hydrocarbon

Hey, I'm building a new front wheel for my Riese & Müller Load 60 and I'm trying to decide on the lacing pattern.

Here's the stock wheel, laced 2X on both sides to a 100 mm disc hub with about the same flange height as the incoming 110 mm hub.






I'm wondering if the spoke angle at the rim will be excessive if I go 3X on the new build. I've seen 3X and even 4X BMX wheels, but it seems like it can start putting a fair bit of bending at the spoke nipple after a certain point.

And good guides or resources on how much is too much when it comes to spoke angle? Or can I get fancy and maybe machine out the holes a tiny bit to allow better alignment?

Build details below (Newmen Evolution SL 110X15 hub with 56.6 mm flange diameter, Alex MD30 rim with 380.6 ERD, 32H)


2X lacing

3X lacing

Dan Burkhart 

3 x will give you a spoke entry angle of over 8 degrees. Not horrible, but with a small rim like that, I would go 2x. Spoke angle will be around 6 degrees.

hydrocarbon

Thanks for the reply! Yeah I was playing with the numbers and it seemed like there was a difference when I just put in 2X on one side and 3X on the other without considering offset, but I get almost the same worst-case total angle between 2X and 3X lacing: 13.5 vs 13.8 degrees on the non-disc side with the 35.7 mm offset.


2X vs 3X

Unless I'm doing the numbers wrong, I would prefer 3X for strength and for spoke availability (182/184 mm is in stock locally, 172/174 requires custom cutting and threading). Any reasons to consider 2X if the non-disc-side angle is only 0.6 degrees less?

Seems like the heavy-duty cargo bike 20" builds like the 35-mm-wide Atlas rim / 110 mm hub wheel on the Tern GSD use 2X lacing (with 13G spokes on that one), but I'm not sure why that's the case.

Andrew R Stewart 

My question is about the axle length/hub width changes. From 100mm to 110mm. Is the fork/dropout able to handle that difference/increase of width? Andy

hydrocarbon

Andrew R Stewart Not the one the bike came with, but I'm building a wheel to fit a new fork with 110-mm axle spacing which will replace the incredibly-bad stock Suntour that has seals so crappy that the fork fills with water and locks out.

With the new wheel and a lower headset swap to EC44 from the internal 1-1/8" one, I can install a tapered-steerer Manitou to make what could be the world's first longish-travel-fork Load. Can't wait for the parts to arrive.

headasunder

Why would 3 cross be stronger

ClydeClydeson

headasunder The more the spokes cross the closer the spokes are to parallel to the force from the hub caused by disc brakes, hub motors, dynamos, etc.

For instance, a radially laced (0 cross) wheel build has zero ability to handle load from the hub as the spokes are perfectly perpendicular to the hub - spokes can only pull in a straight line toward the nipple at the rim so they need to be angled such that they can pull against whatever the hub is trying to do. Every added cross at the spokes decreases the angle of the spoke leaving the hub, and so increases the spokes' ability to resist hub forces.

Radially laced wheels were becoming stylish or more common in the late 90s, then disc brakes came out and stopped the fad almost immediately.

Andrew R Stewart 

"Not the one the bike came with, but I'm building a wheel to fit a new fork with 110-mm axle spacing which will replace the incredibly-bad stock Suntour that has seals so crappy that the fork fills with water and locks out.

With the new wheel and a lower headset swap to EC44 from the internal 1-1/8" one, I can install a tapered-steerer Manitou to make what could be the world's first longish-travel-fork Load. Can't wait for the parts to arrive".Hydrocaebon

Thanks for the greater details. Your bigger goal is interesting. Fork replacement for a "better" design, sliding seal wise. The through axle will also help to keep the sliding members aligned and thus less wear. As to water getting inside- I find this a harder goal to expect if the bike is exposed to the elements often. Nature has shown the ability of water to get into anything .Andy

hydrocarbon

Andrew R Stewart The problem with the Suntour is that it doesn't have what can properly described as a seal, but instead uses a plastic bushing sleeve. This allows significant play even when new, and doesn't form an effective barrier to water. This is a huge problem in a wet environment; my fork gets about 30 mm travel out of its claimed 70 and is rusting internally like every other one I've seen around here.


