Refitting tyre

gaz

Cycle Camera TV
Location
South Croydon
Got a slow p during the day. So tyre was flat as a pancake when I got to it. Right so I got It off, replaced the tube and pumped away. Hissssss! Had a look and one side of the tyre by the valve had popped off the rim :s
whip it off and replace it again. Before pumping I check and again the tyre won't sit over that part of the valve, it looks like the tube might be blocking it. So I pump the tyre up a litle and wiggle it into place. Pump it up. A few mins later hissssss. And he tyre is off the rim in the same place. WTF?

Any ideas on what is causing this and how to fix it?
 

yello

Legendary Member
Location
France
How does the rim look? Any noticeable dents, deformations, etc

Could you try swapping the front & rear tyres over just to see what happens?
 

Norm

Guest
You say it's by the valve? I'm going to guess you are using narrow (>25mm) tyres with a presta valve. It's often a bastard to get them to seat properly, but you need to do it or that bugger will blow faster than a tart by the docks.

The issue is that the valve takes up much of the width available inside the rim.

I'm sure there's plenty of ways to do it but this one works for me. Start off with one half of the tyre in the rim, put in the inner tube slightly inflated, and locate the valve through the hole in the rim. Put the locking nut in place loosely over the valve, then start to push the other half of the tyre over the rim, starting at the valve and making sure that the tyre is fully seated. If the tyre does sit properly in the rim, then tighten the locking ring on the valve stem. Making sure that you keep this bit in place (I hold the rim against my legs) work the tyre onto the rim in both directions away from the valve, so the last bit of the tyre you need to put back onto the rim is on the opposite side from the valve, and push / lever this into place.

Once you think the tyre is fully on the rim, run it round checking both sides that the inner tube is not trapped. I do this by pushing the tyre away from the rim to make sure that I can't see any inner tube, spinning the wheel to check it all the way round and doing this on both sides.
 

yello

Legendary Member
Location
France
Anything that doesn't look like a rim should! Dents or dings.

What sort of tyres do you have? Wired? Folders? If wired, it could be that the tyre bead is crimped/broken and causing the tyre not to seat correctly. Have a look at the edge/rim of the tyre and look for anything sticking out.

Or as Norm ^^ says!
 
OP
gaz

gaz

Cycle Camera TV
Location
South Croydon
Wheels are fulcrum racing 7's, tyres are vittoria rubino pro's 23mm. tubes are specilaized 700c 20mm.

I'll have a look tomorrow lunch time and take my time with it!
 

Tynan

Veteran
Location
e4
you know your stuff gaz, is this a trap?

once the tyre is on, push the valve inwards so it's inside the body of tyre, allowing the tyre to sit properly on the rims, inflate, tighten nut
 
OP
gaz

gaz

Cycle Camera TV
Location
South Croydon
Tynan said:
you know your stuff gaz, is this a trap?

once the tyre is on, push the valve inwards so it's inside the body of tyre, allowing the tyre to sit properly on the rims, inflate, tighten nut
nah. just having a problem with these tyres!

But that is a very nice tip! ta.
 
OP
gaz

gaz

Cycle Camera TV
Location
South Croydon
Tynan said:
once the tyre is on, push the valve inwards so it's inside the body of tyre, allowing the tyre to sit properly on the rims, inflate, tighten nut
This worked, cheers, never heard that before ;)
 
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