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DT Swiss 370 LN Ratchet hub blew up?

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HighsideClyde

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Discussion starter · #1 ·
My new bike has less than 20 miles on it. Came with the Roval Traverse wheelset which uses the 370 LN Ratchet rear hub. I took a strong pedal stroke and nearly wiped out because it felt like the hub just completely gave out -- thought I snapped a chain at first. I didn’t take it apart because I want the shop I bought it from to handle all of it since it will be handled through warranty, but it just feels like all the teeth sheared off the ratchets… which would be hard to believe honestly. When pedaling forward, it grinds like it wants to engage, but can’t handle even the lightest possible pedal stroke. It also still makes a normal hub sound when back pedaling.

Anyways, just wondering if anyone has heard of or encountered any major issues like this with that hub. I was under the impression these hubs are very durable, but now my faith has been shaken. Anyone know how warranty will work? Will it be through Specialized or Roval?
 
#2 ·
It takes a lot of force to shear off the ratchets. I never heard of that, especially on an new set of ratchets. For me it sound like there is too much grease or anything between the ratches, so that they can't engage.
If the wheelset is new, just take it to your dealer.
 
Discussion starter · #4 ·
Nakkipata said:
It doesn’t have a 370ln hub, only the freehub system. The hub itself is a Roval hub and it is common for the hub threads to fail which holds the ratchet system. Otherwise there is just too much grease.
Click to expand...
So you’re saying that the internals are basically just spinning around in a stripped out hub shell? I had really wanted to take it apart myself, but decided to let the shop do everything since I didn’t want to interfere with any warranty process. I’ll ask when the shop calls what they found... maybe they can send me a couple photos.
 
Discussion starter · #5 ·
wheel builder said:
It takes a lot of force to shear off the ratchets. I never heard of that, especially on an new set of ratchets. For me it sound like there is too much grease or anything between the ratches, so that they can't engage.
If the wheelset is new, just take it to your dealer.
Click to expand...
I suppose that it is possible that there is too much grease and it’s preventing the ratchets from mating with each other. Just seems odd that when the issue occurred it wasn’t gradual… it happened all at once like a snapped chain, which led me to believe it was something more catastrophic. Time will tell! I’ll report back what the shop finds.
 
#6 ·
HighsideClyde said:
So you’re saying that the internals are basically just spinning around in a stripped out hub shell? I had really wanted to take it apart myself, but decided to let the shop do everything since I didn’t want to interfere with any warranty process. I’ll ask when the shop calls what they found... maybe they can send me a couple photos.
Click to expand...
Yes, this or too much grease. With those hubs it is most likely the stripped hub shell but your lbs will find out. Stripped hub shell cannot be fixed.
 
Discussion starter · #7 ·
Nakkipata said:
Yes, this or too much grease. With those hubs it is most likely the stripped hub shell but your lbs will find out. Stripped hub shell cannot be fixed.
Click to expand...
If it truly is a stripped hub shell, then I would be weary of just getting a replacement under warranty. Should mine that broke not have passed QC, or is it a fatal design flaw which is likely to strike again? I wonder if there is any chance they would warranty it with an upgrade
 
#9 ·
HighsideClyde said:
If it truly is a stripped hub shell, then I would be weary of just getting a replacement under warranty. Should mine that broke not have passed QC, or is it a fatal design flaw which is likely to strike again? I wonder if there is any chance they would warranty it with an upgrade
Click to expand...
It isn’t anything unusual with dt swiss hubs but more common with oem hubs that uses dt swiss freehub internals.
 
#10 ·
If you can't get an upgrade, just sell the wheel you are given.

Strange, sorta related story.....years ago, I stripped out the rear on a Rocky Mountain Instinct. RM decided to cover it under warranty, which was nice because I think I was officially out of warranty. They ended up sending a full wheel set (front and rear) however, they were a different model (narrower and XC-ish) and they weren't even compatable with my frame. Oh well, I sold them to pay for a new rear wheel of my choice.
 
#11 ·
I had that happen and got a new wheel from warranty, the replacement wheel hub has survived, except the bearings **** the bed after a couple of months, and the rim dents easily and goes out of true constantly. Bearings apparently are a wear item and were not warrantied, but were easy to knock out and replace. Specialized has a two year no fault warranty on the wheels, and lifetime materials and workmanship. I figure I will run these to the end of warranty, and then if they break get a better brand. Truly shitty wheels.
 
Discussion starter · #12 ·
Update from the bike shop!

I talked to the head mechanic. He said the hub shell is not stripped out (but has seen that recently on a lower spec Specialized Stout hub). There were some metal shavings inside and the faces of the 18t ratchet mating surfaces didn’t look great. When just mating them up by hand they seemed to mate up and engage ok, but when reassembled inside the hub for a test the rings were obviously not engaging with each other correctly… we were kinda wondering if the pressure from the springs was too weak to really press the two rings together with enough force as well?

He put in a 18t rings and springs kit that the shop had in stock and it was all good to go after that.

He also called DT Swiss and they said that they were really surprised to hear about that issue with the rings. Gonna try to warranty through Specialized and see if they will upgrade the wheel/hub, but Specialized will probably pass the buck to Roval or DT Swiss.

Will post again when I have more news!
 
#13 ·
As follow Clyde, feel your pain but thats why I only use the DT350 with ratchets. Have killed 3 ratchets in my lifetime - 2 came from overgreasing and 1 came from faulty spring. After learning my lesson, I handle cleaning and greasing the hub instead of the bike shop (plus is super easy). Always carry extra 18t ratchet in my pack so if it happens again on the trail and swap out in 5mins without having to walk out.
 
Discussion starter · #14 · (Edited)
Went for my first ride since the initial hub incident today and everything worked great. Upon returning home I decided to inspect the ratchets just because. The photo below shows what I found. The part circled in red shows that some piece of metal sheared off some how, and then I suspect it also caused the gouges circled in blue. I also suspect that the sheared piece of metal made its way in between the ratchets and caused them to not mesh correctly. That would explain the metal shavings the mechanic found. Shared photos with the shop, and hopefully will receive a new hub or wheel through warranty.

Image
 
Discussion starter · #18 ·
OttaCee said:
Looks destroyed

View attachment 2018707
Click to expand...
Wow good eye! I took it apart again just now and took another photo. Interestingly, the ratchet sits in there just fine, but definitely not an ideal situation. Still waiting on word from the shop for a warranty solution.
 

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