I have an ‘85 Le Mans (IV) 1000, which has a problem with the front wheel. When left for a month or more the front tyre deflates. The local motorcycle shop have checked it out an the only think they have found is corrosion inside the rim. I’d like to replace it but there are not many LM 4 wheels around now. Does anyone know whether or wheets from the V65 or the 850 Le Mans models have compatible hubs as there seem.to be quite a few of these around on eBay at the moment.
Thanks
Hi if you have a slow leak of air try checking the valve or if you think the rims are the problem have the wheel re laced by a good company plenty of them in the mags and benoes cheers for know
They will be mag wheels
Does that model use a 16” wheel? If so, perhaps a Lario front wheel would suit. It would be much cheaper to get the existing wheel repaired though. If the wheel is true, and the valve has been replaced, couldn’t you repaint the inside surfaces of the wheel to seal any casting porosity?
I do have a feeling that a V65 small block wheel will fit, I had one for sale a few years ago and my mate with a Le-Mans 5 bought it as a spare.
If your mk 4 has the 16 inch front wheel it will be different and maybe an opportunity to change it for an 18 inch.
Alternatively could you put a tube in it? Although my tube tyres seem to loose pressure with the modern poor quality rubber they use.
Can you not just clean the corrosion off. Had to do the same on my Monster as it was leaking from the rim. Just gave the bead seat a once over with a rotary wire brush then with some wet and dry, problem solved.
It’s an alloy, so a leak could mean either a crack in the rim or bed, or a porous casting. I don’t know how old it is, but the original powder/plastic finish to the wheel should have prevented the latter at the factory - that used to happen in the 70s, but it’s long been sorted out.
I would take it to a mag wheel specialist, and get it crack tested and checked for alignment (square to the axle with no run-out at the rim). Car alloy wheel specialists should be able to strip off the coating, do a repair, and re-finish it in a similar colour finish. They can also sort out minor rim scrapes and so forth. Usually not too expensive.
Rob
Thanks to everyone for the ideas. Aa suggested by many I’m going to investigate rennovating the wheel before doing anything rash. To answer on the wheel size, it is a 16” wheel. It seems that many people don’t like these. Having ridden many more modern sports bikes, I don’t experience the problem. For me fast steering has its benefits. I had an LM2 some years ago so I also understand why little like the larger front wheel too.
I had a similar issue with my Aprilia Caponord 1200, there was a bit of corrosion around where the valve seats and the valve seating had also perished a bit, the tyre would lose around 15-20 psi over 2 weeks, replacing the valve after cleaning the seating area sorted the problem.
In the 80s on my Le Mans & Le Mans 11, and similarly now on my SP1000, I run tubes in my tubeless tyres. It was the done thing back in the day - must have been a known problem with these rims, and I see no reason to change the habit.
The rim shape is not suitable for tubeless tyres, by design, rather than due to defective manufacture.
The rims on the LM3/4 were tubeless rims.
Rob