danm65

I've been looking at the RSD aluminum middlechild. I just noticed that all of the middlechild models have a straight headtube but can accept a tapered steerer do to the headset. What would be the reasons for doing that? Are there any downsides to doing it that way?

qclabrat

I think that's the 44mm headtube. I have that on my Niner ROS9. If I recall correctly, it's stronger and easier to manufacture.

Kapusta

The only potential downside is that in order to use a fork with tapered steer tube you need a headset that adds stack hieght below the head tube, which has the same effect as increasing the fork hieght (axle to crown distance). In other words, it raises the front end of the bike.

However, I would think that any MTB frame designed in 2020 would have taken that into account, so it may be that the frame is already designed with that extra fork hieght in mind.

So it is not necessarily a bad thing, just something to be aware of.

unterhausen

I'm sure that bike comes with a 1.5" tapered steerer. Straight steerers are not common except on low-end bikes. I always thought straight 44mm head tubes were ugly, but I'm getting used to them. There is no extra stack height (axle-crown) in using a straight head tube. Integral headsets are getting a lot more common. It appears that the middle child has an external headset. If it does have a straight steerer, it would not cause extra stack height to switch to a tapered steerer

Kapusta

Oh, I thought the OP was looking at a frame.

If these are complete bikes, then clearly the bike is designed for the external bottom headset, and the the extra fork height is already baked into the design.

So.... yeah, no issue.

danm65

Thank you everyone for your responses they've helped alot.

Darth Lefty 

I think this is a steel vs aluminum thing. The tapered ZS head tubes are hydroformed. Steel would be machined or spun