Spoke Tensionometer

For discussions about bikes and equipment.
mig
Posts: 2695
Joined: 19 Oct 2011, 9:39pm

Re: Spoke Tensionometer

Post by mig »

given perfect components and materials then a front wheel's spokes would all be at equal tension at the finish of a build. i find this rarely to be the case however mainly i think as rim extrusions are no longer that consistent. cheaper materials used maybe?

spoke tension gauges are however quite interesting to use for builds if used for for consistency of tension rather than blindly following the numbers they produce.
User avatar
NATURAL ANKLING
Posts: 13780
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: Spoke Tensionometer

Post by NATURAL ANKLING »

Hi,

Comparitor only!

Use it as such.

If you get the "stress relieving" done the rest is easy...............................
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
NickJP
Posts: 793
Joined: 24 Sep 2018, 7:11pm
Location: Canberra, OZ

Re: Spoke Tensionometer

Post by NickJP »

When I started building wheels in the 1970s, I never considered relying on anything other than feel for spoke tensions, and I built wheels that way for about 20 years: those wheels all held up fine - I still have some of them in use. Sometime in the 1990s I purchased one of the Wheelsmith tensiometers, more out of curiosity than anything else. I really just use it for checking equality of spoke tensions when I'm getting towards the end of a wheelbuild, though with aluminium rims I often find that you need slightly uneven spoke tensions to get a nicely true wheel, as the extrusions, particularly at the join, are rarely free of some deviation. Carbon fibre rims are much better in this respect: it's easier to build a perfectly true wheel that remains true. Since the advent of disc brakes I've mainly been using CF rather than aluminium rims, as wear from braking and getting consistent braking are no longer a factor with rims.
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Spoke Tensionometer

Post by Mick F »

All very interesting comments guys! :D
I'm taking a punt on a cheap tool to see the relative - but not absolute - tensions. I'm going to aim at equal readings with them tight and "feeling" correct.

The tool is going to be with Yodel sometime today, and may be delivered by Friday.
(fingers crossed)
Mick F. Cornwall
User avatar
NATURAL ANKLING
Posts: 13780
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: Spoke Tensionometer

Post by NATURAL ANKLING »

Hi
It does depend a lot on the rim stiffness.

I dismantled a skip rim once and it went like a banana, but it was perfectly true when built up.
That rim was probably the cheapest nastiest rim you could lay your hands on, made with minimum aluminium for sure.

If a rim is a deep V Section or maybe a CF material, it might be possible to get it perfectly in line and with even spoke tension.

And that's an ideal world.
But the wheels we build Are not always ideal.
With rim brakes, the rim needs to be true within about 1 mm TIR (total included reading) Lateral.
So it won't be unusual to find you have a slight different tension in spokes.

If your wheel stays true and needs minimum attention over the years than you've probably got it right especially if you've not broken any spokes or no spokes have come loose.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
rjb
Posts: 7183
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Spoke Tensionometer

Post by rjb »

I thought that tool looked familiar. Discussion spoked by NA. What goes around comes around. :lol:
viewtopic.php?t=127043
Image
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Spoke Tensionometer

Post by Mick F »

Well spotted! :D
I guessed there'd be another discussion somewhere!
I'll have a good read though it later today.
Mick F. Cornwall
rogerzilla
Posts: 2876
Joined: 9 Jun 2008, 8:06pm

Re: Spoke Tensionometer

Post by rogerzilla »

If you've built lots of trouble-free wheels for many years, a tensionometer purchase merely tells you you were doing it right.

Manufacturers' specs for rims are now so conservative that the tensionometer may just put you in a quandary. If the maximum tension allowed by the rim is only 100kgf but you are using a 11-speed road hub with a 45:100 left:right tension ratio, you cannot get the left spokes adequately tight unless you ignore the specs.
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Spoke Tensionometer

Post by Mick F »

I'll wait until the thingy arrives, and then have a play with it.

The fact that the front wheel is radially spoked both sides with the same length both sides of course, will be a good test.
No real interest in the absolute tension, but it would be interesting to see if the wheel is perfectly true using this tool.

The rear wheel - radial LH and 2x RH and non-equal each side, may prove even more interesting.

Shrugging shoulders here. :wink:
I will wait and see how I get on.
Expect a report in the next few days. Knowing Yodel and eBay, I may not get the thing until next week!
Mick F. Cornwall
hoogerbooger
Posts: 672
Joined: 14 Jun 2009, 11:27am
Location: In Wales

Re: Spoke Tensionometer

Post by hoogerbooger »

Shall await your views on whether the cheap tensionometer helped significantly.

( I also mainly use pitch as a test of balanced tensions after truing........but when I have been insufficiently methodical in the steps ( from a start point of equal amount of spoke thread showing on respective sides)....I have produced a straight round wheel.....which based on pitch clearly doesn't have equalish tensions on the respective sides. In those cases I 'tuned it' back to equal tensions on sides picking a pitch close to/a bit below a similar finished good wheel .....as a new start point for truing. It's often well out of true at this 'tuned' new start point.)
old fangled
Mike Sales
Posts: 7860
Joined: 7 Mar 2009, 3:31pm

Re: Spoke Tensionometer

Post by Mike Sales »

I once read somewhere that middle C (or keyhole C on a piano) is the pitch of the right tension. Of course I compared a Mike built wheel and it was gratifyingly close.
I agree with those who say that the aim is a true wheel, and because of variations in the components, this may result in uneven tensions.
Truth, good tight spokes, and thorough stressing, are the elements of good building.
I find, as noted above, that the extreme dishing needed by a high number of sprockets is hard to achieve, with almost slack spokes one side and very high tensions on the other. I cannot really approve of such wheels.
I have never had a tensiometer in my hands!
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
rogerzilla
Posts: 2876
Joined: 9 Jun 2008, 8:06pm

Re: Spoke Tensionometer

Post by rogerzilla »

Any musical note will only work for a specific combination of spoke length, gauge, snd number of crossings.
mig
Posts: 2695
Joined: 19 Oct 2011, 9:39pm

Re: Spoke Tensionometer

Post by mig »

does the wheel have to be held/supported in the same way each time the pitch of a spoke is tested?

does the rim not resonate a little with each pluck?
Mike Sales
Posts: 7860
Joined: 7 Mar 2009, 3:31pm

Re: Spoke Tensionometer

Post by Mike Sales »

rogerzilla wrote: 26 Oct 2022, 9:27pm Any musical note will only work for a specific combination of spoke length, gauge, snd number of crossings.
by mig » 26 Oct 2022, 10:01pm
does the wheel have to be held/supported in the same way each time the pitch of a spoke is tested?

does the rim not resonate a little with each pluck?
I did not take this test very seriously and did not repeat it.
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
hoogerbooger
Posts: 672
Joined: 14 Jun 2009, 11:27am
Location: In Wales

Re: Spoke Tensionometer

Post by hoogerbooger »

For what it's worth when testing by pitch I hold the wheel horizontally by the skewer ( hand on underside of wheel) and tap the spokes midway using a screw-driver.
old fangled
Post Reply