06 Crack...Am I the first???

[Neo]

I have just discovered a crack on my 06 Sherco 250 on the front cross brace. Right at the top of the radiator.

It’s funny, but I’ve recently had my daughters GasGas 70 down the welders...3 times!!! And I’ve been running GasGas frames down as a result. But now my Sherco is giving me frame problems....but not too many, I hope.

I ride most days, with a minimal amount of abuse. So a few questions spring to mind:-

1. Am I the first to have a cracked late (06 to 08) Sherco frame?

2. Has any else had a crack in this same place on a black frame Sherco?

3. What do you think would have caused this to break like this?

4. Would it be best to remove the radiator for TIG welding.... I am not sure if it’s best to weld both sides? But there is enough space to paint behind the weld after it’s re-done.

5. Would it be best to clamp the outer frame sides (to close the gap) prior to welding..... Or it is best to weld across the gap?

6. Does anyone know what would be the best colour match paint to use?.... I previously read a TA thread on black paint, to use on a Sherco. But the paint manufacture is not available in Australia.


Any help with these questions would be appreciated


Best of balance.

Neo

[David Lahey]

I would be looking for a cause for this crack. It doesn't look like a manufacturing fault. It is quite unusual to get a crack from the sort of riding you do without there being something wrong somewhere else on the bike.
I suggest checking that the motor mounting bolts and any other structural connections are tensioned properly.
Another thing to check is the exhaust mountings for breaks/looseness and if the exhaust system is touching the frame somewhere it shouldn't be.
Another factor may be if the motor has been modified in a way that increases the out-of-balance forces ie an additional flywheel weight that isn't properly balanced.

[Stu]

jeez Neo, lay off the Red Bull, but then again you may need the wings. That is a serious crack. How long before you noticed any problems?

[Neo]

Ok Stu, I’ll try to back off the Red Bull…..
I only noticed the crack on Monday….but it looks like its been there a while to me.


David, why doesn't it look like a manufacturing fault, to you??? ....I was once told that the weakest points of any weld, is either side of the weld.
I’ll check all the motor mounting bolts tonight. But I know that exhaust mountings are all good and the engine has not been modified..…..this baby runs really smooth. And I only ride C grade stuff
I also have frame protectors either side of the frame/radiator. So I know she's not taken a knock around there at all.
Would you clamp the outer frame sides (to close the gap) before welding it?
Any other thought??


Best of balance.

Neo

[David Lahey]

Yes the weld being there does increase the likelyhood of a crack forming right beside it.
Why I didn't think it was a manufacturing fault is because:
The appearance of the weld is OK ie no visible thinning at the edge of the weld.
The steel pressings appear to be well formed.

If it was my bike I would find out what steel it is before welding ie maybe needing special weld procedure.
I would not try and close the gap. There is nothing to gain by doing that.
Take the radiator, fuel tank and steering stem out, remove the ignition electrics from the bike, drain the gearbox, clean the grease out of the steering bearings and shield the motor from the welding.

[BJ]

Take the radiator, fuel tank and steering stem out, remove the ignition electrics from the bike, drain the gearbox, clean the grease out of the steering bearings and shield the motor from the welding.

I agree with David.... don't clamp the crack but make sure the engine bolts are tight so the frame is rigid like it was jigged. Otherwise (though unlikely) when the weld cools it may cause a distortion. Other than that I would replace the wheel bearings, grease the rear links, fit new brake pads, cables, hoses, check the brake disc bolts and sprocket bolts and call it a general service AND lay off the Red Bull! If you are cracking frames and the bike was not previously owned by a red plater you MUST be too tough on it and all those other parts will be getting ready to let go!

And you wonder I don't put any fuel in my bikes when you ride them? The sooner they stop the safer they are

[jmclean]

Unless other people have had a similar problem with this frame, you'd have to consider it an exception. If it was due to under-engineering or a manufacturing fault we'd expect to see other owners with the same problem. It looks like a stress crack to me.

Clearly Neo is not an abusive rider so we need to consider other factors.
I'd also be looking at how the bike has been tied down on the trailer. This also applies to your GG.

Cheers, Jim

[Neo]

Thanks Jim,

My Sherco has only ever been on a moto-bike carry, Car rack, once (about 14 months ago)....And our GG maybe 8 times in the past year.
But thanks for giving this some thought.

Best of balance.

Neo

[Smiddy]

Hey Neo,
How does your bike carrier hold the bike on?
We broke the lower engine mounting arm on our '94 Fantic through clamping the forks to a rigid bar on the trailer, due to inducing bending stresses into the headstock from the mounting running too low. Under braking and accelerating of the trailer, it caused fatigue faliure...
I still run the same clamping method, but now ensure the clamp is at the very top of the upper stanchion.

[nic g]

hi neo

After reading this I raced to the shed to have a look at my 06 and I too have a crack.... well it's a hair line crack at this stage!, have you repaired yours? how did you do it?

nic