Rim / Tyre Widths

In the market for some lighter wheels to shed some bike weight. With my weight and riding style I’m probably into a decent XC build being good enough for my hardtail.

rim width on XC tops out at 25mm ID. Planning on running 2.4 conti’s.

Is 2.4 too wide to go on a 25mm rim? Or am i worrying about nothing other than the obsessive implants from reading too much! I know there’s all sorts of numbers and recommendations but real world……instant death or unnoticeable compared to a 30mm ID rim?

If weight is your main concern then i25mm is gonna be the lightest option, if your pockets are deep a carbon wheelset can come in at 1200g. i30 is real popular right now with 2.4mm XCO type tyres, again carbon saves you weight both on the wheels and your wallet.

2.4″ on i25mm will be fine.

I was looking for similar a while back, didn’t want to stump up for carbon and got Stan’s Arch MK4 i28mm on Bitex hubs with Sapim bladed spokes, 29er wheelset with tape and valves came in at 1700g. I’d REALLY like a set of i29 Roval Control SL’s…

I’m still not a carbon convert and definitely not on wheels. Last new wheelset – 6” nail straight through the tyre and inner wall. Patched up with some resin and perfect. Carbon would be fubar’d. Lifetime crash etc…. Not for me!

Where’d you get the build done or were they off the peg?

I’m trying to get a wheel weight around 1600g. Seen a bitex build at JRA that suits and spot on weight wise. Potentially up to a kg in total off my wheels with a change of cassette and tyres too which is massive. But wondering if tyres will squirm all over and defeat the object.

https://www.spokesmanwheels.co.uk/

Has an eBay shop but you’ll get a better price emailing them direct, can custom build to your spec / needs.

currently running magix mary 2.6 on 25mm internal rims without any issue. ran 1.4 conti baron’s before again with no issue.

As an employee of a major tyre brand, a 25mm rim is either too narrow, too wide or absolutely spot on for a 2.4″ tyre… Depending on who you speak to…

Certainly there’s a reason most DH rims are still around 25mm wide internal width and the tyres are in the 2.4-2.5″ range. I know Chris Porter is a big fan of DT Swiss EX471 rims and 2.3-2.4″ tyres and have conversed in detail with him about the “fashion led” reasons behind wider rims that have in some cases forced the hand of some tyre manufacturers to make their tyres work better on wider rims when they already worked very well on narrower rims.

Anyway… The real answer is I wouldn’t obsess about it. For sure, there’s differences between 2.4″ tyres, some are wider than others, some more aggressive. But if your rim is anywhere in the 25-30mm internal width range, the tyre is going to work just fine and you’ve nothing to worry about. If it’s wider than 30mm it’ll probably still be fine to a point, albeit it’ll be a little squarer than ideal, and narrower than 25mm it’ll still work fine it’s just it might be a little more susceptible to tyre roll under hard cornering than on a wider rim. I’ve run a 2.8″ Michelin Comp 32 back in the day on a 21mm internal Mavic 821 rim and it didn’t kill me, and I have friends who’ve ridden 2.3″ High Rollers on 35mm internal width rims too and they’re still alive… Even if their bikes were a little hard to turn and stood up on their own when they dismounted them! 😉