Diverge with 105 4iiii

Hi guys, getting close to buying a Diverge Comp Carbon.
All my pm’s are stages on 170mm cranks so it looks like I’ll need a new one if I get the bike as the 56 comes with 172.5’s.

Does anyone know if a 105 4iiii fits okay without fouling?
I’d prefer a GRX Stages but they’re all out of stock and the 105 is -£100 too so a handy saving for other goodies.

Thanks in advance :+1:t2:

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There is another thread on here about this. I dont totally remember but I checked with 4IIII a while back if my memory isnt totally gone. I believe it will work but the q factor might be a little different. I would phone or email 4iiii’s. They are great to deal with.

I’m using a 105 4iii on my 10 speed GRX crankset on my Topstone. I wasn’t aware of any q factor change before reading it here. And I haven’t noticed in the real world since!

Can’t comment on the fit, but they have instructions on how to check if you’re sending in a crank?

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If you get a 4iiii then see if you can compare the reported power outputs against your existing Stages. I have had both and there was 5-6% difference between the them. If you can use an existing PM the it might be better to get a new 170mm crankset.

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Thanks everyone. Thinking about it, I have a 4iiii XT and a plain 105 crank here so between the two I should be able to measure the fit and check before I order. Although if someone had said they’d done it I’d have ordered in advance to make sure it arrives with the bike :rofl:

It would be good to offset the 4iiii to match the Stages (both of which feel similar) but are there any tips to do so?
A long HR based steady state effort on both bikes I presume??

Clearance check is here on the 4iiii website.

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As mentioned above, the q factor is different, add some spacers on the pedal spindle to get it close to right

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Ooo even better. Went to the shop to confirm my order and they had a 170mm crankset on the system :sunglasses:
So can save the cash and use my existing UIltegra one.

I’d compare them individually against the output from your trainer on the same workout then look at the average powers with respect to the trainer power and adjust the 4iiii one accordingly. Then do it again to check.


That’s the great thing about 4iiii! I found them to be consistent with my trainer (accounting for a bit of drive train loss), while I had a Stage GRX that was consistently higher than my trainer by 10-14%.

At least if the 4iiii is significantly off, you can tweak it a bit if needed to align to the trainer or another power source.

Any updates? Does the left side PM have clearance on your Diverge?

Yep, I’m running a 105 4iiii :+1:t2:

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