Good video, thx. I need some help to understand, why the deflection increases with spoke tension. My intuituon tells me, it should be the other way around. More spoke tension withstands the force of the tensiometer, so it should deflect less.
Good question! What you’re asking is what puzzled me to no end when I first started wheelbuilding. The weird thing is that I still haven’t seen this discussed anywhere on wheelbuilding forums. I wasted a ton of time at the beginning trying to figure it out myself ☹ Basically, the tension reading corresponds to the amount of compression on the spring, not the perpendicular deflection of the spoke. So, a spoke with very little tension applied to it will cause minimal compression of the spring which produces as smaller number. A highly tensioned spoke will significantly compress/deflect the spring which produces a larger number. Put another way, there is an inverse relationship between the reading on the spoke tensiometer and the amount of deflection on the spoke. My spoke tensiometer works exactly the same as the Sapim tensiometer. At the top of page 3 of the Sapim manual, you can visualize what exactly is happening. Here’s the link to the manual: www.sapim.be/sites/default/files/sapim_tensiometer_english.pdf I hope that all makes sense. Please subscribe to my YT channel. Cheers!
I have exactly same tensio, and its main drawback is that it uses thrust bearing instead of roller bearing, and the readings highly depend on how tight the tension bolt is. But the thing is that even if you try to tighten it as little just to remove the play in the bearing, it still introduces significant drag, which badly contributes to reading error. Just try to tighten or untighten the bolt for just fraction of revolution, and you'll see the difference. Or you can remove the spring and see how much friction there actually is. There's another version sold in China under brand Teny Bike or Toopre, they use roller bearing, which doesn't require any tensioning, it has much less friction. I wish I knew that when ordering mine. In the future I'm going to switch to the Jobs Brandt tensio, there are some nice guy from Poland, who produces them on demand. Also, Wheelfanatyk makes them. These type of tensios are much better than any existing tensio on the market.
Interesting. I would have thought the friction created by the thrust bearing is inconsequential, but I'll take your word for it. It isn't a particularly precise or well made tension meter, so it is something I should think about upgrading at some point. The Wheel Fanatyk one you mention I'm familiar with and is not crazy expensive. The Brandt one I'm not familiar with but will look into. It definitely is the weakest part of my setup. Thanks for the advice!
@@bikesbymike Jobs Brandt is the engineer who invented the tensio, as well as the author of the The Bicycle Wheel book, he made the drawings open to everyone who wants to produce it. First it was Avocet/DT Swiss, later FSA, now Wheelfanatyk makes them. If you'd like to have the best one, then you may search for Filip Kralyevski tensiometer, he has further improved it by added precise cross roller table bearing. You may contact him directly, if you'd like to order one. Now, regarding the thrust bearing of our particular tensio, believe me, the friction it makes affects the reading horribly. For example, if I measure 2.00 for a 100 kgf, just touching the bolt for a very very tiny fraction causes the reading to jump all the way from 1.9 to 2.1, which totally distorts the existing conversion table. And unfortunately, it is not possible to tighten it light enough, because then there will be a small play left, which will give inconsistent results. And as soon as you take the play away, you get friction in response. I even applied light grease, it improved the situation but no tremendously. The bearing is junk, the tool isn't precise at all, even the original DT Swiss tool is not a great design decision, but hey, they built it primarily for their own spokes, they never claimed it is intended to be used universally.
Really weird. Let me repeat here. I was saying that Jobs Brandt is the inventor of the Wheelfanatyk's tensio, it was initially produced by Avocet, then FSA and later by WF. The good thing about it is that anyone can use the diagrams of Brandt, they are open. Another guy from Poland makes them by demand, he added linear bearing, improving the precision drastically. @@bikesbymike
This is such a cool video Mike! You motivated me to go next level with my wheel building and build a spoke tension meter calibration tool for myself. However I see that this amazing crane scale unfortunatly is no longer for sale.
Good to hear, Roland! There are plenty other crane scales equally as good. Just make sure the top and bottom hook holes/attachments will fit whatever connection you'll be using and make sure it is rated to at least 200 kg. They are all reasonably accurate, but you may want to get one that does indicate its level of accuracy.
