Rear Wheel Lost All Tension

[Rob H]

Over the years I’ve built tens of pairs of wheels and never had an issue with any of them until now. The wheel in question was the first MTB wheel I’ve built with a boost rear hub and ironically the build I was most proud of until I rode it. All the right hand spokes were tensioned was to 125 with 4% variants, which I was dead chuffed with, and about the limit of the Park Tools TM1 gauge which I use. The left hand side where about 70 due to difference in spoke angle this was less than I expected and makes me skeptical about how beneficial boost actually is. Trueness wise I was a bit sloppy only about 20 microns but the stickers on the rims were about 12 microns and it was starting to do my head in having to constantly adjust my reading to take them into account. So all in all this should have been a bombproof wheel yet a couple of miles into my first ride it lost all tension, and ideas why? The only change I made to my build was to use a Wheel Fanatyk nipple bath to soak my nipples in oil before fitting where on previous wheels I used a cotton bud to apply copper grease to the end of the spoke.

Any suggestions as to why I lost tension?

Before someone states the obvious I de-stress the spokes after every adjustment and before every tension meter reading.

For those that are curious the wheel spec is as follows;

Hope Pro 4 Rear Hub
Stand Flow MK2 Rim
DT Swiss Double Butted Spokes
Sapim Alloy Nipples

 

[RickTheUncivil]

Re:

I wonder if oiling nipples is a good idea?

But back to your question....

I wonder if oiling nipples is a good idea? Even under tension does it encourage things to move and work loose?

 

[cce]

I can't see any flaws in your working.

i always oil my nipples and the only ones i've had come undone were in my early days of building when i wasnt tensioning high enough

 

[Rob H]

Re:

Given the difference in spoke angles and the relative difference in spoke tension do you reckon I need to increase the tension to something like 150 & 90? I need to work out the exact ratio as I wonderingly if 70 is a little too low.

 

[Rob H]

Re: Re:

I wonder if oiling nipples is a good idea?

But back to your question....

I wonder if oiling nipples is a good idea? Even under tension does it encourage things to move and work loose?

Nothing wrong with lubing your nipples, very common practice.

 

[cce]

Re:

70 is plenty. Word on the internet is the park over reads a bit but not *that* much

I can foresee bad things happening to the rim at 150, even the Instagram wheel mafia don't go past 130 driveside for 11 speed road stuff and that has dreadful angles

 

[Woz]

Re:

Ok, I'm no wheel builder expert, but you say 'lost all tension'. Is it like flopping about and out of true. What is the tension now if you have a guage to quantify the
loss. Like 10% or?


I do by feeling and have a pair of Mavic Classics and the rear needed five rides and five tension ups to be remotely usefull and this wheel was deemed the pros choice for Paris Roubaix. Admittidly it's old stuff, but they were as good as NOS.

 

[Rob H]

Re:

I could physically move the rim an inch side to side, that loose, but once they start to loose tension it all goes downhill pretty fast

 

[mattr]

From memory stans typically have very low max tensions. Sort of 110-120 region. The downside of light, un eyeletted rims i guess.

As for oil, what oil is the important thing. I've been taught with two different oil types and tried a few others. The right stuff makes life easy, the wrong stuff you might end up having to add 20 or more kgf to get the wheel to stay tensioned.

 

[Rob H]

Re:

Very interesting, what oil do you recommend? I went for a very thin oil and I’m wondering if a thicker oil would have been better