as RPM, said, you might have caught a bit of tube between tyre and rim, i always put a small bit of air in the tube just to keep it round, fit tyre, then walk the tyre around the rim, making sure the tube is sitting properly, then inflate.
@31trum started
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as RPM, said, you might have caught a bit of tube between tyre and rim, i always put a small bit of air in the tube just to keep it round, fit tyre, then walk the tyre around the rim, making sure the tube is sitting properly, then inflate.