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· Air Force
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280 Posts
Discussion Starter · #1 ·
This is my father’s wheels that were built to be fairly strong but light weight as well. The rims are Ambrosio Neme SIS 2000 rims with 32 DT revolutions spoke and the hubs are Tune but I don't know which ones. There weren't that many miles on the wheels and my father just rides for recreation, no racing and on paved bike paths.

One afternoon he called me at school and said he was having some bad luck. The day before one of his tubulars went flat on the rear wheel and the following day the front hub broke across 4 spokes. This was at a stoplight when he just started up again. Anyone have any ideas why this happened and if anything can be done through Tune?
 

· passive/aggressive
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236 Posts
ouch. Radial lacing, looks cool fails spectacularly.

Seems that tune should warranty that though, unless as mentioned there was a no radial lacing clause.

When he started? This looks like a front hub no?

IMO stress from braking cause the hub to fail as he stopped, tension and wind up I bet. The force from moving his body on the bike caused it to break as he accelerated.
 

· Air Force
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280 Posts
Discussion Starter · #4 ·
Yes it was just after coming to a stop at an intersection and starting back up. This is the front wheel. My dad isn't that heavy, only about 185lbs or so and its on a 32 spoke wheel. I didn't this something like this would happen. If these things do happen then why us radial lacing??
 

· passive/aggressive
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236 Posts
Radial lacing creates loads towards the thinnest part of the flange between the spoke hole and the rim radial (obviously) to the hub. cross lacing change the angle of the reaction force to place much more material between the spoke head and the flange edge.

Why is radial lacing popular? Because it looks cool and is marginally lighter than cross lacing but only marginally. It can be stiffer and with bladed spokes more aerodynamic but that is probably a stretch too.
 

· Registered
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995 Posts
What caused the hub to fail was the 32 spoke hub. The more holes in a hub, the less material there is between holes. This is only a problem with radially laced wheels. Lacing the wheels heads in didn't help maters either. Bummer to hear about it, but at least he didn't eat it hard because of the hub failure.
 

· Registered
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214 Posts
Tune covers radial lacing up to 28 spokes; for 32 hole, they require crossed patterns. As pointed out above, as spoke count increases, the actual support for each spoke hole goes down. As a result, when they fail it isn't a single-spoke failure but rather a "zipper" failure like you see here. Larger flanges, flanges with the holes further recessed from the edge of the flange, and lower spoke counts are the three basic ways to address this problem.
 

· Air Force
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280 Posts
Discussion Starter · #10 ·
twinkles said:
Bummer to hear about it, but at least he didn't eat it hard because of the hub failure.
He actually didn't get going at all and the rim hitting the brake prevented him from moving forward. But he did have a 2 or 3 mile walk to the lbs.
 

· Air Force
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280 Posts
Discussion Starter · #12 ·
So is it worth even trying to contact Tune for a warranty? How is there customer service and do they do replacement at cost?

Thanks for all the info. This just suck because my dad thought he was getting a strong light wheel for the money, if only they were 32 three cross like my wheels.
 
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