I’m still relatively new to motorcycle ownership having had 2 years on a Honda 125 (with my CBT) then buying a V7 as my first ‘big’ bike.
Both bikes have tubeless tyres. The Honda never needed topping up (or so rare I don’t remember doing it) whereas my V7 has always lost 2psi a day from the OE Michelin rear tyre and about 2psi a week from the front. The bike has the cast wheels and there has been no impact and no visible damage to the rim.
A couple of friends with years of riding bikes tell me this is ‘normal’? Is it? Was I just lucky with the Honda?
I’ve inspected both tyres several times very closely and there is no damage whatsoever. They are seated centrally looking at the edge of the rim and a mold line in the sidewall. Soapy water around the valve base doesn’t indicate air loss - no bubbles.
The upside is it means I definitely remember to check (and remedy) tyre pressures before each ride.
Getting the tyre removed and refitted to see if that helps (and I guess checking the internal view of both wheel and tyre) feels like an expensive thing when topping up the air is free. I doubt MG would see it as a warranty issue?
I’d welcome people’s thoughts on this.
Cheers.
I’d say 2psi per week is acceptable, but 2psi per day sounds like a problem which needs fixing.
Ian
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As Ian says 2 psi per week is probably ok 2 psi per day is a problem - possibly a puncture that you have not found yet e.g. a nail or similar?
You mention warranty - is the bike new? If so the dealer should sort this out
Thanks both.
I initially thought a small puncture but if so it’s closed back up very well. There isn’t a mark on the tyre - I’ve sat there for ten minutes at a time looking.
The bike is new to me but an ex demo with 300 miles on it when I bought it. Now has 1700 but the tyre pressure drop has remained consistent since delivery.
I’ll call the dealer and see what they say. Thing is they are 2 1/2 hours ride each way and that’s on motorway so not the most exciting ride on a V7. There are A roads which are OK but nothing I’d normally choose either. Main reason for my hesitation is that visiting them means a day off work using my precious annual leave.
I guess another option is putting some sealant in (which is what we do with tubeless mountain bike tyres) but I’m not sure tyre shops like dealing with the mess when it needs a new tyre?
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Is the valve core tight? Take the cap off and look for bubbles from valve area. Bit of soapy water helps.
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I did try soapy water around the valve/rim interface but didn’t think to remove the dust cap and try the core - I’ll give that a check, thanks.
You’re right to be concerned about some/most tyre sealants - tyre fitters and repairers don’t like them because they leave a sticky mess on the inside of the tyre and the wheel rim. However, there is one sealant that works differently and doesn’t create a mess inside the tyre. You can buy it online and put it in yourself or lots of bike dealers offer it as a service. Here it is: AIR SEAL Tyre Sealant by Air-Seal Products.
I’d guess your 125 might have had tubes in the tyres.?
But whatever, just like a car, I find some loose nowt, while others are like teabags.
As you say, checking the seating and valve would be my first call.
Oddly, I’ve always found the tyres on bikes used daily never seemed to need attention, while those sat waiting for a sunny Sunday were always needing a bit of air when plucked from the garage.
The Honda was definitely tubeless. I had the rear replaced due to a screw going in and I watched the guy do it.
Coming to motorcycling from pedal cycling I was/am still amazed tunes are still a thing on motorbikes.
I ride the V7 just as I did the Honda - weekends are a definite whatever the weather (this is why shaft drive was a top priority for me) and some weekday evenings or lunch for a small bumble to clear my head.
The friends I was talking to thought temperature played a part and said their bikes lose more over winter but this one is still losing the same 2psi even during this 25 degree heat.
I’m going to play with soapy water once more (removing the dust cap this time) and then see if anyone tyre shops near me use/approve of the sealant mentioned above. I’ve seen sealant improve year on year with mountain biking but it’s easy to clean a mountain bike wheel at home when you need to. The bike will only go to tyre fitters as I don’t have the space, tools or time to do it myself so I need to make sure the sealant isn’t going to cause extra headache in the future.
Have you tried deflating the tyre fully, soaping around the seal, and seeing if it will reseat better.?
(I’m guessing your V7 isn’t running spoked wheels like mine.?)
Though you’d likely need access to a compressor to do it effectively, (although I once managed to seat a tubeless car tyre using only a foot pump.. I was younger and fitter back then.!)
I think I need to chat with you about going tubeless on pushbikes, having a devil of a job doing it with my sons leccy Mondraker..
Let us know how you get on with the sealant, and PM me if you’ve any ‘magic tricks’ to aid going tubeless on pushbikes.. 
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Take one wheel off at a time. Half full the bath with water. Put wheel in water. Wait for bubbles. Best done with beer in hand! Cheers Phil
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I can’t believe you’re seriously suggesting that Phil.. 
With wet hands there’s a real risk of spilling the beer 
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I just saw the word beer and I’m going for it.
The tyre can wait! 
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