Thanks for sharing. I'd like to build a similar jig. Could you please provide more insight on the construction of the lower part, especially how is the threaded end of the spoke connected with what bolts and the M8 rod at the same time making it possible to twist the rod. Michał Warsaw, Poland
I’ll try to describe it as best I can. The threaded end of the spoke connects to a spoke nipple that pokes out of the M8 acorn nut. I drilled a hole in the acorn nut large enough for the nipple to fit through, but small enough so that the nipple flange at the end doesn’t slip out. The acorn nut threads onto the M8 threaded rod and locks into place with a M8 hex nut. Then that rod assembly fits through the “floating” piece of aluminum extrusion framing and then the top (fixed) piece of framing. On the top side of the fixed piece of framing, I’ve threaded an M8 Star Grip Knob onto the threaded rod with a needle thrust bearing washer between the knob and the top of the fixed piece of framing. The floating piece of framing moves up-and-down with two sets of the v-slot support plates and bearing guides that connect to opposite ends of the floating piece of framing. The only hard part of this job was drilling a hole in the acorn nut. It was very hard steel, so it took a long time to drill through it. You must use a good quality drill bit AND some type of metal drilling lubricant. My complete parts list in located in this Google Drive file: drive.google.com/file/d/1fHQS8V0aiqN47WqOOdiJXyxSPLv7Y3f8/view?usp=drive_link Good luck!
Great video - just built a similar jig using your parts list with the aluminium extrusions etc, many thanks! quick question - when held horizontally as per your video - the scale initially records the weight of the component parts pulling on the crane scale, before tension is applied, so .. wondering if it’s necessary to subtract the weight value of the relevant system parts from the final reading? Thinking this is less of an issue if the calibration tool is held horizontally, might be worth doing, and easier to account for if the tool is positioned vertically? Possibly overthinking this …
Nice job! You raise a really interesting issue, but this is why I think it's a mute point. There is very little tension on the spoke created by gravity pulling down on the components while the jig is in the horizontal position. I tested this myself and found it to be about .5 kgf, although this may be within the error range for the scale I'm using (it measures in .1 kgf increments but I doubt it is accurate to that increment). Regardless, whatever the number, it is minimal and I would say inconsequential given the very high tensions we are measuring on spokes. I measured this .5 kgf figure by unweighting the components with my hand from underneath, zeroing out the crane scale, and then removing my hand to let the force of gravity pull down on the parts. I'm trying to recall my Grade 12 physics, but I do not think subtracting the weight value makes sense. Whatever that gravitational force is, let's assume .5 kgf, it continues to exert that downward pull even when the spoke is under full tension. So as long as you keep the jig in its horizontal position the entire time, there is no need to subtract that weighted figure from your final reading. I should also mention that I saw no difference in my tension readings moving the jig from a horizontal position to vertical. If it read 100.0 kgf in the horizontal position, that's what it read in the vertical position. It may have deviated by +/- .1 or .2 kgf but I attribute that to inaccuracy in the scale, flex in the spoke, or flex in other components of the jig. Since I don't think that the weighted number should be subtracted from your spoke readings, placing the jig vertically really doesn't change the situation. Gravity exists in that scenario as well. I may be wrong, but that's my thoughts on all of it. I have a friend who is a particle physicist researcher, so maybe I should put the question to him to be 100% certain :)
@@bikesbymike Thank you for the fast - and comprehensive reply, very useful, agree as you say in the scheme of things, probably inconsequential, thank you!
Excellent design and great video! When you put the spoke tension meter in place, the force increases. Is there a reason you used the displayed force before you put in the tension meter instead of using the increased force? Thank you!
