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Friday, May 18, 2012

Thin Casing Tires, a Few Things You Should Know

Posted by FatBob on July 13, 2011

While testing the Niner JET9 , Calvin had first hand experience with the new breed of super light 29er tires. This seems to be an industry thrust to get lighter and lighter tires. We really try hard not to make sweeping generalizations on 29eronline. Before you make your next tire choice read this and watch the video.

Certain Tires we have ridden have not made it 50 miles before having side wall tears. Another set of tires by a completely different company had similar problems. All instances were not in particularly rocky conditions. This incident with the Schwable tires left Calvin over the bars and on the ground. We were initially scratching our heads. It seems as though a small twig got lodged in between the bead hook and rim wall. The tire went flat and would not seal back up. Besides being a pain, a flat tire isn’t typically news. The news comes when there is potential for injury. The rock step down Calvin was doing was nothing special. The tire pressure was at about 35 PSI which for tubeless tires is firm. Thin wall tires can be dangerous as they wrinkle under load. The casing seems to be so soft and thin they are prone to tears and burps.

This little twig managed to compromise the bead hook of the Schwable Tires

Now the tires cost about $85 a piece. In the event that there is a tear the tire is a throw away tire. After less then 50 miles, that is a waste of money.

Will this happen to you? Should you buy the newest generation of super light tires?

If you race and like to roll the dice then be our guest. Lets face it, walking to an aid station or fixing a flat is a nice way to lose a race. Is the 50 grams worth the gamble? That is up to you.

As a trail rider I see less of a practical application for these tires. The weight penalty for reliability and safety seems well worth the the extra weight. While supple casing are nice, and light weight is appreciated at what cost? For us we recommend a slightly heavier tire with a more reliable bead and heartier side walls. If I am spending $85 dollars on a tire I want to get a season out of it.

Be safe, and enjoy the video. We are all ears for comments agree or disagree.

Parts That Fail by: Donn O

Posted by FatBob on May 15, 2010

I stopped by Storm Endurance Sports today to replace some worn out Magura brake rotors and pads when I got some bad news about my Thomson Elite X4 stem.  My ace mechanic found substantial cracks on both sides of the upper clamp section of my Elite X4 – see photos.

This shows how tuff our 29eronline testers are on the equipment.  I have broken a few frames in my time but this is my first stem.


I just browsed through Thomson’s web site – I could not find anything about a warrantee but they did say that their stems are the industry’s strongest and in fact they state that the X4 stem is so strong that it is rated for use on Free Ride & Downhill bikes.  We are not talking about a cheap Chinese made component here; this is supposed to be best available stuff.

So how the heck can a light weight 140 lbs cross country rider break it?  I don’t know but I will have to shell out some serious green to replace it.

This goes to show you that even the best stuff needs close inspections on a regular bases – you don’t want to be the guy in the TV commercial that is hammering down the mountain and his front wheel comes off and he has to ride downhill  on one wheel.  Make sure that you do a crack check several times a year and you might save yourself some serious pain!EDIT: Most manufacturers suggest checking before every ride! Please be safe.


Sort of Good Parts Gone Bad Part 2

Posted by FatBob on November 12, 2009

This months sort of good parts gone bad is brought to you by Rock Shox and Wellgo.

In addition to the usual 2 X-9 rear derailleurs and big chain rings, this month we have a sweet Maxle rear axle and a set of Magnesium Wellgo pedals that are contributing to the failure list.

Now the Wellgo pedals are to be expected. To their credit I got a couple of seasons with them. The Niner WFO9 seems to have been their match. Time to get some heavier duty flat pedals.san lee new trail wfo linkage 025

The surprise to me is the Rock Shox Maxle rear axle. I noticed play in the rear of the WFO9 . I knew it could not be the frame. I mean come on a Niner  with rear end slop, no way! I thought maybe the Dt fr440 hub. It checked out fine. I did notice that the rear QR was pretty loose. It did not seem to be engaging at the right point. I tried to ratchet it tighter. It would not budge any further. I then backed it all the way out to see if the threads were bad. All seemed well. Tightened it back up. Same thing. The QR seemed really loose. When I tried to remove it, it was threading out really slow. That’s when it happened. Maxle rear axle failed! I have yet to call Rock Shox.san lee new trail wfo linkage 023

I guess that’s why the manufacturers tell you to check your bike every ride. I since switched to a standard open drop out. I guess that’s why its good to own both.