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Offline Farley121

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Phenolic Piston
« on: January 18, 2016, 05:00:06 PM »
  Hi All,

I'm looking to replace my pitted brake piston with phenolic.  I found one at the Power Barn but am somewhat skeptical.
It says that it does away with the spacer normally used and shows a hollow piston.  That spacer is required for the pad to self adjust and sit flat to the disk, and I'm not sold on the idea.
Has anyone used this style before, or have a better source?

http://www.power-barn.com/honda-replacement-phenolic-front-brake-caliper-pistons-for-cb350-cb360-cb400-cb450-cb500-cb550-cb750-45107-323-020/#

Thanks
« Last Edit: January 18, 2016, 05:10:30 PM by Farley121 »
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Offline Trad

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Re: Phenolic Piston
« Reply #1 on: January 18, 2016, 05:27:35 PM »
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Offline Farley121

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Re: Phenolic Piston
« Reply #2 on: January 18, 2016, 05:51:59 PM »
  Thanks Trad,

By the look of the photos on Godffrey's site, they are the same.  Literally, the same photos are used by Power Barn.  I will assume they are one in the same product and the omission of the spacer may not be as important as I expected?
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Offline sixthwisconsin

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Re: Phenolic Piston
« Reply #3 on: January 18, 2016, 06:09:10 PM »
Quote from: Trad on January 18, 2016, 05:27:35 PM
Godffery makes nice ones. He's a great guy to deal with too.

http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Parts+and+service/PHENOLIC+Replacement+brake+Caliper+piston/PHENOLIC+Replacement+brake+piston+for+Honda+CB350+to+CB550+and+CB750/


+2
Great service.
Probably the same units but Godffrey supports this group and if you need any other brake parts or thinned/drilled rotors, he's your man.
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Re: Phenolic Piston
« Reply #4 on: January 18, 2016, 07:31:52 PM »
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Offline DaveBarbier

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Phenolic Piston
« Reply #5 on: January 19, 2016, 04:59:31 AM »
Godffery makes them and Powerbarn is a reseller. I bought one from Powerbarn and one from Godffery for my dual disc setup. I'll never go back to metal...stainless or chromed steel.

The plastic spacer is omitted with the phenolic. And it may be obvious, but the hollow side faces the pad. Otherwise you'll just use excess brake fluid filling the piston.

Someone else can correct me but I don't think the spacer is there to help the pad self align. The pad can't rock in the caliper bore; if it does it'll get stuck. The pad (fluid side) is fixed and moves along the arc of the caliper arm, the other pad (dry side) rocks and self aligns using the convex dome cast into that caliper half.

I think the plastic spacer is there to help dampen vibration and noise.

By the way, Farley121, this is what I instantly thought of when I saw your username, haha.
« Last Edit: January 19, 2016, 05:03:54 AM by DaveBarbier »
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Offline MoMo

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Re: Phenolic Piston
« Reply #6 on: January 19, 2016, 05:16:33 AM »
I've used the phenolic piston in quite a few rebuilds.  A great product that I got several years ago from forum member Kevin when he was selling them...Larry
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Offline strynboen

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Re: Phenolic Piston
« Reply #7 on: January 19, 2016, 05:58:11 AM »
your brakes vil sqvezze for long time..to the pad are veared inn. using the vrong pads.the pad is not deseined to be parelel it must be abel to kompensate for the radius movent of the caliber arm..some pads have a round back side and vill Work fine on a flat piston...but be care to find the right pad/piston kombinasion
Honda did thange the caliber a bit over time..and aftermarked did not alvays find the universale to fit all bikes perfekt

the nylon ring is not needet on a bakelit cast piston..but you need the korrekt pad,, made like on Photo..
« Last Edit: January 19, 2016, 06:06:05 AM by strynboen »
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Offline MoMo

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Re: Phenolic Piston
« Reply #8 on: January 19, 2016, 07:01:46 AM »
strynboen,  I think the fact that the phenolic piston is chamfered inside allows the stock pad to work.  At least the phenolic pistons I used were chamfered....Larry
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Offline strynboen

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Re: Phenolic Piston
« Reply #9 on: January 19, 2016, 07:08:18 AM »
 i dont have maket it klearly..yes.think it vork just as good/badd as the  most metal piston...its the pads it all abaut..few types Work good..theu need that "doot" at the back side to make the pad balance aut the radius moving arm..most pads dont have that  kurved back side..and stays parallel=dont Work before they are veared some aut..and screming a lot the first seson..
the erly 750 have some ekstra gear..build in the caliber to kompensate all this
..later it vas made more simpel..and some kombinasion of aftermarked parts..make it vork vorse..
« Last Edit: January 19, 2016, 07:10:32 AM by strynboen »
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Offline Farley121

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Re: Phenolic Piston
« Reply #10 on: January 19, 2016, 07:28:05 PM »
  Thanks to everyone for the replies.  Looks like I will be ordering one.

Cheers
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Offline Mooshie

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Re: Phenolic Piston
« Reply #11 on: January 19, 2016, 08:30:54 PM »
Quote from: DaveBarbier on January 19, 2016, 04:59:31 AM
Godffery makes them and Powerbarn is a reseller. I bought one from Powerbarn and one from Godffery for my dual disc setup. I'll never go back to metal...stainless or chromed steel.

The plastic spacer is omitted with the phenolic. And it may be obvious, but the hollow side faces the pad. Otherwise you'll just use excess brake fluid filling the piston.

Someone else can correct me but I don't think the spacer is there to help the pad self align. The pad can't rock in the caliper bore; if it does it'll get stuck. The pad (fluid side) is fixed and moves along the arc of the caliper arm, the other pad (dry side) rocks and self aligns using the convex dome cast into that caliper half.

I think the plastic spacer is there to help dampen vibration and noise.

By the way, Farley121, this is what I instantly thought of when I saw your username, haha.

+1 I bought from Kevin as well many years ago. It is amazing.  And no spacer needed/used.  Bike actually stops (after I rebuilt the master cylinder).  Great purchase.
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Online scottly

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Re: Phenolic Piston
« Reply #12 on: January 19, 2016, 08:43:54 PM »
Another plus for phenolic pistons is the lighter weight; a K7 phenolic piston weighs over 1/4 pound less than a stock K7 piston. That's over 1/2 pound of un-sprung weight  on a dual disc set-up.
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Offline DaveBarbier

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Re: Phenolic Piston
« Reply #13 on: January 20, 2016, 02:13:16 AM »
Another plus for phenolic is heat transfer. The phenolic material won't transfer the heat from the pad/disk to the brake fluid as much as metal. But the whole caliper is still aluminum so maybe that'a a moot point...it's early and I think I'm still sleeping.
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Offline Pan1cReaper

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Re: Phenolic Piston
« Reply #14 on: January 20, 2016, 08:21:39 AM »
Glad this came up, I need a new piston anyway as mine is pitted. I think I will order from Godfrey.
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Offline Farley121

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Re: Phenolic Piston
« Reply #15 on: January 21, 2016, 06:19:09 PM »
I'm going to guess that this is one of the few, cheaper than OEM replacements that actually exceeds the original.
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Offline MoMo

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Re: Phenolic Piston
« Reply #16 on: January 21, 2016, 09:05:52 PM »
Quote from: Farley121 on January 21, 2016, 06:19:09 PM
I'm going to guess that this is one of the few, cheaper than OEM replacements that actually exceeds the original.



In my experience that is true
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