Good question. I’ll try to explain it without confusing us both ;) The short answer is that the way I did it is the typical way it is done. But here is my thinking on why it makes sense to do it this way. The tension of the spoke on the rim is created by the connection of the spoke at the point of the hub and the rim without the spoke tension meter attached to it. So if I put the spoke into the calibration jig and tighten the tension until the crane scale reads 100 Kgf without the spoke meter tool attached to it, I know for sure that it is exactly 100 kgf. So, when I now attach the spoke tension meter tool to the spoke on the jig it is for the purpose of measuring the amount of deflection at exactly 100 kgf. The force does increase a bit by adding the tension meter tool, but this is inherent in the design of the tool. The important point in all this is that by doing it this way I can perfectly replicate the scenario using the calibration jig (with a known force) with the scenario whereby the spoke is fitted to the rim. So, if on the jig I get 3.5mm deflection at 100 kgf, I know that a reading of 3.5mm deflection for a spoke mounted on a rim must be exactly 100 kgf. I’m not interested in the tension of the spoke with the spoke tension meter tool attached to it any more than I’m interested in the tension of the spoke when I squeeze it with my hand, because that’s irrelevant to how the wheels are ridden. I don’t think I’ve explained this terribly well, and my reasoning may be off, but that’s my take on it. I should ask my friend who is particle physics professor who could provide a more scientific answer.
Thanks. It’s not essential and there are cheaper ways to accomplish the same thing. But without the rollers/sliders, that black aluminum extrusion piece would twist around as I was tightening or loosening the knob on the top, so I’d have to hold it in place. Not the end of the world, but a clumsy design.
I used an old L bracket (corner brace) that I had lying around. A metal shelf brace also works. Cut it to the right size and drill a proper size hole to secure the spoke head end.
@@ningbai1005 I can think of two options. 1) Your could use an acorn nut setup like I used to hold the nipple end of the spoke, or 2) Use a U-bolt w/t a mounting plate like in this link. Just drill a hole in the plate large enough to thread the spoke through. shop.forcesinc.ca/products/flsp261-u-bolts-with-mounting-plates-stainless-steel-304-inside-dia-1-thread-size-1-4-20-height-1-3-4-pack-of-1?variant=42895961686235¤cy=CAD&gclid=CjwKCAiAkrWdBhBkEiwAZ9cdcFZmiQ7TZ-dUL6Q7FWIBnD0m2jv3rQPlMwdl0l8m_uDABZpJca6uSRoCJQUQAvD_BwE
@@bikesbymike I could clearly see your point but there are quite a few straight pull blade spokes which I use having their blade wider than their heads. any thoughts？😂
@@ningbai1005 Right--good point! I've put J-bend aero spokes in my calibration jig with no issue, but straight pull spokes have a smaller head. Maybe cutting out a notch (to slide the spoke in from the side) instead of drilling a hole in the U-bolt mounting plate would work. You've given me yet another reason to avoid straight pull spokes :)
Great video! I’ve learned lots, but two main things: 1) buying or building a calibration jig is likely more important than an expensive tensiometer, once you have a means to calibrate as required, the quality of the meter doesn’t matter as much. 2) I have nowhere near the skill, understanding or equipment necessary to build one for myself so I’ll have to buy one. Saaay, how much would you charge…? (Seriously). I’m in AU, so our currency is generally comparable.
Yeah. You're bang on with your first point. The important part is the conversion chart, not your choice in tension meter. If you saw my recent video "Battle of the Spoke Tension Meters," you would have seen that even the cheap Park Tool tension meter performed reasonably well. I thought about building and selling spoke tension calibration jigs when I first made mine, but quickly decided against it. Just not economically viable. The parts are too expensive when buying single items from multiple retailers and paying MSRP. And I'm not serious enough about it to buy in bulk and negotiate wholesale pricing. I spent about $400 just in parts for mine. Your best bet is to shop around as there are a few available for purchase. AliExpress has one for $500. A Few others a bit cheaper. I have no idea how good any of them are. If you want a no cost solution and have another set of wheels with known tension, you could do what musicians do and go by the sound made when plucking a spoke. Low tone = low tension. High tone = high tension. Slight changes in tension are quite easy heard. One of the top bike mechanics in Toronto did it this way, although he also played a string instrument. Good luck!
Thank you!
Thank you!
Thanks!
You’re awesome. Thank you 🙏 And thanks for watching!
Good video, thx.
I need some help to understand, why the deflection increases with spoke tension.
My intuituon tells me, it should be the other way around.
More spoke tension withstands the force of the tensiometer, so it should deflect less.
