Nice tutorial for a single point calibration. Knowing where the maximum spoke tension is and knowing that the measurement is repeatable is good enough.
I built some tension gauge calibration fixtures in the shop today... Although, I'm using a pallet to support a load of bricks of weights I know. The first fixture has four holes which will accept tie-down strap hooks eventually holding up each corner of the pallet. A smaller hole is also in the piece to accept a 14ga. "J" end of a spoke to be tested. The metal bobble looks like a triangle with the tie-down hook holes at the bottom and the spoke accepting hole near the point. The top spoke nipple side of the equation is nothing but a small 4" length of angle iron with a rim-sized hole. The angle iron also has a scrap bin tie-down hook welded in place. So, hang the hook/angle-iron piece from something of strength, insert the spoke-material-to-be-tested, hook up a pallet to hang from the lower triangle, load up the pallet with the appropriate weight of bricks, and verify the conversion of the actual spoke tension gauge reading. Now, why did I go with the pallet/brick setup? Using an accurate bathroom scale I can calibrate the device via my weight upon visiting any health facility. This way, I always know the bathroom scale is accurate. And if I weigh out the bricks with the bathroom scale, the accuracy of the scale is transferred to the spoke tensioning contraption... The bathroom scale was $20 and seems accurate enough. I'm only working with one bike, so the the setup will suffice. Obviously, if I find myself needing to chart other spoke dimensions, I'll get a crane meter and weld up something similar to the one in the video. But even then, my pallet of known weight bricks will validate the crane meter.
Hi, thank you for interesting tips and infos. I really don't worry about "accuracy" so much, because I, an amateur MTB rider, can't spot the spoke tension difference of 10kgf, for example. I only need so much accuracy as is adequate for building evenly-tensioned wheels which feel rigid enough for my usual mountain riding. Your setup is low-cost, accurate-enough, and easy-to-build. A nice idea:)
Just relaying my current work effort to solve the same issue. I keep popping rear spokes on a 36 hole street bike wheel in under a few hundred miles. I need to make sure my cheapie Chinese tension gauge is accurate. I'm not putting my solution out there as better than another. It's just the one that works for me at my unique intersection of cost, fabrication ability, precision, and tolerance of error. The wheel is on a 1970's Schwinn Continental... So, my notions of works-for-me is a bit off compared to a latest-and-greatest rider/builder. If you'd like to see a few photos of the set-up. Search Facebook for, "Russell Stephan another bicycle build," and examine the handful of photos at the tail-end of the album.
Re, video. Oh, I probably will. I put up one concerning a very accurate on-bike wheel truing tool which should help folks looking for a true wheel but not needing or wanting to blow cash on a professional stand. th-cam.com/video/CuVFUn4E1yY/w-d-xo.html
If you're respoking a wheel, one quick way is to get the readings off the current wheel using the cheap meter, and then use that approximate range for the new spokes.
Yeah, I think that these cheap tension meters are actually supposed to be used like that. Uncalibrated tension meters have no use other than to compare tension among spokes anyway.
The downside about this tensiometers (including the simpler ParkTool TM-1 type tensiometer) is that they need to be calibrated for each type of spoke you gonna build the wheel with. That's not an issue as long as you have that nice calibration stand. However, Jobs Brandt's tensiometer has much better design and doesn't take into account the cross section of the spoke, it can zero out at the spoke before measuring the tension, thus can work with any type of spoke without any precalibration required. Wheelfanatyk produces such tensiometer, it is a bit expensive, but it totally worth it, especially the digital version. It can also be equipped with data cable with pedal system to directly transfer the readings to excel spreadsheet or similar software.
