Width (internal): 35mms
Weight (pair): 1,660g
Available: 27.5 x 41mm, 29 x 41mm
Ibis is proudly surfing the fine line between ‘more’ and ‘too much’ with this monster 41mm wide (external) rim. It comes in both 27in and 29in diameters and is truly impressive to behold.
Ibis has been developing this rim profile for a while and has also been talking to tyre companies to see what tyre designs are in the pipeline. This is very important here because of the dramatic effect that such a wide rim can have on tyre profiles. Ibis suggests that there are many tyres that work well on this jumbo profile, and that it can turn a 2.35in tyre into an effective 2.5in monster, while still clearing forks and chainstays. It also allows a lower pressure than before, due to a greater air volume and wider profile.
The rims are a big ‘D’ shape, tautly laced to nondescript, but capable-looking hubs. The rear hub works with Shimano ten (and 11) speed and there’s an XD driver available for 1×11 SRAM fans.
I’ve tried a number of different 27.5in tyres on the 741s, with widely differing results. Some tyres, like Schwalbe’s Magic Mary or the Maxxis Minion, naturally expand their toothy profiles perfectly into knob-filled jumbo-ness. Other tyres, like the Conti Trail King 2.2, turn into sausages of delicate-looking sidewall, with a laughably narrow mohican of tread at the top.
Just about all of the tyres I tried successfully mounted tubeless with only a large-volume track pump. I was able to run tyres at some silly-low pressures without many incidents. On smoother trails, 15psi was possible and I regularly ran them tubeless around the 20psi mark. The amount of grip this gives you is impressive, addictive and very easy to take for granted. There were a few pinch-flats that wouldn’t seal with sealant, but that was when exploring the lower pressure limits. After six months, the hookless beads and rim surfaces don’t look to have suffered at all.
The 741s (and by inference, the 941s) are fantastic wheels that’ll change how you view tyres, pressures and grip. However, you must make sure you have a tyre that can expand to fit or you’ll end up with vulnerable sidewall exposed or a concave tread. With the right tyres, though, they’re unbeatable.
|Tested:||by Chipps. for|