# Fixing a dent?



## Son (Jan 9, 2007)

OK, here's the thing. The left side round (upper) tube of my Heckler's rear swing got a dent. It measures like an inch by half and it's probably like 5mm (0.2 in.) deep, but it isn't too sharp.

I don't think the tube will fail in a jump, but it just looks nasty.  That said, I'd like to get it fixed. So my question is, has anyone gotten dents fixed and if so, how?

I was thinking the only way to do it could be to drill a couple of holes to the opposite side of the tube and with a rounded tip of a nail hammer the dent out, back to shape. Of course it won't look as good as new, but probably better anyway. Then an aluminum welder could weld the drill holes shut, and I'd then get the rear swing sand blasted and powder coated.

What do you think?

I'll get pics of the dent this weekend if anyone wants to see.


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## 71 10-7 (Nov 8, 2004)

I'm not a body man but I always wondered if you could use Bondo on aluminum? As long as the dent isn't structural and the Bondo sticks, sand and repaint. Anybody know if this would work?


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## Son (Jan 9, 2007)

It won't. Powdercoating is the only way to go when painting frames and bondo won't like the heat treatment they give the frame after painting.


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## NEPMTBA (Apr 7, 2007)

Try wedling a loop made out of aluminum rod in the center of the dent then pulling it with a slide hammer or lever. Better then poking holes in your frame and rewelding them. After the dent is out you can cut off the loop and grind and finish.:thumbsup:


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## Son (Jan 9, 2007)

Yeah, that would probably be better, if the loop sticks, of course. 

Or then I could just have a welder fill the dent with an aluminum weld.


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## Walt (Jan 23, 2004)

*Don't weld it at all.*

Drilling holes and welding them is going to cause some major stress risers, and you'll be destroying the carefully heat treated crystal structure of the aluminum. I would just find a powdercoat-friendly putty (such a thing does exist, though I don't know any brand names) and do it that way.

Actually, I would just leave it. Anything you do is going to make the frame weaker, cost you lots of money, or both. Hecklers look good with dents. Makes you more hardcore.

-Walt


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## NEPMTBA (Apr 7, 2007)

Son said:


> Yeah, that would probably be better, if the loop sticks, of course.
> 
> Or then I could just have a welder fill the dent with an aluminum weld.


 I'm... just on a Rant!...LOL!:madmax:

Why wouldn't the welded loop stick? We remove dents from Vintage Motorcycle Gas Tanks all the time... Yes, Gas Tanks that are way thinner than a bicycle frame!

I don't know what your dent looks like or how stressed it is. Some times I have used "Pig Putty" a very fast drying epoxy to remove dents! Epoxy the loop and pry up and tap around the dent with a ball peen hammer lightly to relieve stress in the area. The worst that can happen is the putty will fail. No damage to your frame.

I don't get all the hoopla about "Oh don't weld it will create la la la la la....BS! Are you gong to have it X-rayed after welding? Hell no! It's a bicycle with a dent!

They make it sound like a piece of "art" and it will never be the same if someone takes a welder to it! It was originally welded by a robot or a person who only knows how to turn on/off the welding machine that's set a "fixed" heat range. He has no personal interest in weld depth, contamination, penetration or any other non facets of his job.:madman:

We have welded many frames ourselves and never had one re crack or fail! Even head tubes! S**t that's what we do, "Repair stuff" Too many in the the bicycle industry have an idea that "once broke/never fixed" by re welding! :nono:

There are Motorcycle, Quads and Sprinters out there that have won Nationals we welded and did weld repairs on from simple motor mounts to frames to major swing arm reconstruction. S**T we have welded stuff at the race track in a time of need and it made "Hanging Grapes" look good and it worked! Your not under pressure, shop around find a great welder/fabricator and you will have him for future needs.

Common sense will tell ya...if your willing to spend the dough to find a professional welder/fabricator with the knowledge to make it stronger then it was originally. Might weigh a bit more when done, but worth it to have it running again. Anything can be fixed. Might cost a bit, but then again whats your "old favorite" worth to you to have it up and running again...

