Yet Another G29 P-Frame Build

Hi there,

I’m planning to build a 36er with a Schlumpf hub and Light Bicycle carbon rim. Before I order all the parts, I just wanted to verify a few details with the experts on this forum.

1) 36H or 32H?

I’m 80% sure I want 36H. On the order form I’ve already selected 36H + disc brake (the hub order hasn’t been confirmed or shipped yet). I figured 36H would be best in my case since I’m using a 100mm bearing spacing, which results in a weaker wheel/narrower spoke angle. I wouldn’t want to weaken it further. Then again, the thought of a wheel 4 spokes lighter is tempting…

2) Spoke Length?

UDC doesn’t have the Light Bicycle rim listed on their calculator yet. So I’m not entirely sure I’m receiving the correct results when I input the data I do have.

3) Frame choice?
Currently, the KH 36" frame is out of stock everywhere. Since I’d like to finish building this sooner than later (hopefully before Spring warmth returns), that seems to be a no-go. I’m not particularly keen on the Nimbus Universal 36" frame, either. As silly as it is, I find it a bit ugly. Which leaves me with the Mad4One Sonic Bang. I’ve read conflicting info whether it is compatible out-of-the-box. But I do love the M4O’s clean bearing cap design and variety of color choices…

That about sums it up. Everything else has been clarified for me in previous threads.

Thanks! Can’t wait to put this all together!

2 Likes

There are other frame options for 36er but I’m not sure, if they’re availabel in your region: frames for unicycles - QU-AX

I forgot to mention the Qu-ax frame. Yes, they’re not available in my region. And due to the lightweight construction, the frame is limited to 180mm rotors – I’m using 203mm.

And I should mention Flansberrium as well. Just not in my budget as much as I love Jakob’s work.

1 Like
  1. There is no right or wrong. I don’t think you will break a 32H wheel even if it is theoretical weaker than a 36H. But then again a 36H gives that peace of mind. Also for the small weight saving (~40g?) maybe just go for the strong option. Light wheels are nice (I have 4 unicycles 27.5" (32H), 29" (32H), G29" (36H) and 36" (36H) with carbon wheels) and feels super responsive but there are also some drawbacks in my opinion so aiming for the lightest build possible might be fun but not necessarily “better” depending on how you define “better”.

  2. Not sure what length/dimensions you are missing. Just use a “custom” calculator like Online Spoke Calculator for Hubmotors and Ebikes

  3. The bearing caps of the M4O “M” frame fits like a glove. I assume they are identical on all frame sizes. But just write/ask mad4one directly and they will know. Also have a look in the thread Schlumpf 2022 Build Questions - #135 by Hammer for a lot of nice information about building.

2 Likes

Hey :wave:

Should be a fun one - I can testify to the fun that’s to be had with this building process.

My main question is why you’re committed to the 100mm spacing?

The current deal is the best value when you look at the 125mm hubs. Those used to be a £200 uplift and in my view they make the best 36” wheel with either a LB rim or standard aluminium one.

Of course it locks you to using either a Nimbus or Flansberrium frame - and you may not like the wider stance of the hub / crank spacing.

But 125mm hubs were a big thing that they got made - and now having those coupled with an asymmetrical rim from LB is it just the best mix.

32h I’d skip - as it locks you into using a carbon or non-uni-specific rim. 36h is great as LB offer this hole count but you’re still able to use dedicated unicycle rims which are all in 36h.

If I was building a set up that was set on using say a specific rim that only comes in 32h - that’s when that hub set up is worth it. But it is less versatile.

As for a frame - I’d off the peg, I know the KH36 fits like a glove and the new brake tabs but hole for the reaction torque bolt is spot on.

Then I’d say it would be best to go custom - via Jakob. (But I would say that wouldn’t I?!? :joy:)

Spokes - I’d wait and get those carefully calculated to the ERD of the rim - and be sure to have LB drill spoke hole angles to match your hub set up. I am sure I posted the details for these before but can dig out the numbers.

Spoke length again - I have paid for calculator that I can help you with if you want….

3 Likes

Almost everything has already been said: 36H, 125mm, M4O should fit.

A few more info:

  • RGB frames should perfectly work with 203 mm rotors if you don’t plan on jumping big drops. That’s the only case when they failed. Besides, they have been reinforced to avoid the issue. So, if they were available in your region, that would have been a great choice.
  • KH frames seem to be available at the French shop “CDK”. You may ask Romain, the shopkeeper, how much it would be to send such frame to your location. Certainly not more than for a M4O frame :slight_smile:

36H of course with internal brake disc !

1 Like

This is one consideration that’s been gnawing at me ever since deciding to sell my old G36. And frankly, I don’t have a great answer. I come from flatland riding so I grew comfortable with 100mm spacing and zero-Q cranks. So when I came back to unicycling over a decade later, 100mm made the most sense in my mind. Plus, I felt comfortable with the 100mm non-disk G36 I was riding before. Now I guess I’ve got it in my mind that’s the best way to go.

But maybe to assuage my concerns I should put it to a public vote. We’ll see if that helps change my mind :thinking:

Poll linked below. For whatever reason polls don’t work in the middle of other text.

Looks like they only have the old right-side disk tab 36" frame.

