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Re: Scary stuff

Posted: Fri Jan 29, 2010 10:10 am
by vince
Doom Patrol wrote:
dirtyhandslopez wrote:
Innocenti-71 wrote:I had a spanish one go like that one, just got off the freeway. Luckily.
That's worrying. I've got a spare Spanish layshaft in the shed. :shocking: I thought it would be fine, being Spanish as their engineering seems pretty good generally.
Doom
Dont take one picture out of context there are a lot of Lambrettas out there that are perfectly happy, many are pushed well beyond their original design limits with the power of modern motors and stresses of track racing and sprinting.
I think an application of a good visual check before fitting coupled with a dose of common sense and you wont get stuck by lightening, this is a rare occurence and if it wasnt for sites like this you probally wouldnt even know about it :!: The shaft that broke looks old might have been in a engine that had suffered lots of seizures in the past and these stresses have to go somewhere.

Ride on and enjoy.

P.s. I once had the top of a damper break of in the paddock at Snetterton it could of happened whilst moving and locked the rear wheel up but such is life ;) Did it put me off NO !

Re: Scary stuff

Posted: Fri Jan 29, 2010 10:21 am
by Innocenti-71
I´m just wondering if there might be a relationsip between "snapping off" and the now very common use of impact wrenches to fit the rear hub nut.
I also fancy this for getting the nut off and on before setting it correctly with the torque wrench...but the impact type just delivers quite high torque peaks in just 1/10sec.
Maybe this stresses the material already and the 40+years and the TS1 do the rest.

Anyway I have a picture of the first owner of my totally standart SX200 back in ´72 where he just had this happening. So it might be not uncommon "those days" as well.

Re: Scary stuff

Posted: Fri Jan 29, 2010 11:52 am
by Doom Patrol
vince wrote:Doom. Dont take one picture out of context there are a lot of Lambrettas out there that are perfectly happy, many are pushed well beyond their original design limits with the power of modern motors and stresses of track racing and sprinting.
I think an application of a good visual check before fitting coupled with a dose of common sense and you wont get stuck by lightening, this is a rare occurence and if it wasnt for sites like this you probally wouldnt even know about it :!: The shaft that broke looks old might have been in a engine that had suffered lots of seizures in the past and these stresses have to go somewhere.

Ride on and enjoy.
I like your style Vince. Yes, you're quite right of course. I don't think I've ever heard of one snapping like that. So yes, ride and enjoy. :smug:

Re: Scary stuff

Posted: Fri Jan 29, 2010 2:32 pm
by RinB
Well all I can say is, may be this didnt help Tesco Pete :D if it was this scoot he was on

Image

Picture took off the ferry going to Sweden.
Pete 2 up with the Patron saint of scootering JED. :lol:

Pete also snapped his Shock this trip I wonder why. :lol:

He also tried keeping up with me and burnt his 6 plate clutch out. Jed was not on scoot then :lol: :lol: :lol:

Smiffy

Sorry Pete Hope your shoulder gets sorted properly & quick m8

But on the side of what to buy well Ive seen Indian, spanish & italian ones go luckily not
on my scoots.
May be MB's is the way to go there new and would be tested well & quality made,
but still could one of these go, who knows (Ps not slagging off MB)

If you look at it this way how many have been made over the years 100's of thousands even
millions

Re: Scary stuff

Posted: Fri Jan 29, 2010 2:37 pm
by RICSPEED
makes me wonder i fitting an arm like the outboard rear disc set up is a good idea ,they do it on the race autos

Re: Scary stuff

Posted: Fri Jan 29, 2010 3:34 pm
by vince
Looking at the above picture maybe its a weight loading fracture. :lol: Just checked picture on link and the shaft that broke had started to fail before it actually broke, there are tell tail rust marks on old wounds.But without taking the shaft out and having it checked by NDT you would not be able to tell.

Re: Scary stuff

Posted: Fri Jan 29, 2010 4:21 pm
by shocky
RICSPEED wrote:makes me wonder i fitting an arm like the outboard rear disc set up is a good idea ,they do it on the race autos
the gts has this extra arm as standard and im sure for a very good reason :?:
http://www.vespaspares.co.uk/Spares/epc ... /04.04.jpg
im supprised no one had come up with a longer layshaft, suspension arm and a second rear shocker might cost a few quid but then again some spend thousands
i can change a back wheel( yes i do carry a spare on long runs :o ) on my gts on the side of the road in less than 20 mins as you only need 4 tools

Re: Scary stuff

Posted: Fri Jan 29, 2010 4:38 pm
by dirtyhandslopez
Innocenti-71 wrote:I´ve seen this before... Is this a pattern layshaft?
If the groove for the O-Ring is made "sqare" and not curved like an "u" it might cause a crack when stressed.
Wonder wether this might be a worthwhile modification, fitted with an oversize o-ring.

But you are right Vince, this has only happened onece in 26+ years of scooting, it's not an epidemic.

Re: Scary stuff

Posted: Fri Jan 29, 2010 6:00 pm
by RICSPEED
seen a pic of a twin shock lammy but cant for the life of me find it now :(

Re: Scary stuff

Posted: Fri Jan 29, 2010 8:16 pm
by CPH Lambretta
I just bought one of the new MBD Layshafts because I didn't fancy useing a 40 year old layshaft on my new Imola engine.