I've read about such a tension meter before, but there seems to be no fundamental difference between a "conventional" meter and Mr. Brandts meter. Unless a spoke has a built-in torsion gauge or something similar, there is no way to get the absolute tension value of it. You wrote "~zero out at the spoke before measuring the tension", but the meter only tells you how much the spoke deflects. You always need to CONVERT those deflection values to tension force using the PRECALIBRATED chart or diagram. And one and the same deflection reading leads to different tension force values depending on what material is used and what shape or diameter the spoke has. So in a nutshell, a deflection-based tension meter inevitably needs calibration before it can be used as a deflection-tension converter. If I misunderstand what you mean, then I apologize in advance. I really ain't interested in spoke tension meters much. For me it doesn't matter at all if it is a cheap Chinese meter or a high-brand expensive metering device as long as it can let me build a practically well-tensioned, well-balanced and tuned-to-my-liking wheels. I have made my tension meter calibration tool for that purpose and not for increasing the value of my Chinese tension meter. Anyway, thanks for watching!
@@MindDesignFactory of course, it is absolutely possible to build without aiming for absolute correct value, much more important is to keep the spoke tension balanced across the side of the wheel. Regarding the zeroing out, I meant the Brandt's tensiometer measures the deflection only, while other ones also take into account the thickness of the spokes, which inevitably affects the reading. So, if someone leverages tensiometer a lot with different spokes, then he/she is advised to use Brandt's tensiometer to not bother with precalibration for each type of spoke, only general periodic calibration is required occasionally. Otherwise yes, all tensiometers deflect the spoke to get the reading.
Hi, if you fix one end of a spoke and hang a 100kg wight at the other end, it will work, yes. I would do that myself too, if I could manage to make a rig for that and buy a set of weights (10kg, 30kg, 50kg, 80kg and so forth). Your method would be much better than using a calibration tool actually, I think. Thanks for watching!
9:30 But the problem is that you can't get a clean reading with a measurement like that. If you set 53 kg, this value must not increase when measuring the spoke (so when bending the spokes). In your case the value increases above 60 kg. Therefore, you must fix the eyelet at the bottom of the scale. This can also be done with screws. Then the scale is no longer pulled when measuring and you have the real tension value. nevertheless a good performance
Hmm, ok, here is a very basic physics. When you measure the tension of a spoke of a wheel, the spoke is deflected and the both ends of the spoke are pulled inwards. Namely, the spoke tension increases actually while you are bending the spoke. The force applied to bend the spoke is counteracted by the pulling force at both ends of the spoke, that's why the spoke is stable even when you deflect it using the tension meter. So fixing the scale's eyelet won't have any significant effect. Moreover, if you fix the eyelet of the scale and thus one end of the spoke and you repeatedly measure the tension of it by increasing the pulling force above 100kgf, then the spoke is soon stretched for good and is not usable as a test spoke longer. As I said before, we are not dealing with rocket science. It is only about the spoke tension of a wheel owned by an amateur rider. If you need more precision and very fine tuning, then you can get those by spending loads of money and leaving all the trouble over to pro bike shops. You say "the scale is no longer pulled when measuring and you have the real tension value". Now it should be clear: When your scale is locked at 53 kg by fixing the eyelet and you measure the spoke tension, the "real tension" value while you are measuring is obviously not 53 kg, but 60 or similar kg.
You should aim to scale reading before you apply the tensiometer. So, if the scale reads 120 kg, then when you apply the tensiometer, the reading will increase by +5kg, but you need to calibrate your tensiometer to 120 kg, because the real reading of non deflected spoke is still 120 kg. It doesn't matter how much the tensiometer affects the reading as long as you have correct reading without tensiometer. Hope this helps.
How are your reading compared to the readings before the calibration? I wonder how much the tension meter was out of calibration before you calibrated it.
Sorry I didn't even record how much the pre-calibrated values deviated from the calibrated ones, because the pre-calibrated values differed ridiculously much from the accompanying conversion table. I thought the accompanying conversion table was a joke. It was clear that my tension meter came without any factory calibration what so ever. I contacted the seller and complained that the accompanying conversion table was no use, and they admitted that the meter was not for building wheels but for comparing and equalising the spoke tension of a wheel. As long as this model of tension meter is concerned, I think the measured values of one and the same spoke vary a lot from tension meter to tension meter.
@@MindDesignFactory thanks a lot for your answer. I was about to invest for either a tension meter or a truing stand. I think truing stand is the way to go for me.
