Heppe ceramic piston conversion on ZRace XG calipers

[jonathanf2]

I had a pair of older ZRace XG calipers I haven't been using and recently one of my GRX calipers on my gravel bike had an oil leak. I decided to try the XG calipers but I swapped out the alloy pistons for the Heppe ceramic pistons. I've heard the newer release of XG calipers have ceramic pistons now, but I haven't confirmed that personally.

Heppe ceramic pistons:
https://www.aliexpress.us/item/3256806823730247.html

ZRace XG calipers:
https://www.aliexpress.us/item/3256804839023933.html

For reference on taking apart a ZRace XG caliper, you can watch these videos:

Trace Velo :
https://youtu.be/0XLtA8cRMH0?feature=shared

Water injection piston removal:
https://youtu.be/oRIMyk30eWw?feature=shared

I'm using Ultegra 11 speed hydraulic shifters and just to make note, these particular Shimano shifters work best with Shimano brake calipers due to the very tight piston tolerances. The downside is that they're a pain to align while trying to avoid disc rubbing. On these aftermarket XG calipers it's a good idea to squeeze the shifters a few times without the brake pads if the brake pull feels a bit soft in order to get the pads closer to the rotor.

Performance:
I did two back-to-back days of climbing and descending on the local mountain dirt trails which consisted of about 2300ft/700m (each day) of climbing with steep elevation. With the previous alloy pistons these particular XG calipers would get hot on descents, becoming sticky and rub the disc rotor. With the ceramic piston conversion, the XG calipers were able to brake the entire descent down the mountain without any piston stickiness.

Anyways, I highly recommend this conversion on any brake caliper setup that uses alloy pistons. 

[ZacItaly15]

are the OEM Shimano piston made of ceramics? E.G. BR8170

[kbernstein]

are the OEM Shimano piston made of ceramics? E.G. BR8170

Yes

I've ordered a pair to replace an old BR7000 caliper with a broken piston. The shimano dealership said they don't even carry spares and told me to just buy a new one. Maybe I can salvage it 

[jonathanf2]

are the OEM Shimano piston made of ceramics? E.G. BR8170

I don't think all them. Looking at my GRX400 hydraulic calipers, they look like alloy pistons. Though I haven't taken them apart yet.

In general, ceramic pistons are definitely better than alloy especially for long descents.

[gbrnole]

the latest version of the XG caliper does use a composite piston. not sure if it is ceramic but it's at least the same as the material used in the 4-piston version featured in the Trace Velo video. i recently installed the latest XG version calipers on my son's road bike.

[fhold]

the 4 piston version is phenolic. Should be better than aluminium but not as good as ceramic. As to my knowledge that's also the material hope is using.

[jonathanf2]

the 4 piston version is phenolic. Should be better than aluminium but not as good as ceramic. As to my knowledge that's also the material hope is using.

The ceramic pistons are holding up quite well on my XG calipers. I'd recommend them on other calipers that fit the same diameter. They're a nice upgrade and heat dissipation works well. They're a nice cheap upgrade and well worth the effort.

[fhold]

Offtopic but can anyone link a working bleeding kit - I don’t seem to have the right adapter

[ZacItaly15]

the 4 piston version is phenolic. Should be better than aluminium but not as good as ceramic. As to my knowledge that's also the material hope is using.

it's very difficoult to overheat the 4 piston XG4, I tryed but the descent wasn't long enough!

[jonathanf2]

it's very difficoult to overheat the 4 piston XG4, I tryed but the descent wasn't long enough!

With the 2 piston XG calipers using stock pistons, they'd get sticky after long descents. With the 2 ceramic pistons they hold up fine after long descents. My only issue I have with them is with Ultegra 11 speed hydraulic shifters. It took me a few mineral oil top-offs to get tight brake pull.