So after a year of denying tubeless I’ve switched and am loving it. Now I’m thinking of getting a set of proper tubeless rims like the Flow Ex. Would it be worth the change? There’s a good bit of weight saving and a wider profile.

I ran ex721s on my HT for 2 years, never needed looking at.

I put Flows on my 160mm FS. Lasted less than a year. Rim dented way too easily, big enough dents to stop it running tubeless.

Now I’ve got a EX823.

yeah ive knackered a rear flow EX too.

I run a 721 on the rear and a flow EX on the front. Perfect balance for me. The 721 is a proper tough rim and has handled everything I’ve thrown at it so far (on a HT too) but I think you can get away with a lighter rim on the front, as it generally gets less hammer.

Thanks for the thoughts – I know 721’s are bombproof. And seem to work nicely with the low pressures I’m now running tubeless.

How hard are you guys running the Flow Ex’s to knacker them?

I ran Flows (the original ones, not the EXs so there may be some differences that account for my experience) without any issue for about four years. This included trips to the Alps, Peak and Wales.

At the time I was 105kg+ and my DH style was always a little ‘bull in the china shop’. I also knew several senior level DH racers who ran them, although they were significantly lighter and smoother riders but still they would beat them and had few problems.

721s and 823s are DH rims and heavy (the 823s in particular are ridiculously heavy to be using as a trail rim in my view but its a free country!). If people are that hard on wheels then I guess it’s a better choice than replacing them every six months but you’ve got to wonder whether a) they are using them for uplift days at DH tracks or b) they’re just too darn clumsy.

721 is a harder rim- not so much stronger, exactly, but they definitely resist dents better so if you’re in the habit of running too-low pressures then Flows are much more likely to give you gyp. I’ve pretty much ruined my Ex for tubeless in just a few rides, it still works fine but it’s got a big flat spot and won’t hold air any more. It did take a big ol’ hit to do it though, but I’m not delighted about it. Still, it’s still fine for tubes so I suppose I could say it’s still ahead of the 721.

The Flow I had on there before lasted 3 years of constant use, first on a big trail bike then onto the dh bike, it finally cracked at the valve hole and tbh I can’t fault it at all for that, one of my old 721s crached in multiple places under much the same treatment.

Bottom line is, yes they are less tough but they’re still very sturdy, it takes a proper kicking to damage them badly… But, they’re easier to ding.

So after a year of denying tubeless I’ve switched and am loving it. Now I’m thinking of getting a set of proper tubeless rims like the Flow Ex. Would it be worth the change?

Runing EX721’s tubeless here for over 6 months and no issues with a rim strip, running XM719’s with just yellow tape. What are these proper tubeless rims you talk about?

Running Flows for guiding in the Alps. 4000m+ of descending every day on rocky terrain.

Just retired the rear after 2.5 seasons (cracking around the spoke holes). Front still going strong.

Have dinged them a few times, but nothing major. Always goes back with the adjustable spanner technique!

Still holding air tubeless, no problem.

What are these proper tubeless rims you talk about

Ones that have been designed around running tubeless instead of the need for a rim strip. The 721 is a great rim, just wondering if it might be a bit overkill for most trail riding, where a Flow Ex will still be strong enough to run some low pressures and get a bit of extra weight saving.

Ones that have been designed around running tubeless instead of the need for a rim strip.

That would be my XM719’s then.

prezet – Member

The 721 is a great rim, just wondering if it might be a bit overkill for most trail riding,

they’re not ‘that’ heavy – around 550grams. you can get lighter, but not enough to get excited about.

The Flow Ex’s on my hardtail are still in good nick after about a year I guess. I tend to run them sub 20 psi and I am around 95kgs. Only had a handful of hard landings in that time though.

FWIW I tried to “ghetto” my 719s, it never worked adequately- yellow tape, bmx tubes, whatever, they always needed a lot of pressure to keep the tyre on the rim, otherwise they liked to fall into the rim bed in corners. And it’s not like I’m a hard-cornering beast! YMMV but I’ll not waste time trying to do tubeless without a proper rim again, was an interesting project but spoiled too many rides and almost put me off tubeless entirely.

For contrast, my friend uses stans rim strips in his 721s, got them working fairly easily and he runs them at very low pressures.

but I’ll not waste time trying to do tubeless without a proper rim again, was an interesting project but spoiled too many rides and almost put me off tubeless entirely.

Couldn’t agree more, not been. Mentioned here but I’m on 819 and they’re utterly bombproof ( but a little over sturdy) having said that I’m only 74kgs but running them on a HT they’re still straight after 3 years and still run tubless no prob

I was running mine with a tube at 30 – 35 PSI when I dinged it.. did case a gap pretty hard though.

yeah I run my 721 rear tubeless with a Stans rimstrip. Works fine.