Spoke Tensionometer

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David9694
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Re: Spoke Tensionometer

Post by David9694 »

I bought a Park tension meter but stopped using it after a couple of pairs. I rely on feel, ping and pong.
Spa Audax Ti Ultegra; Genesis Equilibrium 853; Raleigh Record Ace 1983; “Raleigh Competition”, “Raleigh Gran Sport 1982”; “Allegro Special”, Bob Jackson tourer, Ridley alu step-through with Swytch front wheel; gravel bike from an MB Dronfield 531 frame.
Manc33
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Re: Spoke Tensionometer

Post by Manc33 »

I got one similar to the one in the first post but it's ZTTO (£17).

It's quite fiddly to use because it has to be not rubbing against itself anywhere but it seems alright.

I don't fancy my chances if that spring at the back came flying off, should probably have goggles on!

It seemed like the spokes were perhaps getting a bit too tight at what it said I should have the tension at and I remember not quite going as far as it recommends, after deciphering the enormous table of numbers you get with it.
We'll always be together, together on electric bikes.
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GuyBoden
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Re: Spoke Tensionometer

Post by GuyBoden »

For spoke tension, could you use an electrical instrument tuner with an inbuilt microphone?

Image
NickJP
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Location: Canberra, OZ

Re: Spoke Tensionometer

Post by NickJP »

I bought myself one of these Wheel Fanatyck tensiometers a while ago, not because I really needed it but because I like tools. The readings are extremely repeatable, unlike my old Wheelsmith, where a bit of guesstimation is usually involved. The Wheelsmith also lacks conversion tables for spoke sizes that didn't exist when it was designed, such as Sapim CX-Ray or D-Light spokes, both of those being spokes I quite frequently build with. I tend to use the Wheel Fanatyck unit towards the end of a wheel build to verify the spoke tensions and check how even the tensions are:
PXL_20221108_014343456.jpg
Another bit of tool porn that I purchased a few years back, just because:
IMG_20170322_145645.jpg
I think this must be an inherited trait, as my father was exactly the same. When he died and we were sorting out his workshop, we found about three dozen pairs of pliers (all of them good quality) and somewhere north of 60 screwdrivers.
rogerzilla
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Re: Spoke Tensionometer

Post by rogerzilla »

You were lucky. My dad's tools contained a lot of AF spanners and some very worn-out screwdrivers!
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Mick F
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Re: Spoke Tensionometer

Post by Mick F »

I bought a set of AF spanners from Halfords in Wigan when I was maybe 14.
I wanted them for my bike .............. little did I know that nuts on a 1960s bike were are "bike size", so none of my spanners were any use. :cry:

Mind you, as I grew older and owned cars, all the AF spanners fitted!
I still have the set.
Mick F. Cornwall
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NATURAL ANKLING
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Re: Spoke Tensionometer

Post by NATURAL ANKLING »

Hi,
Although I own Many small tool kits today.......I have many more tool boxes....I started buying tools when I needed them at 16, for motor vehicles.
Everytime I need a particular size spanner / socket what ever...I walked to local car parts factor and bought it, they were open on sundays too :)
I reckon I have at least 200 screwdrivers, you never use just one screwdriver on a new job (never seen before fasteners on a never seen before machine) Some screwdrivers get that perfect fit without slip, so you might have several No - 2 pozi drivers, insert bits are also use-full to carry too, the larger sizes you can also use a spanner on too.
I am not talking bike mobile tool kits though.

Before I had breakdown recovery, I would carry a comprehensive tool kit in the camper, it weighs in at nearly 30 kgs, and fits in a plastic tool box, would cost me an estimated 2K plus to replace at todays prices :P

On car breakdown, its limited on what they will do and where and how often.
I would never ask another person to change a wheel :? any more than I would let anyone touch my bicycle................... :twisted:
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jb
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Location: Clitheroe

Re: Spoke Tensionometer

Post by jb »

NickJP wrote: 8 Nov 2022, 2:21am I bought myself one of these Wheel Fanatyck tensiometers a while ago, not because I really needed it but because I like tools. The readings are extremely repeatable, unlike my old Wheelsmith, where a bit of guesstimation is usually involved. The Wheelsmith also lacks conversion tables for spoke sizes that didn't exist when it was designed, such as Sapim CX-Ray or D-Light spokes, both of those being spokes I quite frequently build with. I tend to use the Wheel Fanatyck unit towards the end of a wheel build to verify the spoke tensions and check how even the tensions are:
PXL_20221108_014343456.jpg
Does it include a load cell or is it just a digital DTI?
Cheers
J Bro
NickJP
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Re: Spoke Tensionometer

Post by NickJP »

jb wrote: 8 Nov 2022, 11:09am
NickJP wrote: 8 Nov 2022, 2:21am I bought myself one of these Wheel Fanatyck tensiometers a while ago, not because I really needed it but because I like tools. The readings are extremely repeatable, unlike my old Wheelsmith, where a bit of guesstimation is usually involved. The Wheelsmith also lacks conversion tables for spoke sizes that didn't exist when it was designed, such as Sapim CX-Ray or D-Light spokes, both of those being spokes I quite frequently build with. I tend to use the Wheel Fanatyck unit towards the end of a wheel build to verify the spoke tensions and check how even the tensions are:
PXL_20221108_014343456.jpg
Does it include a load cell or is it just a digital DTI?
It's just a digital readout, and you convert the readings to kgF using a conversion table. However, the digital indicator has a USB port on the side, and you can also purchase a data cable plus foot pedal to interface the tensiometer to a PC so the readings can be output to a program that performs the conversion. I didn't bother with that: https://wheelfanatyk.com/collections/me ... put-cables.