Good question! What you’re asking is what puzzled me to no end when I first started wheelbuilding. The weird thing is that I still haven’t seen this discussed anywhere on wheelbuilding forums. I wasted a ton of time at the beginning trying to figure it out myself ☹
Basically, the tension reading corresponds to the amount of compression on the spring, not the perpendicular deflection of the spoke. So, a spoke with very little tension applied to it will cause minimal compression of the spring which produces as smaller number. A highly tensioned spoke will significantly compress/deflect the spring which produces a larger number. Put another way, there is an inverse relationship between the reading on the spoke tensiometer and the amount of deflection on the spoke.
My spoke tensiometer works exactly the same as the Sapim tensiometer. At the top of page 3 of the Sapim manual, you can visualize what exactly is happening. Here’s the link to the manual:
www.sapim.be/sites/default/files/sapim_tensiometer_english.pdf
I hope that all makes sense. Please subscribe to my YT channel. Cheers!
I have exactly same tensio, and its main drawback is that it uses thrust bearing instead of roller bearing, and the readings highly depend on how tight the tension bolt is. But the thing is that even if you try to tighten it as little just to remove the play in the bearing, it still introduces significant drag, which badly contributes to reading error. Just try to tighten or untighten the bolt for just fraction of revolution, and you'll see the difference. Or you can remove the spring and see how much friction there actually is. There's another version sold in China under brand Teny Bike or Toopre, they use roller bearing, which doesn't require any tensioning, it has much less friction. I wish I knew that when ordering mine. In the future I'm going to switch to the Jobs Brandt tensio, there are some nice guy from Poland, who produces them on demand. Also, Wheelfanatyk makes them. These type of tensios are much better than any existing tensio on the market.
Interesting. I would have thought the friction created by the thrust bearing is inconsequential, but I'll take your word for it. It isn't a particularly precise or well made tension meter, so it is something I should think about upgrading at some point. The Wheel Fanatyk one you mention I'm familiar with and is not crazy expensive. The Brandt one I'm not familiar with but will look into. It definitely is the weakest part of my setup. Thanks for the advice!
@@bikesbymike Jobs Brandt is the engineer who invented the tensio, as well as the author of the The Bicycle Wheel book, he made the drawings open to everyone who wants to produce it. First it was Avocet/DT Swiss, later FSA, now Wheelfanatyk makes them. If you'd like to have the best one, then you may search for Filip Kralyevski tensiometer, he has further improved it by added precise cross roller table bearing. You may contact him directly, if you'd like to order one. Now, regarding the thrust bearing of our particular tensio, believe me, the friction it makes affects the reading horribly. For example, if I measure 2.00 for a 100 kgf, just touching the bolt for a very very tiny fraction causes the reading to jump all the way from 1.9 to 2.1, which totally distorts the existing conversion table. And unfortunately, it is not possible to tighten it light enough, because then there will be a small play left, which will give inconsistent results. And as soon as you take the play away, you get friction in response. I even applied light grease, it improved the situation but no tremendously. The bearing is junk, the tool isn't precise at all, even the original DT Swiss tool is not a great design decision, but hey, they built it primarily for their own spokes, they never claimed it is intended to be used universally.
@@bikesbymike seems like my last reply was masked.
@@atexnik ...weird. I don't see your last comment anywhere. Not being held for review.
Really weird. Let me repeat here. I was saying that Jobs Brandt is the inventor of the Wheelfanatyk's tensio, it was initially produced by Avocet, then FSA and later by WF. The good thing about it is that anyone can use the diagrams of Brandt, they are open. Another guy from Poland makes them by demand, he added linear bearing, improving the precision drastically. @@bikesbymike
This is such a cool video Mike! You motivated me to go next level with my wheel building and build a spoke tension meter calibration tool for myself. However I see that this amazing crane scale unfortunatly is no longer for sale.
Good to hear, Roland! There are plenty other crane scales equally as good. Just make sure the top and bottom hook holes/attachments will fit whatever connection you'll be using and make sure it is rated to at least 200 kg. They are all reasonably accurate, but you may want to get one that does indicate its level of accuracy.
@@bikesbymike Thanks Mike ☺️
Thanks for sharing.
