First Look: Renthal 1XR Chainring
About 18 months ago we began a project to develop a retention chainring for 1X drivetrains. We saw problems with wide/narrow in terms of durability and use in muddy (British!) conditions. After going through a number of different designs, including ultra tall teeth and a whacky chainring with three in-line teeth, we proved the best levels of chain retention were achieved with alternating wide and narrow teeth. So, we went back to the wide/narrow format and tackled the issues that it caused. Here’s what we did:
As the tooth face wears, the inner chain plates come into contact with the wide section of the chainring tooth. When this happens the efficiency of the chainring is lost, as the chain is no longer running on just the roller. To alleviate this problem and extend chainring life, we profiled the face of the wide section to allow clearance for more tooth face wear to occur before the chainring has to be replaced. Durability is further bolstered as we use a full width tooth face and manufacture from 7075 T6 aluminium, which is then hard anodised. We bench marked the two market leading chainrings and the Renthal 1XR showed considerably improved longevity.
Mud condition performance
In heavy mud conditions, two issues occur; mud quickly builds up on the shoulder that links the wide section teeth and it can clog on the x-section wide teeth. Both of these cause efficiency and premature wear issues at best. At worst, it can cause the chain to lift up and de-rail. We tackled this in three ways. We significantly lowered the shoulder between the wide section teeth, giving mud room to evacuate. We also added mud grooves in the tooth bed to further speed the process. Additionally, the profiled front section of the wide tooth allows clearance for mud to purge out, rather than clogging.
Renthal 1XR – Ultimate chain retention. All conditions.
• Alternating 1.8 / 3.5mm width teeth
• CNC machined 7075 T6 Aluminum
• Hard anodized surface finish
• Mud grooves in the tooth bed
• Ultra stiff I-Beam cross section
• Mud clearance and wear-proof profiling
• 104mm BCD, 32, 34, 36 and 38t
• £49.95 / €59.90 / $59.90 USD
|The Renthal 1XR chainring tooth profiling ensures the highest level of chain retention, in all conditions. Alternating 1.8 / 3.5mm width teeth interlock with the chain for ultimate security, with no loss of efficiency. The 1XR can be used with a clutch-type rear derailleur, without a chain guide. The reduced frontal profile of the 3.5mm wide teeth increases mud clearance for the inner chain plates and extends longevity. Durability of the hard wearing 7075 T6 aluminium construction is maximised with a hard anodised surface treatment and mud evacuation grooves in the tooth bed. We used a number of riders in the UK to test the chainring for retention and durability, as the harsh UK weather provides the best test-bed. Yeti/Fox riders Jared Graves and Richie Rude used the chainring last year and the MS Mondraker team also used them at the back end of the WC DH season. – Ian Collins, Renthal Marketing|
Pinkbike has just received a 1XR ring to test. We’ll be putting it through it’s paces, so expect a full review soon.