Rims,tape,tires and pressures

[woodbutcher]

Not sure if this post is in the correct place but we are talking Mavic SUP rims on my Look so l guess it may be ok in the vintage section. Anyway here goes, this morning when l got the bike out ready for a ride l found the front tire to be completely flat This afternoon l thought ok l will stick a patch it and hope for the best but when l removed the inner tube l saw not a small hole but this weird distortion (see photo). My first thought was that the spoke had poked through the rim and punctured it but the bar tape is perfect and there is no sign of damage to the rim anywhere. The tube is a Wolber made in France, l have examined it very carefully and l noticed that at the point where the distortion has happened the tube has a slightly thicker ring in the rubber....could this be where the tube is joined ? Not that l know how inner tubes are made. Leading on from all this waffle, does anyone know where l can get info on tyre pressures in relationship to the type of bike / wheel and weight of rider. Phew, got that off my chest !!

 

[MichaelW2]

Remove the rim tape, examine the rim, send a photo of that bulge if you have any doubts. Check for overly long spokes sticking out into the tube. Replace any spokes that are too long with shorter ones. Replace with Velox cloth tape.

 

[woodbutcher]

Remove the rim tape, examine the rim, send a photo of that bulge if you have any doubts. Check for overly long spokes sticking out into the tube. Replace any spokes that are too long with shorter ones. Replace with Velox cloth tape.

Sorry, in my description of the rim condition l used the words "bar tape" when l meant rim tape. As l say l cant see or feel any distortion or bulges ii the rim. However l will replace the rim tape etc.
Can you see in my photo that the tube has been distorted and almost "nipped" together , really strange .

 

[Racing roadkill]

That’s showing typical signs of being forced through a spoke hole, where the rim tape has sunken into ( or been broken ) by the spoke hole. Use Velox rim tape

http://www.wiggle.co.uk/velox-rim-tape/

Replace the tube and run the pressure at about 90-100 psi or there abouts.

 

[roadrash]

As a rough guide , and to be adjusted for individual preference and comfort , have a look at this... plenty of similar charts to be found via google

 

[raleighnut]

As a rough guide , and to be adjusted for individual preference and comfort , have a look at this... plenty of similar charts to be found via google


View attachment 430621

That only applies to hooked or 'Clincher' rims though, old straight sided rims won't cope with much over 70psi.

 

[mikeymustard]

That chart seems unnecessarily high? I wouldn't put anything like that sort of pressure in my tyres, I'm 110kg, I ran my 25mm at 120psi once and I thought I was gonna lose my fillings!

 

[woodbutcher]

That chart seems unnecessarily high? I wouldn't put anything like that sort of pressure in my tyres, I'm 110kg, I ran my 25mm at 120psi once and I thought I was gonna lose my fillings!

I may be wrong on this but are the weights on the bottom line referring to the load per wheel rather than the overall load. If so that makes a bit more sense to me because l am 63kg and the bike is 9.5kg total 72.5kg so divided in half, for a 23mm tire the pressure should be about 80psi.

 

[woodbutcher]

Just an afterthought .....l am not American so it is tyres not tires ! In my defence l was tired when l wrote the thread headline

 

[Salty seadog]

Just an afterthought .....l am not American so it is tyres not tires ! In my defence l was tired when l wrote the thread headline

I'm tyred too so I'll be off to bed soon.

 

[raleighnut]

I may be wrong on this but are the weights on the bottom line referring to the load per wheel rather than the overall load. If so that makes a bit more sense to me because l am 63kg and the bike is 9.5kg total 72.5kg so divided in half, for a 23mm tire the pressure should be about 80psi.

It says at the bottom of the chart that it is for individual tyres and reckons a 45% front 55% rear weight split which is probably right IMO.