Rim tape size advice

EasyPeez

I have Pacenti Sl25 rims - internal width listed as 20mm. I'm looking to fit some tubeless rim tape (the thinner the better - recommendations welcome) but not sure what size to buy. My presumption would be 19mm width but then I thought perhaps I want narrower than that, to just cover the well at the centre of the rim?

One of my reasons for buying (apart from the fact that the stuff I have on there currently is cheap, nasty, thick, and badly fitted!) is in the hope of helping with fitting tyres - currently the rims seem very tight with all kinds of tyre combos proving difficult to mount, so I figured some thinner, better fitted rim tape might help a bit.

This being the case, does it make sense to go for a very narrow width of tape and just cover the central well where the spoke holes are, or do I want to still cover up over the flanges(not sure that's the technical term?!) where the bead will eventually sit?

Thanks in advance for any help.

whyamihere

You don't want to go narrower than the internal width, if anything you want to go a bit wider, especially if the channel is quite deep. I'd be looking for tape around 20-23mm, going towards the wider end if the channel is deeper.

term1te

I'd go for tape fractionally wider than the internal width of the rim. As has been said, the width it will be stuck to will be greater than the measured width, if that makes sense. I have some Swiss DT 440 rims, that claim to have an inner width of 19mm. I just couldn't get a seal with 19mm tape, but 21mm worked fine.

EasyPeez

Of course - being a bit dim I hadn't reckoned on the central channel, being deeper, meaning that extra width of tape is required to fill it too. Thanks for the help, much appreciated.