Hub question

Does exist 125mm, alu, ISIS, NO disc hub, 32 holes?
Maybe an older model for Oracle 36"…
I am stll experincing my new spokes and I am facing big issues with lateral stiffness. So I need a 125 hub with no disc (so I’ll use a KH spirit EBD) and Alu (not to deny spokes’ weight saving) and 32h to match the Brauss rim

Regarding the hole mismatch there are ways to lace 36-32, I know someone here did it with a Schlumpf.

Here is a page that describes it too.

Thank you! I am already doing crazy stuff so I can make it that way

Just looking at the photo of the 36-32 completed wheel. It could hardly have been taken against a worse background.

Here is caseytronic’s Schlumpf 36-32 article.

Since you mention lateral stiffness, you might find Ali Clarkson’s latest video on his ‘rope spoke’ wheel interesting if you have not see it already. ( I should maybe also put this into the thread that discusses this stuff. )

In it he talks to someone who has developed a parametric finite-element bicycle wheel model and done some analysis of steel versus ‘rope’ spokes under vertical, lateral and torsional loads. The lateral-load discussion starts about 26 minutes, but you probably need to watch it all to understand the modelling and loading conditions for the analysis.

As an aside, one interesting thing I took from this video is that spokes fail because of lack of tension and the fatigue that that causes cycling in and out of the zero load condition. So basically it is slack spokes that fail (at the head at least).

I’m facing a lot of issue:

  1. Brauss rim with 32h and presta valve… always ride tubeless… now doesn’t exist any Presta Valve 36er tube on sale, nor won’t to tubeless everytest (done it 4 times already, now I cannot go on) and true again the spokes and so on
  2. 2wheelers are experiencing problems with elongation with 29" wheel… it is a fresh breeze solve the same problem with the same augmented elongation issue on a 36er
  3. They are speaking about 2wheeleer hub… now consider the different lenght of a q-axle alu 32h ONLY DISC hub… the disc side spokes are almost vertical and rub every brake but using a 203 disc… you can imagine the lateral stifness of an elastic vertical spoke.
  4. I already understand that the tension is the only key, but the non disc side cannot reach high tension without having a wheel completely offset (I get to about 2mm side offset) towards the non disc side.
  5. High tension means that the disc side strings are almost tightened as a knife blade (small, hard on touch and you risck to cut your skin) and the rim seems ready to explode
  6. Remember the spokes are hand made? The first 5-6 done are a bit different each-other… I cannot get similar pitch or equal tension readings.
  7. I cannot have every spoke outside the hub to check the tension using weight (builded spokes cannot be removed unless cutting them).

Now, I understand that I need to cut them, buy a 125mm alu hub 36, lace it in a 32h and lace it again. But is hard to decide if trashcan all the tests already done during long nights. However seems like lateral stiffness is the only real issue for those spokes in Uni applications. So short cranks, 125mm hub, small rims are all useful solutions. I ordered a 125 schlumpf… disc ready!!! So need to invent other ideas ans solve my issues

Yes, you have quite a few problems to address there. As you say the lateral stiffness with the large wheel seems like the main issue, especially when the difference in lateral displacement in the FEA model seems significant for a ‘conventional’ bike wheel – I’d need to look at the video again but they are probably assuming the modelled load is distributed across two wheels as well. The relatively narrow flange spacing coupled with the big wheel seems like a fundamental problem.

Given you have a fairly novel, non-commercial, application, it might be worth trying to contact the guy who developed the parametric FEA wheel model to ask if he would run the model for you for your setup. Given the model is parametric it should be pretty quick to set up – that might let you see if what you are trying to do is even practical with a symmetric flanged 125mm hub and a 36" rim. He gives his contact details at the end of the video, or you could reach out to him through Ali C. GIven the novelty of it he might be interested in helping.

I know you want to do this with a carbon rim, but as an initial approach have you considered using a 36 hole non-disc hub with an Aluminium 36 hole 36" rim (eg dominator 2)? That would allow you to run a symmetric spoking pattern with all spokes the same length and you will get the most triangulation possible. You can also use a ‘normal’ 36" or 29" tube with a Schrader valve to do your testing.

It would give you a simpler setup to see if you can get the required lateral stiffness. If you can make it work then there is a chance the effort of lacing a 36 hole hub into your Brauss rim is worth it.

Fair enough it has the disadvantage that you need to do this twice and the added expense of another rim (and potentially another hub), but doing this in a couple of iterations might give more chance of overall success.

Anyway, just a couple of suggestions…

Thank you for your ideas. I’ll get in touch with him and see what will happen. For buying another rim… I’m struggling with money spent and I’m running out of time to spend on Uni-project… so will wait a bit. Maybe I could drill the rim to use a Schrader valve and go on testing a bit before cutting the spokes and build a 29er for a future Hatchet (already own a carbon 29 rim ready for the schlumpf to arrive)

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I drilled the rim and last test went ok!