[RussJ]

Ah, that's nice that they can handle a bit more torque. Most stems are calling for 5 at the max. You guys recommend going for a little lower, say 4.5 to 5, and seeing if that's sufficient?

Just need to make sure your bars are tight without exceeding 6Nm. Thanks!
Russ / Wren

 

[eri]

Stem arrived Saturday. 90mm really is only 84 grams. Really smooth finish inside and out, whole thing is cold like metal but light like plastic and sculpted like liquid.

I'm sorry to see the mighty chromag go, loved its graphics and interesting machined finish.

The -6 degree drop gets the bars as low as brake lever clearance allows.

What is surprising is how much I notice the 125 gram weight reduction. Used to be the back of the bike felt light, the front heavy, now it feels really balanced.

My impressions: weight reduction feels like a big deal. Climbing I noticed the stem is not nearly as stiff as the chromag, but not noodley enough to matter. Mainly small sharp shocks are damped.

 

[kylepeveto]

I just bought one of these Wren stems. I’m kind of afraid of using it. How are they holding up over the long term?

 

[scant]

2years old, no issues for me

 

[GRPABT1]

I ordered a 40mm and it's on the way. They assured me it's certified for DH use so that's good enough for me on my enduro bike.

 

[MountainBored]

My 50mm stem is flawless after 1.5 years. I send it down lots of rocky trails and have crashed several times. No worries about the stem.

 

[eri]

Update after almost 2 years: stem will no longer hold, headset loose after each ride. Cleaned fork steerer with acetone, etc, but stem just won't hold the headset at max recommended bolt torque. Stem doesn't move side to side but slides upwards during rough descents. Top and bottom edges and parts of the inside of the wren show worn paint. I put the chromag back on and it is solid as a rock. I might try harder to get it to hold - ideas?

I'm 180 (but carry 10-15 lbs on rides), ride lots of steeps with roots and 1-2' steps, hardtail with 120mm fork.

 

[phlegm]

Update after almost 2 years: stem will no longer hold, headset loose after each ride. Cleaned fork steerer with acetone, etc, but stem just won't hold the headset at max recommended bolt torque. Stem doesn't move side to side but slides upwards during rough descents. Top and bottom edges and parts of the inside of the wren show worn paint. I put the chromag back on and it is solid as a rock. I might try harder to get it to hold - ideas?

I'm 180 (but carry 10-15 lbs on rides), ride lots of steeps with roots and 1-2' steps, hardtail with 120mm fork.

Carbon paste? Might be just enough to allow it to hold at recommended torque.

 

[thesmokingman]

Update after almost 2 years: stem will no longer hold, headset loose after each ride. Cleaned fork steerer with acetone, etc, but stem just won't hold the headset at max recommended bolt torque. Stem doesn't move side to side but slides upwards during rough descents. Top and bottom edges and parts of the inside of the wren show worn paint. I put the chromag back on and it is solid as a rock. I might try harder to get it to hold - ideas?

I'm 180 (but carry 10-15 lbs on rides), ride lots of steeps with roots and 1-2' steps, hardtail with 120mm fork.

Are the bolts stretched out? It reads like they are no longer holding. The wren is built very weight weenie so I'd lean towards more xc than chunk with it.

 

[Taildragger]

Sounds like a 'star nut' issue, did you check that?

 

[phlegm]

Sounds like a 'star nut' issue, did you check that?

That's a good point. I'm curious if the replacement chromag eventually loosens too? If so, it is that nut/expander. If not, something else.

 

[thesmokingman]

The star nut is for back up, its not intended to hold it together indefinitely. The stem still has to perform its function whether there's a star nut or not.

 

[phlegm]

The star nut is for back up, its not intended to hold it together indefinitely. The stem still has to perform its function whether there's a star nut or not.

That's correct, but if the stem "grip" is marginal, the starnut/expander could also be failing. Either way you have a potentially dangerous issue.

 

[thesmokingman]

That's correct, but if the stem "grip" is marginal, the starnut/expander could also be failing. Either way you have a potentially dangerous issue.

Poster has swapped the failing stem so no issue. I'm just curious whether the bolts are stretched or the stem is fatigued. These wren stems are very weight weenie man, the stem bolts are stupid lightweight (M3) so I wouldn't be surprised if they gave up.

 

[eri]

Well... chromag has lasted now for more than 7 hours of pounding and headset is still nice and tight.

Starnut: like others have said it shouldn't be involved in holding stem in place, its for setting the bearing load.
M3 Bolts: they are small, but they are steel and they laugh at that thin aluminum. I very much doubt the steel bolts are aging or stretched.

The wren stem... to my eyes it looks 'fine' in the glare of the kitchen lights. The part that grips the steer tube is greatly hollowed out, the chromag has a full radius to grip the steer tube.

When I tighten the wren onto the steer tube it sort of seemed to deform, to my eyes, in the dark garage.

On both stems I have about 2mm of gap between top of stem and top of steer tube. Maybe this is the sort of stem that needs a spacer on top of the steer tube, so has a full steer tube to grip?

Well... the wren is super light but I'm surprised how much more I like having a tight headset and solid feel at the bars. Just a small amount of play at the headset was making me consider upgrading to a float 34, but with a tight headset I'm now really happy with the 32.

I'm sort of wondering if sanding steer tube or stem with a course grit sandpaper might improve the grip and get the stem working again, but now that I've rediscovered a stiff stem I have stopped really caring.

Prolly for the best.

 

[phlegm]

...

I'm sort of wondering if sanding steer tube or stem with a course grit sandpaper might improve the grip and get the stem working again, but now that I've rediscovered a stiff stem I have stopped really caring.

...

I mentioned carbon paste above, which would achieve the same thing, however I've never had to use it on the steerer/stem interface.

 

[RX93]

I ordered a stem from them and they're back to using T20 screws.

 

[thesmokingman]

I ordered a stem from them and they're back to using T20 screws.

I was referring to the thread pitch, but yea still teeny sized bolts T20 included. From the bikeradar review, which apparently means they still have not improved the strength of the bolts.

"To get right to the point, in my opinion T20 bolts just don’t cut it. Fortunately, Wren seems to agree. Before I had even voiced my concerns, they had already made a running change to T25 Torx bolts. Problem solved. That should make it a lot easier to install and adjust, not to mention ensure that you have the right tool on your multi-tool."

 

[GRPABT1]

On both stems I have about 2mm of gap between top of stem and top of steer tube. Maybe this is the sort of stem that needs a spacer on top of the steer tube, so has a full steer tube to grip?

This. I wouldn't try and run such a weight weenie part without giving it the best chance it can to work, pretty sure no stem manufacturers would recommend running the stem proud of the top of the steerer tube. I always cut my steerers with plenty of extra height, if anything it helps for resale or potential frame upgrades.

Carbon paste on the steerer and a little grease on the threads and under the bolt heads is also a good idea.

 

[phlegm]

...

Carbon paste on the steerer and a little grease on the threads and under the bolt heads is also a good idea.

FYI, the opposite combo of grease on the steerer and grit on the bolts is bad.