Grease on a carbon frame

Probably done loads of times before but can you use any grease to fit headset bearings and bb’s in a carbon frame. I have a tube of bike hut grease with Teflon additive. Doesn’t give any other info on what’s in it. I’ve read petroleum based grease can harm the carbon resin, but that maybe a myth. Have no idea what mine contains. It appears to be made by weldtite and at a guess it’s the same as the tf2 stuff which is ok for carbon. I’m tempted to buy a tube of park stuff which specifically calls out that it’s safe for carbon frames however

ill obviously using the specific carbon paste to fit seatpost etc, but that obviously would be a disaster on headset cups!

I’ve heard the same and use a synthetic grease – normally Silkolene Pro RG2, though I’ve currently got a tube of Rocol Sapphire which isn’t quite as good. Synthetic greases tend to be nicer than petroleum ones anyway.

Based on a quick Google search your Bikehut grease is the same as Weldtite TF2, which is a lithium (petroleum-based) grease. I’d get something else for your carbon frame.

Interesting.. tf2 specifically says it’s safe for carbon frames!!

Clearly I’m talking out of my arse in at least one regard then :D

The above was only based on a 30s google, maybe either Bikehut grease isn’t the same as Weldtite, and/or Weldtite is actually synthetic. Either way – I still wouldn’t use a petroleum-based grease in a carbon frame.

The frame makers manual should specify which grease to use. And whether to use any grease or not

What’s present in a petroleum grease that’s damaging to a carbon frame (that isn’t in a synthetic grease)?

At a guess I’d say the petroleum!?

I recently bought a carbon frame and some quick googling told me that there’s no such thing as specific carbon safe grease i.e. all grease is fine for carbon. Obviously I’m not an expert and the internet may actually be incorrect

It’s a giant defy. I can’t see any mention of grease in the generic user manual

Scroll down for the Cervelo POV… https://velo.outsideonline.com/mountain/mountain-gear/tech-faq-keeping-your-carbon-frame-clean-and-secure/

Hmm, I’d be curious what ‘s in a petroleum derived grease that will damage carbon that isn’t in a synthetically derived one.

And if you’re thinking it’s some part of the petroleum acting as a solvent you’d better be real careful lubricating the chain as that’s a lot lighter solvent, and some goes on the chainstay sure as eggs is eggs

It’s a giant

Well history would suggest your warranty is now void due to you working on it yourself rather than taking it to a main dealer. so which grease is the least of your worries

While at uni, I remember a module that contained a lecture about design and liability.

The example was about a screwdriver which had failed in use and injured the users. The defence claimed that the screwdriver was not being used as a screwdriver but instead as a pry bar on a tin of paint. The prosecution claimed that it was reasonable to expect a screwdriver to be used in such a way. The prosecution won.

Point being, if grease was that dangerous and damaging to carbon frames, not only would you have to warn users not to add any, but also to keep away any that might come from other sources. Imagine leaving a bike somewhere warm and a little grease deeper out of a headset or bottom bracket bearing? As above, you’ve have to be very prescriptive about chain lube as well.

This possibly comes from another industry where a different resin is used. Similar to how people thing EV batteries will only last 3 years because that’s all they get out of an iPhone.

Perhaps it comes from the early days of carbon bike failures where someone was looking to shift blame, like telling people they’d fitted a bottom bracket with a rock.

However, any design engineer who specs a resin that isn’t safe against grease isn’t doing a particularly good job when designing a bicycle

Just buy some carbon grease, you’ll be needing it for other areas (seatpost etc) and can use it without issue elsewhere, this is great as it doesn’t contain abrasive beads and is grease only:

Motorex Carbon Paste

I’ve never given a moment’s thought about what grease I’m using in any of the various carbon frames I’ve had currently or in the past. I’m still here.

Iirc there is a theory that some grease can cause the carbon laminate to swell which wouldn’t be ideal for a seatpost. Might be marketing guff – I went with the carbon grease.

Iirc there is a theory that some grease can cause the carbon laminate to swell which wouldn’t be ideal for a seatpost.

Yes, see the link that I posted ^^

For epoxies, it takes quite a long time or highly elevated temperatures for this (Fickian) diffusion to occur to any significant degree. The end result, if you could force it into such a condition, is a minor degradation of mechanical properties and a small amount of swelling. The test we designed was to demonstrate that any effect of compounds typically used around a bike is negligible. (my bold)

I think you can buy carbon fibre fuel tanks. I think the bigger issue is carbon being conductive and hence risk of fire rather than serious carbon issues.

as said above I’ve never given a thought to the grease I use other than it being either “bike grease” or something like silkolene. Carbon or ally bikes. So far in 15 years of carbon bikes I’ve not had an issue yet.

dont over think it I’d say. Road sh** in winter will do more damage to carbon / aluminium interface as well as individual parts than any grease will. Unless you grease your disc brakes to stop the squeal!! 😁

What’s present in a petroleum grease that’s damaging to a carbon frame (that isn’t in a synthetic grease)?

At a guess I’d say the petroleum!?

In this context, no.

Synthetic fuel, grease or oil is still made from the same stuff. It’s just been through the cracker usually.

Mineral oil based products are made from the oil out the ground, distilled, treated to remove anything you don’t want, and additives added etc.

Synthetic versions start usually with cracked products which generally means they don’t contain as many unsaturated bonds, branched chains and other things that tend to make the products unstable.

So synthetic oil lasts longer in your engine without breaking down. Synthetic grease lasts longer under high temperature /pressure, etc.

You might be confusing it with Silicon based grease which is what you use if the rubber in the seals isn’t compatible with mineral oil and vice versa, silicon lubes can be used on silicon seals, or *cough* other stuff *cough*.

[Edit outside the 15 minute window] there’s an important missing ‘t in that last sentence. You can’t use mineral oil with oil based seals and you can’t use silicon grease on silicon seals.