Hi All,
Some advice reqd.
I had new Michelin's fitted last year and shortly after noticed I was losing tyre pressure.
Brought machine back and the valve stems etc were changed.
Shortly after noticed same again and losing a lot of pressure overnight.
Not going back, there so advice needed as to how or what to apply to the stems to stop them leaking.
I have new one's from Motorworks...so hopefully they will be a better job

Thanks in advance
Rod

Corrorion round the bead area could be contributing to leakage. After a while, gunk builds up and they often don't take the time to clean it off before fitting new sneakers. BMW's 15mm diametre valve stem is a bit different from most other manufacturers'. Have they replaced them with the correct version? Liberally squirt water round the stems and along the bead and look for air bubbles...

yes agree twb

the bead area is a good place to start

here's one i'm doing at the moment

after a bit of work with acetone ..( works well ).... still to remove all the crap ...perhaps a bit more buffing to get it all cleaned off ...but you can imagine the before pic



my last front rim used to loose a few pounds week to week and looked very similar after a clean up



the residue is I guess due to the soapy liquid used in gaining a seal during tyre fitment ...

keep at it mate

Just to be on the safe side... check you don't have a nail in your tyre.

I'm with the 'corrosion on the bead' guys. My front rim has to have a new coat of sealant at every tyre change, otherwise it loses approx 6psi a week. Between my tyre fitter and myself we cleaned and polished... and still had to use sealant. He says it's common in cast rims of this age.

I agree with the others  - I had this problem a few years ago when I got back into K's and went to my local BMW dealer - they tried to sell me a new rim !!

I found a local tyre specialist who used sealant and problem disappeared - he even did it for free as they are not meant to work on motorcycle tyres :-)

The seal of the tyre bead against the rim is the most likely cause, but apparently the wheel itself can become porous with age.

On Airhead Snowflake wheels which were not intended for tubeless tyres, but which we intended to use on them anyway, we'd throughly clean up the detritus that accumulated on the bead area and then clearcoat the entire inner surface of the wheels. I never had leaks and never had a tubeless tyre, without a tube fitted, let go on the non-tubeless approved wheels. Reducing porosity is essential.

I had to smile when I started to read this thread.
I Bought a K1100lt earlier this week that had been stood for 17 years!! All's not well as you can imagine and after pumping the tyres up to get the bike into the van,the next day the front was flat again. After several recharges, I decided to investigate with soapy water for curiosities sake. It's leaking like buggery from around the valve stem.
Just as well it's having new tyres!

good find mike