strength of bottle bosses on a carbon frame

jomoj

I have a bracket for a minipump that bolts onto bottle cage bosses and can be fitted between cage and frame and was planning to use this on a new carbon bike. I've seen warnings about the fact that the tube wall can be cracked around the boss if the bottle is allowed to rattle about so was wondering how strong the bosses are on carbon frames (bit of a general question I know) and whether using a longer bolt to fit through the bottle cage and clip would be a problem - potentially increasing the leverage of the cage when the bottle is being taken out and put back.

possibly paranoid but this is my first carbon frame and I don't want to knacker it prematurely!

schweiz

...and I thought I was paranoid when putting my bike on the car bike rack!

It'll be fine!

KINGGARY

It will be fine, I've had that setup on my last 2 carbon frames with no issues and I use large water bottles which increases the load.

jomoj

cheers - I'm just a bit late to the carbon party, it's a bit of a mental hurdle to get over.

Monty Dog

Problems with cracking I suspect would be due to vibration e.g. loose screw in frame rather than the additional load of the bottle cage and pump. Just make sure that the screws are firm and suggest you don't use those humungous 1 litre bottles that people use. Also use a cage that grips the bottle firmly - some superlight ones are pretty flexy and you can see the bottle moving - also means it's more likel to fall out.

jomoj

cheers, shouldnt be a problem with loose bottles, I have some Lezyne Flow cages which are pretty grippy, if anything a bit too secure.

markdavidhill

jomoj wrote:

cheers - I'm just a bit late to the carbon party, it's a bit of a mental hurdle to get over.

Went to the carbon party. Left before midnight.