Welding vs a new frame?

[nathanwhite]

So owing to a silly mistake, I have snapped my rear suspension link mount lug. I've been taking to Phil at metal doctors and he says he can stick it back on for $150 or so. however I have been looking around wreckers and found a (supposedly) straight frame for $250.

It's a cast aluminium frame and Phil has expressed concerns that putting the lug back on may render not as strong as when it was originally cast.

So is it worth dishing out extra to get a new frame vs welding the lug?
Also any way of measuring a frame to tell if it's straight?

[skippa1]

So owing to a silly mistake, I have snapped my rear suspension link mount lug. I've been taking to Phil at metal doctors and he says he can stick it back on for $150 or so. however I have been looking around wreckers and found a (supposedly) straight frame for $250.

It's a cast aluminium frame and Phil has expressed concerns that putting the lug back on may render not as strong as when it was originally cast.

So is it worth dishing out extra to get a new frame vs welding the lug?
Also any way of measuring a frame to tell if it's straight?

put it this way....you can save $100 and risk rear suspension failure which may cost your life, or spend an extra $100 and get a part that should be as good as the original. If you only value your life at $100 or less, then get it welded. Re measuring....dont know.

[carburator]

unfortunatly the upper suspenion mount on the SV650 ( presume thats the frame you have snapped )
does'nt allow for triangulation brackets. to spread the load into the frame as a aftermarket option.

from a engineers point of view, id always be dubious throwing a leg over the bike thats welded up
with no secondary way of reinforcement..

before you buy the newer frame Id get a weld crack testing kit ( three spray cans job ) and test the
lugs on the new frame before handing over yur money, if the wreaker doesn't like that idea walk away..

[schrodingers cat]

So owing to a silly mistake, I have snapped my rear suspension link mount lug. I've been taking to Phil at metal doctors and he says he can stick it back on for $150 or so. however I have been looking around wreckers and found a (supposedly) straight frame for $250.

It's a cast aluminium frame and Phil has expressed concerns that putting the lug back on may render not as strong as when it was originally cast.

So is it worth dishing out extra to get a new frame vs welding the lug?
Also any way of measuring a frame to tell if it's straight?

Yes there is. But the fact that you're asking means it will be a larbrorious task FOR YOU.

Essentially you need to ensure that:
Looking from the rear,
The rear axle centre line is parallel with the the swingarm pivot centreline
The steering head is perpendicular to the rear axle/swingarm centre line
THe steering head centre line is on the same centre line as the rear wheel centre line

You could piss around and check the steering head castor angle and height if you know the values.

You'll need a nice level pad to work on, good quality straight edges, levels and decent ruler/s. A plumb bob wouldn't hurt either

If you stick with what you have and tell your welder chappy to spend an extra hour making sure it is nice and beefy - lots of lovely preheat and a bit of gussetting you'll be back good as new only better and dealing with what you know.

[bogan]

Not sure if you've considered this (and fuck knows why I thought of it) but it'll drop the resale by a lot more than 100 if its welded up.

And I wouldn't fuck around with welding aluminium casting just to get it back to stock.

[nathanwhite]

put it this way....you can save $100 and risk rear suspension failure which may cost your life, or spend an extra $100 and get a part that should be as good as the original. If you only value your life at $100 or less, then get it welded. Re measuring....dont know.

Unless the replacement frame is also damaged. At which point I would have a snapped lug, and a disassembled bike

unfortunatly the upper suspenion mount on the SV650 ( presume thats the frame you have snapped )
does'nt allow for triangulation brackets. to spread the load into the frame as a aftermarket option.

from a engineers point of view, id always be dubious throwing a leg over the bike thats welded up
with no secondary way of reinforcement..

Thats exactly what I would be discussing with him, popping it back on is no problem, reinforcing it is.
What do you mean by upper? It's the link mount under the swingarm, I would have thought that was the lower mount?

Yes there is.

lots of measuring stuff

If you stick with what you have and tell your welder chappy to spend an extra hour making sure it is nice and beefy - lots of lovely preheat and a bit of gussetting you'll be back good as new only better and dealing with what you know.

This is what I'm thinking.

Not sure if you've considered this (and fuck knows why I thought of it) but it'll drop the resale by a lot more than 100 if its welded up.