See also https://www.spokeservice.ca/utilities/spoke-tension.
Last edited by NickJP on 29 Nov 2022, 6:28am, edited 1 time in total.
rjb
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Re: Spoke Tensionometer

Post by rjb »

GuyBoden wrote: 7 Nov 2022, 8:17pm For spoke tension, could you use an electrical instrument tuner with an inbuilt microphone?

Image
Save a few Bob for your cafe stop and download a free music tuning app. :wink:
Lots of choice, I fiddle with this one :wink:
https://play.google.com/store/apps/deta ... uitartuner
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
jb
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Re: Spoke Tensionometer

Post by jb »

NickJP wrote: 8 Nov 2022, 8:09pm
jb wrote: 8 Nov 2022, 11:09am
NickJP wrote: 8 Nov 2022, 2:21am I bought myself one of these Wheel Fanatyck tensiometers a while ago, not because I really needed it but because I like tools. The readings are extremely repeatable, unlike my old Wheelsmith, where a bit of guesstimation is usually involved. The Wheelsmith also lacks conversion tables for spoke sizes that didn't exist when it was designed, such as Sapim CX-Ray or D-Light spokes, both of those being spokes I quite frequently build with. I tend to use the Wheel Fanatyck unit towards the end of a wheel build to verify the spoke tensions and check how even the tensions are:
PXL_20221108_014343456.jpg
Does it include a load cell or is it just a digital DTI?
It's just a digital readout, and you convert the readings to kgF using a conversion table. However, the digital indicator has a USB port on the side, and you can also purchase a data cable plus foot pedal to interface the tensiometer to a PC so the reading can be output to a program that performs the conversion. I didn't bother with that: https://wheelfanatyk.com/collections/me ... put-cables.

See also https://www.spokeservice.ca/utilities/spoke-tension.
Thank you for that info.
I suppose you get greater accuracy of the deflection, it would be good if it also related it to the exact force being exserted as that's what makes the simpler devices differ in their readings.
Cheers
J Bro
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GuyBoden
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Re: Spoke Tensionometer

Post by GuyBoden »

rjb wrote: 8 Nov 2022, 8:46pm
GuyBoden wrote: 7 Nov 2022, 8:17pm For spoke tension, could you use an electrical instrument tuner with an inbuilt microphone?

Image
Save a few Bob for your cafe stop and download a free music tuning app. :wink:
Lots of choice, I fiddle with this one :wink:
https://play.google.com/store/apps/deta ... uitartuner
Thanks, I already have a chromatic guitar tuner. I've tested it on wheel spokes and it does an ok(ish) job, wobbles a bit between values. :lol:
axel_knutt
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Joined: 11 Jan 2007, 12:20pm

Re: Spoke Tensionometer

Post by axel_knutt »

GuyBoden wrote: 16 Nov 2022, 2:28pmwobbles a bit between values. :lol:
I'm not surprised, if you look at the tone with a spectrum analyser you will find that there two tones, not one. The first is the one you're expecting, with a frequency associated with the distance from rim to hub, but there's a second one at a higher frequency related to the rim to crossover distance. That alone is enough to make measuring absolute tension by tone impractical, but it gets even worse.

If you build a test rig, you can accurately tension a single spoke in isolation, and see there are still other sources of significant errors. The first of these is spoke diameter, easy to determine if you're using plain guage, but most use double butted, and you won't get the right answer using an average of middle and end diameters because the ends actually play little part in determining the frequency. You can see this by clamping a small (300mg) weight to the spoke: it makes about 9% difference in the middle, but the effect is too small to mearure with it 25mm from the end. Disregarding the ends altogether, and calcuating on the basis of the middle diameter gives a similar error to that obtained with PG spokes.

Secondly, spokes are more rigid than a guitar string because they're shorter and thicker, so if you don't compensate for it, this also introduces a large error that gets even bigger at lower spoke tensions as the rigidity of the spoke becomes more significant.

Then there's measuring spoke length, you need to be careful to determine whether the spoke touches the nipple where it enters the counterbore, or where it enters the thread, and similarly whether it touches the hub flange or hole first.

The errors all add up, and it makes a difference to whether you end up with 10% or 30%. Either way, it wouldn't compare favourably with the human ear, which can detect errors of <1%
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thps
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Joined: 9 Jul 2022, 8:21am

Re: Spoke Tensionometer

Post by thps »

can someone tell me how to read the outside numbers on the analog sapim meter? for example big number 70, small number 30. I look at the conversion table for spoke tension and it just shows mm.

https://www.sapim.be/sites/default/file ... nglish.pdf
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531colin
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Re: Spoke Tensionometer

Post by 531colin »

The Sapim gauge uses a regular (commercial) engineers dial gauge for the "output"....it measures the displacement of the arm, in millimetres.
You read it much the same as a clock, where the minute hand goes a full circle and the hour hand goes an hour.....a twelfth of a circle.
Google "how to read a dial gauge" for example.
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