I'm interested in something like a Vittoria gravel airliner but I have several hesitations. They seem like they're designed around a 23i rim and mine is a 27i. Only 4mm there, not a huge deal.
The tire size goes up to 40mm. My current tires are 45s. Ope.
Between these two size issues, should I worry? Being held together with a zip tie seems like it should be fine but I have no experience with these. I could size up to the XC size, but I'm not sure I could physically get that into a Challenge tire.
I have been using the Vittoria liners for a few years; initially on 23mm ID rims and for the last 1.5 years on 25mm ID rims. I really like them; I have two wheelsets, one has 44mm Tufo Thundero's and the other has Challenge 40mm tires. The zip tie connection has not been an issue at all; agree it seems a bit janky but I appreciate the simplicity and it just works. My thought on using them on wider rims is that it should help a bit with tire removal as it can be tougher due to the insert supporting the tire when you try to press it in to break the bead. I had to buy one of those ubiquitous clamp tools. I considered the mtb version of the liner but decided against it and I'm glad as I think it would be too big.
I have done a handful of different inserts for mtb, gravel and CX. The Vittoria ones take up a bit of volume. The only gravel/cx wheels they are still in are my 47s. I don't think the recommended sizing matters if you are mostly using them for rim protection. I don't know why the internal rim width matters here. Wider might even be nicer since they are a pain to remove the tire while using. I had the same one in a pair of cx tires and it was miserable removing that tire at the end of the season. Second hardest tire removal of my life, second only to my mtb race wheels with a Vittoria insert being used.
Those Vittoria inserts can absolutely be ridden flat as well.
I use the Rimpact tire liners on my all-road bike. They are awesome. Their gravel/XC inserts are for 25-30mm inner diameter and tires 40-55mm, so would be perfect for your setup. (I'm actually using the "CX" inserts as I have 23mm-(i)wide rims and 40mm tires; these are the Strada Bianca tires, so not for chunky stuff. I'm slowly converting over all of my different bikes/wheels to use inserts.)
The vittoria liners are a pita to remove. I’ve switched to https://tubolight.bike EVO SL for my 650b2.1” and 700c2.2” wheelsets and have never looked back.
Still run the cushcore CX gravel inserts in my 700c40 set, would now prefer to run the EVO gravel in those.