Hi, you can true a wheel without a tension meter but can't do without it to build a good wheel. And there is no art involved in measuring a spoke tension but much practice is needed to true a wheel. So one vote for a truing stand, me too :)
@@MindDesignFactory I'll try the zip tie method before buying the truing stand. In fact I tried it and result wasn't that bad but I didn't take apart the tires for it. With tires in the rim, it's hard to see contact points while looking directly to the tire. I guess I'll achieve a much better result with the tires off the rim. Besides I'll also be able to do the radial truing whcih in turn can help truing laterally too. I'm sure I'll buy truing stand one day but I'll be looking for a deal for it probably. Thanks a lot. :)
This crane scale is not meant to be calibrated at user end. There is no use in calibrating it anyway because it is not a precision measuring tool meant to be used in industry.
There are two ways to calibrate it. 1: you create your own conversion table from scratch with each kind of spoke that you want to deal with. 2: you adjust the meter's spring force so that the readings match those on the supplied conversion table. But with the method 2 you need to verify first that the supplied conversion table is trustworthy in the first place. I think I will go with the method 2, but I don't have any of those spokes that are on the supplied conversion table right now. I have tried, just for a test purpose, calibrating a 2.0 - 1.5 - 2.0 butted spoke using the data of 1.8 - 1.5 - 1.8 on the table. After adjusting the spring force, the readings at each tension force up to about 100kgf are pretty much close to those on the table. I will upload a video how to calibrate the meter using the home-made tool. But I have to upgrade the tool first so that it will stand with the tension force over 100kgf...
![[MTB maintenance] How to set up a spoke tension meter - a cheap Chinese tool](/img/n.gif)
Nice tutorial for a single point calibration. Knowing where the maximum spoke tension is and knowing that the measurement is repeatable is good enough.
Thank you:)
I built some tension gauge calibration fixtures in the shop today... Although, I'm using a pallet to support a load of bricks of weights I know. The first fixture has four holes which will accept tie-down strap hooks eventually holding up each corner of the pallet. A smaller hole is also in the piece to accept a 14ga. "J" end of a spoke to be tested. The metal bobble looks like a triangle with the tie-down hook holes at the bottom and the spoke accepting hole near the point.
The top spoke nipple side of the equation is nothing but a small 4" length of angle iron with a rim-sized hole. The angle iron also has a scrap bin tie-down hook welded in place.
So, hang the hook/angle-iron piece from something of strength, insert the spoke-material-to-be-tested, hook up a pallet to hang from the lower triangle, load up the pallet with the appropriate weight of bricks, and verify the conversion of the actual spoke tension gauge reading.
Now, why did I go with the pallet/brick setup? Using an accurate bathroom scale I can calibrate the device via my weight upon visiting any health facility. This way, I always know the bathroom scale is accurate. And if I weigh out the bricks with the bathroom scale, the accuracy of the scale is transferred to the spoke tensioning contraption...
The bathroom scale was $20 and seems accurate enough.
I'm only working with one bike, so the the setup will suffice. Obviously, if I find myself needing to chart other spoke dimensions, I'll get a crane meter and weld up something similar to the one in the video. But even then, my pallet of known weight bricks will validate the crane meter.
Hi, thank you for interesting tips and infos. I really don't worry about "accuracy" so much, because I, an amateur MTB rider, can't spot the spoke tension difference of 10kgf, for example. I only need so much accuracy as is adequate for building evenly-tensioned wheels which feel rigid enough for my usual mountain riding.
Your setup is low-cost, accurate-enough, and easy-to-build. A nice idea:)
Just relaying my current work effort to solve the same issue. I keep popping rear spokes on a 36 hole street bike wheel in under a few hundred miles. I need to make sure my cheapie Chinese tension gauge is accurate. I'm not putting my solution out there as better than another. It's just the one that works for me at my unique intersection of cost, fabrication ability, precision, and tolerance of error. The wheel is on a 1970's Schwinn Continental... So, my notions of works-for-me is a bit off compared to a latest-and-greatest rider/builder.
