Did it unthread? Strip out because of not being fully threaded? Other?

 

I heard a noise on a ride and thought I had broke a spoke or cracked a rim. The next day I applied the front brake and started checking my headset for creaking with the front brake applied. I looked down and could see that the dropout was moving front to back and rocking on the end of the stanchion.

It had not failed completely, If I had ran it for another ride I would have lost the dropout off the end of the stanchion.

Bunny hopping water bars on a fire road at 40mph and losing a dropout is not on my list of things I want do in life.

I contacted Wren and they said this is how they are made at the factory and that if I requested another fork this is how they are all made. 4 threads of engagement and epoxy to permanently affix.

There was no surface prep, just glossy paint with the epoxy flaking off. I have scuffed the paint off and loctited it together, 48hr cure time and heat cycling. I took it on one ride with no creaking, but babying it. My rear hub died and am waiting on Onyx, or I would be continuing to evaluate the fix.

Wren advised me that they had incorrectly told me that a 220mm rotor was acceptable and that was likely the cause of the failure. They told me they are in communications with the engineers in manufacturing but the cost is too high to fix it by changing the dropout design.

They know its an issue, its not likely to be changed, use a small front brake rotor, dont go fast, dont ride hard.

Its a great feeling fork that needs to be fixed but I cant wait for it.

I have a Mastodon 140 Pro ext on the way with IRT valving. I just dont want anyone to die using this fork.

 

Aren't the stanchions keyed into the uppers? How did they back out?

 

This is the dropouts

 

anchoring brake torque into to a threaded assembly held with failed epoxy

yeah, I'd not ride that

 

Yeah I am not liking it... even with the new Stanchion assembly they sent me. I cleaned all the old epoxy off but I found that if I thread it all the way down so that it butts up into the bottom of the stanchion I have to back it off nearly half a turn to align the dropouts and the stanchion keyway. I feel that its all on borrowed time. I know it needs to be forged material to be light but maybe I can weld up something that clamps and threads with weight penalty.

Its a very dangerous failure, not at bad as the crown failure a couple years ago but pretty close.

 

I assumed those parts are welded or have some other permeant connection.

So they acknowledged the problem and said due to cost they won't fix it?

Maybe they should Google "Pinto" and find out what happened out to a company that made a car with a flaw and documents showed they knew about the issue but decided not to spend the money on the fix since lawsuits would be cheaper.......

 

That is what I was told in my last communications with Wren. They have since failed to communicate and update me as they said they would do after talking to their engineer.

They dont owe me anything... I liked their product immensely until it failed. I would install the new stanchion but it does not have enough of a safety factor for me to ever trust it again unless the dropouts are redesigned.

 

It would seem that it relies almost entirely on epoxy, since the key ways seem to dictate the position of the stanchions in the dropouts? In other words, they can’t be tightened?

I can’t imagine Marz shivers and other inverted forks were like this. I’m sure they fully tightened down.

The threads don’t look very deep either?

 

It would seem that it relies almost entirely on epoxy, since the key ways seem to dictate the position of the stanchions in the dropouts? In other words, they can't be tightened?

I can't imagine Marz shivers and other inverted forks were like this. I'm sure they fully tightened down.

The threads don't look very deep either?

You are correct, the threads are shallow, you cannot tighten it down and even if you could you would only gain one half rotation because they dont manufacture the threads tall enough on the stanchion. The way the stanchion and drop out interface only allows approximately 4.5 rotations and then must be backed off to index the keyway and the dropout/axle alignment.

Because of this design they apply epoxy to the bottom of the stanchion where the air valve is and the bottom of the inside of the dropout. This flat is friction held in place by an o-ring and is supposed to help support the stanchion.

Please inspect your forks daily, if I had not caught my dropout rocking....You guys all know what could happen. Wren should issue a bulletin to all its suppliers so that customers can be notified.

 

Home - SaferProducts

www.saferproducts.gov

Safety related complaints can be made at the above link.

 

Just have to wonder if they can afford the settlement of a liability suit... I think that might be a few million more than the 24k they "cannot afford" to stay out of court after someone is severely maimed by piss poor "engineering". Evidently, Wren cannot afford to do a little prevention, how on earth are they going to pay for airlift of a rider to the E.R. let alone, the cost of the E.R. visit??

The ambulance chasers will freak out!

 

Pavement+slicks+e-bike+220mm disc+40mph= you need a motorcycle fork!
That said,all forks should be designed to handle this kind of loads without failure,as a car mechanic I would never send out anything left loose with epoxy or lock tight doing structural support. Unfamiliar with Wren internals but couldn’t the dropout be tightened fully then jigged up to machine the grooves in the proper orientation?

