SS caliper pistons - why so heavy?

elefantrider

elefantrider

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Recently picked up some UK-made - SS caliper pistions (06-1896) as pictured on the left of the below image, and couldn't believe the weight of these!

Why do they need to make these things so thick and heavy?

SS caliper pistons - why so heavy?


Commando Caliper Pistons



  • Part Number 06-1896, $19.99 each, the stainless steel piston from Andover Norton.
  • Part Number 06-1896/SS, $0.00 each, the stainless steel piston from Molnar Precision LTD., made in England.
  • Part Number 06-1896/A/SS, $29.49 each, the stainless steel piston from Miles Design, made in USA.

https://www.nwno.org/resources/OldBrittsWebsite/14_061896.html

The ANs seem to have the smoothest transition fron flat to side, aka contoured bevel edge.
The middle one from Molnar is lightest but it seems those are not made anymore.

Although they appear to be the best finished, I did not consider the ones on the right, as the are not designed per the originals with the center machined chamfer. Unsure if their flat face will perform any diferent in practice but the chamfer seemed like a good thing to have on new, thick pads.
 
Last edited:
Do not get the Miles design, there is no relief machined on the back unlike the others. Push the Miles one back into the caliper and there will be no route for the brake fluid to get behind the piston and push it out.
 
Great info. I plan on making a few of these in stainless and wondered about the purpose of the stepped surface on the back.
 
Is that the reason they have concave machining on the inner side?

The other 2 seem to have flater-machined inners and are 22-25 grams lighter.
 
elefantrider said:
Is that the reason they have concave machining on the inner side?
Click to expand...
Whether it has or has not it is advisable to insert the inner piston only far enough to fit the pad as the drilling is in the sidewall of the caliper so pushing the piston too far can block off the drilling.
 
I am curious as to if there's a a valid reason, besides maybe ease of manufacturing, the A-N one has a steep dish machined inside. Bottom left image. That seems like a lot of unecessary material contributing to the extra weight.

You can clearly see the inner sidewall is shorter on the leftmost A-N one.
 
ludwig said:
To reduce weight, I made a set of titanium pistons and an alu screw-in plug, but assembled, it is still a super heavy caliper.
Click to expand...
Nice!

I assume you polished the titanium or used a coating maybe?

Did they work good against the rubber seals and aluminium bores for a long while?
 

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