How to protect the Brompton chain from rain and grit?

[plancashire]

I ride a Brompton M3 most days, even when it is raining. I ride on roads and bike paths, some of which sometimes have soil or sand on them, as is usual. German concrete cobbles are bedded in sand so there's always a little about. (Permeable surfaces are coming to Britain too!) The bike has completely inadequate protection for the chain, which is low down, so it gets covered in grit and needs cleaning far too often. I've made two improvements so far but I'm looking for other ideas. I extended the mud flap at the bottom of the front mudguard to actually intercept the stream of muck. I also added a small triangle of plastic cut from a PET bottle to shield the chain from the mess spewing out from the side of the too-narrow mudguard round the rear wheel. I have searched the net for chain guards but I haven't found anything yet. I find it difficult to believe that a British company could make a commuter bike so unsuitable for riding in the rain. Does anyone have any suggestions to reduce the crud hitting the chain?

[meic]

No suggestions to prevent the grit hitting the chain.
However if you are not already doing so lubricate your chain with a dry lubricant like White Lightning Clean and do not use any wet oil lubricants on the chain. So the grit doesnt stick to the chain.

Then accept it as a price of using that path that you will need to buy new chains etc on a regular basis.

[gilesjuk]

I've fitted one of those chainrunner chainguards which only really works if you have hub gears or singlespeed (wish a push down tensioner). But it turns out it's just cable housing or certainly looks the same. So I've bought some of this:

http://cgi.ebay.co.uk/7mm-Conduit-Wire- ... 6413000726

[plancashire]

Thanks for the suggestions. I think I have found a partial solution myself. I removed the mud flap on the front mudguard and refitted it with a stiffener (a piece of PET bottle) and a long extension piece made of wide black sticky tape stuck back-to-back to itself and sandwiching the existing mud flap. This is aligned exactly behind the front tyre and reaches quite close to the ground. You need a stiffener because the flap is now heavier and will bend downwards onto the tyre when the bike is parked. My original flap had already developed creases and two holes where it kept flexing as I parked. The way the flap was fitted to the curved mudguard made these creases inevitable. You can't fix a flat plane to a surface curved in two directions without creasing or stretching.

The extended flap now catches much more muck than the original flap, which was too short and mounted wrongly as well. The chain has remained clean for much longer.

[SA_SA_SA]

Scott oiler active fluid instead of oil, on a brompton just apply direct from the bottle: is less sticky than oil