 

Pavement+slicks+e-bike+220mm disc+40mph= you need a motorcycle fork!
That said,all forks should be designed to handle this kind of loads without failure,as a car mechanic I would never send out anything left loose with epoxy or lock tight doing structural support. Unfamiliar with Wren internals but couldn't the dropout be tightened fully then jigged up to machine the grooves in the proper orientation?

It definitely could be done this way or they could just make the drop out half an inch taller and put a cinch/pinch bolt on the back side. I recommend everyone inspect their fork. Hold the front brake down and grasp the brake side drop out and gently rock the bike to check for play. A little bit of preventative maintenance and inspection goes a long way.

Mastodon on the way.....

 

Frankly, with four 1.25 pitch threads holding an aluminum part to an aluminum stanchion, it would be a wonder if it didn't let go with far lighter braking and riding. The brake torque is significant and there could have been a better fastening method employed in a critical area. This is a quality item that bills out for a premium price point, we as users and owners of such products are entitled to reliability and safety being job ONE... I would expect this from some low end product but it is unacceptable at any price point, period.

Wren, get your head out of God knows where and do your bloody job, seriously! Serious bodily harm or death is going to be on your hands if you cannot offer a product with honor and integrity. I am thinking that 24,000 bux is not going to be a down payment for an accidental death and dismemberment claim. Again, Wren, try being honorable and use integrity in everything you do and offer.

 

Amen to that... It is so close to stellar product that could rival the market. As for now my bike sits waiting the Mastodon and an Onyx hub.

Biktrix has been stellar in their support of me....Replacement fork, new wheel and hub shipped out to me. They are getting to the bottom of this.

 

I spoke with Wren today and they are waiting on the factory engineers to come up with a fix or to evaluate the problem...

 

It could well be that the design is okay but Wren (or it's vendor) is failing in the manufacturing processes. Epoxy gets used a lot in aircraft, even for structural items. But for it to be effective the choice of epoxy matters and the prep, application, and cure processes have to be done to spec. I'm pretty certain that applying epoxy over paint isn't remotely following the prep instructions (likely a type of acid etching), which probably makes the application method and cure process they are using irrelevant. So this could well be a self-inflicted wound by Wren.

Also, that he first said a 220 rotor is okay but now says it really should be 203 max makes it look like Wren really had no idea what the safe operating limits are.

Unfortunately I have a Wren on my El Gran Jefe tandem so I'll have to watch this. Fortunately it gets transported with the front wheel off so I'm always handling the stanchions.

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

The stancions on my Wren 150 are anodized as opposed to painted however, that needed to be glassbeaded appropriately prior to doing a hokey, glue it together move.
Now, for the threaded aspect... They could have easily used a longer threaded section and resolved a prollem before it became a prollem, just sayin'.
Perhaps aircraft engines falling off has sompin to do with epoxy and four threads of a couple bolts letting go at the most opportune time.

 

Deleted dupe

 

Maybe I should give some more context to my reply above.

If I'm right, and Wren's design philosophy is sound, and your unit got shipped in violation of their QC detection, and you're not getting reasonable communication, then I'd be willing to bet a chain-of-command is being either accidentally or purposefully ignored. I'm sure that there's someone in the org who would REALLY want to know about glue up failures and would be REALLY pissed off if they received the info very late in the game.

I guess what I'm getting it is that I usually want to give non-conglomerate manufacturers the benefit of the doubt. Perhaps in other professional industries, but I've been in some of those meetings if you get me. Many were competent, and the times where competence was absent, well... I could have used some ear plugs. Men who I would otherwise have thought were incapable of yelling.

One thing I can almost guarantee is that Wren's engineers are intelligent. Whether their orders are carried out to 100% satisfaction on the assembly floor is another matter, and I would ask you to apply Hanlon's Razor to the specific individuals responsible, whoever they might be. I have never met a lead engineer who deliberately designed something bad, is what I'm getting at.

 

I thought Wren was mainly selling generic Chinese parts, their fork being a modified version of "the fork of many names". Do they really have engineers, or do they rely on the company they order from?

 

Should I even consider the 23 Wren Fat fork over the Mastodon? I just can't seem to find any new reviews or updates on it and IF past problems have been addressed. I like the look and specs on it and the fact that it will fit a Cake Eater, but not if it will give me problems, especially in colder conditions. Anyone running one in the winter with success here? Thnx!

 

There is something new on the horizon at Wren, its being tested by a buddy. It may be significantly better than a mastodon, but since its not out yet, i get the Mastodon and wait.