Have it Bondo...ed and "Imron" it instead of powder coating...as strong as powder coating if multi coats are appied. Imron provides better shine!

In summation: Sorry... to sound off color... :madmax:just pisses me off to hear the same old, same old, about fixing simple things like bicycle frames.

Try all your options... Good Luck!:thumbsup:

LC ...End of Rant! Back to the Trails... and I'm bringing my Welding Goggles and Pig Putty with me...LOL


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## Walt (Jan 23, 2004)

*Huh?*

Vintage motorcycles have aluminum gas tanks?

NEPMTBA makes a good point, though. It's just a bike. Go ride it, or else find someone who does aluminum repairs and find out for yourself if the repair is going to work out. I've personally seen a lot of attempted aluminum bike frame repairs, and they all eventually cracked again. If it does, c'est la vie. You tried. If not, sweet!

I think the putty/Imron idea is pretty good, too, especially since it sounds like the dent is mostly just aesthetic.

-Walt



NEPMTBA said:


> Why wouldn't the welded loop stick? We remove dents from Vintage Motorcycle Gas Tanks all the time... Yes, Gas Tanks that are way thinner than a bicycle frame!


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## swift (Apr 3, 2007)

*I agree w/ Walt*

An aluminum bike is far different than a steel gas tank. Even if the material were the same, the gas tank isn't stressed in the way a bicycle frame is. A gas tank's only job is to hold 6lb per gallon gasoline. ...A gallon milk jug could accomplish this.

Based on some of your suggested fixes, it seems that you are willing to spend a little $, if that's what it takes (welder, powder coat, heat treat, etc) to get the job done. This being the case, why not call up Santa Cruz and simply order up a new swingarm? It seems to me like the easiest and safest route to go.

Personally, I'd ride it like I stole it and make a point of showing the dent to everyone who would look at it. :thumbsup:


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## NEPMTBA (Apr 7, 2007)

Walt said:


> Vintage motorcycles have aluminum gas tanks?
> 
> NEPMTBA makes a good point, though. It's just a bike. Go ride it, or else find someone who does aluminum repairs and find out for yourself if the repair is going to work out. I've personally seen a lot of attempted aluminum bike frame repairs, and they all eventually cracked again. If it does, c'est la vie. You tried. If not, sweet!
> 
> ...


 Walt:

Yes, they did back in the day..some were so thin you could dent them just from knee pressure trying to hang on to one of those old crotch rockets!

LOL!


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## the_Big_Ring (Jan 10, 2006)

I have used this stuff http://www.lab-metal.com/ with success to fill dents in steel and powder coat over them. I have not tried it with aluminum though.

-Clark


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## Son (Jan 9, 2007)

swift said:


> Based on some of your suggested fixes, it seems that you are willing to spend a little $ if that's what it takes (welder, powder coat, heat treat, etc) to get the job done.


Welding and painting really wouldn't be much. Sandblasting and powdercoating would be 30 to 50 €.



> This being the case, why not call up Santa Cruz and simply order up a new swingarm?


This is the prev. gen. Heckler, so they're out of anodized at least. Don't know about powdercoated ones.

Anyway, will have to check that Lab-Metal thing...


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## CrustyOne (Oct 29, 2007)

I would fill it, least damaging way really, DONT go trying to push/pull it back, youll cause a crack, either immediately or some time down the road......you sure its not bent too?

Oh yea about aluminium morcycle tanks.....yey, my old Suzuki pe175 had an ali tank..was like paper and dented up real easy


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## PMK (Oct 12, 2004)

Fill the dent with Hysol, sand smooth, mask off both sides and scuff sand, clean and prep, then wrap a couple of plies of carbon fiber over each tube and give them a song and dance about light weight prototype. 

BTW, don't sand to the aluminum and then put carbon on as it may corrode.

