can a curved stem be rebent?

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Peter Stock

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Sep 23, 2025, 1:41:04 PM (6 days ago) Sep 23
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I have a Pocket Rocket with a too long curved stem riser.
Has anyone thought of or tried having a stem riser rebent, to adjust the Reach or Stretch?
I expect the paint would be trashed but I also think it could b be doable. Maybe once (more than once might compromise the strength)


Peter Stock
Toronto, Canada

John Thurston

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Sep 23, 2025, 2:41:43 PM (6 days ago) Sep 23
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While I'd be ready to accept re-bending chain stays, and (in some cases) fork blades, in both of those cases there are two of them sharing the load. I might be ready to accept re-bending the stem riser, but I'd expect it to be re-formed on an appropriately shaped and supportive mandrel. I would not accept re-bending it by someone who says, "I have a press we can use. Hold my beer."

And given the stem-riser is a single point of failure, with high consequences in the event of failure, I would not seriously consider any of those options. I would contact Bike Friday and have new stem-riser made (which I have done three times since taking delivery of my Llama in the 90s) . Of course, my decision is based on my budget limits, my hesitance to risk my teeth/chin/shoulders, and my location on the southern* side of the US/Canada border. I don't know where your budget/risk/tariff tradeoffs place you.

* Actually 'western' side, but that confuses a lot of folks

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John Thurston
Juneau, Alaska

robert clark

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Sep 24, 2025, 11:09:07 AM (5 days ago) Sep 24
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A friend in same town as bike friday (building Danish  style  cargo  bikes)
 had a tubing bender to deal with 4130 high strength alloy steel 
It was on a heavy steel  post anchored into the concrete floor...  

What tools are in Your shop, Peter?

robert clark

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Sep 24, 2025, 11:24:39 AM (5 days ago) Sep 24
to Bike Friday Yak!, robert clark
I got a custom made  handlebar mast msde  for my Llama..
 the insert, the bottom  end  OD = 1 inch , the ID of 1.125" tubing.
as a result the original adjustable height folding one in aluminum is available
It takes regular threadless headset type stems at the top... 
the wedge that secures it into the fork steerer  is accessed  when the fold hinge is open.

Doug Litchfield

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Sep 24, 2025, 1:18:46 PM (5 days ago) Sep 24
to robert clark, Bike Friday Yak!
I had a similar problem, having bought a second hand NWT from someone considerably taller/longer than me.
The price was right and "I have always wanted one."
The one piece and curved at the top unit, like I suspect yours is.
I had a friend with a pretty nice home workshop.
We cut the steer tube just before the tube starts its curve toward the handlebar clamp (at least we thought we did!), cut a relief channel a la seat tube,
and I used a BMX style seat tube clamp as extra protection.
I have used both a 1 1/8 quill stem adapter with standard 1 1/8 stem, and a 1 1/8 faceplate quill stem depending on handlebar choice. 

Doug Litchfield
Tucson, AZ.

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Geof Gee

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Sep 27, 2025, 10:42:39 AM (2 days ago) Sep 27
to Peter Stock, Bike Friday Yak!
Before you do anything like that, have you checked with Bike Friday how much a new mast and/or new swam stem would cost?

When I last checked, I remember the prices being very reasonable.  

-G
Arlington, VA

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robert clark

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Sep 28, 2025, 12:40:53 PM (yesterday) Sep 28
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the process is  get the adjustable one.. ride and decide 'best' then mail it back.
witout changing any of the ideal dimensions...  they make a new curved one from that setting.

Peter Stock

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Sep 28, 2025, 1:03:39 PM (yesterday) Sep 28
to robert clark, Bike Friday Yak!, geo...@gmail.com
I actually have an adjustable "fit" stem. (though I am not sure if the base fits this steerer)
I can figure out what fit I want. indeed I know from another bike the bar position I want. 

I am just asking if anyone knows if I can rebend an existing stem to that position.

Given this stem is fairly uselessly (to me) I guess I might as well find someone - a frame builder would seem the best choice. or a pipe worker - to try reshaping it and see what happens.

peter stock
toronto canada
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