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View Full Version : Some Reed Valve REEDS questions



arlaunch
01-07-2017, 12:43 PM
Good morning folks,

Looking around through some old boxes of parts i found some interesting combinations of reeds

I have been using Vforce 3's lately and likely for evermore.

But!

Can somebody on here tell the world how the mid eighties and later evolution of reeds and reed valves unfolded?

I have a metal reed valve set that belongs to an 85 Honda 250R ATC. OEM R's had metal reeds right?

Then there is another poly/glass fiber? type reed valve set that seems to have 2 distinct stiffness/stages that also belongs to an 85 Honda 250R ATC. I am not sure if this is the first revision up from the metal pedals or not. The metal pedals are quite flimsy and i am guessing flutter big time at high engine demand as they open to pressure very easily.

Last is a pic of a valve that belongs to a 1986 Honda 250R ATC. This one has what looks to be carbon fiber reeds over the older poly/glass fiber stiffer base. Any body know approximately what year these came out?

The 86 valve, boot and plastic insert are clearly different than the 85.

https://c2.staticflickr.com/1/614/32046308801_25b66c0c57_k.jpg (https://flic.kr/p/QPPH8x)Metal (https://flic.kr/p/QPPH8x) by aklaunch (https://www.flickr.com/photos/62604787@N04/), on Flickr

https://c1.staticflickr.com/1/667/32016129472_a0cbafcfff_k.jpg (https://flic.kr/p/QMa2Sh)2 stage Plasti (https://flic.kr/p/QMa2Sh) by aklaunch (https://www.flickr.com/photos/62604787@N04/), on Flickr

https://c3.staticflickr.com/1/633/32016113802_05c2575b4a_k.jpg (https://flic.kr/p/QM9Xd7)Carbon Fiber (https://flic.kr/p/QM9Xd7) by aklaunch (https://www.flickr.com/photos/62604787@N04/), on Flickr

fabiodriven
01-07-2017, 12:58 PM
You got the order right to the best of my knowledge, at least I discovered each in the order you have them listed.

Metal was first and also the worst because if they break...

Second I discovered were the two stage white plastic reeds. I don't know if there was any performance difference, but they'd certainly do less damage to an engine if they broke.

The set that looks like carbon fiber, those have been around longer than one might expect. The first time I opened up a bike and saw those I felt like Columbus when he discovered America. Then I realized they were actually quite common, lol.

bkm
01-07-2017, 02:38 PM
I remember TDR selling carbon fiber reeds back in the mid 90's, maybe even earlier.

Sent from my SM-G900V using Tapatalk

El Camexican
01-07-2017, 03:09 PM
The only thing I can tell you from personal experience it that depending on the size of the engine (and many other factors) the fiber reeds seem to lower the rpm that the engine starts to make decent power and it softens "the hit" a little.

The broken metal reed VS fiber reed makes sense, but I've never met anyone who told me they had a metal reed brake on them. I'd suspect the biggest risk with any reeds is that a retaining screw comes loose. That's something V-Force has eliminated with their design. For the rest of us there's Loctite.

As far a longevity is concerned the steel reeds have to win. I've seen carbon fiber reeds degrade after a few years of sitting in an engine. The steel ones are still going strong on some engines after 25 years.