The fork was cleaned before a fast ride that included dropping off a few high curbs with about 50 kg in the cargo box, and this is all the movement I got.

The mechanic at the shop that sells and services bikes equipped with them (e.g. Riese & Müller, Tern) says it's the worst-sealed fork he's ever seen. Some owners have resorted to drilling 2-mm holes in the lowers to allow the water to escape after it seeps in. I figured I'd simply be better off getting a better-quality fork instead of trying to do anything to this hopeless thing. It also lacks any adjustment other than limited preload, and uses a crude friction damper that probably isn't helped much by operating in a rusty-water internal environment.


Note the complete lack of O-rings or other proper sealing elements. The "dust seal" component is made of ineffective cheap plastic.

Not a single other fork or shock I've used has this problem; not even my Reba which is still using the seals it came with in 2008. It's hard to understand why they use such crappy suspension components (the original rear shock sucks too) considering the high component and build quality of the rest of the bike. In any case, I'm very much looking forward to everything arriving for the new fork setup; the adjustable air shock makes a huge difference already!

Darth Lefty 

Good 20 inch suspension forks are really really rare. That machete Junit is fairly unique. You have to wonder about the damper valving, since it is designed for little kids on mountain bikes and not for your application, but probably anything would be an improvement from what you’ve got.

That said, the dust wipers on any forks are not a total barrier to the elements. Sometimes they’re airtight if they’re in nice condition, but it’s not a given. On the Suntour forks you need to keep them greased. It’s only grease. There’s no oil. On nicer forks there’s an oil bath in the lowers transmitted to the stanchions by foam rings and that keeps it from scratching or rusting but the oil gets depleted.

hydrocarbon

Darth Lefty
Yeah, I considered the spring rate and damping, but I figure I can just put heavier-weight oil and maybe some volume reducers in if that's a problem. Plus the front wheel of a cargo bike isn't normally that heavily-loaded anyway; there's way more weight on the rear wheel unless you're strapping in uranium ballast all the way at front of the box or something. Besides that, the only complaint I've seen about this fork is that it doesn't really go soft enough for kids, so I'm pretty confident it will work well. As you said, anything is an upgrade from the Suntour.

There are some decent forks out there in 100X15 and 1-1/8" straight steerer such as the MRP Rustler, RST Spex/Spark, and Prevelo Heir, but I got the Manitou for 40% off so that helps offset the effort of building up a new wheel and swapping the headset to be able to use what appears to be the best option available in 20".

I've given up hope on the crappy Suntour fork. I don't even like it brand-new, and the salty coastal climate pits the cheap chrome plating even though I rinse it after every ride. None of my better-quality forks and shocks have this problem under the same riding conditions. Anyway, I'll try to remember to post up photos once the build is done! Can't wait to try a real fork on this amazing chassis; an air shock on the rear was a huge improvement over the el cheapo crude coil spring it came with. I can't understand why Riese & Müller puts these on its flagship bike when the rest of uses such high-quality components.

Darth Lefty 

Since that’s a really fat tire, have you checked about clearance?

hydrocarbon

Darth Lefty
Yeah I checked and it seems like it offers more clearance than the Suntour, plus it has wider axle spacing so I don’t anticipate any problems.

But if there are any issues, it's possible to modify the fender at the crown, replace it with something lower-profile, or run different tires — those Supermoto-X 2.4”s aren’t stock.

One thing I am wondering about is whether it would be crazy to drill and tap mounting threads for the headlight in the crown, or just rig up something external with hose clamps or similar…

hydrocarbon

Ha, I managed to find the spec table in the manual, and Suntour lists a puny 58 mm maximum tire width (2.25") for the stock fork. Interestingly, R&M equips their Packster model with that fork and the big 2.4" Schwalbe.

So I'm guessing the new Manitou will work just fine.