Muni Frame Weight Nimbus Steel vs Oracle vs KH

I’ve traditionally ridden the Nimbus steel 24 ,26, and 29 frames because I appreciate steel for its strength, stiffness, reliability, and the Nimbus steel frames for their lower cost.

This holiday season I found some good deals on some aluminum nimbus Oracle frames and a used KH24, so I drank the kool-aid (so to speak) and got them.

UDC lists all the steel frames as being 810g which seemed suspiciously uniform to me, so I weighed mine to see actual weights so I’d know how much weight I was loosing on the lighter aluminum stuff. I thought I’d share the weights below as I couldn’t find any numbers on the forums or anywhere else.

Disclaimer - My scale isn’t the greatest, measured weights may a vary a bit.

Nimbus Steel Frame Weights (Incl caps, bolts, and Nimbus 2 Bolt Seat Clamp):

24 Inch Muni Frame: 1125g - on my cheap scale

26 Inch Muni Frame: 1175g - on my cheap scale

29 Inch Muni Frame: 1125g - on my cheap scale


Nimbus Oracle Frame Weights (Incl cap /d-brake, bolts, and Nimbus 2 Bolt Seat Clamp):

24 Inch Muni Frame: 585g (521g + 64g seat clamp - municycle.ca)

26 Inch Muni Frame: 589g (525g + 64g seat clamp - municycle.ca) - was 600g on my cheap scale

29 Inch Muni Frame: 608g (544g + 64g seat clamp - municycle.ca)


KH Muni Frame Weights (From http://www.krisholm.com/en/gear/component/frames - not sure if it includes clamp weight)

24 Inch Muni Frame: 646g

26 Inch Muni Frame: 709g

29 Inch Muni Frame: 766g

Thoughts:

Aluminum frames save around 500-600 grams (1 - 1.25 lbs). Being that this is probably 1% or less of your total body weight it seems somewhat negligible overall, but I think there are cases where it matters ( and I believe Ive felt an improvement using the lighter frames in these areas).

Jumping: You lift the uni while jumping. I can feel a 1lb difference while lifting the uni. If you’re jumping a lot this probably saves arm fatigue.

Technical Climbing: Climbing on uni while trying to negotiate obstacles is exhausting and one uses a lot of energy moving the uni around (swerving, lifting, jumping). I think the lighter frame could make a difference here.

Carrying: If you have to carry your uni over your shoulder to walk sections (shameful, I know) its nice to have less weight digging into it.

I think wheel/ tire weight makes more difference than frame weight, but that has been discussed a lot already. If you’re mostly rolling on less technical terrain I personally don’t think saving 1 lb of weight is noticeable.

Crmo steel is a great material and is stronger/stiffer than 6061/7075 aluminum when comparing metal properties. That being said, the only uni frame I’ve ever broken was a steel Koxx 24 in frame: it cracked at the weld between the leg and the crown. This is a good example of how build / weld quality prb makes a bigger difference in reliability than steel vs. aluminum tubing.

I haven’t taken my frame off to weigh it, but the claimed weight of the 29er frame is 810g. That seems like it’s significantly different than what you measured.

Funny enough, the claimed weight of the Steel 26" frame is also 810g, but the Steel 24" claimed weight is 790g.

The Steel 29er frame is a significantly different design than the 24 and 26, and just feeling the 24 and 29 side by side, the 29 actually feels a bit lighter in the frame department, but hard to say without taking it off the wheel.

I’m with ya. : ) I’m more of a steel person.

I should weigh my 26" Surly Conundrum. I remember when I pulled that out of the box I was impressed with how heavy the frame was. The thing is an absolute tank, but it rides great.

I think the round crown design of the drak 29 frame saves some weight over the welded design of the 26 and 24 frames. Prb makes it easier to use a long bent piece of taper-wall tubing.

I will say I’ve been enjoying my “soda-can” frames a lot. I really feel like I can climb better on the 26 Oracle. The Oracle 29 also has like 10mm more tire clearance than the Drak so I can run a 27 tpi knard on a Nimbus rim. If it weren’t for the clearance issue I’d have just stuck with the Drak.

Im also really appreciating the build quality of the KH 24. The frame shape is great and everything is way solid.

Have you tried any of the steel Qu-ax frames? They seem like a steel frame using a similar leg/crown shape as the KH.

That being said, I like my steel frames too. I 'm selling some on the trading post, but if I don’t get any bites Ill happily keep them. There’s something awesome about a battle scarred but still strong steel frame that just keeps on going. Down here in the desert, rust isn’t an issue, but bashing soft metal against hard rocks is an issue and steel is good for that!

Correction noted - UDC lists the 24 Steel frame as 790g - sorry about the error there.

Not sure why UDC weights are so much less than my measured ones - even without a clamp, bolts, and caps those weights seem a bit light (my Nimbus steel 26 frame still comes in at 975g without a clamp, bolts, and caps). My scale isnt tops, but it came within 20 grams of the spec’d weight of the Oracle 26 so it can’t be that bad.

If anyone at UDC reads this - you might consider adjusting your frame weight specs on the site. It will help folks know what they’re getting.

weight

The first aluminum 27.5 plus frame I built is 502 grams, that being said when you cut weight you also cut stiffness. Just a thought