Checking a rim (just the rim) for trueness.

[GoldSpanner]

What would be the best way to check a rim for trueness? Talking about just the rim here, no spokes, nipples, hubs, nada

I would assume putting it down on a flat surface and simply seeing if there are any raised bits or whatever would be a fairly good indication?

Furthermore, once said imperfections have been identified, any way of sorting them out?

Cheers!

Alex

 

[Spokesmann]

Best tested as a whole wheel, makes it easier and the wheels can be assessed and repair in the whole, a visual inspection would do, the scientifically minded may use a dial gauge as well...

 

[mattsccm]

As above but your way will at least show major dents etc. For roundness you could make a gauge that fits across the outside of a rim..
Rotate it and this will show major issues. Both ways should be enough to show dents that won't pull out when building. If they are too small to show then a good build should do the job.
Of course nothing is perfect!

 

[GoldSpanner]

welllllllll, I had the front wheel laced up, as far as I could tell, with adequate tension.
I had the spoke tensions equalised almost perfectly, yet the thing was flapping around all over the place.

It was a velocity deep v.

I think I've learnt my lesson.

The dt swiss rr 465 looks like a much better rim, which I may replace with.

 

[Woz]

Was it a brand new rim?

 

[GoldSpanner]

Yep. Turns out the have really bad quality control.

 

[Woz]

IMHO if you can get it true and round regardless if all spokes have equal tension, then what is the problem?

There's bound to be a slightly "off" area around the join, and when laced it will pull it all together. Admittedly, I tend
to build and tweak wheels with a fair bit of tension in the spokes to make them stiff.

 

[GoldSpanner]

Well once I had it all at even tension, I gave it a go a truing it. I got about halfway, but by that time the spoke tensions were so uneven I didn't see much point continuing.

Even spoke tension is more important than the wheel being perfectly true, but in this case it would have been unusable.