Marino Frame Dent

[zoster]

Lets be reasonable, welding a plate over it unless done by a highly qualified welder and being heat treated would be worse.

i hope you're wrong, 'cause i WOULD like to put a plate there before trying any more sidehops (i'm just learning them, so chanses are this is going to happen again)

or leave it and zip tie a peice of curved carbon fibre or some hose pipe to the chainstay

is this actually gonna help (how? aren't thise flexible?) or is it just a joke..?

thanks

[LEON]

I have never done that once in 11 years lol. I had a norco once, landed downtube sideways on a rail & literally almost collapsed the frame, but what you've done doesn't look that bad really. I can't see it happening everytime you fail a sidehop

Leon

[AdamR28]

my questions are:

1. would this have happend on a more expensive steel frame (like curtis or lesson)

2. would this have happend on an alu frame?

3. what ca i do about it? i can hammer it back a bit? i can go weld some pieces of metal on that part, like the good boi frame has ... (i am really bummed, since this is a brand new frame and i was so excited about this bike it feels and look great, but...)

4. is there the risk of this frame snapping on me?

1. Yes, maybe worse

2. Yes but maybe not as large (depends on the frame)

3. Nothing that's an easy fix... could weld a plate over as has been said.

4. No

[zoster]

1. Yes, maybe worse

2. Yes but maybe not as large (depends on the frame)

3. Nothing that's an easy fix... could weld a plate over as has been said.

4. No

thanks!

i'll try the plate thingy if i can find a welder. do i need to know the exact material to tell the welder or is it "plain steel" (if there is such thing..)

[eskimo]

Putting some plastic tubing on there would be fine. That guy wasn't being sarcastic about it. It just means no need for weakening the frame from welding.

[zoster]

Putting some plastic tubing on there would be fine. That guy wasn't being sarcastic about it. It just means no need for weakening the frame from welding.

how would that help ? would it disperse the shock more evenly?

how come the frame weakens from welding?

thanks

[psycholist]

how come the frame weakens from welding?

Whether the frame weakens depends on the material its made from and the heat treatment it has before welding. Welding requires a local area in the frame to be heated to its melting point. Once the welding is done it will tend to cool very rapidly (Even more rapid cooling known as quenching is achieved by dunking the metal in water after welding/heating, this is desirable to harden products such as files, drill bits etc, but not desirable in load bearing frames, especially where shock loading is likely).

The rapid cooling after welding usually leaves the metal harder and more brittle at the weld than when you started. At the edges of the weld there will be zones in the metal where it is heated to near the melting point, but not melted. This often softens the material in the area near the weld (Depending on initial heat treatment, cooling rate and temperature reached and time held at high temperature). The result of this is that welds are often hard and brittle with a softer more ductile material around them - the difference in material properties leads to extra stress when the frame is loaded which will lead to cracking, usually just beside the weld.

Heat treatment is used to bring the welds and tubes back to a having similar properties and is more or less essential for Aluminium. There are grades of steel that perform better after welding (Reynolds make a few air hardening steels specifically for bike use with these properties). As for the dent in the chainstay, it's nothing to worry about in a steel frame and no great cause for worry in an aluminium frame either unless there are cracks in the dent that aren't visible in the pictures.

[eskimo]

how would that help ? would it disperse the shock more evenly?

how come the frame weakens from welding?

thanks

Yeah, the impact won't be centralised and dented because the plastic will cover a large area.

And what psycholist said...

I also doubt the tubing Marino uses is high grade or even heat treated. But i'm no expert and i still think it's cool what he's doing.

[pengsmelly]

Hammering the dent out might just make it weaker, just liek on a rim when you hammer out a dent.

so i think the best idea would be to leave it.

i have a couple dents in my frame from sidehops and its going on strong now, well over a year.

[Alex Dark]

Hammering the dent out might just make it weaker, just liek on a rim when you hammer out a dent.

so i think the best idea would be to leave it.

i have a couple dents in my frame from sidehops and its going on strong now, well over a year.

different with an alloy rim though, as steel doesn't work harden half as much as aluminium does.

I would just leave it though

Edited February 24, 2009 by Alex Dark

[zoster]

different with an alloy rim though, as steel doesn't work harden half as much as aluminium does.

I would just leave it though

marino said he uses carbon steel = ASTM A513. any idea if this is difficult to weld and if i need to have the exact same material for the plate that is going to be welded?

i am thinking of reinforcing it, 'cause i think if i bang it again it might be harder to repair..

Edited February 25, 2009 by zoster

[eskimo]

I wouldn't bother with welding shit to it. Plastic is lighter and if you use a decent plastic tube it'll be fine for bashing

Edited February 25, 2009 by eskimo

[zoster]

I wouldn't bother with welding shit to it. Plastic is lighter and if you use a decent plastic tube it'll be fine for bashing

do you know a more elegant way than zip-ties of fitting the plastic piece on the frame?

could some specialized glue work?

