The stupid questions thread.

[droenn]

How close does it get to the spokes if you take chain and cable off and push it to the limit screw by hand?

Potential frame/ wheel flex?
Is the hanger tight?

ok the hanger was tight, and the derailleur takes a bit to push into spokes, but was a bit bent from getting caught.

think I’ve straightened it enough, and think the problem was chain was too short by 2 links causing incorrect setup of b screw. It Looks a lot better but still don’t trust my mechanical skills haha

 

[Staunch]

I've got an M810 Saint caliper on my DJ bike which is super old. It's at least 7 years old, maybe 10 (can't remember which one I replaced) and it was used on my DH bike until about 2015. I've been running it on my DJ bike since then and I went to rebuild it when it was time for new pads + a bleed as the pistons were a little sticky.

Split the caliper, removed the pistons, cleaned everything, re-assembled, bleed, new pads, rode it, all no worries. Now 2 weeks later I've found that the pads are contaminated as all the pistons have a tiny leak.

Is it possible that after so many years of abuse, the grime and gunk around the pistons was the only thing preventing them from leaking after having worn down the tiniest bit? Or have I cocked something else up? I'm 1000% sure it's leaking from the pistons, I didn't mark, scratch, or score or part of the pistons or caliper when removing and cleaning, and the pads were new. Not sure if I try replacing the current pistons with ceramic pistons from a broken Zee caliper I have, or just buying an entirely different caliper.

 

[Cardy George]

I reckon it's possible you've broken the seal.

I'd chuck the other pistons in coz you have them and therefore won't cost anything but a bit of shed time

 

[The Duckmeister]

Give it a bleed, leave the pads out and give it a few pumps. You'll see if there's any oil seeping from around the pistons. If necessary, chuck a bleed block in, but only half cover the pistons, that way you'll be able to see the pistons, and will allow the pressure to build when you pump the brake & reveal leaks.

 

[Staunch]

Give it a bleed, leave the pads out and give it a few pumps. You'll see if there's any oil seeping from around the pistons. If necessary, chuck a bleed block in, but only half cover the pistons, that way you'll be able to see the pistons, and will allow the pressure to build when you pump the brake & reveal leaks.

Each pad has two piston-sized oil patches on the back of it. After initially bleeding the brake I cleaned the entire caliper with isopropyl alcohol and tested with leaks using a bleed block. There was no immediate leak, and the brake worked fine for a whole week. The pistons themselves have oil on them, and the rest of the caliper is still spotless.

I'd chuck the other pistons in coz you have them and therefore won't cost anything but a bit of shed time

Might as well try it, hopefully I can salvage these pads with a bit of fire and sandpaper.

 

[Flow-Rider]

I'd chuck the other pistons in coz you have them and therefore won't cost anything but a bit of shed time

and put new seals in with them.

 

[fatboyonabike]

New Bike Time!..
but seriously, If you removed the pistons, they may have been bedded in the seal in a certain orientation.
if you have rotated them out of that allignment, this may be why neither now seal...Did you remove the seals to see how pliable they were, might have gone hard and brittle enough to not like the new position of the piston!.
just a thought.
instead of using a bleed block, try a nut the same size as the piston, as you pump up the pressure, you should be able to see all the way around the seal

 

[Staunch]

if you have rotated them out of that allignment, this may be why neither now seal...Did you remove the seals to see how pliable they were, might have gone hard and brittle enough to not like the new position of the piston!.
just a thought.

That's a pretty good point. TBH I didn't check the seals, I just assumed they were fine as it hadn't had any issues (apart from being a bit grotty) before I rebuilt it. I'll have a look and use the seals from the Zee caliper if necessary.

 

[fatboyonabike]

That's a pretty good point. TBH I didn't check the seals, I just assumed they were fine as it hadn't had any issues (apart from being a bit grotty) before I rebuilt it. I'll have a look and use the seals from the Zee caliper if necessary.

but seriously..
New bike time!

 

[Flow-Rider]

That's a pretty good point. TBH I didn't check the seals, I just assumed they were fine as it hadn't had any issues (apart from being a bit grotty) before I rebuilt it. I'll have a look and use the seals from the Zee caliper if necessary.

Unless you've marked the seals to cups orientation it will most likely be a waste of time, just buy new seals, sometimes all it takes is to disturb the old seal and they leak.

 

[creaky]

just buy new seals

Where does one source new seals for Shimano brakes?

 

[Flow-Rider]

Where does one source new seals for Shimano brakes?

Don't know, never owned any, probably throw away then.

Edit- looks like there's some around, some seal shops might have something too.

Metal Piston Hydraulic Brake Caliper Parts For Shimano XT/M785/M8000/SLX675

 

[Daniel Hale]

knowing nothing about dirt jumpers, is it a stupid idea to build up an old yeti as-r frame i have to have a go at pump tracks/skate parks bit like a dirt jumper? i think i have all the bits lying around as spares?

 

[Ultra Lord]

knowing nothing about dirt jumpers, is it a stupid idea to build up an old yeti as-r frame i have to have a go at pump tracks/skate parks bit like a dirt jumper? i think i have all the bits lying around as spares?

Run what your brung and all but if it breaks don’t blame us.

 

[moorey]

Haven’t got an old HT in the arsenal, @Daniel Hale?

 

[pink poodle]

knowing nothing about dirt jumpers, is it a stupid idea to build up an old yeti as-r frame i have to have a go at pump tracks/skate parks bit like a dirt jumper? i think i have all the bits lying around as spares?

Well it will rode better than no bike...but it is going to be far from ideal. You got a budget? Maybe you just need a more suitable frame?

Isn't this the frame Rennie used to race 4x/slalom in way way way way way back? When almost every magazine shot of Rennie was him holding a broken yeti frame?

 

[sane]

knowing nothing about dirt jumpers, is it a stupid idea to build up an old yeti as-r frame i have to have a go at pump tracks/skate parks bit like a dirt jumper? i think i have all the bits lying around as spares?

Most bike time for me atm is mucking around, going down the shops, getting the kids away from screens for a bit. I don’t think there’s ever been a better time for a dj rig. If I hadn’t sold mine last year it’d be the most practical thing in the shed.

 

[Daniel Hale]

Haven’t got an old HT in the arsenal, @Daniel Hale?

yep i’ve got an ns eccentric, but it’s 27,5..i have some 26” wheels bb would b 20mm lower, i think i would strike pedals constantly

 

[Daniel Hale]

Run what your brung and all but if it breaks don’t blame us.

i don’t think ill b getting enough air to break it..why do skate parks/pump tracks have guys on shitty little frames weighing 15kg,

 

[Daniel Hale]

Well it will rode better than no bike...but it is going to be far from ideal. You got a budget? Maybe you just need a more suitable frame?
Isn't this the frame Rennie used to race 4x/slalom in way way way way way back? When almost every magazine shot of Rennie was him holding a broken yeti frame?

yes my skill level is so low don’t think ill b breaking it, never busted a rim riding, never used all travel on front fork i think

hardtail still better u reckon?