Repairing Bent Monark Springer Forks...

[Avanti]

I've noticed more than a few vintage Monark springer forks with bent tubes and was wondering if anyone had ever attempted a repair for this seemingly common issue. Thanks, Chris

 

[Schwinnspastic]

I have staightened steere tubes before and have spliced on sections rather try to repair
forks with tube damage...It can be done !
Mark

 

[Avanti]

I have staightened steere tubes before and have spliced on sections rather try to repair
forks with tube damage...It can be done !
Mark

What method would you use in repairing the degree of bend on the forks shown above?

 

[Avanti]

What are your fabrication skills and equipment availability? If you can make a clean cut, have welding skills and equipment, and have a donor fork for a replacement steer tube, simply cut it below the bend and weld a new piece on.
If not, clamp it in a vice as close to the bend as possible and slip a piece of pipe over it for leverage and tweak it back as close as you can.

So you would suggest seeing if the tube can corrected by bending first and it that doesn't work resort to cutting / welding a new piece?

 

[Avanti]

Well, actually I personally would cut and replace as a first step, but I'm pretty well set up for fabrication. If I didn't have a fab shop at my disposal and wasn't confident in my own welding, I would try to bend it back first.

I am set up for fabrication with 20 years experience but I would still try to heat and bend first. Seeing how there is no consensus and apparently no one on the forum has tackled straightening this particular fork, I'll go with the simpler method first.

 

[B607]

I'm trying to figure out how that happens. The fork tube is solidly supported at each end when the headset it tight. How the heck can it bend in the middle? Gary

 

[XC204]

You might be able to press it out on a shop press and some wood blocks one on the back of the bend one on each end a v cut or round grove in the blocks to spread the force . A shop might do it cheap. My homemade press in photo. With all that said I probably would cut and weld but I have done both and have the tools.

 

[mikeeebikey]

I'm trying to figure out how that happens. The fork tube is solidly supported at each end when the headset it tight. How the heck can it bend in the middle? Gary

I am of the same mind!
I had a (wonderful friend) moron grab a shot gun barrel that was on my tool box to use as a cheater bar. Really bent it!

 

[GuitarlCarl]

Slam them forks hard enough, and that's exactly where it would bend! The front fork pushes straight up on the top bracket. Just like prying a paint can lid open, the tube bends with enough force. I wonder after straightening, would you reinforce it with some tubing or bar shoved inside?
Also looks to me like the front forks are just beginning to bend below the springs...
But it might just be the angle of the photo...

Carl.

 

[Bicycle808]

If you're tooled-up to do so, I'd go with CeeBee's suggestion and just splice on a new steerer tube. While I don't doubt that you can straighten that steerer, I think it will easily bend again in a similar way before long. Might as well fix it more permanently from the get-go.

 

[mikeeebikey]

Slam them forks hard enough, and that's exactly where it would bend! The front fork pushes straight up on the top bracket. Just like prying a paint can lid open, the tube bends with enough force. I wonder after straightening, would you reinforce it with some tubing or bar shoved inside?
Also looks to me like the front forks are just beginning to bend below the springs...
But it might just be the angle of the photo...

Carl.

Jeez! And he walked away!!!
I see a curb, 30mph, and the agony of defeat!
Glad you are still with us o.p.
I would have to replace the solid fork, not attempt to get a steer tube straight.

 

[The Black Monark]

I'm trying to figure out how that happens. The fork tube is solidly supported at each end when the headset it tight. How the heck can it bend in the middle? Gary

I crashed my hotrod Monark once way back. I had just aligned and dialed-in the fork, it was working perfectly, very smooth, was checking out the action and travel, ~2mph. Standing up, I went into a dip at an intersection, the fork compressed and bottomed out on the tire/wheel, instantly flipping me over the bars. The fork was bent back ~6". After patching myself up I got the bike into the shop. The top plate had pushed the aluminum topnut off, the spring fork rods were bent a bit, and the fork legs were really bent. The steer tube was fine, no damage at all. I used a Park FT-4 and FFS-2 to put everything right and it's been fine since. I did lock the fork out after that with some thin nuts below the top plate.

 

[B607]

I'm thinking that when the crash occurred, it was the neck that bent the steering tube. Bars get forced forward from riders weight and the bottom of the stem gets forced backwards. Am I all wet? Gary

 

[Wildcat]

I'm trying to figure out how that happens. The fork tube is solidly supported at each end when the headset it tight. How the heck can it bend in the middle? Gary

The headset must have been loose at some point and they bumped into something. Otherwise the bend would be in the forks. The only other time I've seen a bend like that was when the springer was from a girl's bike that had a longer head tube so they used spacers at the bottom to make up the difference.