Quoting NickZac:
The Rubber Rings on a $400 Knife?!?! Huh?!
The first thing I wanted to add to is regarding the ‘rubber’ or ‘plastic’ rings on the knife. These rings are not made of cheap rubber or plastic. In fact, they are made from a material which is one of the strongest on earth; polyurethane. Polyurethane is used in motor mounts on race cars when traditional mounts are torn from high amounts of torque. Many people have expressed skepticism in this for a $400 knife which I understand, but it is important to remember that despite looking like the washers will tear, they are made of one of the most durable shock absorbing materials known to man. Also, keep in mind that:
1) the correct functioning of the Umnumzaan is NOT dependent on these washers. It will still lock open safely with no blade play even if both washers are removed
2) the washers MUST be a softer material because they are absorbing the shock of the blade when being flicked open. If it was not a material that absorbed shock, there would be no reason to use the Hawk Shock Absorber. Of all shock absorbent material which could be used in this application, polyurethane is by far the most durable.
3) the washers can be replaced
In an earlier post, I discussed the polyurethane washers:
“I understand the initial skepticism. I first thought they were a cheap washer or plastic insert. Upon digging deeper, I found out that the materials these washers are made of is Polyurethane...it is the same material used in motor mount inserts on cars which launch from a dig (from not to moving such as drag racing) when traditional motor mounts tear on a regular basis. My buddy and I were running motor mount inserts made of a variety of materials and we would tear them on a rather regular basis. After going to these mysterious rubber (Polyurethane) inserts, we practically never tore them at all. Polyurethane offers both durability and flexibility which few metals are capable of matching as they are either not durable enough or not flexible enough. Polyurethane is an exceptionally strong material and I do not foresee you being able to tear it. I've batoned wood in which the sharper wooden edges make friction contact with the Polyurethane washer and I have also used it while cutting other metals and sharper edges did not harm it at all either. Mr. Reeve would not use it on his flagship folder if it was anything other than practically indestructible. If it did not have the durability capable of matching the rest of the knife (which has a thicker handle and blade than the large Sebenza and has a much beefier pivot design and refined lock), then it would not have been used on the Umnumzaan. I would definitely not let it prevent you from getting one as I think this is the best folding knife ever made in both design and implementation.”
A final thing about the Hawk Shock Absorbing System is that by having the polyurethane create pressure between the base of the blade and the titanium handle, you now have insulation from shock which is not used on many knives. I have read this is a huge advantage for a folder you may hack with as it reduces vibrations that could break the blade off at the base.
:thumbup: