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Carbon bars creaking on big efforts


Jbr

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Okay makes sense I’ll clean that up ! Never actually did it before since the stem doesn't really risks to slip down, but since everyone he seems to put that grease everywhere and the steerer being carbon... anyways, added more grease at the bottom where the spacer is and cleaned the upper part where the stem is, let's see, I had the noise the first time I pulled on the

bars in the garage then no more... we'll see on a real ride.

Not sure why you want to grease to the steerer at all.

 

Grease the bearing interface. Very lightly

 

Carbon paste where handle bar clamps.

 

Every other place on the steerer etc should be dry

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just don't see how it can hurt ? (unlike the carbon paste), if it can prevent the spacer from making nose by rubing either on the headset cap or on the stem 

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First youtube search - Watch "Ask a Mechanic: Carbon Friction Paste Application" on YouTube

absolute rubbish. Be careful what you find on the internet (says the man typing on the internet)

 

how pray would the glass beads find their way into the headset? they're locked in place between steerer and stem!

The only component that will wash down is the fluid/low viscositylow lubricity grease holding the beads in place and this has no effect on the grease in the bearings. Also how much paste is he using? a whole tube on one steerer? Do you ever find carbon paste and glass beads in your BB bearings after being washed down your seat tube??

I've never seen this happen.

I'd rather have carbon paste on my carbon steerer when I'm using an alloy stem because its far worse for my steerer if I crash and the two parts are seized together....

yes the grit provides additional purchase to prevent slippage (good for keeping headsets torqued) but when you overcome the friction the parts move as the beads roll between the two surfaces, think of a brinelled bearing. this is far better than seized components

 

#justsayinguseitdon'tuseit

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Not sure why you want to grease to the steerer at all.

 

Grease the bearing interface. Very lightly

 

Carbon paste where handle bar clamps.

 

Every other place on the steerer etc should be dry

 

 

Dry is a problem. Try servicing a headset on someones zwift bike when a alloy stem has been dry clamped to a carbonsteerer fork without breaking said fork.

 

carbon steerers are  bit of a problem.

firstly when the expansion plug is inserted and torqued up the steerer bulges, even if you assemble it all correctly with the expansion plug within the clamping area of the stem. Now the stem is fitted and okes go bos with the allen key to make sure the stem doesn't slide. Problem is these components are right were their sweat drops. So tight fit, salt, acid and carbon plus alloy = a lekker battery (must measure the voltage sometime).

No thanks, I'll keep using carbon paste on my steerers. Bolt torques of 3-4N.m. are more than enough to keep everything aligned and working safe and allow for movement in a crash. 

 

But also ask yourself how much movement is needed? A carbon MTB bar is going to be damaged just be letting the bike fall over at the coffee shop.

A road bikeoften suffers brakes and shifters out of alignment plus the stem. Would the bars have broken? My road bike has a rectangular steerer tube with a rectangular hole in the stem. The stem won't move in a crash. 

 

is this dry fit another cycling dogma that needs to be busted?

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absolute rubbish. Be careful what you find on the internet (says the man typing on the internet)

 

how pray would the glass beads find their way into the headset? they're locked in place between steerer and stem!

The only component that will wash down is the fluid/low viscositylow lubricity grease holding the beads in place and this has no effect on the grease in the bearings. Also how much paste is he using? a whole tube on one steerer? Do you ever find carbon paste and glass beads in your BB bearings after being washed down your seat tube??

I've never seen this happen.

I'd rather have carbon paste on my carbon steerer when I'm using an alloy stem because its far worse for my steerer if I crash and the two parts are seized together....

yes the grit provides additional purchase to prevent slippage (good for keeping headsets torqued) but when you overcome the friction the parts move as the beads roll between the two surfaces, think of a brinelled bearing. this is far better than seized components

 

#justsayinguseitdon'tuseit

Can you please help me understand the below advice from bianchi?

Bold letters little over half way down pages 1.

