Since it's introduction over a year ago, many skiers who have purchased the Jenex Aero 125 rollerski have reported wheel failure problems. Although Jenex has been working through several iterations of design and  manufacturing improvements to increase reliability, reports of wheel failures continue. Jenex has recently announced a set of recommendations to reduce or eliminate wheel failures.

History of problems

Although the first run of wheels in 2002 worked fine, subsequent runs had problems. In the second run, the hubs were made from the wrong material, causing them to warp. The warping caused some tubes to blow or cause the tire belts to shift. Because the rims were produced in the wrong material, Jenex states the rims were not rigid enough, potentially causing vibration and premature tube and tire failure. In the the third batch, the rims were OK but the tubes would get pinched during the tire mounting process.

Skiers reported flats in as few as 4 hours on new skis. Other skiers reported that the use of speed reducers caused bumps to form on the wheels. One skier experienced wheel warp when coming down a long hill using speed reducers. Both a flat spot and a bump developed on the wheel..

On November 14, 2002, Jenex shipped a new "Split Rim" design. Two halves of the rim can be unscrewed, greatly easing the effort required to replace worn or failed tires. One light weight skier (105 lbs) skier who complained of getting flats every time she rollerskied replaced the wheels with the new split rim design. Her problems disappeared.

Other skiers were not so lucky, and problems continued into 2003. One skier complained about getting three flats. According to the skier, Jenex claimed the three flats were the result of  pinched tubes caused by improper tire pressure. The skier claims he religiously kept the tires pumped to the specified 85 lbs.

Between April and August, another skier had three tires tear at the bead. On a fourth tire, the tread came off in patches with less than 300km on them.

September 2003: Notice the bubble where the bead is separating from the tire.

In August, some skiers report signs of the bead beginning to tear on their tires. Jenex discovers it accidentally shipped split rim wheels without O-rings. The O-rings protect the tire from the rim. Several skiers get free tire replacements when the tires fail. 

Pinch-flats continue to be a problem. Reports are that Jenex expects to ship thicker inner tubes shortly.

I have not heard of speed reducers causing problems since the split rim design was introduced.

Jenex Makes Some Strong Recommendations

On September 13, 2003, Jenex came out with a set of recommendations for making the Aero 125 more reliable:

• It's critical to keep the tires inflated at 85 lbs psi - no more, no less. The slightest air loss reduces the pressure significantly, due to the small air volume in the tire. If you under-inflate, you risk tire and tube failure. 
   
• If you weigh over 165 (75kg), you're better off buying the Aero 150 instead of the 125. Over 165 lbs, air loss increases due to increased tire temperature. In addition, the load stress on the 150 tire is only about half that the smaller 125 tire.
  
• The tires must be inflated every time they are used. Jenex recommends inflating the 125 tires to 90-95 PSI using the Fox shock pump. Generally, unscrewing the pump causes the tire to loose 5-10 PSI, getting them back down to the required 

Following these guidelines religiously should greatly improve you happiness with the Aero 125. (More details can be found on Jenex's web site on the News page (scroll down to the section "The Latest V2 Commentary").

What about people weighing more the 165 who currently on the Aero 125? Some of the newer Jenex Aero shafts have holes predrilled for both 125 and 150 wheels. Replacing wheels may fix your problems. 

If your shafts don't have the extra holes, you can get instructions from Jenex on how to get the holes created. This is NOT a do-it-yourself operation. You'll need someone with professional equipment to drill the holes for you.