[Closed] Internal rim Width Increase -19mm to 25mm

2.6, pushing it? Comfier, more stable ride but potentially slower if you've got draggy, weighty tires. Max I've gone with a 25mm is 2.4. lowest is 43mm gravel tyre (1.7). Swings and roundabouts I guess. What do you desire?

Quite a lot, especially on the 2.6. It'll square off the tyre, allow for lower pressures and prevent rolling of the tyre in the corners. All in you'll get a LOT more traction. FWIW - I wouldn't be running 2.6 on a 19mm. Heck, I'm running 32mm road tyres on ~25mm ID rims.

Getting the most out of the tyres i suppose.

Was thinking a wider rime would “present” they tryre tread in a better profile. Not so pinched, giving a wider flatter cross section.

I have a 2.6 on the 19mm and have yet to die………… but realise I am pushing my luck

I went from 19mm to 25mm on exactly the same tyres and didn’t notice any difference at all.

The 25mm inner should work fine with the 2.3” - and with a 2.6” it’ll be fine. Maybe at the limit a 30mm rim would make better use of the 2.6” width but it’s probably fine margins. I’ve been running a 2.6” Magic Mary on a 25mm inner rim for a while (XM421 rim). Due to a bike change I had a spare wheel with a 30mm inner (XM481) so that’s now got the Magic Mary on and the 25mm one has a 2.5DHF on it. So now have a Winter / Summer front wheel to swap on and off. The hub on the 25mm one is crap at not destroying its bearings as it’s poorly sealed and I think the angular contact bearings in it are very sensitive to pre load so keeping it for the summer makes sense (would 100% NOT recommend Erase Components hubs - they’ve very light and expensive but particularly the front doesn’t seem to like UK weather).

I went from 19 to 25 and noticed quite a bit of difference with 2.3 tires. I run very low pressures though. 15psi

Put magic mary 2.6 on Lewis's bike with 24.5mm rims. They come up at 2.35 inches.

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I'm running 25mm internal rims on my gravel bike..., whereas my FS has got 30mm & 2.4's.

If you're changing, look at 30mm at a minimum - you'll be able to run a lot lower pressures.

I have 25mm wide at the back and 30mm at the front with 2.4 inch tyres

The back one never looks quite right. Although it works

19mm to 25mm is better. But could you hold off for a 30mm deal?

Quite a few downhillers at the world cups run 25mm rims with 2.35, 2.4 and maybe the odd 2.5 so I think you'll be fine, I doubt you're up to their speeds and cornering ability.
Some brands 2.6 are equivalent to anothers 2.4. What's your 2.6.

I heard that downhills don't need the width as they are using much thicker tyre carcasses

The tyres will def look better, which means you'll go faster, right?

I heard that downhills don’t need the width as they are using much thicker tyre carcasses

This is more of a side note than the primary reason, which is that wider rims pull the tyres more square and make it harder to turn. On a Gravel Bike or Fat Bike with a 70deg Head Angle and a wheelbase only just over 1m, then leaning the bike off the edge of the tyre isn't going to be of a primary concern, especially not given their intended use and the fact the tyre treads will be designed to work better with a carcass that deforms easily and a flatter profile. The opposite is true in DH, where the tyre carcasses need to be stiff to make the edge knobs bite in hard cornering and to ward off damage from being slammed into the terrain at high speeds, and the wheelbases are typically up over 1300mm with sub 63deg Head Angles...

At the Chris Porter/Geometron talk @ Geometron HQ a few months ago, one of the audience asked a question about the "most important component on a bike" to which Chris responded unquestionably that it was the tyres, and a debate about form over function (in particular regarding tyre and rim widths for "aggressively" ridden MTB's), which in itself raised a good point... That being that most people riding bikes with less aggressive geometry and less aggressive tyres, will likely benefit from wider rims (to a point obviously) for a given tyre width much more than those pushing the limits of their DH/Enduro bikes will do. In fact, to this end, we're rapidly seeing 30mm wide rims find their way onto all sorts of "XC" bikes now with 2.3-2.4" lightweight fast rolling XC tyres, and it makes sense. For a bike that won't be leant hard, doesn't have the front wheel in a different postcode to the rider, and Head Angle above say 65deg (I have picked that number arbitrarily, don't hang my hat on it for me!), a wider rim for a given tyre width will give more grip at modest lean angles and allow lower pressures for even more grip. It works on road bikes (average disc brake rim now is 19-21mm internal, running 25-28mm tyres typically!), Gravel Bikes (typically 20-25mm internal with 35-45mm tyres), Fat Bikes (typically 60-100mm wide with 4-4.8" wide tyres) for the same reasons. Modern DH and Enduro bikes are becoming highly specialised pieces of equipment, often requiring a riding style closer to that of an MX bike the harder and faster they are ridden.

AN interesting aside... CP even commented about his Supermotor racing days, where they would experiment with rim widths to change a given tyres profile, depending on how tight and twisty a circuit was. Something I wasn't previously aware of, but makes absolute sense when you start to think about it.

Thanks