PK


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## CSPRINGS (Feb 11, 2004)

*hey Neptune...*

Thats a great pic of you and your GF on your tandem. But something here is terribly wrong...the tread on the front tire is backwards.

PS surely that is a fake vehicle ????
Thanks for the pic
CS


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## Evil4bc (Apr 13, 2004)

All these suggestions of "filling " the dent are flat out scary !

As Walt pointed out the SantaCruz has been heat treated to exacting spec's , you will not be able to get the bike back to it's orignal stiffness nor strenght .

My suggestion is if this dent is really bothering you , CALL SANTA CRUZ they have extra Swingarms in stock , I'm sure they will sell you one at a discount under crash replacemtn policy .

Dont try to home fab something , you will jsut end up runining a decent bicycle frame and your hate yourself afterward.


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## gabe (Mar 25, 2004)

_My suggestion is if this dent is really bothering you , CALL SANTA CRUZ they have extra Swingarms in stock , I'm sure they will sell you one at a discount under crash replacemtn policy ._

Best advice yet!


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## PMK (Oct 12, 2004)

EVIL1, why do you fear filling the dent he described, his post described it as a smooth dent with no sharp crease, 25mm long x 13mm wide x 5mm deep.

Filling has no effect on heat treatment, and done right could just be paint touch up.

Sad but true story, years ago I helped a friend get his bikes ready for the NORBA nationals. We took a handful of brand new Cannondales and removed the paint using low pressure plastic media blast, surprising how many dents were filled and painted over.

As good as some builders are, I'm sure a lot are filling dents then painting with the customer never knowing, it's just not practical to have a zero tolerance. From Boeing to Huffy, they all have damage before delivery, and each handles it to minimize lost revenue.

If you want to know you have zero dents, buy a polished bike. Not saying every painted bike is repaired, but unless you remove the paint how would you know?

PK


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## CrustyOne (Oct 29, 2007)

CSPRINGS said:


> T
> 
> PS surely that is a fake vehicle ????
> 
> CS


Its real.....was in widespread service and of great use to the the wehrmacht in ww2


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## NEPMTBA (Apr 7, 2007)

Yes:

Years back working at a Ford dealership. Many of the cars with vinyl roofs and two toned painted cars were done due to damage at the factory. I can remember as a kid my friend bought a car with a vinyl roof and he didn't like it so we peeled it off to make the car look better. What a mess we found! Bondoed dents all over the place.


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## Evil4bc (Apr 13, 2004)

PMK said:


> EVIL1, why do you fear filling the dent he described, his post described it as a smooth dent with no sharp crease, 25mm long x 13mm wide x 5mm deep.
> 
> Filling has no effect on heat treatment, and done right could just be paint touch up.
> 
> ...


Dents = potential frame failure anyway you look at it.

If you really believe most frame builders are sending out bikes with bondo filed dents , you need to wake up and look at the work that really goes into building a frame .

Sure I dont dough that some major manufactures might fill dents but this is like rolling back miles on a new car , sure the dealrs have the technology to do it , but ask your self in the end is this the honest way of building a bike/ selling a car ?
NO !

For this reason most reputable manufactures have scratch and dent sales .

No getting back to the point , filling a dent will not improve the structural integrity of your aluminum bike , nor any material for that matter.

As suggested above , to half ass this fix CALL Santa Cruz and buy a new swing-arm .

Frankly I'm really surprised this thread has gone on as long as it has , really are all you bike snobs just fixing your S with Bondo or magic metal ? 
To this give a good , BWHAAAAAAA Hahahahahahaha yea i LOL'd


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## NEPMTBA (Apr 7, 2007)

But BONDO is GOD!

Hey here's a concept for ya. Ever watch Orange County Choppers? They completely cover Gas Tanks with Bondo and then begin prep for paint. Frames getthe same treatment. I have also stripped C Dale frames to find Bondo!:nono:

So...Bondo Rules! I'm getting a Medium Sized Ball Peen Hammer taking it to my frame thus strengthing the tubes then using multi colored Bondo with only Clear as a Top Coat. Ever see the pretty Peach colored Bondo, how bout Green?:thumbsup:


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## PMK (Oct 12, 2004)

Evil4bc said:


> Dents = potential frame failure anyway you look at it.


