Post by: nairb on September 30, 2023, 06:18:55 PM
In the pic below .......
[attach=1]
Does one nut stay inside the rim and the other outside. I have done it like this for years, but doubt has crept in.
Last week, I put a brand-new tyre and tube + rim tape on a rear wheel. Within 35 miles the inner tube failed for some reason. Not at the valve but within 15 cm. The tyre seems ok. I was still running the tyre/tube in.
Ta
Nairb
Post by: Trigger on September 30, 2023, 06:49:04 PM
Post by: AshimotoK0 on September 30, 2023, 07:58:21 PM
Post by: Bryanj on September 30, 2023, 08:27:47 PM
Post by: Oddjob on September 30, 2023, 09:16:08 PM
Post by: Laverdaroo on September 30, 2023, 09:30:53 PM
Sent from my iPhone using Tapatalk
Post by: AshimotoK0 on September 30, 2023, 10:09:02 PM
Post by: nairb on September 30, 2023, 10:27:58 PM
I have seen other ways of securing the valve or using the two nuts. Example below....
[attach=1]
I had not seen the alternative way or had it mentioned......
[attach=2]
The new setup that failed was on a 750 parallel twin with loads of torque, which used two tyre locks to keep the tyre in place. Maybe they failed. I dont know.
I will try the 2nd pic method and check that those tyre locks do actually grip and hold the tyre.
Post by: Trigger on September 30, 2023, 11:12:56 PM
Just had look at a new inner tube and the nuts are 4mm thick and a standard thin wall spanner is 4.5mm thick so, you would have to find a thinner spanner to lock the nuts together ;)
[attachimg=1]
Post by: K2-K6 on October 01, 2023, 08:29:01 AM
The washer to generally stop the tube fretting against any poor areas inside the rim around that location on motorcycle tubes.
Anyway, I've never clamped the external nut tight whatever the arrangement as it will always indicate there's some movement by leaning the valve over that may need another look at it to find out what's going on inside. Bolted tight to rim, it'll pull the tube off the valve without any warning if it moves much.
I think the washer on them nowadays is dished so that some movement can take place without risk of compromise to tube straight away. Tgey are usually very smooth finish to not present any "cutting" edges to the tube material.
Post by: Matt_Harrington on October 01, 2023, 09:50:36 AM
Post by: Trigger on October 01, 2023, 10:41:28 AM
[attachimg=1]
Post by: Seabeowner on October 01, 2023, 06:56:30 PM
Post by: Seabeowner on October 01, 2023, 07:21:22 PM
Ken, I was wondering why there should be a gap between the rim and 1st nut.Always thought was that you could see if the tube is moving, the valve will tilt. Saves waiting until it tears itself apart.
Post by: AshimotoK0 on October 01, 2023, 09:03:02 PM
I sent my questions, as written at the beginning of this post, by email to Michelin UK in Stoke-on-Trent. I received the following reply from Tony Charlton, Technical Manager at Michelin.
"The inner tube is installed with the conical washer sitting between the inner tube and wheel rim. On a road bike the first lock nut should then be run down to lightly touch the rim, and then backed off by half a turn. The second lock nut is run down until it meets the first one, then the two nuts should be locked together by using spanners to rotate them in opposite directions.
For off road inner tubes being used at low tyre pressures there is a possibility of tyre creep, and the inner tube could be pulled around slightly with the tyre. If the inner tube is bolted to the rim the valve can be ripped out. If the lock nuts are raised further towards the valve cap then inner tube has some leeway to move before this happens. Any movement is thus obvious as the valve stem will no longer be straight and pointing at the centre of the hub, but will be pulled round at an angle by the tyre and can then be seen and corrected."
Post by: McCabe-Thiele (Ted) on October 01, 2023, 09:30:17 PM
PS Now I know why my sack trolley has a wonky tube valve.
Post by: K2-K6 on October 01, 2023, 09:42:31 PM
The rears usually have two beed lock clamps to try and stop this happening, but often not tightened sufficiently to be fully effective, you have to winch them down real tight if you want to run low pressure.
An old endure race mod was to drill a hole on the tyre sidewall to take the valve out through there such that it would then go with the tyre if it rotated in use.
Believe that the moto-gp rears run at about 9 psi static pressure and can rotate to then put them out of balance. Valve not affected as tubeless arrangement.
Post by: Matt_Harrington on October 02, 2023, 09:26:44 AM
Post by: Matt_Harrington on October 02, 2023, 09:35:54 AM
Post by: JamesH on October 02, 2023, 11:59:31 AM
Post by: AshimotoK0 on October 02, 2023, 01:29:22 PM
Well, I learnt a new thing today. Nice thread - thanks for the shared wisdom.
Every day is a learning day J. My mate DodgyRoger (who you know :) ) was only telling me in the pub recently about innies and outies after he was watching one of his favourite late night TV shows. ;D ;D
Post by: Oddjob on October 02, 2023, 02:06:22 PM
Well, I learnt a new thing today. Nice thread - thanks for the shared wisdom.
Every day is a learning day J. My mate DodgyRoger (who you know :) ) was only telling me in the pub recently about innies and outies after he was watching one of his favourite late night TV shows. ;D ;D
Are we talking about nipples?
Post by: Laverda Dave on October 02, 2023, 02:09:22 PM
As noted on Ash's response, off road tyres are prone to moving when run at lower pressure, which you need to see before it tears the valve out.
The rears usually have two beed lock clamps to try and stop this happening, but often not tightened sufficiently to be fully effective, you have to winch them down real tight if you want to run low pressure.
An old endure race mod was to drill a hole on the tyre sidewall to take the valve out through there such that it would then go with the tyre if it rotated in use.
Believe that the moto-gp rears run at about 9 psi static pressure and can rotate to then put them out of balance. Valve not affected as tubeless arrangement.
The comment about the endurance bike mod reminded me of what I used to to do with the rear speedway tyre valve Nigel. I use to push it out of the sidewall of the tyre as it made it quicker to change the tyre and because we used to run the rear tyre between 8-14psi depending on how deep or slick the track was. Iwade was always slick but Milton Keynes was always deep. If the valve came out through the centre of the rim it would get ripped out when the tyre 'crinckled' under power during a broadslide. Speedway tyres are now tubeless.
Post by: AshimotoK0 on October 02, 2023, 02:15:20 PM
Well, I learnt a new thing today. Nice thread - thanks for the shared wisdom.
Every day is a learning day J. My mate DodgyRoger (who you know :) ) was only telling me in the pub recently about innies and outies after he was watching one of his favourite late night TV shows. ;D ;D
Are we talking about nipples?
Bit further down chap :D
Post by: Laverdaroo on October 03, 2023, 09:17:52 AM
Sent from my iPhone using Tapatalk
Post by: Oddjob on October 03, 2023, 10:52:00 AM
Post by: AshimotoK0 on October 20, 2023, 09:31:57 PM
[attachimg=1]
Post by: McCabe-Thiele (Ted) on October 20, 2023, 10:02:35 PM
That said my tyre was fitted the wrong way round according to the rotation arrows - they collected the wheel sorted it & delivered it back f.o.c.