Topic: Caliper Piston

[scottly]

I've got accurate weights of some brake components:
Late 750 42.8mm piston: 215 grams (7.58 oz) Phenolic equivalent: 85 grams (3 oz)
Early 750 38mm piston with domed cap: 202 grams (7.12 oz)
550 38mm piston: 165 grams (5.82 oz)
550 rotor: 2,474 grams (5.455 lbs)
750 rotor: too heavy for my scale, but 6.5 lbs on the scale at the post office.

[Godffery]

I've got accurate weights of some brake components:
Late 750 42.8mm piston: 215 grams (7.58 oz) Phenolic equivalent: 85 grams (3 oz)
Early 750 38mm piston with domed cap: 202 grams (7.12 oz)
550 38mm piston: 165 grams (5.82 oz)
550 rotor: 2,474 grams (5.455 lbs)
750 rotor: too heavy for my scale, but 6.5 lbs on the scale at the post office.

Groovy, Thanks!
I got'a get me a decent scale. =\

[scottly]

Thank you Jeff, for the phenolic pistons!!

[754]

I just use a triple beam, they seem to be cheap, the model i got but only weighs 599 grams.
Used to work next door to a guy with killer digitals..

[scottly]

Frank, my triple beam goes up to 610 grams, but with optional counter-weights goes up to 2610. I made my own 500 and 1000 gram counter-weights, calibrating them with 500 gram weighed standards.

[754]

Where do you hang the counterweights, what do they look like ?

[scottly]

I'll start a new thread with pics tomorrow.

[PeWe]

Piston seal then? Will it survive longer with a specific piston?

[RAFster122s]

There are aftermarket seals for the 38mm pistons and they are a couple $ cheaper than Honda OEM.  OEM the last time I priced it was under $10.

South Sound Honda in Olympia, Washington area is a dealer that ships inexpensively and  offers a very good discount.  Likely cheaper than a generic aftermarket piston seal.

[grcamna2]

Piston seal then? Will it survive longer with a specific piston?

I think you're asking how smooth the sliding surface of the Phenolic piston is(shiny or glossy?)compared to the stock Honda steel piston ? godffery,do you have any pics of your Phenolic ?

[RAFster122s]

Piston seal life should be similar if not same, it is a smooth polished surface, not high gloss but a gloss.
Wish they had the phenolic piston for the common dual piston caliper used by lots of 80s and some 90s bikes.

[strynboen]

have made some rustfree steel pistons..drilled aut and turned the inside diameter..massive is just to heavy...and hold the heat in the system..so it vill boil the fluid..not bu first stop..but at the time you not vant it to fade

[strynboen]

after have maked the inner diameter..i made a shaft..and glued the piston on that...and then made the autside diameter and the groove for the dust seal..running at a dummy shaft...after the lathe vork the pistons need some polishing..to run smooth in the bore

the seal vill hold to the rubber gets old..and not return the piston so vell..theu dont Wear aut..
..pistons get rusty..and get pittet...so they grow stock in the bore(korodes )

[Godffery]

Piston seal then? Will it survive longer with a specific piston?

I think you're asking how smooth the sliding surface of the Phenolic piston is(shiny or glossy?)compared to the stock Honda steel piston ? godffery,do you have any pics of your Phenolic ?

Hello,
I would imagine the seal would last AT LEAST as long with the Phenolic piston, as it would with the steel. Theoretically it should last LONGER due to the complete lack of corrosion & there ultra smooth OD?  To be honest, in all the years I have been using these, I have never had to replace a seal with one yet.

 Here is a link to all the photos I have for the full list of Pistons I make:
http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Parts+and+service/

[RAFster122s]

Hey Jeff would love to see you find the dual piston caliper size for the commonly used in 80s on Honda bikes.
David

[robvangulik]

Hey Jeff would love to see you find the dual piston caliper size for the commonly used in 80s on Honda bikes.
David

Same for my 30mm CBR pistons, I'd take eight at once!

[Godffery]

Hey Jeff would love to see you find the dual piston caliper size for the commonly used in 80s on Honda bikes.
David

Same for my 30mm CBR pistons, I'd take eight at once!

I had considered those, just was not sure how much of a call I would get for them?
I have batches of some Suzuki & Yamaha Pistons that have yes to sell a single one of.  That gets pretty costly to sit on.  =/

[RAFster122s]

Jeff, how many would you need orders for to get a batch.  It would require the right FB page and some forums where those calipers were used and you could get some pull for them started.  Tons of bikes in late 70s and 80s (honda) used those pistons.  So, there is a market you have to tap into. Get the search engines to pickup your pistons and then put a few out for samples to some builders of note who do cb and other Honda bikes and it will get noticed. Dual piston caliper with semi sinstered pads are vast improvement.
David

[rocket johnny]

    i bought one from vintage cb750   it was 35.00   

[Godffery]

Jeff, how many would you need orders for to get a batch.  It would require the right FB page and some forums where those calipers were used and you could get some pull for them started.  Tons of bikes in late 70s and 80s (honda) used those pistons.  So, there is a market you have to tap into. Get the search engines to pickup your pistons and then put a few out for samples to some builders of note who do cb and other Honda bikes and it will get noticed. Dual piston caliper with semi sinstered pads are vast improvement.
David

About 24 or so would be needed to spread out the first run design & set up costs.

[Godffery]

    i bought one from vintage cb750   it was 35.00

In Phenolic, of just metal?

[RAFster122s]

$35 would be a metal piston, likely a K&L brand.  He countered that 4 into 1 had a piston for the caliper for the twin pot caliper.  They do not carry a phenolic piston.
I did not specify and he did not get my implication of phenolic, given you are the only source for them.

David

[grcamna2]

    i bought one from vintage cb750   it was 35.00

In Phenolic, of just metal?

I just looked on their site and only noticed steel caliper pistons avail.

Jeff,
I want to order one,can I call tomorrow/Mon. morn.? or should i only email ?

[RAFster122s]

Sorry, not 4 into 1 but vintagecb750.

[Godffery]

Jeff,
I want to order one,can I call tomorrow/Mon. morn.? or should i only email ?
[/quote]

 Email works best.