Mountain Bike Reviews Forum banner
1 - 6 of 6 Posts

·
Banned
Joined
·
52 Posts
Discussion Starter · #1 ·
Ok this is rather a long story. It begins with the below wheelset that I ordered for an old Dean frame. Stupidly, when i ordered the wheels i signed up for the hope pro 2 SS 135. I did not use my brain - didnt realize that the SS signifies single speed. So now i take the wheen apart and order the right hub. all this would be easy if i was in the states but i live in Kenya and sending parts around is expensive.
I had a guy rebuild my wheel with the new hub. When i noticed that the rim was dished out toward the non drive side i asked a friend to help me correct it by simply loosening the spokes on non drive side and tightening them on the drive side. This seemed to work fine as expected and the wheel remained true.
A few days later I stopped and hopped a bit to change my direction on a tight trail. on the last hop there was a slight noise and when i pedaled one of my spokes was driven up past the rim and through my rim tape. my tubeless rims deflated .
the spoke snapped at about three inches from the hub. It appears that the remainder of the spoke on the hub side spun with the cassette and has damaged about 4 other spokes, surprisingly even some spokes on the opposite side (i was surprised that it reached).
Anyway, what I'm wondering is why this would have happened. was the spoke likely too loose or too tight? would pressure have driven it up into the rim or was this more likely the result of the cassette catching the remaining spoke length and pushing it as i pedaled up through the rim tape.
The back pattern was 2-3 cross. I weigh probably around 160 or so and while i bomb on my trail bike i try to be gentle on this bike as it is what i will use for cross country races. Is there a chance that the guy who strung it could have strung it in a way that was not intended? would taking a picture help?
thanks for any ideas. Below are the details of the wheels.
cheers, Jamie


1 x ZTR 355 Disc Wheelset white powder coat (TR31W) = $700.00
Spoke Rear 2.0/1.5 Silver Double Butted Not Rec'd over 175Lbs (3x ONLY)
Spoke Front 2.0/1.5 Silver Double Butted Not Rec'd over 175Lbs* (3x Only)
Rear Wheel Hope Pro II SS 6 Bolt Red
Rear Pattern 2-3 Cross (Not Rec'd over 170Lbs)
Nipples Rear Blue Nipples
Nipples Front Blue Nipples
Front Wheel Stan's ZTR front QR hub
Front Pattern 2X (Not Rec'd over 170Lbs)
Accessory Rear Rubber Rim Strip with Yellow Tape & Valve Installed
Accessory Front Rubber Rim Strip with Yellow Tape & Valve Installed
Weight 161 - 175
 

·
Premium Member
Joined
·
48,238 Posts
redwarrior said:
Not sure about the failure but you would need different length spokes for the new non SS hub to get the correct dish.
Yup, and related. I would guess the spoke threads had bottomed out and the spoke could not be brought up to proper tension. When spokes are under tensioned they are subjected to a huge load/unload cycle (can totally untension under load), which fatigues the spoke and leads to it breaking.

The spoke would have been sticking out of the end of the nipple, inside the rim. That, combined with the unloading and/or breaking of the spoke, let it puncture the rim strip.
 

·
Banned
Joined
·
52 Posts
Discussion Starter · #4 ·
Shiggy and Redwarrior.
thanks guys. i would make the homer simpson noise but i would likely miss spell it. i will write to notubes and ask them to send out the right spokes.
cheers, james
 

·
Registered
Joined
·
6,762 Posts
Also...

what likely happened is the spoke was under enough tension when it broke to actually shoot it up through the rim tape. Kind of like hooking a rubber band around your thumb and then pulling it tight then releasing it. The energy stored by the tensioned spoke was released when it snapped and the remainder of the spoke spoke sailed off in the oposite direction. Simple physics, action - reaction. Redwarrior and Shiggy already explained why the spoke failed in the first place.
Good Dirt
 
1 - 6 of 6 Posts
Top