I'd like to build a similar jig.
Could you please provide more insight on the construction of the lower part, especially how is the threaded end of the spoke connected with what bolts and the M8 rod at the same time making it possible to twist the rod.
Michał
Warsaw, Poland
I’ll try to describe it as best I can. The threaded end of the spoke connects to a spoke nipple that pokes out of the M8 acorn nut. I drilled a hole in the acorn nut large enough for the nipple to fit through, but small enough so that the nipple flange at the end doesn’t slip out. The acorn nut threads onto the M8 threaded rod and locks into place with a M8 hex nut. Then that rod assembly fits through the “floating” piece of aluminum extrusion framing and then the top (fixed) piece of framing. On the top side of the fixed piece of framing, I’ve threaded an M8 Star Grip Knob onto the threaded rod with a needle thrust bearing washer between the knob and the top of the fixed piece of framing. The floating piece of framing moves up-and-down with two sets of the v-slot support plates and bearing guides that connect to opposite ends of the floating piece of framing.
The only hard part of this job was drilling a hole in the acorn nut. It was very hard steel, so it took a long time to drill through it. You must use a good quality drill bit AND some type of metal drilling lubricant.
My complete parts list in located in this Google Drive file:
drive.google.com/file/d/1fHQS8V0aiqN47WqOOdiJXyxSPLv7Y3f8/view?usp=drive_link
Good luck!
Great video - just built a similar jig using your parts list with the aluminium extrusions etc, many thanks!
quick question - when held horizontally as per your video - the scale initially records the weight of the component parts pulling on the crane scale, before tension is applied, so .. wondering if it’s necessary to subtract the weight value of the relevant system parts from the final reading?
Thinking this is less of an issue if the calibration tool is held horizontally, might be worth doing, and easier to account for if the tool is positioned vertically? Possibly overthinking this …
Nice job! You raise a really interesting issue, but this is why I think it's a mute point.
There is very little tension on the spoke created by gravity pulling down on the components while the jig is in the horizontal position. I tested this myself and found it to be about .5 kgf, although this may be within the error range for the scale I'm using (it measures in .1 kgf increments but I doubt it is accurate to that increment). Regardless, whatever the number, it is minimal and I would say inconsequential given the very high tensions we are measuring on spokes. I measured this .5 kgf figure by unweighting the components with my hand from underneath, zeroing out the crane scale, and then removing my hand to let the force of gravity pull down on the parts.
I'm trying to recall my Grade 12 physics, but I do not think subtracting the weight value makes sense. Whatever that gravitational force is, let's assume .5 kgf, it continues to exert that downward pull even when the spoke is under full tension. So as long as you keep the jig in its horizontal position the entire time, there is no need to subtract that weighted figure from your final reading.
I should also mention that I saw no difference in my tension readings moving the jig from a horizontal position to vertical. If it read 100.0 kgf in the horizontal position, that's what it read in the vertical position. It may have deviated by +/- .1 or .2 kgf but I attribute that to inaccuracy in the scale, flex in the spoke, or flex in other components of the jig.
Since I don't think that the weighted number should be subtracted from your spoke readings, placing the jig vertically really doesn't change the situation. Gravity exists in that scenario as well.
I may be wrong, but that's my thoughts on all of it. I have a friend who is a particle physicist researcher, so maybe I should put the question to him to be 100% certain :)
@@bikesbymike Thank you for the fast - and comprehensive reply, very useful, agree as you say in the scheme of things, probably inconsequential, thank you!
Excellent design and great video! When you put the spoke tension meter in place, the force increases. Is there a reason you used the displayed force before you put in the tension meter instead of using the increased force? Thank you!
Good question. I’ll try to explain it without confusing us both ;) The short answer is that the way I did it is the typical way it is done. But here is my thinking on why it makes sense to do it this way.
The tension of the spoke on the rim is created by the connection of the spoke at the point of the hub and the rim without the spoke tension meter attached to it. So if I put the spoke into the calibration jig and tighten the tension until the crane scale reads 100 Kgf without the spoke meter tool attached to it, I know for sure that it is exactly 100 kgf. So, when I now attach the spoke tension meter tool to the spoke on the jig it is for the purpose of measuring the amount of deflection at exactly 100 kgf. The force does increase a bit by adding the tension meter tool, but this is inherent in the design of the tool.