If you'd like to see a few photos of the set-up. Search Facebook for, "Russell Stephan another bicycle build," and examine the handful of photos at the tail-end of the album.
Your idea will certainly inspire others to try similar things by themselves. Maybe you should upload a video of your tool:)
Re, video. Oh, I probably will. I put up one concerning a very accurate on-bike wheel truing tool which should help folks looking for a true wheel but not needing or wanting to blow cash on a professional stand.
th-cam.com/video/CuVFUn4E1yY/w-d-xo.html
Hi, I watched the video! That nylon-tube-and-bolt is a nice improvisation. Thanks for the link:)
If you're respoking a wheel, one quick way is to get the readings off the current wheel using the cheap meter, and then use that approximate range for the new spokes.
Yeah, I think that these cheap tension meters are actually supposed to be used like that. Uncalibrated tension meters have no use other than to compare tension among spokes anyway.
The downside about this tensiometers (including the simpler ParkTool TM-1 type tensiometer) is that they need to be calibrated for each type of spoke you gonna build the wheel with. That's not an issue as long as you have that nice calibration stand. However, Jobs Brandt's tensiometer has much better design and doesn't take into account the cross section of the spoke, it can zero out at the spoke before measuring the tension, thus can work with any type of spoke without any precalibration required. Wheelfanatyk produces such tensiometer, it is a bit expensive, but it totally worth it, especially the digital version. It can also be equipped with data cable with pedal system to directly transfer the readings to excel spreadsheet or similar software.
I've read about such a tension meter before, but there seems to be no fundamental difference between a "conventional" meter and Mr. Brandts meter. Unless a spoke has a built-in torsion gauge or something similar, there is no way to get the absolute tension value of it. You wrote "~zero out at the spoke before measuring the tension", but the meter only tells you how much the spoke deflects. You always need to CONVERT those deflection values to tension force using the PRECALIBRATED chart or diagram. And one and the same deflection reading leads to different tension force values depending on what material is used and what shape or diameter the spoke has. So in a nutshell, a deflection-based tension meter inevitably needs calibration before it can be used as a deflection-tension converter.
If I misunderstand what you mean, then I apologize in advance. I really ain't interested in spoke tension meters much. For me it doesn't matter at all if it is a cheap Chinese meter or a high-brand expensive metering device as long as it can let me build a practically well-tensioned, well-balanced and tuned-to-my-liking wheels. I have made my tension meter calibration tool for that purpose and not for increasing the value of my Chinese tension meter.
Anyway, thanks for watching!
@@MindDesignFactory of course, it is absolutely possible to build without aiming for absolute correct value, much more important is to keep the spoke tension balanced across the side of the wheel. Regarding the zeroing out, I meant the Brandt's tensiometer measures the deflection only, while other ones also take into account the thickness of the spokes, which inevitably affects the reading. So, if someone leverages tensiometer a lot with different spokes, then he/she is advised to use Brandt's tensiometer to not bother with precalibration for each type of spoke, only general periodic calibration is required occasionally. Otherwise yes, all tensiometers deflect the spoke to get the reading.
Clever and simple. Thanks.
Thanks for watching!
can I just hang a 100kg weight from a spoke to calibrate my meter or would that not work?
very cool animation and build btw
Hi, if you fix one end of a spoke and hang a 100kg wight at the other end, it will work, yes. I would do that myself too, if I could manage to make a rig for that and buy a set of weights (10kg, 30kg, 50kg, 80kg and so forth). Your method would be much better than using a calibration tool actually, I think.
Thanks for watching!
@@MindDesignFactory cheers thanks!
