How much Glass Fibre?

From memory I think glass even in woven format is only 1/4 strength of carbon, so a lot is needed for the required strength of a monocoque construction, don't forget resin quantity should be equal to cloth weight, in practice this is difficult to do and usually more resin is needed to fully wet the cloth, ideally this should then be removed by vacuum, but we're getting into specialised techniques and more money.

There is a method using glass cloth and then using carbon fibre reinforcements, I made a racing shell for a trike this way, (it was destroyed on it's second outing in a practice lap when I rolled the trike on a tight bend) but I had a mould which makes it simple, the thing was very light, very flimsy i.e pushed out of shape easily but strong where carbon was used.

Making a full monocoque out of 100% glass for a racing machine is I would say in a nutshell - WRONG, too heavy and weak.

here is a video of glass fibre monocoque with carbon, it's messing around trying to show how to extract an unconscious person from a velomobile. Note that the bottom where most of the strength lies in these designs is still carbon fibre.

I rode with Daniel the maker (chap doing the extraction) to Spezi with that machine, at one point we were arsing around and I grabbed the edge of the cockpit for a tow, Daniel gave it some power and thee was a loud crack, never worked out what had broken.

Thanks for the replies people, hopefully I'll be able to get something on a track before too long - Covid permitting.

All the best,

Roy