Why not weld the engine cones into the frame? Discuss

[Knowledge]

Why not? They're not intended to rotate in the frame tube, so why not weld them in?

It would save all that hassle with getting offset cones to line-up.

[monument7]

Only my opinion mind you but they will move into the taper when they are not welded so lock in when you tighten the bolt. If you weld them and they are not fully home they will eventually crack the weld and then be loose I would have thought. Probably wrong mind you

[steveg]

Because I can't weld

[Captain Pugwash]

It's a bad idea.

[Knowledge]

Can you expand on this, Captain?

[Digger]

They also have a slot as well as a taper - welding them in would negate both of these.

What happens if the hole gets worn?

Just why would you want to in the first place?

[Captain Pugwash]

The engine cones have a taper for a reason that's so that when the bolt is fully tightened the cones fully grip the engine bolt to the frame at the same time only holding the inner sleeve of the engine mounts, the shock absorbing rubber in the mounts is left to flex so there is no excess movement in the securing assembly. The only movement left is in the shock absorbing flex in the engine mount.
Welding would prevent the snug fit of the engine clamping system preventing the rubber mounts absorbing the vibes as they should.
Plus there would be added wear on the engine bolt as it's allowed to move slightly in the cones. To do there job properly the cones need to be fully free in the frame to pull in and clamp the engine bolt to the frame.

[MickYork]

but Vespas don't have cones......and in general a smoother ride (but that's probably down to other factors).

[Digger]

but Vespas don't have cones......and in general a smoother ride (but that's probably down to other factors).

Neither do lobsters....

[Knowledge]

My thoughts are that you could fit (eccentric) cones into the frame tube, and then put the bolt into the cones (without the engine) and using a short length of tube, tighten the cones into the frame before welding them with a couple of spot welds.

When the engine is put in the frame, the inner tube of the engine mounts will still tighten-up and be "fixed" to the frame, just as Capt P describes.

Is my proposal much different to the official method?

Martin the lobster rider

[Digger]

Might have helped if you'd have said that in the first place Martin.

I can't see how you would do this and get a satisfactory weld without cutting a slot in the tube.

The front of the cone has to be flush with the tube as any protusion will risk the engine hanging when you pull the bar out. I recently bought a pair of offset's on Ebay where the taper was wrong resulting in them sticking out mm or two. It was enough to leave the enging hanging in the frame with no bar through them!

Was a real bastard getting off as well.

[MickYork]

My thoughts are that you could fit (eccentric) cones into the frame tube, and then put the bolt into the cones (without the engine) and using a short length of tube, tighten the cones into the frame before welding them with a couple of spot welds.

When the engine is put in the frame, the inner tube of the engine mounts will still tighten-up and be "fixed" to the frame, just as Capt P describes.

Is my proposal much different to the official method?

Martin the lobster rider

Nice thought but how would you get the bolt out after welding ?

When the bolt tightens up, the cones are pulled in and grip on the bolt (to stop it turning).

If you welded the cones in when tightened you wouldn't get the bolt out......

[Knowledge]

Might have helped if you'd have said that in the first place Martin.

I'm here to promote discussion, not provide all the answers.

Nice thought but how would you get the bolt out after welding ?

When the bolt tightens up, the cones are pulled in and grip on the bolt (to stop it turning).

If you welded the cones in when tightened you wouldn't get the bolt out......

I had the same thoughts, but then I saw a scooter at the weekend with offset cones welded into the frame, and the bolt had come out. I suppose it depends how much you tighten the bolt before you weld it.

Anyhow, the more I think about this welding lark, I think it might be better to cut a lump out of the frame tuble directly above the inlet manifold (and then weld in a plate), and use standard engine cones.

[Digger]

So what makes you think it's a good idea?

[Scooterlam]

In the spirit of discussion,
I guess why anyone wuould want to weld cones in would be to prevent offset cones from rotating and therefore stressing the engine mounting luggs or pusing the engine and in turn the back wheel out of line.
I remember a thread on the old forum where grub screws into the cones was suggested to eleviate rotating cones
fitted after the engine is fitted I guess.

[Captain Pugwash]

In the spirit of discussion,
I remember a thread on the old forum where grub screws into the cones was suggested to eleviate rotating cones
fitted after the engine is fitted I guess.

That's a fix my mate Dave uses, and it seems to work well as there is still enough flex in the cones (with them not being welded) to allow them to grip the frame and the engine bolt and it loosens just enough to remove the engine bolt

[Bettagetabrettabolti]

My opinion is don't do it. Agree with what Puggy says re taper and the slot.
The other thing is that the engine balances on these using them as a fulcrum. When they wear you have to get them out which means grinder - no thanks I'll stick with what - god - Innocenti gave us. You know it makes sense!
Bolti

[hullygully]

but Vespas don't have cones......and in general a smoother ride (but that's probably down to other factors).

but on a Lammy you dont have to hacksaw a rusted engine bolt @ both ends to get an engine out!! & then have to drill the remainder out @ both ends!!!

[Fast n Furious]

but Vespas don't have cones......and in general a smoother ride (but that's probably down to other factors).

but on a Lammy you dont have to hacksaw a rusted engine bolt @ both ends to get an engine out!! & then have to drill the remainder out @ both ends!!!

Indeed it is down to other factors. Namely the fact that the vethspa engine sits inside the frame and the Lambretta engine sits outside the frame.
The Vethspa mounting bolt crushes a tube tight between its 2 chassis mount holes so it doesn't turn under the action of suspension. These have an awful habit of rusting up solid making them difficult to remove without 7lb lump hammers, hacksaws and grinders.

Tapered mounting cones:- Good design.

[roli150lam]

Loctiteing the cones in place would be a less severe option than welding.