😊
9:30 But the problem is that you can't get a clean reading with a measurement like that. If you set 53 kg, this value must not increase when measuring the spoke (so when bending the spokes). In your case the value increases above 60 kg. Therefore, you must fix the eyelet at the bottom of the scale. This can also be done with screws. Then the scale is no longer pulled when measuring and you have the real tension value. nevertheless a good performance
Hmm, ok, here is a very basic physics. When you measure the tension of a spoke of a wheel, the spoke is deflected and the both ends of the spoke are pulled inwards. Namely, the spoke tension increases actually while you are bending the spoke. The force applied to bend the spoke is counteracted by the pulling force at both ends of the spoke, that's why the spoke is stable even when you deflect it using the tension meter. So fixing the scale's eyelet won't have any significant effect. Moreover, if you fix the eyelet of the scale and thus one end of the spoke and you repeatedly measure the tension of it by increasing the pulling force above 100kgf, then the spoke is soon stretched for good and is not usable as a test spoke longer.
As I said before, we are not dealing with rocket science. It is only about the spoke tension of a wheel owned by an amateur rider. If you need more precision and very fine tuning, then you can get those by spending loads of money and leaving all the trouble over to pro bike shops.
You say "the scale is no longer pulled when measuring and you have the real tension value". Now it should be clear: When your scale is locked at 53 kg by fixing the eyelet and you measure the spoke tension, the "real tension" value while you are measuring is obviously not 53 kg, but 60 or similar kg.
You should aim to scale reading before you apply the tensiometer. So, if the scale reads 120 kg, then when you apply the tensiometer, the reading will increase by +5kg, but you need to calibrate your tensiometer to 120 kg, because the real reading of non deflected spoke is still 120 kg. It doesn't matter how much the tensiometer affects the reading as long as you have correct reading without tensiometer. Hope this helps.
How are your reading compared to the readings before the calibration? I wonder how much the tension meter was out of calibration before you calibrated it.
Sorry I didn't even record how much the pre-calibrated values deviated from the calibrated ones, because the pre-calibrated values differed ridiculously much from the accompanying conversion table. I thought the accompanying conversion table was a joke. It was clear that my tension meter came without any factory calibration what so ever.
I contacted the seller and complained that the accompanying conversion table was no use, and they admitted that the meter was not for building wheels but for comparing and equalising the spoke tension of a wheel.
As long as this model of tension meter is concerned, I think the measured values of one and the same spoke vary a lot from tension meter to tension meter.
@@MindDesignFactory thanks a lot for your answer. I was about to invest for either a tension meter or a truing stand. I think truing stand is the way to go for me.
Hi, you can true a wheel without a tension meter but can't do without it to build a good wheel. And there is no art involved in measuring a spoke tension but much practice is needed to true a wheel. So one vote for a truing stand, me too :)
@@MindDesignFactory I'll try the zip tie method before buying the truing stand. In fact I tried it and result wasn't that bad but I didn't take apart the tires for it. With tires in the rim, it's hard to see contact points while looking directly to the tire. I guess I'll achieve a much better result with the tires off the rim. Besides I'll also be able to do the radial truing whcih in turn can help truing laterally too. I'm sure I'll buy truing stand one day but I'll be looking for a deal for it probably. Thanks a lot. :)
Can the crane scale you use in this jig be calibrated?
This crane scale is not meant to be calibrated at user end. There is no use in calibrating it anyway because it is not a precision measuring tool meant to be used in industry.
I have the same one, and It’s wayyy of. How do you go about calibrating it?
There are two ways to calibrate it. 1: you create your own conversion table from scratch with each kind of spoke that you want to deal with. 2: you adjust the meter's spring force so that the readings match those on the supplied conversion table. But with the method 2 you need to verify first that the supplied conversion table is trustworthy in the first place.
I think I will go with the method 2, but I don't have any of those spokes that are on the supplied conversion table right now. I have tried, just for a test purpose, calibrating a 2.0 - 1.5 - 2.0 butted spoke using the data of 1.8 - 1.5 - 1.8 on the table. After adjusting the spring force, the readings at each tension force up to about 100kgf are pretty much close to those on the table. I will upload a video how to calibrate the meter using the home-made tool. But I have to upgrade the tool first so that it will stand with the tension force over 100kgf...
Thank you. I figured out the screw for the spring was the adjustment for the tension. I’m looking forward to the follow up video.