Sealing Tubeless Rims

I have an annoying problem with my 1988 R100GS. The bike has had a big old tidy up over the last 18 months; the wheels were rebuilt by CWC (polished original rims, stainless spokes), the engine, gearbox and final drive have had a rebuild by Overland & Classic (hi Mike!).

Since the wheels came back, I’ve had trouble getting them to hold air. They went back to my local dealer 3 times to try different valves etc to try and get them to seal which was partly successful, then Mike had a go which seemed to nail it - it was down to a slow weep needing topping up weekly or so. It seems to have deteriorated over the past few months though so now the rear went down overnight.

It’s not impossible that I have an actual puncture, but I’ve had a good look round the tyres and can’t see anything. I was thinking of trying Ultraseal (an old BMW staple), reasoning that if the leak is around the rim, it may find and seal it up.

Anyone have any better ideas?

Jon

This has probably been done but worth asking, have you tried increasing the pressure and immersing the rim/tyre in a bath ( tell the wife its a swimming lesson for the bikes next adventure) if no better off use the Ultraseal. Normally its the valve seat that corrodes but you seem to have covered this.

Barny

First of all yer have to decide and find out if its a puncture/valve problem. You need a big tub or loads of soapy water and the wheel off and maybe on its side. After yerve tested for bubbles you should know which/what the problem is !!.
I spent 3 hrs on each rim cleaning and polishing out the "rust and marks" on inside of the rims with green scouring pads and soapy water. check all yer tyre walls where they seat to the rim the I used a smear of ACF 50 onto the rims ( to hopefully protect them from further oxidisation) and refitted the tyres.
Jobs been a good un and OK for over 9 month. You have to just put some time and effort into restoring the rims = they may have had 30 more years of shite on/inside um. same with the valve hole.
HTHY

I ha the same problem with my GS rims.

I tried polishing the rims as suggested , but the only difference was that when they deflated to bead came away from the rim.
Which is not a pleasant feeling, and if you are not towing a industrial grade compressor and generator at the time you might have difficult to get the bead back on the rim.

Cured it by fitting tubes, the best heavy duty ones the dealer has!
I have found that currently available pressure pack sealants work fine with tubes. But I am no expert, I have only had a couple of "nail"punctures in the last half million kilometers.

If you plan on plugging a tubeless tire it is well worth a look at the tire manufactures site to see what is permissible.
Some forbid any type of plug whatsoever, particularly on their higher rated tires, and the few who permit it have restrictions in the size and location of the hole, the thickness of the remaining carcass and tread rubber, and the permitted distance and speed you can travel with a plug.

I use a cup of soapy water and a small paint brush to find the leaks and check it’s not the valve.

The last time I polished mine it significantly reduced the leaks so that, rather than the tyre deflating in 24 hours it would maintain an acceptable pressure for about 2 weeks, however, further oxidation over winter and it’s back to 12/24 hours so I given up and fitted tubes. I think the situation can be aggravated by taking the tyre off which can degrade the bead on the tyre.

When I changed from TKC80s, to Mitas 09, it kept losing air...
Changed valve, reseated tyre twice, still losing air ��
Local car tyre shop (also a biker) gave me some 'Bead Sealer'.
Worked a treat.

https://tyrerepair.ie/product-category/tyre-repair-chemicals/

He said its common enough with old tubeless alloys.

Thanks for the replies chaps. The rims are pretty minty, free of scuzz. I’ve had the wheels in a true of water and the air seems to be leaking out around the rim. I’ve ordered up some Ultraseal, we’ll see how that does.

Great, please keep us informed. Mine is perfect at the rear but the front weeps too so will be interested.

Jon T said:

Thanks for the replies chaps. The rims are pretty minty, free of scuzz. I’ve had the wheels in a true of water and the air seems to be leaking out around the rim. I’ve ordered up some Ultraseal, we’ll see how that does.

Click to expand...

My immaculate wheels from a Mikeyboy special also leaked so I put 'slime' into them and the smallest leakage came from the beading. Sorted