I would say 125 as that makes a stronger wheel (spokes are known to easily break on 100mm/G36). However, that would lock you onto Nimbus frame as long as you can’t afford a Flansberrium frame :confused:

The website is not always up-to-date. You should definitely contact Romain to check :wink:

1 Like

@MatthPeder, if you reach out directly to QU-AX, they will most likely be able to sell you a frame. I live in Boston and they sold me a 36” RGB uni a few years ago. I think maybe their web form just isn’t set up to calaculate taxes and include shipping options for US customers. That said, shipping was $300 EUR for the big unicycle. At the time, though, the exchange rate was so good that the total USD price still came out lower than a 36” nimbus.

I haven‘t read the whole thread yet. Apologies if this has been mentioned already. You say that you‘d like to do the build rather sooner than later, ideally before spring comes around. All I can say is don‘t hold your breath.

Goudurix in Montreal has them, and they ship to the US. I’ve ordered all my Qu-Ax stuff from them.

https://www.goudurix.com/en/frame-muni-aluminium-rgb-19-quax/

1 Like

This should be helpful for getting spoke holes drilled to match hub flange spacing at 100mm:

While I’d personally be nudging you towards a 125mm hub regardless of the limitations re frames for this (Nimbus or Flansberrium) - the good news is however - with an asymmetrical rim such as the one from LB and good spoke hole drilling angles - a 100mm hub can be built up to be pretty strong - and stronger than any 100mm 36er Schlumpf with either the new disc hub or the BrakeFast set up heretofore (using the previous symmetrical rims available)…

So the magic sauce here is the LB rim and probably evens out the gains you’d get from a 125mm 36” wheel build.

The above screenshot numbers should help you figure out spoke lengths for the LB rim.

Lots of chatting mostly to myself here: Game changer - 36er CARBON wheel! - #313 by mindbalance

… around ERD shenanigans - main up shot is LB list the ERD as 755 but in reality this isn’t where the nipples’ heads / spokes are destined to wind into so depending on nipples used - it is needed to add around 2mm per nipple or more again depending on nipple - but that all makes sense 759 being 755 + 2mm + 2mm as a base line.

I built my 125mm hub with 360/362 spokes so you can probably fathom the ERD I ultimately decided to go with.

I’ve probably gone and over complicated it for you now - but wanted to still share this as getting A-OK spoke lengths will make for a really robust wheel. In short. Worth the head scratching and manual ERD measuring when you have your rim + desired nipples :nerd_face:

2 Likes

No, no, this is absolutely the level of detail that excites me. It really helps knowing all the ins-and-outs of wheel building. This will be my first wheel build – other than a failed 19" trials wheel I tried building as a teenager. So I want to know exactly what I’m getting myself into. I’ll still get it professionally done but I’d like to have a sense of what goes into it.

2 Likes
  • 100mm
  • 125mm
0 voters

Well, no – you’d get the same gains with the 125mm hub and the LightBicycle rim, and even if you went with a symmetric rim with the 125mm hub the wheel would still be stronger… The 125mm hub and the LightBicycle rim seem like the ideal combination to me.

The Nimbus is a good frame, it got Ed Pratt round the world with no issues with the frame itself – fair enough you might not like the rounded crown or whatever (I’m not overly keen on the green, but I could live with it… :slight_smile: )-- but you can actually buy one just now, and if you don’t take to it, swap it out down the line for a Flansberrium one when budget permits… if you want to swap to a bigger seat post at that point too, it is not an enormous cost compared to the cost of the actual wheel.

3 Likes

Alright, well, after sleeping on it you all have convinced me 125mm is the way to go. I take it then I’ll require 360/362mm spokes based on the ERD you went with, @mindbalance?

In the back of my mind I was also considering a 29" Schlumpf as a good all-round hill climbing/distance uni (more portable for flights, too) in which case I could’ve used the 100mm hub. But, guess I’ll have to become a billionaire to own two Schlumpfs at once one day!

2 Likes

Very true. I was probably trying to not be too much of an advocate for the hub I’ve got - there’s always that sense that we’d recommend what we have / know, rather than be fully objective.

This is very true in the sense the 100mm hub is more versatile for other wheel builds. Nothing stops you moving the 125mm hub to a 29” wheel but it would require a Hatchet frame or perhaps using a 32” nimbus frame. Not as adaptable I guess - but not impossible to make work.

Going back to the 125mm - as the current deal price it is just the better value - and likely to be a rarer / more unusual Schlumpf down the road. Plus you’ll have zero issues with rotor clearance given the wider hub and better bracing angles of the spokes.

Should be 360/362 but when you get closer to the build - I’d recalculate them as nipples etc make a difference - I can do this for you nearer the time.

If you’re ordering the 125mm you’ll need to let LB know these details for the drilling angles for this - or just say: drill it like Felix’s 36” rim :joy:

5 Likes

It seems to me that a g36 is a wonderful choice for skilled riders whose fitness is good and whose lifestyle and age can absorb the inherent risks of riding significantly faster than they can run. In the (maybe distant) future it’s likely that either fitness or acceptable levels of risk-taking will drop, so having an option for moving the hub to a smaller wheel seems wise. But that could still work with the 125 hub - there may be off-the-peg 125mm 29" frames by then, or the cash available to order a bespoke frame. However failing that, might it even be viable (if not optimally pretty) to simply transfer the hub + rotor to a 29" wheel and keep using the 36" frame? That would make a g29 all-rounder for the cost of a rim, spokes and tyre, and I suspect the frame could could take a seriously fat tyre.

2 Likes

That’s totally doable!

2 Likes