The QUICK question thread.....

[Dales Cannon]

Bike assembly novice here - what do I put on the seatpost when I’m putting a bike together? I assume not grease as it’ll slip so something like a carbon gripper paste?

yes if you can or assemble dry if the materials are the same such as an aluminium post in an aluminium frame. If you are fitting an aluminium post in a carbon bike or vice versa make sure to cover the whole post in carbon paste as carbon and aluminium love each other very much and you may not get them apart if they get wet. If it corrodes it will likely destroy the frame.

 

[Rorschach]

yes if you can or assemble dry if the materials are the same such as an aluminium post in an aluminium frame. If you are fitting an aluminium post in a carbon bike or vice versa make sure to cover the whole post in carbon paste as carbon and aluminium love each other very much and you may not get them apart if they get wet. If it corrodes it will likely destroy the frame.

Cheers. Aluminium post in a steel frame ok dry? Or am I going to create a galvanic cell?

 

[Dales Cannon]

Cheers. Aluminium post in a steel frame ok dry? Or am I going to create a galvanic cell?

They are pretty close on the galvanic scale but I would still put some goo on it. EDIT: a better diaphragm though be aware it also depends on environment. Stainless and aluminium in salt water also exhibit free love. Our catamaran spat out a cross beam in the surf because it was put together with stainless rivets. Had to replace the lot with monel then all ok.

 

[The Duckmeister]

Aluminium post in steel frame will want a very generous coat of grease.

Carbon-carbon is the only combination I'd assemble dry; for carbon-any metal use carbon paste, and for most metal-metal use grease. Do not ever use copper-based anti-seize compound near anything aluminium unless you particularly want to destroy the aluminium part! I recall from my marine industry days the quite blunt warnings about using copper-based anti-fouling paint on aluminium hulls indicating that it will chew ther arse out your boat, while not literally saying "it will chew the arse out of your boat"

 

[ausdb]

Quick, probably dumb question but I know SFA about SRAM derailleur models. Can anyone tell me what model this is? And also what size Allen key is used to tighten the pivot bolt to the hanger? It's 11 speed around 2015/6 based on the Remedy it's attached to unless it's already been replaced. My sons mates been tinkering with his bike and this was loose in the hanger when I looked at the other day but I think he's also mangled the alarm key section inside the hollow bolt.

 

[pink poodle]

Bike assembly novice here - what do I put on the seatpost when I’m putting a bike together? I assume not grease as it’ll slip so something like a carbon gripper paste?

I'm with super duck. I grease it all! Points of contact like that will make horrible noises if they are dry rubbing or if they get moist. A good splotch of lube is the answer. For carbon to carbon the special paste is a wise move.

 

[ozzybmx]

Quick, probably dumb question but I know SFA about SRAM derailleur models. Can anyone tell me what model this is? And also what size Allen key is used to tighten the pivot bolt to the hanger? It's 11 speed around 2015/6 based on the Remedy it's attached to unless it's already been replaced. My sons mates been tinkering with his bike and this was loose in the hanger when I looked at the other day but I think he's also mangled the alarm key section inside the hollow bolt.

View attachment 393575

X01 11spd, not cheap even now.

Bolt will be metric 3mm to 4mm.

 

[Squidfayce]

I think he's also mangled the alarm key section inside the hollow bolt.

probably by trying to losen that side to take the wheel off rather than removing the axle from the other side. Ask me how i know (actually, dont)

 

[The Duckmeister]

X01 11spd, not cheap even now.

Bolt will be metric 3mm to 4mm.

No, 5mm or possibly a T25 or T30 Torx.

 

[Calvin27]

If you are fitting an aluminium post in a carbon bike or vice versa make sure to cover the whole post in carbon paste as carbon and aluminium love each other very much and you may not get them apart if they get wet.

What about Titanium/alu, Titanium/carbon?

 

[ozzybmx]

No, 5mm or possibly a T25 or T30 Torx.

Correct, its 5mm (just checked)

I half read it and thought jockey wheel bolts.

 

[Dales Cannon]

What about Titanium/alu, Titanium/carbon?

I suspect any metal in carbon can be bad juju. I use koppakote between the Ali seat post and Ti frame of the Muru but it gets exposed to salt.

