missing or not?

[timetc]

I have a 1927-8 3 speed scott on a long term rebuild it has a long undertray. I have spent some time at 2 gatherings on the ground!. And all the frames I have looked at seem to have lugs ‘brazed’ on the lower rails leading to the rear wheel to locate the rear of the tray. my tray fits but there is no sign of any brazed lug on the tube (and there is precious little paint to hide it)-were some a simple bolted ‘P’ clip ? 😕

[Anonymous]

If I’ve understood correctly then the rear of the undertray on both my 1929 TT Reps are with U clips that are loose over the frame rails until the through bolts are tightened. I’ve taken some pics below, I hope this give you the info you want.

Cheers,
Rich

[timetc]

Thanks Richard
thats cleared my problem however it looks like they are substantial enough to have been put on before the frame was brazed up!
at least I now have a target to shoot at.

[chris wastell]

I think its only the post war frames that have brazed on lugs for the tray. I’m no expert mind you.

[chstorm]

On the pre-war Scotts, like on my 1936 and 1938 models, the rear end of the undertray is fastened to the frame rails with u-clamps on both sides. These u-clamps consist of two loose halves which have to be dismantled when you want to lower the undertray to get the gearbox out. They are, when installed, held together by the bolt passing through the rear end of the undertray. If these are missing, you will have to locate a set somewhere or have some made.

Cheers,

Carl

[chris wastell]

I have a spare unused set of these that I had machined in steel. I would willingly pass them on for what they cost me but I have to admit that I nearly had a cardiac arrest when I learned the price!

[Anonymous]

Mine are both definitely not two loose halves, they are a one piece machining on both the bikes.

I guess if your frame is not painted you could get a steel U clamp on by heating it to red hot evenly around the strap part of the clamp and bending outward enough to go over the frame rail. Then place over the rail near one end (so the casting act as a heat sink), pull the sides back together far enough to insert a bolt then quickly tighten it to pull the strap part back into a round shape again.

The thing I like about the clamp type rather than the brazed lug type is you can assemble the undertray with no residual stress in it.

Cheers,
Rich

[lewis onions]

Coincidentally I have recently arranged for the manufacture of a few of these clamps. I have two bikes (both with the rear foot brake cross-over shaft) where they are missing and I know of other people with the same problem.

Ken Lack made some a few years ago but was only able to supply me with two of the inner, taller clamps. The later cross-over type certainly came in two parts – the higher clamps carrying the cross-over shaft being inside (I believe) corresponding smaller clamps similar to one half of those used on bikes with a right hand foot brake – like those shown in Richard’s pictures.

Ken does not intend to make any more of thees as they are a bit of a challenge – the clamp fits over the frame at an angle. His were cast in brass and then machined. I have used Ken’s clamps as a pattern but without the smaller outer type there has been a small amount of guess -work involved. The clamps are machined in steel and carry bronze bearings for the cross-over shafts. There will be sets of 4 smaller clamps available as well as sets of 4 with 2 small and 2 tall for cross-over shaft bikes.

I visited the machine shop making the clamps yesterday. Their usual business is the design and construction of robots for Airbus 320 applications but they double as general engineers making anything from agricultural machinery parts upwards. The clamps are likley to be finished in a week and I will post pictures when I am able to.

The cross-over shaft has been another issue – I have two examples and they are different. It is likely that I will get some of these made later to fit with the clamps.

I don’t have the final cost as yet but as is usually the case the expense was in the first set so that there was no reason not to get a run made. If any one is interested (with entirely no obligation), please let me know. The surplus will be avaialble through the spares scheme in any event – assuming that they pass muster with Graham !

Regards

[chris wastell]

Vmcc library has the original drawings for the clamps. The angles are awkward which is what put the price up when I bought mine

[Graham Parker]

I might have missed something here (and apologies if I’m going down the wrong track), but the original posting mentioned a late 20’s 3-Speeder “with a long undertray”, so I’m assuming that the machine in question is a 3-Speed Super – rather than a 3-Speed Flyer.

The articles that mention clamps all seem to be related to Flyers and not Supers.

I’m far from an expert – but my machine is a 3-Speed Super, and I’ve not seen any other examples of these with Clamps as used on Flyers.

I doubt you’d be able to just use these type of clamps as a solution for a Super, as the rear tray mountings would then be too far back and too high.

I think it would come back to making some “P” shaped mounts to clamp / braize to the existing frame.

Would be interesting to know why they have been removed in the first place. May be its been hacked around as part of a “special” in the past. A pic of the frame might help to clarify things?

[dave bushell]

Maybe someone was trying to convert a 2 speeder frame to a 3 speed Super?
Dave

[BRIAN MARSHALL]

There are of course long and short gearbox trays on Flyers, with the long version used on the long wheelbase machines of late 1926 thru’ to late 1928.
These can be identified at a glance by their sloping front “shoulders” compared to the 90 degrees shoulders on all the later trays. Possibly this is why the clamps were not brazed into position…..to allow the use of both lengths of tray, depending on rear wheel diameter and the radius of the rear mudguard. Hope this helps.

[Author]

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