Rear wheel spoke tension issue

Built my first wheels the other week using Roger Musson's guide along with bits and bobs from the Sheldon Brown page. Part list as follows:

Exage Hubs (100mm & 126mm)
DT Swiss Competition Spokes 2.0-1.8 (296mm for front 294mm and 292mm for rear)
Mavic Open Sport Rims - 36 hole

The wheels are laced in the standard 3 cross pattern. Front wheel spokes 20-21 on the TM-1, so around 100kgf - no problems there. The rear wheel has 22-23 (117-131kgf) on the drive side and 15-16 (58-64kgf) on the left. The left side spokes keep coming loose but to tighten them more i'd have to tighten the drive side (due to the dishing) which is already too high. These measurements were also taking whilst the tire was on (110psi), not advised i know but the tire pressure lowers the tension by a good 10-20kgf I'm finding. Without the tire on the drive side is very high.

I've stressed the spokes using Musson's pinch technique and avoided spoke twisting best i could by over tightening and loosing back to the desired position. It's my first build but i really can't figure out where I've gone wrong. My only options that i can think of are thread lock but don't want to go down that route or lower gauge spokes on the non-drive side so they tighten to a higher tension without pulling the wheel dish over.

Lastly I took my TM-1 to my LBS shop today to compare it to theirs. Mine was out but 2.5 units - tested on several spokes multiple times. They said they don't use it much so i don't know how accurate their TM-1 would be. I re-calibrated mine and all the readings here are from the re-calibration.

Anyways any help or suggestions would be greatly appreciated.

Anyways any help or suggestions would be greatly appreciated.

Throw your tension meter in the bin, they're only for Cytech types.

I work on floor with my bike hanging off a broom handle between two chairs - i am far from the Cytech type. I saved up for the TM-1 as it was my first build and I don't have any reference points as to what is "tight." I'm thinking DT Revolution spokes on the Non-Drive side as they are 1.5mm at there centre so should be able to get a higher tension on them, Any thoughts?

Don't really get what you mean 'left side spokes keep
coming loose' ... the tension on the non - drive side should be lower than drive side on a dished wheel, as you seem to already know. Where's the problem? If they're utterly slack, then yeah I guess that's not good.

I've had good experiences with using a less stretchy spoke on the drive side (single butted or plain guage would do it), so that the tension can be lower on that side.

by left side i mean the non-drive side on the rear wheel and by loose i mean i'll pop out for an hour on by bike get back and the wheel is slightly out of true - i check the tensions and some spokes have gone down to 10-11 on the TM-1 - there not wobbly but obviously they should be unthreading themselves like that and after a good few days of riding who knows where the spokes will end up!

So 2mm plain gauge spokes will bring the tension up on the Non-drive side, I'm assuming they'll be a lot cheaper than the DT revolutions too.

If the spokes truly are unthreading themselves then you have something seriously wrong.

The only time I've found spokes unthreading themselves in such a way would be in a radial wheel.

As others have said, ditch the tension meter and go on feel. If when you squeeze spoke pairs you don't have much give, you have reached the right tension. Check relative tensions using tone.

Your best bet in my admittedly very limited wheel building experience - 3 pairs, but all stayed true - would be to unwind everything completely and start again. It's all good practise!

Do they ping when you first ride them? Maybe you need to squeeze harder when stressing them, I also put the rim on the floor in a few places and put weight on it and stick the axle on the floor/bench and put some weight on the rim on both sides, just to make sure.

Ooh, actually, are you using a spoke with a 1.8mm thread in 2mm nipples?

Actually, that would probably pull out.

Nah their 2mm thread and 2mm nipples - I did read about the Ping thing somewhere - isn't that to do with twisted spokes? Anyways I think I'll take mateys advice up there and just redo the whole wheel. I will try the single butted spokes on the drive side too.

How much give are we talking when grabbing the pairs of spokes? 5mm each way sound alright? Again I don't have a reference really apart from going around town grabbing spokes on other bikes that have a 36 spoke 3cross pattern.

Hard to describe... depends how hard you grab! 5mm would be a hard grab... stiff but not stupid is what you're aiming for.

Right I'll go with that and see what happens. Out of interest for your 3 builds what spokes were you using?

DT swiss and Sapim, traditional double butted, but my last build was 20" wheels and for that you can only get plain gauge.

Cheers for that, appreciate all the help lads

I did read about the Ping thing somewhere - isn't that to do with twisted spokes?

Every wheel I've ever built or trued with crossed spokes has pinged.

I generally find a newly built wheel will ping a lot then need trued then ping a little and might need a little tweak and so on until no more ping/no more going out of true.

FWIW, built loads of wheels for myself, lots for customers, mates etc and never used a spoke tension gauge and never had complaints of them going out of true sooner than they should.

I don't really understand how you are not able to judge tightness/tension without the meter, do you use a torque wrench to fasten every bolt on your bike?

Try this http://bikexprt.com/bicycle/tension.htm . All you need is a cheap guitar tuner. No calibration/checking required and is super easy.

You should mega stress the spokes until there are no more pings, then that won't happen.

I always do the laying it flat and weighting the rim thing, think I should be pinching/squeezing spokes too?

Can't hurt, they shouldn't ping when you ride them if you've done it properly.

Squeeze them until it hurts your hands.