 

[Calvin27]

I suspect any metal in carbon can be bad juju. I use koppakote between the Ali seat post and Ti frame of the Muru but it gets exposed to salt.

On a similar note I have a bike that has the fork completely fused to the head tube. It should be alu on alu but who knows what's going on. I've done 2 services on the forks while they are attached.

 

[pink poodle]

What about Titanium/alu, Titanium/carbon?

Double sided tape rolled in sand.

 

[Asininedrivel]

make sure to cover the whole post in carbon paste as carbon and aluminium love each other very much and you may not get them apart if they get wet. If it corrodes it will likely destroy the frame.

Having had a very, very near miss with this I recommend adding more carbon paste. Then when you're finished add more.

 

[Rorschach]

They are pretty close on the galvanic scale but I would still put some goo on it. EDIT: a better diaphragm though be aware it also depends on environment. Stainless and aluminium in salt water also exhibit free love. Our catamaran spat out a cross beam in the surf because it was put together with stainless rivets. Had to replace the lot with monel then all ok.

Aluminium post in steel frame will want a very generous coat of grease.

Carbon-carbon is the only combination I'd assemble dry; for carbon-any metal use carbon paste, and for most metal-metal use grease. Do not ever use copper-based anti-seize compound near anything aluminium unless you particularly want to destroy the aluminium part! I recall from my marine industry days the quite blunt warnings about using copper-based anti-fouling paint on aluminium hulls indicating that it will chew ther arse out your boat, while not literally saying "it will chew the arse out of your boat"

I'm with super duck. I grease it all! Points of contact like that will make horrible noises if they are dry rubbing or if they get moist. A good splotch of lube is the answer. For carbon to carbon the special paste is a wise move.

Thanks all - have read a couple of different things so wasn't sure where to go given the seatpost isn't supposed to move! - will apply some grease and tighten as per specs!

 

[pink poodle]

Thanks all - have read a couple of different things so wasn't sure where to go given the seatpost isn't supposed to move! - will apply some grease and tighten as per specs!

A good seat clamp correctly tensioned will take care of that!

 

[ausdb]

Correct, its 5mm (just checked)

I half read it and thought jockey wheel bolts.

Thanks I tried a couple of size allen keys and it seemed to slip. I didnt have Torx bits with me at the time but will give Torx a go the next time I'm visiting and hopefully before he rides it too much and damages it more., his parents will have a fit replacing a $300 plus derailleur.

I've looke at the SRAM tech manual and it says 5mm hex but this pic on MTB direct seems to be a Torx

SRAM X01 Type 2.1 1x11 Speed Rear Derailleur

Pulling all the good bits of technology from it's big brother (SRAM XX1) the X01 derailleur offers serious punch at a more budget concious price. Sporting the same genius X-HORIZON parrallelogram design to eliminate ghost shifting and ROLLER BEARING CLUTCH to hold the chain tight an reduce chain...

www.mtbdirect.com.au

 

[ozzybmx]

I've looke at the SRAM tech manual and it says 5mm hex but this pic on MTB direct seems to be a Torx

Would you look at the mess of that derailleur Thats what happens to good shit when you lend a bike to your kids (actually the whole bike looks rough)

Alright, I've been giving you a bit of misinformation over the last couple of posts, got a bit of brain fog going on.

The derailleur I went down and checked was an X0 10spd, which is a 5mm hex.

Should have checked the XX1 11spd which is a T25 Torx, so it looks like the XX1 and X0 were Torx and possibly GX down in 11spd were a 5mm hex.

I checked it with a T25 and it loosens/tightens.

 

[ausdb]

Would you look at the mess of that derailleur Thats what happens to good shit when you lend a bike to your kids (actually the whole bike looks rough)

Alright, I've been giving you a bit of misinformation over the last couple of posts, got a bit of brain fog going on.

The derailleur I went down and checked was an X0 10spd, which is a 5mm hex.

Should have checked the XX1 11spd which is a T25 Torx, so it looks like the XX1 and X0 were Torx and possibly GX down in 11spd were a 5mm hex.

I checked it with a T25 and it loosens/tightens.

@ozzybmx Haha, is that a Trek as well? the colour and rear axle/pivot looks a lot like the one the derailleur in question is on and I'm sure this is going to look like that soon!


Even the SRAM manual says 5mm so not your fault, fingers crossed a Torx still works.