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Is it possible to repair a damaged seat tube top?

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Is it possible to repair a damaged seat tube top?

Old 08-29-22, 04:09 PM
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Is it possible to repair a damaged seat tube top?

Hello,

We just bought a Electra Townie E-bike and I (ignorantly) raised the seat post above the minimum insertion line (I couldn't see the faint etched line and again, ugh, ignorant).

When I hit a bump the excess pressure due to leverage from the seat post bent the aluminum frame at the top of the seat tube.

I wanted to include photos but just learned I must post 10x first.

My question is: can this be repaired, and if so, where might I look to find such a (special) shop? I live on the San Francisco peninsula.

I'm hoping some metal-shop equipped bike specialist repair place could cut the damaged top part off the seat tube off - perhaps 1” or 2”, and weld a replacement top on. The bike is aluminum so I realize this may be a long shot. : (

If I can't repair it, note I can still insert the seat post into the tube top, but it just doesn't go down very far (maybe 2"?). Might I be able to smash it down into the tube with a lot of force, and then use some sort of tube clamps to secure it in place...? Maybe? I'm no mechanic or engineer but want to exhaust any possible ideas before buying a new bike.

Thank you! : )
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Old 08-29-22, 04:36 PM
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How on earth can anyone know when you haven't provided any photos? Pretty much anything can be fixed, it's just whether it's worth it or not.
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Old 08-29-22, 04:47 PM
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You are correct.
However, although Bike Forums "Tips for new posts" recommends photos be attached when appropriate, when I attempted to do exactly that for my post (attach clear photos of the problem), a message popped up: "you cannot attach photos until after you have posted at least 10 times."
I've written to them recommending a correction to their "Tips".
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Old 08-29-22, 04:54 PM
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Originally Posted by quasta
You are correct.
However, although Bike Forums "Tips for new posts" recommends photos be attached when appropriate, when I attempted to do exactly that for my post (attach clear photos of the problem), a message popped up: "you cannot attach photos until after you have posted at least 10 times."
I've written to them recommending a correction to their "Tips".
Ignore the response and don’t even give it the dignity of a explanation. There should be someone to help you with your concern or offer to host the pictures. There is a small contingent of forum members who like to scold people and lord their deep knowledge and experience over them. Never really understood the deep knowledge and experience required around a bicycle, even the most complex issue can be explained and instructions required with a quick YouTube search.
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Old 08-29-22, 04:57 PM
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If it were me, I would take it to the shop where it was purchased. My guess is they have seen it all before, and might be able to fix it by bending it back, perhaps by partially inserting the post and then using that to straighten the tube. Who knows, it could be a warranty issue?
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Old 08-29-22, 05:02 PM
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Thank you, Atlas Shrugged. I appreciate the respectful note. Like all forums, there are mix of folks and perspectives.
I would indeed be grateful if someone could post the low-res but perfectly clear photos I prepared when I crafted my first post, about a (I think) somewhat obscure repair question. I could provide a link to a shared google drive with them, or such.
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Old 08-29-22, 05:06 PM
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Hi Polaris,
Thank you for the reply. I took the bike to the shop as soon as I discovered the problem. I had bought it only 10 days prior and they were friendly and seem knowledgable. They said the frame is bent and couldn't be repaired. They gave me a loaner (kind) and contacted the manufacturer and (they said) pleaded my case and were told (based on photos and words) that the frame could not be repaired and since the damage was user error, the warrantee would not help me. They were willing to offer a discount on a wholly-new bike replacement.
I'm hoping I can find a cheaper solution, so found Bike Forums and here we are.
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Old 08-29-22, 05:10 PM
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You can download pictures to your user control panel albums and others can see them
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Old 08-29-22, 05:10 PM
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OK, well now you have nothing to lose by trying to fix that one.

The key thing a photo would help with is seeing how severely it is bent. Can you describe it (like bent 5° or 30° at a point x cm from the top)?

Also, there might be a workaround for the silly photo restriction. Can you upload photo's to your user "album"? If so, we might be able to look at them there.
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Old 08-29-22, 05:12 PM
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https://www.bikeforums.net/g/album/edit/
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Old 08-29-22, 05:20 PM
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Cool, thanks! I created an album "Electra Townie - dmgd seat tube top" as (I guess) part of my Profile. Hopefully everyone can see them.
(I tried pasting a link to my album but nope, not until I've posted 10x, apparently...)
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Old 08-29-22, 05:30 PM
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OK, I found it: https://www.bikeforums.net/g/album/26186550

Definitely not what I had imagined, but it might be fixable.

Here is one from the set in the link above:



Hopefully those more knowledgeable might be able to suggest something.

Was this Epicenter by any chance?