Well OK, yeah I guess when you say it like that, kind of the same as

Welds = potential frame failure anyway you look at it.

Billet Machined stuff = potential frame failure anyway you look at it.

Holes for bottle cage inserts = potential frame failure anyway you look at it.

New style pressed in frame graphics = potential frame failure anyway you look at it.

Corrosion from dripping sweat = potential frame failure anyway you look at it.

Overweight, fat riders = potential frame failure anyway you look at it.

Bike snob no, aluminum structures experienced maybe, and I'm not talking about patio furniture.

I really shouldn't have written those but it was fun, others can add more if you wish.

As for poster #1's dent, do whatever, it's your sled carrying your crotch.

PK


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## Evil4bc (Apr 13, 2004)

PMK said:


> Well OK, yeah I guess when you say it like that, kind of the same as
> 
> Welds = potential frame failure anyway you look at it.
> 
> ...


Nice post above , I really didn't get it though .
This link might help you in the future 
BTW: what are new style "pressed in frame graphics " never herd of this before ?

Now getting back on topic .

For those of you who still do not believe a dent will harm your frames structural integrity try this simple experiment:
1. take a beer can un-dented and stand on it , see how long it will support your weight
2. take another can and flick a small dent into it then stand on it and see if it will still support your weight ?


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## richieb (Oct 21, 2004)

a) Gas tanks are not structural members of a motorcycle...that arguement does not apply.
b) welding a tube makes it weaker than the original dent did.
c) If you have the option of replacing the swingarm, that's the only ay to get it 100% strength in your frame.
d) Many aluminum alloys need heat treating after any welding..."pulling" the dent will cost more than a swingarm after re-finishing, etc...
e) It's a mountain bike with a dent...deal with it...IT'S A MOUNTAIN BIKE, not a trophy.

Just my 2 cents as a visitor frm another forum...


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## problematiks (Oct 18, 2005)

Ok, I get the "a dented tube is weaker than an un- dented one".But how can you make the tube weaker by simply putting on some putty/whatever that doesn't need high temperatures and then repainting the frame?
Anyway, I personally can live with a dent or two on my frame, but if Son wants it fixed, it's his choice, a piece of art or not.

Marko


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## RoyDean (Jul 2, 2007)

Evil4bc said:


> For those of you who still do not believe a dent will harm your frames structural integrity try this simple experiment:
> 1. take a beer can un-dented and stand on it , see how long it will support your weight
> 2. take another can and flick a small dent into it then stand on it and see if it will still support your weight ?


Are beer cans's designed to be stood on? Are they designed to be stood on while dented?

Mountain bikes are designed to be ridden on. They're also designed to be slightly dented from use. My scalpel has a nice sized dent just above the BB shell on the downtube, and I've been riding it for 2 years without it folding in half...

I guess, nobody is really arguing that a dent will weaken to tube... they are arguing that a small dent doesn't compromise the integrity of the frame to the point where it's unsafe...


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## Zippy_Slug (Jun 11, 2007)

I know not if this would work for a frame.. but I've seen it suggested for small dents in car bodies, of course it could be an urban legend as i've never tried it either. SO..

Get: Computer air spray duster, and a hair dryer.. preferably a really friggin' hot high watt hair dryer

1) disregard the air spray duster instructions
2) turn can upside down and frost over the dented area until it's nice and cold
3) have the hair dryer already hot and blow the dent which you just made super cold until it gets hot.. 
4) repeat as necessary..

Not sure this will work with a tube, or minor nicks.. as car panels will already have a stress pressured against the dent.. a tube might already be compromised and not "pop" back after repeated hot/cold.. 

If anyone tries this.. let me know how it turns out.


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