Navigator Pista problems with 25mm tyres

All,

Can you help?

I've owned a pair of Navigator Pistas for a good while now and they've been no trouble with 23mm tyres. I've recently tried fitting 2 pairs of 25mm tyres and neither pair will bed onto the rim smoothly. Each time I spin the wheel, I get a huge bobble where the tyre doesn't sit flush on the rim.

I've done some searching on-line regarding tyre compatibility with these rims and I've drawn a blank so I'm flummoxed.

Any ideas? Are Navigator Pista rims only good for 23mm tyres or less?

Thanks in advance.

I’ve never had a problem with them, ran 28s with no issues. Have you tried the age old technique of running a toothbrush with soapy water around the rim/bead and inflating to get them to sit correctly? Always seems to work for me - sorry if that’s really obvious!?

700c is only a 'sort of' standard with small variations of erto 622mm rim bead and tyre bead sizes meaning some tyres go on certain rims well but are difficult to fit on others. Are the tyres wired or folding bead? are they new or have previously been levered? Navigator pista are narrow rims but i found wired vittorias a little hard to seat fully and that wasnt the case with contis. Likewise i recently had a customer with basic alloy wheels from a giant which were about 2mm smaller in diameter to another rim placed next to it. Consequently every tyre we tried just blew straight off the rim until we tried folding bead Ultra sport 3s.

Chaps,

Many thanks for your responses. I'll give the toothbrush method a go. Perhaps I'll try another brand of tyre too.