Jenex 100SR Issues & Recommendations

Wed, Dec  7, 2005 - By Nathan Caproni

I am a serious skier from Spokane, Washington. I have used several of Jenex rollerskis, including the Aero 150. I have owned the 100SR (with both ATRA speed reducers and the brake system) this entire past dryland season and skied a few hundred Ks on them.

We have some steep hills (up to 12% grade) near Spokane on parts of our rollerski trail system and I can report that the speed reducers work quite well and the brake is very effective. I really like the increased stability and light quick feel compared to the Aero 150.

The following are a recommendation for to help rollerskiers and a couple issues that need some attention:

The Ball Bearing Solution

I recommend that every skate pair of Jenex rollerskis have a 1/4-inch ball bearing inserted under the spring for each Pilot binding (or similar instrument that compresses the binding spring 1/4-inch). This increases the spring tension and helps keep the ski closer to the boot to allow quicker and better technique.

Wheel Wear Problems

A big issue is WHEEL WEAR! I weigh 190 pounds and ski a lot of hills with a power focus. I have had to replace the tires 3 times this season.

My average distance for replacement has been in the vicinity of 100-150K!

This is not good. However, Jenex has developed and is currently testing a different tire design that both eliminates the grooves (which created greater friction) for a smoother pavement interface, and adds more rubber (increasing the wheel diameter to 105mm). Early testing reports indicate 300% greater wear. This will be a welcome improvement for 2006.

Speed Reducer Roller Arm Issues

Finally, I have had a problem with the speed reducer roller arm cutting into my front tires and very quickly wearing them out. Here is a description of the problem and how to fix it.

The speed reducer system uses a single offset lever which compresses a spring-loaded roller bearing arm into the tire. This force increases friction against the tire effectively slowing it down. However, the tension force needed to engage the lever to the highest setting forces the roller bearing arm into a canted position. This canted position is bad because the roller bearing hits the tire at an angle forcing the roller bearing edge into the tire. The roller bearing should hit the tire evenly creating a smooth interface.

However, this angled position effectively cut my front right tire in half after about 75K of doing heavy hill work. The solution is to have Jenex install a second lever on the opposite side of the standard lever. This would create a dual-lever, evenly-pressured engagement of the roller bearing into the tire. I will be sending my 100SR rollerskis back to Jenex to have this upgrade performed. The addition of this second lever to each ski will only add a very small amount of weight to the ski front.

Attention to the issues listed above should provide a great pair of 100SR rollerskis that I think are the best in the business for terrain versatility while maintaining a smooth, stable, and light platform for correct technique.