The important point in all this is that by doing it this way I can perfectly replicate the scenario using the calibration jig (with a known force) with the scenario whereby the spoke is fitted to the rim. So, if on the jig I get 3.5mm deflection at 100 kgf, I know that a reading of 3.5mm deflection for a spoke mounted on a rim must be exactly 100 kgf. I’m not interested in the tension of the spoke with the spoke tension meter tool attached to it any more than I’m interested in the tension of the spoke when I squeeze it with my hand, because that’s irrelevant to how the wheels are ridden.
I don’t think I’ve explained this terribly well, and my reasoning may be off, but that’s my take on it. I should ask my friend who is particle physics professor who could provide a more scientific answer.
Nice design. Just wondering what the benefit of the sled / roller guide is? You obviously added it for a reason to your 2nd design.
Thanks. It’s not essential and there are cheaper ways to accomplish the same thing. But without the rollers/sliders, that black aluminum extrusion piece would twist around as I was tightening or loosening the knob on the top, so I’d have to hold it in place. Not the end of the world, but a clumsy design.
@@bikesbymike Thanks, that clears things up!
Nice design！What did you use to secure each end of spoke？
I used an old L bracket (corner brace) that I had lying around. A metal shelf brace also works. Cut it to the right size and drill a proper size hole to secure the spoke head end.
Thanks for reply，However any idea for straight end of straight pull spokes？
@@ningbai1005 I can think of two options. 1) Your could use an acorn nut setup like I used to hold the nipple end of the spoke, or 2) Use a U-bolt w/t a mounting plate like in this link. Just drill a hole in the plate large enough to thread the spoke through. shop.forcesinc.ca/products/flsp261-u-bolts-with-mounting-plates-stainless-steel-304-inside-dia-1-thread-size-1-4-20-height-1-3-4-pack-of-1?variant=42895961686235¤cy=CAD&gclid=CjwKCAiAkrWdBhBkEiwAZ9cdcFZmiQ7TZ-dUL6Q7FWIBnD0m2jv3rQPlMwdl0l8m_uDABZpJca6uSRoCJQUQAvD_BwE
@@bikesbymike I could clearly see your point but there are quite a few straight pull blade spokes which I use having their blade wider than their heads. any thoughts？😂
@@ningbai1005 Right--good point! I've put J-bend aero spokes in my calibration jig with no issue, but straight pull spokes have a smaller head. Maybe cutting out a notch (to slide the spoke in from the side) instead of drilling a hole in the U-bolt mounting plate would work. You've given me yet another reason to avoid straight pull spokes :)
Great video! I’ve learned lots, but two main things: 1) buying or building a calibration jig is likely more important than an expensive tensiometer, once you have a means to calibrate as required, the quality of the meter doesn’t matter as much. 2) I have nowhere near the skill, understanding or equipment necessary to build one for myself so I’ll have to buy one. Saaay, how much would you charge…? (Seriously). I’m in AU, so our currency is generally comparable.
Yeah. You're bang on with your first point. The important part is the conversion chart, not your choice in tension meter. If you saw my recent video "Battle of the Spoke Tension Meters," you would have seen that even the cheap Park Tool tension meter performed reasonably well.
I thought about building and selling spoke tension calibration jigs when I first made mine, but quickly decided against it. Just not economically viable. The parts are too expensive when buying single items from multiple retailers and paying MSRP. And I'm not serious enough about it to buy in bulk and negotiate wholesale pricing. I spent about $400 just in parts for mine.
Your best bet is to shop around as there are a few available for purchase. AliExpress has one for $500. A Few others a bit cheaper. I have no idea how good any of them are.
If you want a no cost solution and have another set of wheels with known tension, you could do what musicians do and go by the sound made when plucking a spoke. Low tone = low tension. High tone = high tension. Slight changes in tension are quite easy heard. One of the top bike mechanics in Toronto did it this way, although he also played a string instrument.
Good luck!