21 replies to this topic

[tony27]

I've seen late model gassers with squashed frame tubes so sherco isn't the only brand to suffer from this, even the montesa & beta beam frames will dent if dropped hard enough

I'm pretty sure the gas gas bottom yokes have a large flat section on the yoke that matches up to the frame where contact is made that has 2 bonuses, 1 is increased steering lock, second is the more important, the larger area coming into contact with the frame spreads the forces & goes a long way to preventing the type of damage in the photo

[NZRalphy]

I'd say that the tube strength will be compromised as it is. Not a lot....... but i'd sleep easier if was mine... and it was repaired. Get a quality piece of 4130 Cro-moly tube that is one size bigger than the dented tube, cut it to 40mm long and split length ways, get a good TIG welder to weld it over the dented tube. Get him to work quickly to minimise heat effects.

Clean it up slowly with a file. Do the other side to match the looks and, likely, no one will notice.

Oh and remove the electronics before starting to weld.

Ralph

[hrc1]

The Gassers have the bottom yoke angled to nearly match frame angle.
But it's not quite exact & a little filing is required.
Fans of good steering lock do this & add sticky plastic to protect paint.

Could the sherco yoke be profiled to match the frame tube angle better?

[HAM2]

for artie, on May 12 2010, 02:24 AM, said:

What happen to putting fork stops on the frame?

Poor design Sherco.

This 'design-aspect' was foreseen by 'Baldilocks' the great Shaman of the Mountain (Ben Nevis!) .

[Wayne Thais]

NZRalphy, on May 12 2010, 09:08 AM, said:

I'd say that the tube strength will be compromised as it is. Not a lot....... but i'd sleep easier if was mine... and it was repaired. Get a quality piece of 4130 Cro-moly tube that is one size bigger than the dented tube, cut it to 40mm long and split length ways, get a good TIG welder to weld it over the dented tube. Get him to work quickly to minimise heat effects.

Clean it up slowly with a file. Do the other side to match the looks and, likely, no one will notice.

Oh and remove the electronics before starting to weld.

Ralph

Exactly and you will create stress risers all across the welds top and bottom.

Design a sacrificial plate that can attach to the rad mounting bolt.

[for artie]

tony27, on May 12 2010, 01:07 PM, said:

I've seen late model gassers with squashed frame tubes so sherco isn't the only brand to suffer from this, even the montesa & beta beam frames will dent if dropped hard enough

Tony, anything will dent "if dropped hard enough".

Every Mont I have owned has had stops. and I have owned many. The Beta has stops. The Scorpa too.

All motorcycles have fork stops, Street, MX, Enduro.

A trials bike is the one that spends more time on the stops than the others type of bike.

also, trials bikes are subject to alot of get off's and it is here where the bike may cartwheel and the front end banged about.

Allowing a sharp edge bottom clamp to impact a frame tube in a critical area with the forces that can be generated is a poor design.

The pity is that its an easy fix. Weld on a small wing tab and Bob's ur uncle, but then maybe its just an oversight.

Edited by for artie, 12 May 2010 - 03:52 PM.

[geebee]

Hi

Thanks for all your sugestions guys.

I do however think that the photo makes it look worse than it actually is.

I see the structural integrity being only partially reduced and well within any safety allowance of the design.

I have decided that as it is not broken, I will not fix it.

However to reduce future further damage, I will implement Ishys remedy.
(My lad was talking with Ishy on the ferry on Friday)

Although for the bottom clamp to hit the frame tube, the radiator has to be dislodged, that sharp edge must still constitute a Sherco design failure.

Next job is to check the radiator as it did need a little coolant in the latter days of the six.

Best Regards

Geebee