 

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.bianchi.com/wp-content/uploads/2019/06/Fork_Installation_instruction_Eng.pdf&ved=2ahUKEwjmm-TCx7TvAhXlheYKHVC-BEsQFjABegQICBAC&usg=AOvVaw0CfZC7wWLq-DG2CY9Z09_J

Edited by BMXER
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have you mailed to ask them why?

 

they don't make the same recommendation for the seat post and frame. Forks can turn in a crash. Seat tubes can't.

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Sorry, found it on the internet.

It must be wrong.

 

 

:thumbdown:

 

I'd agree that for carbon stem onto carbon steerer then dry fit. (i'll still use carbon paste on my bikes) 

For alloy on carbon then I want to know why no carbon paste. Does the manufacturer prefer that you have a seized stem? How is this better?

Edited by DieselnDust
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A road bikeoften suffers brakes and shifters out of alignment plus the stem. Would the bars have broken? My road bike has a rectangular steerer tube with a rectangular hole in the stem. The stem won't move in a crash. 

 

Off topic, but a good opportunity to ask.

I was thinking about this on my ride on sunday. My seat post is D shaped, one of the advantages spouted by the manufacturer is saddle alignment (left/right) is never out.

This got me thinking, why dont we see the same method used on steerer tubes ? A D shaped steerer (just the top portion) with stem made to accommodate. This will take care of the dreaded handlebar misalignment. 

 

or am I missing something crucial here.

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Off topic, but a good opportunity to ask.

I was thinking about this on my ride on sunday. My seat post is D shaped, one of the advantages spouted by the manufacturer is saddle alignment (left/right) is never out.

This got me thinking, why dont we see the same method used on steerer tubes ? A D shaped steerer (just the top portion) with stem made to accommodate. This will take care of the dreaded handlebar misalignment. 

 

or am I missing something crucial here.

 

 

good question.

 

the steerer on my bike is rectangular with a matching hole in the proprietary stem. Integration is such a big thing at the moment it boggles the mind that flat sided steerers aren't used more often. In most cases its more to allow for more space to route gear cables into the headtube.

My previous bike also had a flat sided steerer but used a conventional round clamp stem. This i found bizarre. The new bikes set up makes more sense. it can still be slightly off but its much easier to set up.

 

If the dry fit recommendations are to prevent damage to the steerer then how does the manufacturer get around the stems clamp deforming to out of round (and biting into the carbon steerer) when the bolts are tightened to 5-6N.m as recommended on the stem?? In a crash the moving stem will do more damage to the steerer than carbon paste.

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  • 5 months later...
On 3/15/2021 at 10:49 AM, DieselnDust said:

1. could be the headset bearings or the bearings on the seats. A service of this area could be useful.

 

2. Bolt torque or just corrosion between bolt and thread. Remove bolts and apply blue loctite to the bolts before reinstalling

 

3. Headset spacers with a snug fit can also creak as the steerer flexes. The rub could be against the steerer itself or between the interface between the spacers and the spacers to stem.

 

4) if using lock on style grips check for corrosion between the clamp and bar and clean that up. apply carbon paste to the clamp before reassembly

Tried searched the worldwide  web but can't find the torque spec required to tighten Lyne Amp handlebar?

Do i use 5nm or use amp stem torque guideline but that is alloy?

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20 hours ago, MajG said:

Tried searched the worldwide  web but can't find the torque spec required to tighten Lyne Amp handlebar?

Do i use 5nm or use amp stem torque guideline but that is alloy?

5nm is fine for the bars. Ive never seen carbon bars wanting more than that. Always 4 or 5

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On 8/28/2021 at 1:30 PM, MajG said:

Tried searched the worldwide  web but can't find the torque spec required to tighten Lyne Amp handlebar?

Do i use 5nm or use amp stem torque guideline but that is alloy?

Stem face plate torque guidelines should be sufficient. Most bars are made to withstand compressive forces in the range of hat applied by the face plate torque spec plus a safety factor. 

Some super light bars have their own specs but Lyne Amp is not one of those

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4 hours ago, MajG said:

Going with the 5nm and some carbon paste

Thanks gents

Remember to tighten in a criss cross pattern. Each gets a small turn until all 4 reach 5nm. 

Dont torque each to spec from the start. 

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