 

Sounds good Jayem. Or I could just stay with the carbon rigid fork and wait. Keep us posted on the new Wren in the works too!

 

I was an early Wren adopter, so I was one of the first to have a bad fork, mine was really dangerous: the steerer tube loosened, allowing the fork to turn regardless bar position.

They replaced the fork, but I got out as soon as the Mastodon was released.

Wren is not high end stuff, anything innovative from them is not gonna be worth waiting for, just saying 🙄

 

Incidently the Carver Carbon Beast forks, I've seen on AliExpress under their generic brandings, both the original QR version and the thru-axle version. And their various titanium forks, handlebars, posts and frames can be bought direct from Ali also. Pretty much the same goes for all of Wren's stuff. The fact they don't actually manufacture anything, simply rebrand chinese made parts is likely why they weren't forthcoming with an answer about the crappy dropout assembly that started this thread. Unless they have someone on staff fluent in mandarin, its probably hard to get answers out of the chinese engineers.

 

Don’t be such a sissy I have absolutely ridden the piss out of mine it’s just fine maybe the had to refill the gluing/epoxy machine on your fork. Or it was the first or last in the run possibly. I have had my juggernaut up to 53mph* (down a 7% grade) towing a burley coho xc trailer.

 

I have had my juggernaut up to 53mph* (down a 7% grade) towing a burley coho xc trailer.

Are you sure those numbers are correct?

 

Had a few a long time ago and had a leg come unglued. Never buy those crap forks again.

 

Does anyone know if this issue has been resolved? Atleast there hasn’t been new cases on this forum.

 

Here in AK they are fairly rare, there's a few of them, but even fewer are ridden hard. The V3 Mastodon goes to 160mm of travel and there's no good reason for the Wren.

 

Just bought a Wren. Price was pretty much the same than Mastodon. 780€ vs. 820€. To my understanding Wren has a better cold weather performance.

 

I've had one for the better part of 10 years now that I run on my old custom steel fatbike that uses a 135mm front hub. I ride it on my Michigan XC style singletrack trails with zero concern. 🤷‍♂️

 

I don't know if it is the same fork as discussed in the thread, but I saw one Wren fork in the ITI this year, and the guy riding it seemed happy with it.

Tyson Flaharty on Instagram: "Off tomorrow at 2 pm for the 2025 addition of the Iditarod Trail Invitational! This year the goal is McGrath approximately 300 miles from the start. From all the crazy weather in Alaska this year the trail is looking fast and fun. Tracking on https://trackleaders.com/iti25f.php follow along! Trying some new gear and hoping for the best! #iditarodtrailinvitational2025 @itialaska @wren_sports @apocalypse.designak @9zero7bikes #fatbike #alaska #iditarod #itialaska #alaskawinter #gotime"

141 likes, 6 comments - tyson.flaharty on February 22, 2025: "Off tomorrow at 2 pm for the 2025 addition of the Iditarod Trail Invitational! This year the goal is McGrath approximately 300 miles from the start. From all the crazy weather in Alaska this year the trail is looking fast and fun...

www.instagram.com

 

I don't know if it is the same fork as discussed in the thread, but I saw one Wren fork in the ITI this year, and the guy riding it seemed happy with it.

Tyson Flaharty on Instagram: "Off tomorrow at 2 pm for the 2025 addition of the Iditarod Trail Invitational! This year the goal is McGrath approximately 300 miles from the start. From all the crazy weather in Alaska this year the trail is looking fast and fun. Tracking on https://trackleaders.com/iti25f.php follow along! Trying some new gear and hoping for the best! #iditarodtrailinvitational2025 @itialaska @wren_sports @apocalypse.designak @9zero7bikes #fatbike #alaska #iditarod #itialaska #alaskawinter #gotime"

141 likes, 6 comments - tyson.flaharty on February 22, 2025: "Off tomorrow at 2 pm for the 2025 addition of the Iditarod Trail Invitational! This year the goal is McGrath approximately 300 miles from the start. From all the crazy weather in Alaska this year the trail is looking fast and fun...

www.instagram.com

I talked to him directly about it and the thing was nearly locked out with about 2" of suspension, not working as intended. He did it for shits and giggles...much like I race the Foes at Blue Booty in the winter. I think the story was someone gave it to him. It didn't "fall apart", but it wasn't working right either.

 

Just received mine. Rebound dampening is ok in my opininion. It looks like a DNM fork. Might be the same factory that produces them.

 

oh to bad really after this fork mostly for the wrack option and easy maintenance, any option any one know of that is similar inverted or not but got option for (suspended) fork mounts/wrack, home mechanic friendly and can handle big loads on the braking caliper ?