(Unqualified thoughts: I would try to bend that top part back in so that the clamp will fit over it, and then address the bend by the weld -- assuming that is a bend I am looking at -- by using the seat post as a lever along with a rubber mallet).

Last edited by Polaris OBark; 08-29-22 at 05:47 PM.
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Old 08-29-22, 05:48 PM
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I'm guessing you are up against the 5 posts/day initial limit as well.
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Old 08-29-22, 05:59 PM
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Originally Posted by quasta
Hi Polaris,
Thank you for the reply. I took the bike to the shop as soon as I discovered the problem. I had bought it only 10 days prior and they were friendly and seem knowledgable. They said the frame is bent and couldn't be repaired. They gave me a loaner (kind) and contacted the manufacturer and (they said) pleaded my case and were told (based on photos and words) that the frame could not be repaired and since the damage was user error, the warrantee would not help me. They were willing to offer a discount on a wholly-new bike replacement.
I'm hoping I can find a cheaper solution, so found Bike Forums and here we are.
I hate to break the news to you, but there will not be a cheaper solution, I would take the discount. you might be able to recoup some of the loss by taking the parts of the damaged bike and selling them

Here is why: aluminum is difficult to repair and often needs to be heat treated after repairs, which not many shops are set up for and then you would need to think about paint.

also if you extended the seatpost too far, I would say there is a good chance your frame is too small so you could adjust that with the discounted bike
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Old 08-29-22, 06:07 PM
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Originally Posted by Polaris OBark
If it were me, I would take it to the shop where it was purchased. My guess is they have seen it all before, and might be able to fix it by bending it back, perhaps by partially inserting the post and then using that to straighten the tube. Who knows, it could be a warranty issue?
Or they might be able to get a new frame and swap over the parts. Those frames are not very expensive.

Edited to add: as squirtdad notes, that frame might be too small for you. Those bikes generally come with pretty long seatposts -- if you really HAD to extend it beyond the minimum insertion line to fit properly, then the shop should not have sold you that bike. Now, if you were fooling around and don't understand bike fit, and extended it too far, that's on you.

Last edited by Koyote; 08-29-22 at 06:12 PM.
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Old 08-29-22, 06:18 PM
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Originally Posted by Polaris OBark
OK, I found it: https://www.bikeforums.net/g/album/26186550

Definitely not what I had imagined, but it might be fixable.

Here is one from the set in the link above:



Hopefully those more knowledgeable might be able to suggest something.

Was this Epicenter by any chance?

(Unqualified thoughts: I would try to bend that top part back in so that the clamp will fit over it, and then address the bend by the weld -- assuming that is a bend I am looking at -- by using the seat post as a lever along with a rubber mallet).
I don't think that it fixable in any sort of reasonable cost or safe way. this is aluminum per op, which is more prone to fatigue cracking than steel, so bending back is likely to increase risk for unplanned failure basically things that you could bend into place if they were steel is a problem with aluminum

just bending back the the "tabs" at the seat post is making them likely to crack

then trying to bend the seat tube is likely to have negative impact on the weld, if it does not cause cracking and getting it aligned well enough to put a proper sized seatpost in will be a challenge

If you can find a welder to take this one, it will be hundreds of dollars, it may need heat treatment which the welder may or may not have and of course new paint,

cut losses now
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Old 08-29-22, 07:17 PM
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I'm not sure I'd call it 100% user error.

First of all, that is a mighty tall seatpost. How did you manage to get a frame small enough that it required the seatpost to be raised that far? Did you buy the bike at the bike shop above?

Ok, I looked at the Townie Go Step-through page, and it seems to be one size fits all. Listing them to fit 4'11" - 6'1" or 4'11" - 5'11" depending on the model.

I think the "Step-Over" models are also one-size, but for larger people.

Then most of them have a monotube seatstay. By doing it that way, they have to add a fairly high seat mast.

That means, even if the seatpost was put in at exactly the minimum insertion line, it would still be mostly unsupported, and the result could be the same.

One option for designing the monostay on a step-through would be to put the pinch notch forward, and thus they would be able to raise the monostay and shorten the mast.

Anyway, the shop should sell you a bike that fits. And that Townie doesn't fit you. And, it is a mighty poor design for taller riders.

Whew, you didn't mention the exact model, but those things are EXPENSIVE!!!

If it was me, I'd first go back to the shop and point out the problem with the one-size-fits-all frame that is way too small. And, then the problem with the mast making the minimum insertion line in the wrong place.

If you get nothing, try to find someone willing to do the repair (in aluminum).

