flexible bow or weak bow?

July 1, 2008 at 03:47 AM · Seems like a good question. Anybody?

July 1, 2008 at 04:40 AM · A good strong and flexible bow is usually made out of pernambuco, and it requires a bit of handling in order to bend. If the bow is lighter, and doesn't take very much to tighten etc. then it is a weaker bow.

July 1, 2008 at 04:49 AM · I had the misfortune of trying too many weak bows; the rule I now use is this:

If I need to tighten it beyond playing tension to rosin it well, it is a weak bow.

July 1, 2008 at 09:44 AM · I've heard from my friend, that a real Tourte bow has to be overtighten to play (he said the stick is very soft), and yet it's a very sensitive and agile bow with great control.

I've saw some old timer soloists, their bow stick has been tighten until giving you an impression that you can slide your thumb in between hair and stick freely.

I think a really good bow has to be flexible/soft but yet very easy to control and hold up strong bowing well.

July 2, 2008 at 02:01 PM · Just found an example video clip, although not old timer.

http://www.youtube.com/watch?v=Vzc1fLVE2lc

Not sure it's due to the angle, or was the bow really tighten THAT much.

July 2, 2008 at 09:36 PM · It's a question of both semantics and personal preference. A bow that's flexible to one might be weak to another. I depends on what you're used to. I have a Hill bow that is quite soft, but when I play on it for a while and get used to it I like it. I have other bows that are much stiffer, and then it takes a little time to get used to those. I've found that very stiff bows seldom sound great.

In my opinion, a bow can be categorized as genuinely "weak" when it develops a severe warp when tightened to playing tension, and especially when the warp really affects the playability. I'd also say that a bow is weak when a majority of players find they can't make it bounce or ricochet well. Maybe one more definition for a weak bow: unable to hold its shape under normal playing condition after

being recambered.

July 4, 2008 at 10:26 PM · How do I tell whether a bow is flexible or simply weak?

I am not sure what the difference is between flexible and weak. A mechanically very stiff piece of wood can be made so thin that it is extremely flexible. You may have a skinny bow stick of stiff wood, or a fat bowstick of more limber wood. They will not play the same.

The Stroup gauge can be used to measure stiffness (flexibility) of bows. I don't own one, but I am considering building one (but they are certainly not a necessity). Most people judge the stiffness by feel. Here is a site that discusses measurements of bow stiffness with the Stroup gauge http://giannaviolins.com/Articles/bowobserv3.html

Usng the Stroup gauge, weight is placed in the center of the bow and the bow is supported just behind the head and just forward of the frog. The deflection is measured in thousandths of an inch. To construct a similar device, know that if you use a two pound weight, the deflection is twice that of a one-pound weight.

If you are looking at deflection tables, be sure to determine if they are in the English (inch-pound) system or in the metric (kilogram-millimeter) system. American bowmakers mostly do everthing in metrics except for balance point and deflection measurements.

This site shows how the Stroup gauge procedure is applied to measuring the stiffness of arrows for archery: http://www.meta-synthesis.com/archery/archery.html . It is applied similarly for violin bows.

You do need to measure deflection very accurately. You can do this with a machinist's dial indicator micrometer ($10 on ebay) set up on a stationary rod above the bow and set to zero with no load. This is the kind of micrometer with a spring-loaded pin that measures deflection as the bow moves.

It is also very important to test the stiffness along the bow by hand to make sure there are no localized stiff or limber areas along the playing length. It should gradually feel stiffer going from the head to the frog when you press your thumb on the top of the stick while supporting the frog end in one hand while the face of the head is on a table or work bench. Press the top of the bow at small incremental distances along the bow. You should find no locally stiff or limber spots.

I suggest testing a range of bows first to find the stiffness you like (don't worry about price). Once you know the stiffness you like, you can test bows in your economic range that meet that criterion.

Keep in mind that most folks go with what 'feels best', not with what 'measures best'. Don't let the gauge over-rule how the bow actually plays. You should also look for a bow with proper balance.

July 16, 2008 at 07:02 PM · Simple...if the bow scrapes against the string as you play a standard forte, then it is likely weak and not the right bow for you. The reason makers use Pernambucco in the first place is because of its flexibility, therefore, I'm not even going to consider this a distinguishing factor amongst bows.

The thing about tightening the hair could be misleading. Sometimes, hair is too long so no matter how much you tighten it, it always seems a bit slack. This is especially true in more humid conditions. If you are trying a bow and you have this problem, make them check for this...otherwise move on.

However, this whole conversation is moot if you are dragging wood across the string from 1/4 to 3/4 on your stick. Plus, you're going to go through hair like no tomorrow.

Every player has different technique, so it is pointless to look at a catlogue and have it tell you these things. Know whether you require a strong stick or a softer stick going into your search and you will save yourself a great deal of time and effort.

July 17, 2008 at 12:46 AM · In 2000-2001 I tested a number of bows for various "static" factors I was able to measure and thought might might have effects on bow performance:

http://members.aol.com/bowedstrings/bow-calculator.xls

The data format is EXCEL spreadsheet. I would have ocntinued (since I was given access to an incredible bow collection and had just complete a rig for testing them), but after 9/11/01 I decided my heart was more into making music thatn testing bows.

In my opinion, this idea of flexibility and soft or stiff and hard does not really address the issues that well.

If a bow is flexible, it is important WHERE it is flexible. I think really great bows are flexible pretty much over their entire length and crummy bows, that may have the same total flexibility may have the "bend" almost entirely in a short section of the stick. For example, the F.N. Voirin I tested is flexible over the entire length of the stick, produces a great tone, and has wonderful off-string behavior - you can see how "soft" it is in the spreadsheet, but with the right (small) amount of hair it is pretty-near perfect.

The amount of hair on a bow, while it will not affect the flexibility of the stick, does work in combination with the stick to affect the playing qualities. So, sometimes a bow of average stiffness may seem soft (in playing behavior) because it has too much hair, or it may seem stiff, because it has too little hair.

A bow should be chosen for its playing (and sounding) qualities on the instrument it will be used on. Even bows by the very greatest makers are not optimal for all instruments. It is advisable to have a routine of musical variety and bow strokes to test every bow you sample.

Andy

July 17, 2008 at 01:53 AM · Interesting spreadsheet Andrew,

I'm curious about the meaning of your results in column X and Y though.

What is the implication of a negative number here? Does a smaller number here mean that a similar force (similar to, say, the Arcus CF bows in magnitude) would need to be applied lower in the stick?

I find it interesting that the Arcus CF have the largest valus in these columns, yet they have exhibited some of the greater ease in off the string, as well as up-bow staccato behavior I've come across.

July 18, 2008 at 09:03 PM · "...If a bow is flexible, it is important WHERE it is flexible...." Andrew

My experience is consistent with Andrews post. My luthier told me my bow had spot of "weak cross grain" toward the middle resulting in a tendency to bounce more no matter how I played or tightened the bow. A good luthier/bow maker can tell you if you have a weak spot on the bow.

I bought less expensive bow and it sounded better because it was not weak anywhere.