And I wouldn't fuck around with welding aluminium casting just to get it back to stock.

Noted. I have no resale plans for the time being, possibly in the distant future, but not for another 6-10 years. (If something else doesn't brake in that time)

[bogan]

Noted. I have no resale plans for the time being, possibly in the distant future, but not for another 6-10 years. (If something else doesn't brake in that time)

You have an SV with no resale plans how long have you had it?

How did you snap it btw?

[nathanwhite]

You have an SV with no resale plans how long have you had it?

How did you snap it btw?

Since November.

I had already installed everything shock related and was about to start on the exhaust. I saw two washers still lying out that didn't fit the exhaust mounts. A quick look at the service manual said they were actually part of the suspension system. So I pulled it apart again and reassembled with the two washers in. I was getting close to the specified torque when the lug snapped.



Or should I just sell it and get a Bros?

[BMWST?]

Since November.

I had already installed everything shock related and was about to start on the exhaust. I saw two washers still lying out that didn't fit the exhaust mounts. A quick look at the service manual said they were actually part of the suspension system. So I pulled it apart again and reassembled with the two washers in. I was getting close to the specified torque when the lug snapped.



Or should I just sell it and get a Bros?

how do you know that apart from any prevoius damage that the lug on the other frame isnt already suspect...Do you know why it snapped,some thing was not in line,or in the right position right???

[bogan]

Or should I just sell it and get a Bros?

No, they're all for me, find something else

I often hear of people who think the SV is good at the time, then end up finding it too beige after a short while, so it might well be worth considering resale even if you currently don't think you'll sell it for 6 years or more...

[Drew]

So it snapped off the frame up by the seat/tank?

Weird. Did the two washers go between the shock and said mounting points by chance? Would explain why it snapped.

If it was a cast block, then welding it is the less desirable I think. But I'm no engineer.

I've been told by clever engineers not to have it done anyway. Ocean? Where the fuck you at?

[Karitane pete]

Won't you have to re vin and Reg if you use the other frame?

[nathanwhite]

how do you know that apart from any prevoius damage that the lug on the other frame isnt already suspect...Do you know why it snapped,some thing was not in line,or in the right position right???

On my frame it could have snapped from over tightening, overloading or have already been on the way out and I just helped it.
The other frame, I have no idea the condition of. I would assume from a bike wreckers, that a frame would be straight and not cracked, but that would be very hard to tell.

No, they're all for me, find something else

I often hear of people who think the SV is good at the time, then end up finding it too beige after a short while, so it might well be worth considering resale even if you currently don't think you'll sell it for 6 years or more...

It's not the bike, it's everything else. I'm a student, so not going to be getting a bigger (more expensive) bike for a least 2 years. Then it's onto a job. At this point (provided stable decent income) my focus will shift to getting a house annnnd there goes all my money for ages.

So it snapped off the frame up by the seat/tank?

Weird. Did the two washers go between the shock and said mounting points by chance? Would explain why it snapped.

If it was a cast block, then welding it is the less desirable I think. But I'm no engineer.

I've been told by clever engineers not to have it done anyway. Ocean? Where the fuck you at?

No, it snapped down under the swingarm, where the linkage connects to the frame.
There is a bit of confusion over this. I think a picture would help.

Won't you have to re vin and Reg if you use the other frame?

That was what I was wondering, what woluld it take to get the bike legal with a new frame. A lot of work it would seem.

[DEATH_INC.]

Have you got a pic?
Even without seeing it though, I'd still say I'd weld it. It still has one good one on the other side that will probably do the job on it's own anyway. As long as it's ground right out and done properly I doubt it'll be a problem. I'm pretty sure there will be places to reinforce it a bit with some extra weld too.
Most cast parts of the frame are welded to extruded bits somewhere, so we know they can be welded.
Why be scared of welding cast ali...it's already been melted once at least...

edit: "look properly dick...there's a pic already."
Ok...I'd definitely weld it back together...looks like lotsa room for reinforcement. Though it'd be tempting to make a new bracket out of some flat instead...less likely to break again.

[Drew]

Yip, weld that shit. Because of the action pushing rather than pulling on that bit, it's gonna be fine.