expatbrit

So -- Trek X-Cal. Blowing spokes at a great rate ON road, with a 195lb rider.

Fixed a couple, shop said 'we'll warranty the wheel'. Great, I thinks. That sounds good.

So the 'warranty' wheel turns out to be a StaTru rim, though on a shimano hub. Original X-Cal wheels were Bontrager Mustang TLRs.

I've no real basis for comparison; shop claims the new rim is 'better' and 'sturdier'. Not too worried about weight, but a quick google suggests that StaTru rims are pretty Cheapy McCheaperson?

Did I get stuffed?

seat_boy

I would have expected that they would just retensioned the wheel.

I've never heard of StaTru rims, so no opinion on them.

vredstein

Bontrager Mustang TLR is a tubeless-ready rim, much more expensive and versatile than a comparable non-tubeless ready rim. Mountain bikes with tubeless ready wheelsets are a big upgrade and upcharge versus an identical mtb without tubeless-ready wheelsets. If the replacement rim isn't tubeless-ready, you got STUFFED!

Not sure why they didn't provide an identical replacement. You want to make sure they have properly trued AND tensioned the replacement wheel. I'm willing to the bad wheel was a rear disc wheel that was never removed from the bike, trued, and tensioned during the initial build. Because it's disc brake wheel where rim brake rub isn't an issue, many shops don't bother truing the wheels. They forget that high, even tension is needed for the wheel to be strong regardless of whether it's rim or disc brake. Low, uneven tension=weak wheel.
There's no reason why a properly tensioned wheel with a good quality hub and rim (such as the Mustang) should break if ridden on the road and not abused.
Look at the wheel. You'll see pairs of spokes cross on both the right and left side of the wheel. Pluck each of the spokes on a pair. They should emit the same tone-"ting/ting". If you hear a "ting/tong", you know one spoke is at a higher tension than it's crossing companion. When subjected to a side load, such as when cornering, the spoke at the higher tension takes more stress. High enough stress and a big difference in tension will result in the rim bending, the high tension spoke cracking the rim at the nipple eyelet or any number of other modes of failure.

expatbrit

That's kinda what I figured. Oh well. I'm not running tubeless right now, even though I know the wheels were ready. I don't know if the new ones are or not -- wanna bet 'not'?

That's what I thought. Maybe I can just get the wheel re-tensioned (elsewhere) in town. It's a good wheel, and then I'll have a spare.

You're correct; it's a disk wheel. (Unsuprising on a mid-range MTB, of course).

Thanks! I was getting them breaking at the hub. I'm heavy, but not THAT heavy and I rarely even dropped off kerbs, let alone jumps and the rest that bike should take fine..

cpach

One thing to be aware of is that the remaining spokes may be fatigued from being detensioned. You might consider having the wheel rebuilt with new spokes, at least on the drive side. You could take the opportunity to upgrade to butted spokes which would also improve your wheels reliability.

195lbs should not be breaking spokes on any stock wheel.

vredstein

You really should confront the shop that replaced the wheel. Find out whether the new wheel is tubeless ready. If not, don't let them tell you you can concoct some "home-brew" solution to make them work. A good deal of the cost you paid for that bike was because it had tubeless-ready wheels. If you decide to sell the bike, it's worth much less without them. Just because you don't use tubeless now, doesn't mean you won't in the future, and if you decide you want to, you'll have to pay a hell of a lot to get the wheel replaced. If the shop doesn't make it right, it's worth your time to contact Trek directly and tell them the story. Please pursue this. I work for a store that sell Trek. We need to police ourselves to make sure the brand's rep doesn't degrade because other shops aren't doing right by the customer.

vredstein

Spokes break at the hub, at the spokes elbow when they aren't tensioned correctly. This is the area where the spoke will flex, just like bending a paperclip back and forth until it breaks. The heavier the rider, the more spoke tension is needed to maintain the wheel's strength.

Grimlock

Is it possible the wheel you're using now is a loaner wheel while they wait for a warrantied wheel from Trek? You should go back to the shop and talk to them. I'm sure they have better explanations than we do. Do keep us posted though.