Bow hair quantity
Hi everyone, I've been playing violin for about a year and a half now, using my Ary France pernumbuco bow that has been rehaired once (the factory hair was kind of kinky). Now that i'm at book 4 Suzuki, I was starting to feel that my bow was too jittery/bouncy on quick full strokes, and that the wood of the bow would often scrape the strings if I played with low tension.
Somehow I read the carbon fibre bow review site posted here, and in there it says that the amount of bow hair affects the playing qualities of the bow. I did a number of experiments, counting and cutting the bow hairs down from 220 originally to 180, then to 155 and again to 135 where it now stands. The playablilty of the bow changes at different hair numbers. At 220 and 155 hairs, it was rather bouncy/uncontrollable. But at 180 and 135 hairs, the feeling of quick whole bows is very secure and controlled.
The bow plays more wonderfully now, compared to when i first bought it. Much smoother, and i feel that i can get more sounds out of it without having it bottom out. It's almost like i bought a new bow! Still, the sound is much brighter and focused than the "dark" sounding bow i thought i bought.
Still, I haven't found much information on the Internet as to determining the right amount of bow hair on a bow, and what experienced violinists tell their bow rehair person to get the kind of effect they want. Do people tinker with the number of bow hairs on their bow/ type of hair? How do you know if it is optimal?
Replies (11)
About 8 years ago I experimented with a number of violin, viola, and cello bows. I measured the stiffness of the sticks in a reproducible way and counted the number of hairs on each. I came up with a fairly simple algebraic expression relating various parameters of the bows to good performance and adjusted the number of hairs (on those I owned) to meet those values.
Until AOL stopped supporting websites, I had the resulting EXCEL spreadsheet posted on line. Since then I have had to repost my information with a new server you can download and play with the spreadsheet at:
http://www.victortechnology.com/bow-calculator.xls
It aloso has links from: http://www.victortechnology.com/bowedstrings:violin-bow-review.html as well.
Andy
Thanks for the great info Josh! I'm glad the results of my experiment with bow hair quantity is quite close to your experience with bows. My bow's a flexible student model so it would have been near the lower end of your range. I did get 220 bow hairs though, which puzzles me as it was a very good rehair. As far as i can tell, the hairs were straight and evenly distributed in a nice ribbon (I checked against a light) and tensioned at about the same amount. However, the bow stick just couldn't resist my hand pressure at a good hair tension. Now it can, and I don't get the loss of grip and bright harsh sound from overtightened hair. It also bounces less aggressively and absorbs impact better.
I don't know if hair amount is a well known variable amongst violin players. I've checked Carl Flesch's and Fischer's violin instruction books and they make no mention about quantity and quality of hair. The focus is always on hair tension.
Dear Andrew! I never figured out the bow calculator, but I'll keep trying. I don't know how to get the value for k=f/x for my bow. Did you clamp the bow and place a weight at the tip and measured the deflection? Was it the part of the shaft before the head itself?
Dear Don, there have been many posts about hair tension, quality of hair and rehair, but not about quantity of hair. I don't think there has been a thread on the number of hairs actually used.
I did some simple web searching, and found that the value for number of bow hairs ranges from 150-200 (attributable to Raffin and Milliant's book L'Archet) to 100-150 (some baroque bowmaker's website). That's a pretty wide range.
Thank you for your replies. I do think I've gotten something out of understanding this variable in bows.
Ken,
I clamped the bow at the frog end -- actually, I clamped a fountain-pen cap (or similar cylindrical shape) to a "table" and inserted the screw end of the bow and rested the entire frog end on the table. I removed the frog and put it and the hair out of the way. Then I hung a weight from the tip end and measured the deformation. I did not always use the same weight because the heavier weight would have deformed the softer bows too much, and the lighter weight would have reduced the precision with which I could measure the stiffer bows.
I should have added that being aware of the differences between different hairs, once I had the bow at what I considered an ideal number of hairs, I weighed the bow and wrote the weight on the tip (in pencil). This then became the target weight for rehair.
