Spoke Tension

greenbarnett

I'm currently building my own wheels and I'm looking for some advice on the correct Spoke Tension. I have used Mavic Open Pro 32 hole 700c rims, Shimano 105 5700 hubs and DT Swiss Competition 2.0 - 1.8 -2.0 Spokes on a 2 cross pattern. I have Park Tool Tension meter but unsure what to set the tension at. Any help will be gratefully appreciated.

hypster

Mavic recommend a tension of 90-110kg for the Open Pro rim. I generally aim for the upper end of this range on the drive side to make sure the non drive side is adequately tensioned. Using 1.8mm spokes that should equate to a TM-1 deflection reading of around 21.5. However, my TM-1 over reads by quite a fair amount and if I built a wheel to this deflection setting I would probably end up with a DS tension setting towards the lower end of the suggested Mavic tension of maybe 90 kg (if I'm lucky). That would also mean that the NDS spokes would be at a tension of maybe 45kg which would be too low for comfort I think.

I originally checked my TM-1 against a much more expensive (and accurate) DT Swiss tensiometer owned by a pro wheel builder that I know. Thereafter I allowed about an extra 10% on top of the reading I was getting on the TM-1 for the wheels I built and had no problems. An alternative is to check the DS tensions on a similar reliable wheel if you have access to one and maybe use the same TM-1 deflection setting.

Eventually I designed and built my own calibration device so that I am able to check the accuracy of my TM-1 against a known standard. If you are interested it is being discussed in this thread:

viewtopic.php?f=40004&t=12961811

ugo.santalucia

21 front and 23 rear drive side are good numbers... don't go lower than that and ignore Mavic's blurb about max tension... Harry Rowland has been building these rims for 20 years and his spokes are tight as hell

greenbarnett

hypster. Thanks for the tips and i'll check out that thread.

greenbarnett

thanks ugo. i set the front at approx 23 - 24 so i might back them off a bit and settle for 22. cheers

drlodge

ugo.santalucia wrote:

Harry Rowland has been building these rims for 20 years and his spokes are tight as hell

My HR Open Pro CD rims are certainly fine after 3000+ miles, his spoke tension is nice and even.

wishitwasallflat

drlodge wrote:

ugo.santalucia wrote:

Harry Rowland has been building these rims for 20 years and his spokes are tight as hell

My HR Open Pro CD rims are certainly fine after 3000+ miles, his spoke tension is nice and even.

My Open Pro Harry Rowland wheels are still true after 5500+ miles and I weigh over 17stone and ride rough roads!

cycleclinic

The park gauge underreads by 10% at least. So if you set the gauge at 23 you may only have 1000N. Bear that in mind.

Mavic actually state a recomend tension of 700-900N for the Open Pro but you can't build a stable wheel with that so 1200N DS works. On the park gauge though that may be 26!. I have a spoke tension claibration rig. Essentially a jig to which a load cell is hooked up to a spoke which I can load. I can then put the park gauge on and take a reading. Tomorrow morning I will do this for you at let you know what reading 1200N is and 900N so you have the front wheel and DS rear tensions.

greenbarnett

thecycleclinic wrote:

The park gauge underreads by 10% at least. So if you set the gauge at 23 you may only have 1000N. Bear that in mind.

Mavic actually state a recomend tension of 700-900N for the Open Pro but you can't build a stable wheel with that so 1200N DS works. On the park gauge though that may be 26!. I have a spoke tension claibration rig. Essentially a jig to which a load cell is hooked up to a spoke which I can load. I can then put the park gauge on and take a reading. Tomorrow morning I will do this for you at let you know what reading 1200N is and 900N so you have the front wheel and DS rear tensions.

thecycleclinc. Thanks for the tips. I've not readjusted yet so I'll keep this in mind when I'm working on them again.

Cheers