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Hi, newbie here looking for some advice.

I have an alloy bike that I am using for commuting and winter training rides, and I also have a carbon road bike that is currently in hibernation.

I am looking at some upgrades primarily for the alloy bike. I had thought that I might get a carbon seat post and new saddle, the idea being that I could then swap the set post over when the better weather comes along.

However, I have came across a comment on anther site saying that carbon posts should not be used on alloy, due to corrosion and slippage.

Can anybody confirm that this is the case?

Thanks

11 comments

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Psycling [50 posts] 3 years ago
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Been riding an alloy frame with carbon seat post for the last two years as a winter trainer/commuter. Not experienced any problems so far.

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jimmo62 [55 posts] 3 years ago
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Agree with the above, had a carbon post in an alloy frame for years with no problems

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stepho [90 posts] 3 years ago
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I have a carbon seat post on my alloy frame and no issues at all.

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TheHatter [770 posts] 3 years ago
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a lot of alloy bikes come spec'd with carbon posts so it really isn't a problem.

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Raleigh [1667 posts] 3 years ago
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Yep, got a Carbon 'mast (as I think I may start calling seatposts now) in my S1 with few problems.

Just give it a wipe with a cloth every few weeks to stop grit scratching it up.

There have been stories of 'masts getting stuck, but tbh they probably left it in there for about a year. Its only if you cycle by the sea (which I do), where the salt can kick start electrolysis when you need to be a little proactive, otherwise, you'll be fine.  1

My alloy post did get stuck in my steel Condor, but that's a different story...

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Bedfordshire Clanger [344 posts] 3 years ago
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Not a problem - put some grease on the post to stop it from sticking if it's a very tight fit and don't clamp it too hard.

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Gman59c [58 posts] 3 years ago
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Excellent news, thanks guys!!

I have just ordered a new Fizik Cyrano Carbon post and was looking forward to trying out this weekend.

All systems are go!!

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therevokid [971 posts] 3 years ago
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added bonus of a carbon post in an alloy frame is "buzz"
reduction ...  1

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Lost faith in t... [116 posts] 3 years ago
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Bedfordshire Clanger wrote:

Not a problem - put some grease on the post to stop it from sticking if it's a very tight fit and don't clamp it too hard.

DO NOT put grease on your carbon seatpost in an alloy frame. over time it expands the carbon which will then be near enough impossible to take out of your frame or adjust.

some companies say use carbon specific grease but i wouldnt use this eaither. you are better off no grease at all and setting it to the correct torque.

Copied from another site :
From Easton:
No grease on carbon posts. Grease contains certain minerals that can attack clear coats, can penetrate the resin matrix and could cause swelling of the composite laminate. Can you say "stuck seat post?" Don't use grease.
John G. Harrington
Vice president, bicycle products
Easton Sports, Inc.

From Campagnolo:
No grease. In some cases it can be dangerous to use grease as the chemical composition can cause a reaction between materials. Besides, it increases the torque required to clamp the post.
Richard Storino
Campagnolo USA

From Deda:
Absolutely no grease on carbon, ever. Also, do not use solvents to get old grease off, or to get old grease out of the seat tube. John Harrington of Easton and I believe that many solvent residues in the seat tube soften the gel coat of the carbon, then bond the gel coat to the inside of the seat tube, freezing the seat post in position for eternity.
Tom Franges
Deda Elementi North America tech support

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jimmo62 [55 posts] 3 years ago
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You could use the carbon fibre grip paste if the post slips, I assume that is what it is designed for.... I have used it in the past. However if you can get away without it seems that from the above posts the manufacturers prefer it.....

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Lost faith in t... [116 posts] 3 years ago
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we use it on carbon posts in carbon frames but when its aluminium and carbon it sill tends to cause problems with the materials bonding together.

we normally get 2-3 customers a year who have used carbon paste/grease who ask us to try and remove there post for them but there is no chance.

they normally have to go to an engineering firm to get the post reamed out or try some home brew remedies of chemicals which normally make matters worse lol.