When we reviewed the Ibis Ripley a few weeks back, our one small complaint was the noticeable flex in the rear end. Ibis contacted us and told us about GnarCore, an eccentric and pivot pin upgrade kit for the Ripley that can increase the rear end stiffness by 10%.
The $34.95 upgrade is actually standard equipment on all Ripleys that are currently shipping, but a few of the early ones, like our test bike, were made with a lighter weight part. For instance, the exploded illustration above appears to have an older design, with the newer nut style, but an older aluminum pin.
We obtained a GnarCore and documented the installation process on this unique suspension system. Click inside to see why adding some weight makes this bike better…
The GnarCore system consists of a full replacement of the upper and lower eccentrics and their pivot pins. The system adds 23 grams, primarily due to a more robust lower eccentric and a changing of the lower pivot pin from aluminum to titanium. Both of these changes are said to assist in adding stiffness to the rear end.
10 of those grams are in the pin, which is made from titanium, and the larger end nut that changes from a 14mm nut to a 6mm Allen.
The lower eccentric is also noticeably thicker, and about 7 grams heavier.
Although most of the changes were to the main parts, there are subtle changes throughout the pivots that must help keep it all together. This change to the lower eccentric cap made it slightly thicker, yet didn’t change the weight.
Impressively, the machine tolerances of the pieces were very tight. Sliding the eccentrics in and out of the bearings required the assistance of light taps with the dead blow hammer, and inspection revealed that the bearings were in perfect condition after a lot of use.
Due to the unique nature of the design, full removal of the rear end was not necessary to make the swap. The shock clevis held the rear end together while it was slid back and out of the way for the replacement parts. And from the outside, the only way to tell is the slightly different color of the lower pin.
It is December here in Minnesota, and while we have had some warm weather, the trails are still closed. We won’t be able to get to a full test of the replacement till spring, but a quick spin around the block on pavement did reveal an increase in stiffness that could be felt. Ibis has said that all Ripleys are already shipping with GnarCore eccentrics, so there are actually very few Ripleys out there without the upgrade.
