Ask the experts

[D(C)]

Trying to get my body position on my trail hardtail closer to my full suspension bike. It looks like a 40mm rise bar will do it (out of room for more stem spacers). Any recommendations for a compliant 31.8 bar with 40mm rise? Relatively light rider (155 lb) so don't need anything too beefy.

If you don’t need wider than 760 mm, the Renthal Fatbar Lite feels pretty nice. It has less backsweep than average, which may be good or bad depending on preference. If you need wider or want more backsweep, the Chromag FU40 is a good choice. Of course, none of this is scientific in terms of compliance, but they have felt good to me.

[J. Barron DeJong]

What’s the correct number of pieces for a Shimano brake piston?



Two real questions:

Is it worth buying a replacement piston to fix, given that Shimano doesn’t sell them, so it will be some sort of knock off (and I guess if the answer is yes, any ones in particular)?

Did I do something that caused this? The damage was all on the back side of the piston, internal to the caliper. FYI, I just use a plastic tire lever when pushing pistons back in.

[Andeh]

Did I do something that caused this? The damage was all on the back side of the piston, internal to the caliper. FYI, I just use a plastic tire lever when pushing pistons back in.

Judging by the frequency that this happens to my buddy who runs XTRs on all his bikes, the answer is "you bought XTR brakes." I seems like he's cursing about this every 6 months or so.

[dannynoonan]

What’s the correct number of pieces for a Shimano brake piston?



Two real questions:

Is it worth buying a replacement piston to fix, given that Shimano doesn’t sell them, so it will be some sort of knock off (and I guess if the answer is yes, any ones in particular)?

Did I do something that caused this? The damage was all on the back side of the piston, internal to the caliper. FYI, I just use a plastic tire lever when pushing pistons back in.

Pushing the pistons back a tiny bit cockeyed will cause that, the back of the piston contacts the caliper bore and it can chip. I don't know if it helps much but I always use an old pair of brake pads when pushing pistons back, to create a perfectly flat surface at the point of contact.

[J. Barron DeJong]

Pushing the pistons back a tiny bit cockeyed will cause that, the back of the piston contacts the caliper bore and it can chip. I don't know if it helps much but I always use an old pair of brake pads when pushing pistons back, to create a perfectly flat surface at the point of contact.

Noted, thanks.

Anyone find that a proper piston press helps prevent this? Looks like most just wedge in there, which seems like it could create the same issue.

I think the SRAM one is different but maybe doesn’t fit into a Shimano caliper body?


Edit:

Hmmm…

[Dumbest Known Time]

As a PeePee 1.0 owner I hadn't ever considered sticking it in a brake caliper. Do you think I need the 1.2 firmware update or should it be good to go?

[El Chupacabra]

As a PeePee 1.0 owner I hadn't ever considered sticking it in a brake caliper. Do you think I need the 1.2 firmware update or should it be good to go?

Depends on how firm it is, and whether firmness lasts for more than four hours.

[McShortyShorts]

Can the endcaps of a DT350 front hub be swapped between 15x110 boost and 20x110? I need to get new wheels but I want to make sure the front one is single- and dual-crown fork compatible

[volklpowdermaniac]

[QUOTE=J. Barron DeJong;6919366]Noted, thanks.

Anyone find that a proper piston press helps prevent this? Looks like most just wedge in there, which seems like it could create the same issue.

I think the SRAM one is different but maybe doesn’t fit into a Shimano caliper body?


Edit:

Hmmm…



[/]
Sucks about the piston, if you go back a page or two had exact same issue . Fortunately had an old Shimano caliper I was able to harvest one from. Was able to get it back in using just a little careful alignment and pushing. As I’m sure you saw the pistons crack into one bagilon pieces so make sure the old one is completely out.

[J. Barron DeJong]

Sucks about the piston, if you go back a page or two had exact same issue . Fortunately had an old Shimano caliper I was able to harvest one from. Was able to get it back in using just a little careful alignment and pushing. As I’m sure you saw the pistons crack into one bagilon pieces so make sure the old one is completely out.

I replaced the caliper right when it happened, so will keep this around as a spare for parts at least, if not worth rebuilding with an aftermarket piston.

I think I got the pieces out, but will definitely need to look more carefully if I ever end up wanting to use that caliper again.

