Weight differences between nimbus and KH (same wheel size)

Disclaimers:

  1. I’ve done a search, no other threads as pointed as my question
  2. UDC says a nimbus with a duro is 17lbs and a KH with a high roller is 12lbs. :astonished:

I have a nimbus 26 and a KH29. The 29er is noticeably lighter but with the tire pressure I like to ride with it’s a given that I’ll eventually end up with a pinch flat as soon as I start hopping/dropping. I’ve tried a few tires, all the same, so it looks like I’ll need to ride a duro to avoid pinch flats. That precludes the 29er for my hop/drop rides.

That got me to the point where I’d like to lighten my load in the 26" wheel size. It really wears me down when hopping stairs. I’d rather not spend the full price for a KH26, having two unis in the same size is the last thing I need since my wife is bugging me for a KH24 and I want a 36 before I start doubling up on unis that are the same size.

Ok, long winded speech out of the way. Now the questions>

  1. How much weight savings would be found in a simple frame swap (nimbus steel > to KH or nimbus aluminum)? UDC only lists the weight for the oracle frame.
  2. Would that even be enough, or is there a significant weight savings to be had in an upgrade to a drilled rim?

I’m guessing that I’d have to do both to see/feel any significant difference and the worry is that with the duro tire the weight savings wouldn’t really be significant anyway. I did get an opportunity to hop around on a KH24 and was amazed at how much difference there was between it and my nimbus 26… but then again that was just testing via hopping in a parking lot and not really putting it through the motions via hopping up stairs or something.

I guess I’ll skip the whole process if the answer is to replace the frame and the rim, at that point I may as well save up for another uni. Any input is appreciated, thanks.

The primary weight difference is in the tire, if you are sticking with the Duro you’re not going to be able to loose too much in other areas. A frame swap will save you somewhere between .75 and 1 lb; a drilled rim will save you 100oz.

The primary weight difference is in the tire, if you are sticking with the Duro you’ll limit what you can drop and it won’t be as noticeable when riding as weight loss at the wheel. A frame swap will save you somewhere between .75 and 1 lb; a drilled rim will save you 100oz.

The primary weight difference is in the tire. A frame swap will save you somewhere between .75 and 1 lb; a drilled rim will save you 100oz.

Really? A drilled rim saves 100 ounces (6.25 lbs)?

Sorry, mixed my units: 100g.

Sorry, wrong units: 100g

Sorry; wrong units: 100g

No, not really; 100g. Sorry for the units gaffe.

Hub, spokes, nips weigh the same. Rim strip for holed rims is extra weight.

A lighter tire and tube (or tubless) would be your best bet for improving how it rides relative to weight.

The Nimbus rim is heavier than a KH rim, depending on which one you have, but not so much because of the holes as the rim design; the Stealth 2 is a heavy and very strong rim.

If you’re gonna go as far as to rebuild your wheel, then you should skip the KH/Nimbus rims altogether and go to an MTB rim like the Velocity P35, which is just as strong but far lighter.

I couldn’t find a frame weight for the KH or the Nimbus II. The KH and Oracle should be similar (Oracle 525gm), for the Nimbus II the difference in frame material is more than just weight, aluminum frames have thicker tubing to be equal in strength to steel, so the weight difference for what is already a light component is not go to be very significant, 200-300gm. Maybe someone has a Nimbus II 26" frame weight?

26" Lighter vs heavier:

Velocity P35 vs Nimbus Stealth 2 = save 300gm
Hans Dampf 2.35 vs Duro Wildlife 3" = save 800gm
Duro DH tube vs Tubeless = save 300gm
Nimbus Oracle Aluminum Frame vs Nimbus II Steel Frame = est. 300gm

I’d start with the tire and go tubless.

Thanks for all the info. It’s starting to sound like the bulk of the weight difference that I experienced between the nimbus 26 and the KH24 was in the frame and tire; even though both had the duro I imagine that the 24" duro is still lighter than a 26" duro. Then maybe some negligble weight savings in the rim.

Missed the edit window, sorry.

Also note… I’m only looking to shave weight to make hopping up stuff less strenuous and tiring. I’m okay /have struck a balance ;)/ with the rotational weight.

If you want to do big drops, I don’t think you need to do anything other than get a beefier tire for your 29er and run high pressure. I don’t do drops more a meter, but I have no problems running drops that are 1-2’ running on a Hans Dampf or an Ardent. I do raise the psi when I’m doing rides with more drops and hard edged obstacles.

There is a big difference in hopability between a 29er and a 26er, so I’m not sure you’ll ever get that kind of performance from 29er, but you can certainly try. If I were looking for big drop and hopability on a 29er, the best tire would be the highest volume tire, which is going to be the Surly Knard 29 x 3"; available December 2012.

My suggestion would be to ride the 29er more and force yourself to ride the harder terrain, adjusting air pressure up, and dropping seat height down, see what you can do. I ride tech muni on my 36er, so wheel size really is immaterial, but doing more of a trials style riding is going to be easiest on a smaller wheel. I have a Nimbus muni 24" for teaching, it’s really small and slow, so I don’'t like riding it for long distances, but it certainly is agile.

Don’t believe the weights that are published, they are rarely accurate. UDC USA has the 26" Duro listed at 600gm, but in reality it’s closer to 1600gm! If you want lighter, change the tire and tube on your 26er, you can learn to hop and drop on lightweights tires, mountain bikers already do major DH and air time on the Ardent/High Roller/Advantage, they all ditched the Duro years ago.

They also have suspension…

But your other points are good.

Suspension, gears, bah! Totally overrated :wink: