This has always bugged me. When building a rear wheel sometimes the necessary dishing to get the rim centred is so much that the drive side spokes can be super tight but the non-drive side ones are a tiny bit loose (lose). Is there a way round this? Or is it just the way it is? I've never had a wheel come apart, so I guess it's ok, but the noticeable difference in tension irks me somewhat..
Use an asymmetric rim.
Use an asymmetric rim.
Is this a thing?
Jobst does not appear to regard this as a problem. I think it's just teh way it is.
Assuming the spokes are the right length the drive side's always going to be tighter because of the angle off the hub isn't it?
Go BOOST!
If the non drive side are actually loose you might have made a mistake. Most rim/hub combinations should have something like a 55-60% of the drive side tension on non-drive side. So still tight.
Are you measuring tensions at all? Or just assuming "that's round and true, must be tight enough".
Asymmetric rims move it to more like 100/60-65ish tension, so better, but not "fixed".
Ryde are all asymmetrically drilled too.
[url= https://www.ryde.nl/rims ]https://www.ryde.nl/rims[/url]
A number of fatbike rims are also drilled in ways that allow for it.
Is this a thing?
Thanks! That's waaay wider than anything I have ever built though..
Ryde are all asymmetrically drilled too.
Interesting stuff, I didn't know about these rims..
It's normal for a cassette wheel: think about the triangle formed by the hub and the two sides of spokes as you look at the wheel in line with the rim. The horizontal forces on each side must be equal, which means that the side with the more vertical angle has to carry much more vertical tension. (Basic trigonometry is left as an exercise for the reader 😉 )
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Various approaches mitigate or reduce the problem:
- Rim design: asymmetric rims shift the top of the triangle towards being in line with the middle of the base, but only a bit
- Hub design: reducing the non-drive side flange offset moves the middle of the base towards being in line with the top
- Hub type: non-cassette hubs (singlespeeds or hub gears) can have the drive side flange further out and thus normally have symmetrical triangulation
- Rim and hub system: using more spokes on the drive side than the non-drive (normally 2:1) evens up the tension in the spokes whilst retaining the dish by using more of them in the side that has the greater total tension
- Radial non-drive spokes: only for rim braked wheels, but using radial lacing on the non-drive side can help reduce fatigue problems caused by low tension on that side (as well as providing a probably negligible triangulation benefit)
But yes, a dished wheel normally carries very high tension on the drive side and much less on the non-drive. Balancing the two can be a bit of an art sometimes.
Ryde rims are nice, but don't like rocks IME
If the non drive side are actually loose you might have made a mistake. Most rim/hub combinations should have something like a 55-60% of the drive side tension on non-drive side. So still tight.
Are you measuring tensions at all? Or just assuming "that's round and true, must be tight enough".Asymmetric rims move it to more like 100/60-65ish tension, so better, but not "fixed".
They're not really 'loose' as in baggy but there is a noticeable difference in tension, although I notice it the most when tightening the nipples (lol).
Nope, I've never measured the tension, pretty much as you say 'that's round therefore it's good' combined with how tight they feel (both as I tighten the nips and the old 'squeeze two spokes together and see if they move' malarkey)
I've got a pair of Trace 29's on my 29er hardtail (bargin buy from superstar with CK hubs). They've been fine for over a year. They have no eyelets (like stans) but I've seen no cracking or issues.
But yes, a dished wheel normally carries very high tension on the drive side and much less on the non-drive. Balancing the two can be a bit of an art sometimes.
Thanks, this is the reassurance I was looking for!! 🙂
Use an asymmetric rim.
Is this a thing?
I've got a pair of Mavic rims that are, can't see them on the current Mavic website though, which is a pity as I really quite like them.
Edit - of course the other option is a smaller cassette or an offset rear triangle (which is uncommon but does exist).
I built a singlespeed wheel for a mate recently. Using the same length spokes and getting equal tension on both sides was a bit unnerving, tbh 🙂
11 speed road wheels are sometimes a bit silly in this regard, with NDS spoke tension being mid-40s % of the drive side. As others have said, it's just the way it is, and as long as tension is nice and even, it shouldn't cause a major issue.
you can raise the drive side tension a bit, then the NDS tension *has* to come up to get the right dish, but there's only so far you can go before the rim cries enough
The process i use for a rear wheel is as follows:
Lace the whole wheel, with very loose spokes first.
I then tighten the drive side spokes up to about 2/3rds of the final tension concentrating ONLY on getting the wheels round. I don't do ANYTHING about getting the wheel true.
Then, i switch sides and work on the NON-drive side to JUST concentrate on getting the wheel true AND DISHED properly.
When the wheel is both TRUE and ROUND and DISHED I go over all the spokes to get the correct tension. this way i get tension by adjusting ALL spokes on both drive and non-drive sides.
The wheel then stays TRUE and ROUND.
Simples. (well, kind of)
Asymmetric rims move it to more like 100/60-65ish tension, so better, but not "fixed".
I’m just getting around to my first Asymetric build (WTBs and DT350) and reached for the current Musson calc. It does relative tensions now as well as accounting for stretch of spokes. It seems to reckon I’ll be carrying more like 100/90 ... Will be interesting to get it built and measure. Will be after Christmas before this happens though.
[quote=Bez ]- Rim and hub system: using more spokes on the drive side than the non-drive (normally 2:1) evens up the tension in the spokes whilst retaining the dish by using more of them in the side that has the greater total tension
Is how I built the rear wheel for my road bike - 32 hole hub laced to a 24 hole rim with 16 DS spokes 3x and 8 NDS spokes 2x. The disadvantage is that it significantly reduces lateral stiffness, as most of that comes from the NDS spokes. Which is also an issue with:
- Hub design: reducing the non-drive side flange offset moves the middle of the base towards being in line with the top
...whilst that helps balance the tension, it's generally considered a bad idea due to the loss in lateral stiffness.
One other option you missed is to use thinner (more heavily butted) spokes on the NDS - ie DT Comp on the DS, DT Rev on the NDS. One of my MTB wheels is built like this. It doesn't increase the tension of the NDS spokes, but because they stretch more it makes it less likely for them to go slack (which is what you're trying to avoid).
Currently swapping rims on two hubs. Built up a stans crest today and although drive side tension is higher NDS is pretty good. I build them in a similar way to lardman^. Having a go at a ryde trace trail asymmetric rim tomorrow. Just got remember to make sure it's the right way round !!!.
One other option you missed is to use thinner (more heavily butted) spokes on the NDS
Yeah, I nearly put it in but thought it was heading too far out of triangulation issues. Like you I've used the Comp/Rev mix before (along with the 3x/0x combo).
