Truing wheel

NWMTB

Hi


I have some asymmetric carbon rims which need truing, having gone through the spokes with my park tool spoke tension meter a few were quite low so I have tightened them but it's still not much better.

Does anyone have any tips on how to true asymmetric rims? Is the spoke tension equal on them?

I could easily take to a shop but like to give things a go my self first

The Rookie

You true it the same way as any other rim,

Best to bring those that are slack up to a sensible tension and then adjust spoke tensions to align the rim as it should be.

If the spokes are the same length and angle each side then the tension will be the same left and right, if they aren't it won't!

NWMTB

Thanks. Spokes are equal length, I tensioned them all the same last night and it still has the buckle in it unfortunately. Seems to be at one point and when spinning the wheels it looks as though one side goes down!?

Any tips on that? Is the tension too little/high on one side and throwing it off?

Thanks

cooldad

You need to do some research. It's not just a matter of getting equal tension, you need to adjust the right ones to straighten the wheel, which generally entails increasing the tension on one side and reducing it on the other.

The Rookie

You can build a completely useless wheel with even tension, that only matters ONCE you have it true.

kinioo

NWMTB wrote:

Hi


I have some asymmetric carbon rims which need truing, having gone through the spokes with my park tool spoke tension meter a few were quite low so I have tightened them but it's still not much better.

Does anyone have any tips on how to true asymmetric rims? Is the spoke tension equal on them?

I could easily take to a shop but like to give things a go my self first

Well, checking / adjusting the tension of the spokes is not actually truing, is it ?

Listen to what Rookie says and find few clips on YT.

If the rim is not massively out it should take you longer than 5--10min.

No need for special tools / stand etc.

Use your bike frame/fork plus zip-ties.

C.

kinioo

kinioo wrote:

NWMTB wrote:

Hi


I have some asymmetric carbon rims which need truing, having gone through the spokes with my park tool spoke tension meter a few were quite low so I have tightened them but it's still not much better.

Does anyone have any tips on how to true asymmetric rims? Is the spoke tension equal on them?

I could easily take to a shop but like to give things a go my self first

Well, checking / adjusting the tension of the spokes is not actually truing, is it ?

Listen to what Rookie / CD say (you cant go wrong) and find few clips on YT.

If the rim is not massively out it should take you longer than 5--10min.

No need for special tools / stand etc.

Use your bike frame/fork plus zip-ties.

C.

Rightarmbad

If all you spokes are even tension on each side, the wheel should be true.
But, depending on the rim you have, there may be a variance around the rim join that will cause a little bit of tension difference over 4 or 5 spokes.
If it is not the rim join causing the buckle, then your rim is bent and then it is up to you to choose how far from even tension to go to achieve whatever balance between even tension and buckle you think is best.
If you find the tensions far out to get the wheel reasonably straight, get a new rim.

The Rookie

Poppycock, as above yo can build a completely out of true wheel with even spoke tension, trueness comes first!

cooldad

Poppycock! Well played sir.

Rightarmbad

The Rookie wrote:

Poppycock, as above yo can build a completely out of true wheel with even spoke tension, trueness comes first!

No you can't.
You haven't built many wheels have you?

You can however build a reasonably true wheel with tensions all over the place.

Unless the rim itself is a wobbly piece of shit, or somebody drilled the holes in the hub off centre, even tension is a true wheel.
When I build a wheel the rim guages never even come near the rim until the very final touch up true, up until that point it is all built with closer and closer tensions until it is near perfect.

I think you may be smoking poppies if you think otherwise.

The Rookie

Yes I've built wheel,s and I can also do trigonometry, perfectly possible, noting that as the spoke angles are almost invariably different then you can't possibly equalise left and right and keep the dishing right.

Rightarmbad

Rightarmbad wrote:

If all you spokes are even tension on each side, the wheel should be true.
But, depending on the rim you have, there may be a variance around the rim join that will cause a little bit of tension difference over 4 or 5 spokes.
If it is not the rim join causing the buckle, then your rim is bent and then it is up to you to choose how far from even tension to go to achieve whatever balance between even tension and buckle you think is best.
If you find the tensions far out to get the wheel reasonably straight, get a new rim.

You can't read either it seems.
It says 'if all your spokes are even tension on each side'.
Dish away merrily.

The Rookie

Well if you want to be a pedant, the dish could be way out still have even tension on each side.

The fact remains that equalising spoke tension in no way guarantees a true wheel.

Rightarmbad

The Rookie wrote:

Well if you want to be a pedant, the dish could be way out still have even tension on each side.

The fact remains that equalising spoke tension in no way guarantees a true wheel.

No, fact remains, truing a wheel in no way guarantees a even tension wheel and will not be reliable.
But truing a wheel by evening the tensions will make a true and reliable wheel.

Dish has nothing whatsoever to do with even tension, dish wherever you like, the tension should be even for all spokes on their respective sides of the wheel.
If it is not, you built a shite wheel.

If all the components are good, even tension will always be a true and reliable wheel.
You can however build a shitty tension wheel that appears to be straight by trading small amounts of out or roundness to pull the wheel straight to compensate for uneven tension. This wheel will never be reliable.

Do up one spoke tight or loosen it and not only does a buckle appear at that spoke, but also roughly at a tangent to it, IE have a sqiz at 90 deg from it and you will find a smaller buckle, and to a ever lessening effect all over the wheel.
You can then go on forever straightening buckles until all these buckles add up reasonably straight wheel with a small but hard to see out of roundness, as out of round requires many more turns of a spoke to create than a sideways one, thanks to your smartarse trigonometry.

By building with tension, you never set up this death spiral of tension unevenness as by equaling tensions always in the long run brings the wheel true, even if the overtight or loose spoke appears to worsen a buckle when evening the tension, never be tempted to tighten an already tight spoke or loosen an already loose spoke, the problem arises somewhere else in the wheel. If that's the scenario that presents you, forget straightness for the time being and go hunt down too tight and too loose spokes, eventually they will all start to gel and the wheel will come into true.

Only a fool would continue on to straighten a wheel with uneven tensions by adding more uneven tensions.
Building is the same, why fruck up a build only to have to spend an hour to fix up your own fruck up?
Build it with even tensions and then make small allowances to even tension to allow for manufacturing discrepancies.

To think anything else is to not have a clue.

cycleclinic

I build wheels for living. I get a wheel straight then I even out tensions. Get tensions even first and its all over the place because the rim wall thickness is never consistant on any rim.

Now someone will tell I have no idea what I am doing just you watch!

If you are any good at this (I am) when building a wheel or truing you dont end up with major unevenness with a straight wheel which means evening out easy. some wheels I see for truing are all over place (tensions) and it is quicker to de tension the wheel and re tension. sometimes I see factory wheels from some well known on line retailers (own brands) with the wrong spoke lengths in them. This is not ideal and can complicate things if I cant turn the nipples any more.

What I have read above is people arguing over the same thing. Major unevenness should be addressed before the wheel is straight but if you have good feel you wont get major unevenness by getting the wheel straight.

Just beware OP the Park guage does not tell you the absolute tension well. the chart often gives tensions that are 10-15% too low but this varies from gauge to gauge.

The Rookie

Thanks TCC, exactly what I was saying.