Building up a wheel later today with a Raceface ARC HD Offset rim and realizing I’m not 100% sure which is the drive side.
Nothing on the rim indicates such and it’s my first time using an offset rim. Am I correct in assuming the cassette side is the right side of the rim in this photo?
by Ornery-Shoulder-3938
9 Comments
https://preview.redd.it/htfjirpdf2ng1.png?width=2046&format=png&auto=webp&s=aef71c7dbe630b23e776e8c26ea5ff8613355a21
Drive side spokes are shorter. Use a spoke length calculator. You will need the rims ERD and hub dimensions.
The cassette would be left side in your photo. The idea is that the spoke holes are centered between the flanges while keeping the rim centered between the endcap faces.
Edit: the rim offset is an important part of your spoke calcs. Make sure you account for that when you do it.
The goal of the offset is to get both sides as close as possible as for lenght and tension. In the rear normaly, the offset is to the non drive side.
Everything is still dependant on the hub.
And for a front hub the offset would be opposite as the flange is offset for just the rotor up front, fyi
Left side ,cause the short spoke goes down and the right more to the side
thread a spoke through each of the two kinds of hole and connect each to a nipple, then pull each towards the centre of the wheel with your fingers and it should be obvious at what angle each spoke is intended to run at.
it’s years since i used those arc rims (in my experience they are a bit soft and dent easily, but anyway), but iirc the most offset hole is for a spoke that is at a steeper angle. and since the spoke “crosses over” the centre on the way out, it’s on the opposite side to what you naively expect. in other words, the most offset holes, on the right in your photo, are the “widest” angle and will come out inside (ie towards the centre of) the wheel running to the left. while the narrower angle (more central holes) goes to the right. and so drive side is right.
which contradicts the other, upvoted answer here, so someone is wrong, which is why i suggest trying it yourself.
Asymmetrical offset should match the flange offset of your hub. Usually front hub flanges are offset to the right away from the rotor and rear hubs to the left away from the cogs.
Cassette would go on the side away from the table in the first photo. If you’re using the same rim for a front wheel, that would be the rotor side.
Drive side spokes have too steep of an angle (because cassettes take up so much space). Asymmetric rims try to correct this by moving the drive side spoke holes further towards the non-drive side.