Ibis launches three sets of new carbon wheels. We had the opportunity to ride one of them on a Ibis Ripley in Moab during the last week, being the first media worldwide to see and ride them.
The idea behind Scot Nicol’s new product is easy: wider rims are better. The reasons are well known to our readers.
Wide rims support the tire’s sidewalls better, allowing lower pressures without the tires folding over or burping. This dramatically increases stability and traction. This shows up as faster cornering and braking, better grip in all conditions. How much lower pressure can you go? In general, for a given rider, using tires you’ve used before in a given locale, you will be able to run lower tire pressures with wider rims. How much lower can only be determined through experimentation. Typically, test riders are running 4 – 6 psi less than normal. Light riders on moderate terrain are running as low as 15-17psi.
Wider rims dramatically reduce the incidence of burping. With wider rims the tire sidewall can’t exert as much force on the bead to unseat it and allow air to escape.
Ibis’ wheelsets will not set a new weight world record, but consider that, given the same weight, carbon rims are more stable and strong that alloy ones. Ibis says: “Impact damage is way most carbon rims die. The rim we’ve designed is much stronger in the area where impacts occur since it’s a solid rectangle instead of an inverted “J”. This spreads the impact out over a larger area that is also supported by more material.
We tested the impact strength of several major brands of carbon fiber rims and discovered that the change to hookless bead was a major advantage in impact strength. We also optimized the layup to further increase strength. In the end, our rims are 50 to 300% stronger in impact than competing rims we measured. We don’t want to throw anyone under the bus, but we do want you to know that these are well-respected and well-known manufacturers.”
The rims are engineered to be stronger than the spokes so the rim can’t be damaged if a spoke gets broken by a stick etc. Each spoke hole is individually reinforced with extra carbon material to achieve this while still building a lightweight rim. “We build with 32 conventional spokes (available at any bike shop) and standard exposed nipples. This allows tuning without special tools or dismounting the tire and rim tape. In our tests we found that although you can reduce the weight by using fewer spokes it hurts the long-term durability and also is more prone to damage from sticks getting lodged between the spokes. A 24 spoke wheel with even 1 broken spoke often can not be ridden as the tire will be hitting the frame. With 32 spokes you have a better chance of riding out after a mishap. The spokes are triple butted 2.2 – 1.5 – 2.0 gauge with 7075 high strength alloy nipples and stainless washers.”
The 41 mm wide rims typically increase the tire width about 3 -5 mm at the widest part of the casing. The diameter stays about the same. The shape of the tread cap will be flatter as well. The 741 and 941 change the shape of the tire and you will want to select a tire that has a good profile on the wider rims. Generally we have found that tires that start with a rounder profile across the tread cap work the best.
We have thoroughly tested and qualified these hubs, working closely with the factory to refine them and insure high performance and durability. The hubs are backed by Ibis’ world class service and all small parts and tools will be made available through our dealers and on our web store. The hubs feature Enduro bearings throughout and a durable and smooth freehub system available in Shimano or SRAM XD format. The hubs are adaptable to 9mm QR, 15mm through axle in front and 9 mm QR or 12mm through axle in the back.
Prices: 1.499 Euro
Availability: immediate, 941 in May
41 mm outside, 35 mm inside width, 27.5” / 650b diameter
1669g for the set, 777g F, 892g R.
Rim only 475g.
28 mm outside, 22 mm inside width, 29” diameter.
1545g for the set, 721g F, 824g R.
Rim only 390g.
41mm outside, 35 mm inside width, 29” diameter.
1745g for the set (estimated). 821g F, 924g R.
Rim only 490g.
We rode in Moab the 928 wheelset on Ibis’ 29er Ripley (120mm of travel). Carbon rims have a big impact on big wheels, and that’s what we could feel when we switched from the Notubes ZTR Archex, that we rode the day before we received the new Ibis carbon wheels.
The 928 wheelset rides more precise especially in the cornering, where the stiffness makes the difference. It’s not the kind of stiffness that makes the whole bike feel too harsh, we would say this is the right amount of it. Because the inside rim width is “only” 22mm, the “wider is better” does not apply to this wheelset, but we will keep you posted when we will review the 741.
Moab rocky terrain and some of the trails we rode (especially the Portal trail) felt as the perfect way to test ride the Ibis 928 wheelset. Some major impacts, due also to the low tires pressure, did not have any consequences on them. We rode 1.8 bar on the rear and 1.7 on the front.
Accelerating the bike on a uphill trail like the “Great Escape” was fun, this is definitely one of the points that you should consider if you plan to buy a carbon wheelset: on a 29er, their stiffness and lightness make the difference when you are charging it.
The final graphics are elegant and not invasive. As Scot Nicols says: “We tend to keep things understated, rather than “in your face”. On the other hand, we will definitely be offering a different graphic treatment on the rims as an option”.
Stay tune for the long term review!