<html> Terry, Rim thicknesses vary in Kawai pianos according to the design of the particular model.  This would be true of Boston pianos as well.  The inner rims in these pianos are made from either Matoa or Callophyllum, both of which are Asian hardwoods with the density of hard maple (Callophyllum is a little harder than Matoa). If you compare an RX-2 rim thickness to a Steinway L, for instance, you will find that the total rim thickness is quite a bit more in the Kawai.  The inner rim alone is almost as thick as the entire L rim.  The outer rim in Kawai pianos (and other Kawai built pianos) is a softer wood, and is not considered as important structurally. One of the thickest rims you will see in any piano is the Kawai EX concert grand, with a rim that is hard to get your hand around.  All of that Matoa makes for a really heavy piano, too! I do not have any specifications on belly rail wood - it is a dense hardwood, and is the same in all Kawai grand pianos.   I suppose if the Boston dealers decide to start bragging about some special belly rail wood, I'll have to get the specifications and let everyone know that they are the same as well. They appear to be identical during construction.  The specifications wars that dealers play are so silly. Don Mannino RPT At 07:21 AM 2/21/2003 -0500, you wrote: <blockquote type=cite class=cite cite>Hi Don. Thanks for the reply. Interesting info. Digging further into this, are other structures like rim and belly rail materials and thicknesses the same on both pianos (for a given size)? Just what are the rims made of (species) - or does it vary? Thanks. Terry Farrell   ----- Original Message ----- From: "Donald Mannino" <donmannino@attbi.com> To: "Pianotech" <pianotech@ptg.org> Sent: Friday, February 21, 2003 12:46 AM Subject: Re: Boston and Yamaha opinions wanted > Terry, > > I meant what I said; the material _qualities_ are exactly the same, with the noted exception that Kawai uses some modern materials like ABS action parts where we feel they improve the quality of the piano, while Boston sticks to the Steinway story and uses all wood. > > The RX pianos all have the vertically laminated bridge root, and the bridge cap wood and grain orientation is the same also.  This was first used by Kawai in the EX concert grand in the 80s, and was put into standard production for both Boston and Kawai RX pianos when Steinway asked that Kawai make the Bostons this way.  > > With the bridge cap you will find that, depending on the relative density of the Maple supply at the time, the factory will either quarter saw or flat saw the wood.  This is a subject I have inquired about with our engineers, and the company policy applies to Boston and Kawai models.  The engineers from Japan told me that when their density of the supply of maple becomes a little lower, they quarter saw the wood.  When the density is above a certain point, they stop worrying about whether it is quarter sawn or not.  Whether or not one agrees with the policy, it applies to Boston and Kawai RX grands.  It's conceivable that the workers sometimes save the harder wood for the Kawai pianos, and that could explain your observations.  You should check more of both kinds, though. > > I have seen Bostons with the angled or flat-sawn wood in the bridge caps, and I have seen lots of RX grands with quarter-sawn caps. > > You should also note that Steinway NY is known for flat-sawn bridge caps as well.  It's the density that the factories feel is most critical. > > Don Mannino RPT</blockquote></html>