[Benneke10]

I was given a few hundred packs of expired Clif Shot Bloks from a friend who accidentally had an amazon subscription and forgot about them... they expired between 1 and 3 years ago, are they safe to eat still?

[Phall]

I’ve been eating gu’s and bars, that expired between 2019 and 2022 this year, still alive. Don’t break a tooth!


Sent from my iPhone using TGR Forums

[BigHerm]

Carnauba wax never goes bad!

[Roxtar]

Noted, thanks.

Anyone find that a proper piston press helps prevent this? Looks like most just wedge in there, which seems like it could create the same issue.

I think the SRAM one is different but maybe doesn’t fit into a Shimano caliper body?

I have the Park tool and don't really use it because of that reason. The rather steep angle creates a lot of side load.
I generally go old school. Just leave the pads in place (or better yet, use an old worn set) and use a screwdriver to press them in. The srewdriver lets you get to the center of the pistons, removing the side load and getting even pressure.

[Boissal]

Don’t break a tooth!

Agree that this is the biggest risk by far. I occasionally will try and munch of cliff blocks that I opened and didn't finish a few rides back, those things turn into cubes of the hardest substance known to science.

[singlesline]

I was given a few hundred packs of expired Clif Shot Bloks from a friend who accidentally had an amazon subscription and forgot about them... they expired between 1 and 3 years ago, are they safe to eat still?

Technically that's a "Best By" date and not a safety/expiration date.

They don't have to guarantee flavor/texture, but it is purely a suggestion and they should be totally fine as long as they weren't open or stored somewhere crazy.

[zion zig zag]

Agree that this is the biggest risk by far. I occasionally will try and munch of cliff blocks that I opened and didn't finish a few rides back, those things turn into cubes of the hardest substance known to science.

I'll occasionally have a half eaten pack in the hip belt pocket of my ski pack come the first tour of winter. They're essentially hard candy at that point.

[Benneke10]

They are mostly still pretty soft. I have a lot.. if anyone wants some expired bloks let me know! Happy to share

[NT]

What’s the correct number of pieces for a Shimano brake piston?



Two real questions:

Is it worth buying a replacement piston to fix, given that Shimano doesn’t sell them, so it will be some sort of knock off (and I guess if the answer is yes, any ones in particular)?

Did I do something that caused this? The damage was all on the back side of the piston, internal to the caliper. FYI, I just use a plastic tire lever when pushing pistons back in.

I've had this happen to two different XT 4 piston calipers. Both times took it to a shop and they were able to get it warrantied by shimano. Apparently it's a known issue.

[Whiteroom_Guardian]

Ok so I'm pretty sure this site exists but you need a paid subscription?

I need to find what current carbon frame is most similar in geo numbers to my Size 2 GG Gnarvana. Does anyone have access to this site? I can't even remember what the site is called. I think I need to just bargain basement blowout my bike and get a brand new one sadly.

[Andeh]

Just get a Blister subscription and ask them for a recommendation. Let them do the legwork. Plus it will take into account how the bike actually rides, beyond the geometry numbers.

[NT]

Ok so I'm pretty sure this site exists but you need a paid subscription?

I need to find what current carbon frame is most similar in geo numbers to my Size 2 GG Gnarvana. Does anyone have access to this site? I can't even remember what the site is called. I think I need to just bargain basement blowout my bike and get a brand new one sadly.

https://99spokes.com/bikes

Filter by geometry and adjust the sliders to be in the range you like. You can compare several bikes at the same time.

No subscription needed.

[zion zig zag]

Ok so I'm pretty sure this site exists but you need a paid subscription?

I need to find what current carbon frame is most similar in geo numbers to my Size 2 GG Gnarvana. Does anyone have access to this site? I can't even remember what the site is called. I think I need to just bargain basement blowout my bike and get a brand new one sadly.

I think you're talking about Bike Insights? The free version lets you compare bike to bike, but if you want to change anything with a bike (i.e., mullet) you need the paid version.

[Whiteroom_Guardian]

Ok so I guess I am asking too much of those sites. Looks like I need to manually input comparison bikes? Maybe I am missing something. I want to put in GG Gnarvana Size 2 and then have the site auto populate the closest bikes based on numbers.

[VTskibum]

Won't do the legwork for you but https://geometrygeeks.bike/ is my favorite of that type. Find some similar bikes via the search and compare a ton against each other to see the numbers line up.