Tyre and rim problem

[bedrock]

I recently purchased and fitted a pair of Schwalbe City Jet 26" x 1.5 tyres and matching inner tubes to my old mountain bike. The rear tyre fitted perfectly but the front tyre doesn't sit well on the rim. The rims have no markings but look quite similar: they are cheap, budget wheels.

It would appear that the front tyre is too tight on the rim and the beading tries to stay in the channel for the spoke nipples rather than spreading out across the rim. One small section of tyre stays in this channel -- at least partly -- and therefore makes for a lumpy ride.

I have tried reseating the tyre several times and changing the rim tape to no effect. I have also tried manipulating the tyre under various states of inflation. I would like to try some lubricant on the tyre bead (we used to use something like grease or soap to get tractor tyres on and off when I was kid) but have nothing suitable to hand.

Any suggestions or do you think this is just the wrong tyre for this rim? More generally, what does one have to check to ensure rim and tyre compatibility for mountain bike kit?

Thanks.

 

[gaz]

The easiest way to see if the tyre is too small for the rim is to measure the rim.
Remove the tyre and measure the distance between the internal walls of the rim and then use the chart on this page to see if your tyre fits.

 

[fossyant]

Try washing up liquid or talc on the beads.

 

[bedrock]

The easiest way to see if the tyre is too small for the rim is to measure the rim.
Remove the tyre and measure the distance between the internal walls of the rim and then use the chart on this page to see if your tyre fits.

The tyres say 40-559 and the rear wheel says 19-559, and presumably that is why they are compatible.

As previously mentioned, the front rim is not labelled but I will try measuring it as per the link. If it's not compatible, I'll have to cycle to the council dump to find another "new" wheel. Only the best...

 

[bedrock]

Try washing up liquid or talc on the beads.

I did consider washing up liquid. Have you tried either of those two yourself?

 

[bedrock]

I just did a search for washing up liquid and bike tyres and it seems to be used mostly for getting tight tyres back onto rims, which isn't exactly my problem. Still, I may give it a go.

 

[bedrock]

I took the tyre off and tried to measure the bead seat diameter of the rim. This I found virtually impossible to do using a regular expanding tape measure. I also tried some washing up liquid, but this didn't change the original problem of some beading staying in the tyre well.

I think that I've concluded this rim is somehow incompatible.

At least I've now learned that 26" wheels have different diameters!

 

[mr messy]

I found the city jets put up a bit of a fight when new, beads wouldn't "pop" into place. Solved automotive styley inflating till they do!!! Usually "pop" when get to max pressure. Compressor comes in handy for this.

 

[bedrock]

I found the city jets put up a bit of a fight when new, beads wouldn't "pop" into place. Solved automotive styley inflating till they do!!! Usually "pop" when get to max pressure. Compressor comes in handy for this.

I have access to a compressor but my the valves are the non-car type. I don't have a pressure gauge and wouldn't like to risk inflating with a hand pump until the tyres go "pop"!

 

[TheDoctor]

If the wheel was the wrong size, you'd not get the tyre on at all!!

 

[mr messy]

I have access to a compressor but my the valves are the non-car type. I don't have a pressure gauge and wouldn't like to risk inflating with a hand pump until the tyres go "pop"!

There's still a little give in the tyre when squeezed at 80psi. I used a compressor because i have one and hand pumping to 80psi didn't appeal, way too much effort lol

i would try again making sure rim tape correctly located and with tyre and rim nicely lubricated.

"Popping" is just a highly technical term for seating bead