 Crankset was also on special at another time.

Interestingly the left side dura-ace with 4iiii weighs almost exactly the same as a left side 105 crank without.