[eskimo]

do you know a more elegant way than zip-ties of fitting the plastic piece on the frame?

could some specialized glue work?

I'd use zip ties myself and cover them up with duct tape. But you could use glue, and i'd think it work extremely well providing you used the correct glue for the job. Which i have no idea what it would be But the problem with that is if the plastic did crack it may cause some hassle to replace. Some thick black plastic tubing cut to shape zip tied and taped would look pretty neat if done right. People always used to do things like that. It's just not really common anymore.

[zoster]

i think i found the perfect thing (or almost perfect) in my neighbors basement. i'll post a pic when i'm done!

[psycholist]

There's a glue I found a while ago called 'Flex and Bond', which might be suitable for this. I've used it to glue metal to varnished wood and it works well. There glue stays flexible after bonding too, so it's more likely to take a few hits...

Based on the description this seems to be the stuff I got, but it was a local hardware/machinery spares supplier I bought it from and the packaging was different.

http://www.weicon.ca/en/produkte/elastisch...e/flex-bond.php

[Mike W]

i hope you're wrong, 'cause i WOULD like to put a plate there before trying any more sidehops (i'm just learning them, so chanses are this is going to happen again)

is this actually gonna help (how? aren't thise flexible?) or is it just a joke..?

thanks

they are flexible but provide alot of protection, alot of begginers do it, you may be better off zip tying some thing more solid to the stay.

I strongly recommend that you do not weld anything to it, see if you can get away with ziptying/jubilee clipping a peice of aluminium/steel/carbon fibre to the stay, even a length of hose will provide some protection !

[Matt Vandart]

Basically steel can be bent a lot without it loosing too much strength, whereas aluminium will break if it gets bent a lot. So hammering it back will not affect strength too much, but I don't really see how you can bend it back. If it is possible weld a small but stiff plate over it as you are likely to hit the same spot again, apart from that you should be fine.

As long as it isn't bent more than it's elastic limit you can bend and rebend steel forever and it will never work harden.

Lets be reasonable, welding a plate over it unless done by a highly qualified welder and being heat treated would be worse.

At this grade of steel + thickness of the material probably wouldnt be alot more maluble than an alloy frame, so bending it back out, would only make things MUCH worse.

Just get in touch with the manufacturer or leave it and zip tie a peice of curved carbon fibre or some hose pipe to the chainstay

Wrong, you can weld it and not heat treat it, by heating a larger area around the weld however I like the plastic hose pipe idea.

Whether the frame weakens depends on the material its made from and the heat treatment it has before welding. Welding requires a local area in the frame to be heated to its melting point. Once the welding is done it will tend to cool very rapidly (Even more rapid cooling known as quenching is achieved by dunking the metal in water after welding/heating, this is desirable to harden products such as files, drill bits etc, but not desirable in load bearing frames, especially where shock loading is likely).

The rapid cooling after welding usually leaves the metal harder and more brittle at the weld than when you started. At the edges of the weld there will be zones in the metal where it is heated to near the melting point, but not melted. This often softens the material in the area near the weld (Depending on initial heat treatment, cooling rate and temperature reached and time held at high temperature). The result of this is that welds are often hard and brittle with a softer more ductile material around them - the difference in material properties leads to extra stress when the frame is loaded which will lead to cracking, usually just beside the weld.

Heat treatment is used to bring the welds and tubes back to a having similar properties and is more or less essential for Aluminium. There are grades of steel that perform better after welding (Reynolds make a few air hardening steels specifically for bike use with these properties). As for the dent in the chainstay, it's nothing to worry about in a steel frame and no great cause for worry in an aluminium frame either unless there are cracks in the dent that aren't visible in the pictures.

Correct, however if he bronze welds it he will not have to heat treat it.

Matt

Edited February 25, 2009 by Matt Vandart

[zoster]

ok, so first i wanted to put a plestic tube piece there, but after Mike W replied, i changed my mind a made an alloy piece from a seatpost rest (lucky me, the inner diameter of the seatpost was the same as the outer diameter of the chainstay). i forgot to take a picture of the modeled alloy piece, so there's only a pic of what remained of the seatpost segment.

the outer is made out of some special tape a guy at a lbs uses as rim tape. If it rips easily, i'll find another solution, but for now it was easy to put on and looks decent. (the metal piece is also bound to the frame with double sided adhesive tape).

cheers to everyone for your support! it was very helpful!

let me know what you think..

[eskimo]

Looks like a good job, hope it works well.

[NVWOCI WVS]

Looks like a tidy repair.

What cranks are they?

[zoster]

Looks like a tidy repair.

What cranks are they?

thanks! czar (sanblasted + clear coat)

[spaceman]

Wow, that was done up really neat!

And may I know what fork are you using?

[zoster]

Wow, that was done up really neat!

And may I know what fork are you using?

the one in the pic is done by marino, but i changed it to a pashley.

i will post a bike spec and pics as soon as i have it complete (i'm still waiting for a saddle from evanscycles, since they sent me a bmx handlebar instead of the saddle... :| )