Originally Posted by
twocicle
Over the last year or so in this Forum we have been noting that tire & rim profile combinations result in varied outcomes. Continental and Compass tires seem to stretch more than some other tires like Schwalbe for example. The Schwable Ultremos I've measured, pretty much maintain their original widths, whereas Conti 4000 and 4Seasons have stretched up to 3mm wider over a week or so from when mounted new. Stretching isn't a bad thing, it just needs to be considered in tight clearance situations.
Zipp 404 is actually pretty narrow inside, something which will jack up the tire height. Using this profile image below, you can see the first Zipp profile is 24.73mm on the outside but only 16.25mm on the inside. The rim well depth is also fairly shallow which reduces air volume and requires a higher psi to maintain sufficient cushion under load.
Maybe try a rim with a wider internal profile to see if that sucks down the tire height?
good edit with additional info.
With itch the rim I have in the fork now I have a hard time seeing that I don't hav space for a 30mm actual width tire. Sure it depends on the actual tire and rim, so I will have to play.
I will will toss a 25mm pro4 on the 19mm internal width wtb i19 team rim to check short term. These tires are egg shaped and measure roughly 29mm wide on this rim.
im not opposed to running a 25c tire, but the added volume of a 28 or 30 would be nice.
The easton rim I plan to use is designed for tubeless so it has the deep centre channel for added air volume and so you can mount a tire easily. I doubt I will use it tubeless this year just based on tire prices and options for the time being. There is a lot of weight on a tandem and I don't need to hurt us or our baby we will be pulling in trying new things. I will do that to myself on another ride. Lol.