There is a "Framebuilders" section that might help.

https://www.bikeforums.net/framebuilders/
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Old 08-29-22, 07:32 PM
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...if you can find a longer seat post than the one they gave you with the bike originally, of the proper diameter, someone (more mechanically adept than you) can probably open up what remains of the frame's seat tube, and insert that new, longer seat post, (it needs to go at least four inches or so past the lowest point of the bottom weld where the top tube meets the seat tube.) Then, once you are sure about the proper height of your saddle, there are a couple of ways you can affix the thing so it stays at that height. One is simply TIG welding it in place, but then you can no longer adjust saddle height. Which might be OK, if you're sure you've got it right. With a really long post design like that, in an aluminum frame, that whole seat clamp with a long estension of the seat tube is an inherently risky design. It presupposes a certain user sophistication that is not always present.

There was another thread about a similar issue here recently. Something about someone wanting his warranty honored, having made the same error you did. I do not know how that one turned out, and I'm not sure they offered him a frame replacement at a discount. Which is about the best a company is gonna do in this situation.
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Old 08-29-22, 07:37 PM
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I think others have the correct opinion, the repair while being doable will be expensive and if not done properly a risk of failure. Remember Al tends to have rapid crack propagation (once a crack is started the complete break off can happen quickly, compared to steel).

These types of bikes are pretty much regarded as a commodity, not a collector's item. Built at the lowest cost with the least fancy materials. If this was a 1930s early Al frame that only a few handfuls were made and you were wanting to display it then go ahead. But for a rider I wouldn't either trust the repair or spend the $ to do a quality job.

I will take issue with the shop having some fault here. This argument is a nice way to blame others for one's inability to read the manuals or pay attention to limits and warnings printed on products. In our instant gratification wanting society we are failing in our side of the contract when we purchase something too many times. Andy
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Old 08-29-22, 07:43 PM
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£1800 bike. Cannondale Warranty REFUSED. What to do?
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Old 08-29-22, 07:45 PM
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Originally Posted by quasta
I'm hoping some metal-shop equipped bike specialist repair place could cut the damaged top part off the seat tube off - perhaps 1” or 2”, and weld a replacement top on. The bike is aluminum so I realize this may be a long shot. :
Originally Posted by squirtdad
If you can find a welder to take this one, it will be hundreds of dollars, it may need heat treatment which the welder may or may not have and of course new paint,

cut losses now


https://trek.scene7.com/is/image/Tre...=1920&hei=1440

Depending on the exact model, it could be between $2500 and nearly $4000.

The frame itself should be cheap if Trek/Electra would sell it. But, apparently they wish to sell the OP a brand new bike rather than just a bare frame. And I'm not seeing bare frames on E-Bay.

So, yes, it may be worth taking on the repair.

I think the bend goes down all the way to the bottom of the monostay.

The frame is probably 6061 aluminum which is reasonably weldable.

If it was me, I would go ahead and get it repaired.

I'd find some 6061 tubing that was at least twice as thick as the one the OP has (larger outer diameter, but still can be reamed to fit the seatpost.

Then cut the entire seattube mast to down below the monostay. Probably either cutting it down to the top tube, or completely removing the seat tube down to the chainstays.

Then replacing the seat tube with one that is 6" taller than the old one.

If the material is too thick, then cut down on a lathe & round corners so that the seatpost clamp fits (or find a bigger clamp).

Now add gussets from the monostay and seatstays up to the now taller seattube.

If replacing the seat tube, one can also go oversized which has certain benefits.

So, if it has a 27.2 mm seatpost, increase the seat tube to take a 30.9mm post, or even larger, 34 or 35mm seatpost.

And, of course, get a new seatpost that is at least 6" longer than what you currently have.
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Old 08-29-22, 07:48 PM
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This was how bikes were constructed back in the steel age...

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Old 08-29-22, 07:53 PM
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Originally Posted by CliffordK
... designed to be disposable.
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Old 08-29-22, 07:55 PM
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New Trek Connect program sells Trek bikes direct to consumer


...what could go wrong ?
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Old 08-29-22, 08:00 PM
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Originally Posted by Andrew R Stewart
I will take issue with the shop having some fault here. This argument is a nice way to blame others for one's inability to read the manuals or pay attention to limits and warnings printed on products. In our instant gratification wanting society we are failing in our side of the contract when we purchase something too many times. Andy
We don't know how the OP bought the bike. But, a bike shop should fit the bicycle they sell to the rider.

I.E. if the bike needs a taller seatpost, get that post and include it with the bike.

Now, the Electra GO seems to be a one size fits all which becomes problematic in this case, and is advertised to fit an extremely broad range of heights.

The Electra is unique with the crank-forward "flat foot" design. So, it may make the sizing different. However, clearly the owner figured out how to set the post way too high, and still ride the bike.

Have those minimum insertion marks on seatposts changed as the seattube masts have grown longer over time?
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