Andy
Greetings,
this subjetc really isn`t discussed nearly enough so its great to have so many contributions. The first time I ever even thought about the subject was when one of the best luthiers and repairers in Japan actually asked me if I wnated 120, 140 or 180 hairs !!!!!!! Previously, by average shops, I had only been aske dif I wanted a good job or a bad job ....sorry, I mean the expensive or the cheap work.
Cheers,
Buri
This is a follow-up to Andrew's excellent advice. I weighed my bow, and filled in the parameters according to the chart, getting a result of having 120 hairs as ideal. My bow was the softest among those on the chart, which surprised me, with a K value of 51.3. The deflection with a 220g pencil box on the head was 4.2cm!
Well there are other properties of a bow that I haven't had time to investigate, but I did pull the bow lapping off my bow, as even though it had the same CG point as a Codabow Diamond GX I got on loan, the Diamond GX tracked better. With the increased tip weight, I felt tracking improved after the modification.
I really like the sound of my bow, but it just bottoms out too easily, and is squirrelly at other places. I find that it makes learning new pieces and sight-reading harder. Should I stick with it? The GX on the other hand was really easy to control and play, but I couldn't change the timbre very much with the Codabow. I wonder if this is a characteristic of carbon fibre bows.
Hi kenneth,
This is interesting. well i got a bow something simillar to yours.
Well i brought my bow(ary france too) to a a very good violin player and when he saw the bow. he made a comment like what u said...towards the end of the bow its will no react as well as the whole length of the bow. Its amazing because he didn't play the bow and he pointed the problem out after few looks :)
So could it be the chambering of the bow. On closer look, he pointed out that the lower end of the bow does not curve like a normal bow. When he tighten the bow to the extreme, he notice that the particular area did not have the tension to "fight" againist the tightness to go back to the proper shaped... haha :) yup. So give your bow a look maybe its that problem.
Regards,
sherman
I'm sorry to report that my website is ALL GONE! My business reasons for maintaining it no longer exist so I just let it expire. This means that my Composite Bow reviews and "Bow Calculator" are no longer on line. But I can email them to those who want them.
Andy
Hi Andrew,
Any chance that you still have that Bow Calculator? Is so, could you send it to me at richard@yatesguitar.com? Thanks!
not sure but i know
hairs:150
weight:10 gr as an standard.
there are 15 grams hairs also but i heard it's not an ideal weight.
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February 10, 2009 at 05:07 PM ·
Hi Kenneth, The proper amount of hair in a bow is a very critical factor in how the bow plays and sounds. Too much hair in a bow and it tends to feel “spongy.” Having a bow rehaired with too much hair is unfortunately, a very common problem. Very often new bows with factory hair have not only poor quality hair, but also too much hair.
You mention that your bow had 220 hairs after being rehaired. Unless you are playing with a cello bow, 220 hairs is way, way too many. The standard quantity of hair in a typical violin bow is usually around 140 to 160 hair, depending on the strength of the stick. Small-sized violin bows get even less hair. A bow with a stiffer stick can tension more hair than a flexible stick.
However, to further muddy the water here, there are different kinds of horsehair that have different diameters. I have a very fine grade of Mongolian hair that is a slightly smaller diameter than other hair. I also have a course white Mongolian hair that is popular with fiddlers, cellists, and bass players. If I take a “standard amount” from each of these two types of hair, I would end up with approximately 160 hairs of the fine hair, but only about 130 hairs with the courser hair. Even though the number of hairs is different, the two hanks of hair are the same diameter (in other words—the same quantity of hair).
Your question about telling the rehair person your preferences brings up a good point. Experienced rehairers should know the optimum amount of hair that should be installed in a bow. However, if you find that you have a preference for less (or more) hair, then tell the person that rehairs your bow to match the amount.
For an interesting read about horse hair, click HERE. This will bring up a pdf article about the different types of bowhair, including some microscope photos of the hair surface and cross section.
Josh Henry, Bow Maker & Restorer
www.FineViolinBows.com