I believe they have the same "official" tire clearance: 700x45C/650x50b. Not sure if either one, unofficially, has more tire clearance though. I don't have personal experience with either frame but I can see some key differences from looking at their geometries. The Elves one visually looks like more of a "race frame." Between the Graro and Aerox, their head tube angles are similar but the Elves fork seems to have two different offsets listed. In the fork description is says 45mm but in the geometry chart it says 56mm which is a pretty big difference. I would guess the rake listed in the chart is the correct one (56mm), the ICAN one has a 50mm rake:
Fork Rake/Offset:
Elves: 56mm
ICAN: 50mm
Less rake/offset will make the steering a little twitchier and more responsive, probably better for CX racing but less nice for a non-technical joy ride.
Another difference I see is the bb drop:
Elves: 76/74mm depending on size
ICAN: 71 across the board
More BB drop lowers your whole center of gravity which is great for stability and making you feel really planted. It also might make your saddle to bar/drop less extreme depending on your setup. If you are riding over a lot of rocks or something, it does put your bb and pedals lower to the ground and closer to rocks and things. You might want to consider shorter cranks if you have a low bb. You don't pedal through corners as much off road as you do on road so pedal strikes are probably less of a risk but it depends on the terrain. Personally, I like a lower bb and newer frames tend to be trending lower, especially now that shorter cranks are getting more popular.
Chainstays:
Elves: 430mm
ICAN: 425mm
Shorter chainstays should make the rear and feel a little snappier and more responsive in a sprint. Longer chainstays might make accelerating feel more sluggish but also make the overall ride feel smoother.
Stack/Reach:
Elves by size:
46-1.44
49-1.42
52-1.41
54-1.41
56-1.40
ICAN by size:
46-1.38
49-1.39
52-1.44
54-1.46
56-1.48
58-1.50
If you divide stack/reach, you can get and idea of how tall the bike is compared to how long it is. A bigger number might make the bike feel more relaxed and less aggressive. Around 1.4 is sort of "normal" in a very subjective way. Larger sized bikes are sometimes more relaxed and smaller sizes are more aggressive but I noticed the Elves sizes are pretty similar across the board whereas the ICAN ones get larger as the frame sizes get bigger.
Based on geometry alone, I think the Graro will feel stiffer and more responsive because of the shorter fork rake and chainstays. You might want to double check the rake of the Aerox fork with Elves though because they do have two rakes/offsets listed. Also If it makes a difference, it looks like the Elves comes with a barstem whereas the ICAN does not...
A part of me is waiting for an Enve Mog "inspired" frame since the mog has big tire clearance (officially 50c, unofficially 55c), shorter chaintsays (420mm) and wheelbase, and a low bb (+/- 75mm). Longer rake though(+/- 55mm), more on par with the Aerox.
