Author Topic: 1925 Sunbeam 500 Model 101  (Read 341 times)

Online Greybeard

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1925 Sunbeam 500 Model 101
« on: 10.08. 2022 14:40 »
My Brother-in-law Terry had a prewar Sunbeam in his garage for some years. The previous owner bought it back when he realised that Terry was never going to restore it. I was interested in the bike but was not able to take it on at the time.
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Offline Topdad

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Re: 1925 Sunbeam 500 Model 101
« Reply #1 on: 10.08. 2022 15:04 »
What a shame that Sunbeam  were not given the prominance they deserved by BSA  , the S7/8  still have a faithful following but to round it off with a scooter that had a reputation of seizing at the drop of a hat ,says a lot about BSA's management.
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Online Rex

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Re: 1925 Sunbeam 500 Model 101
« Reply #2 on: 10.08. 2022 16:25 »
I seem to recall those scoot's had a problem with exhaust valves, and the engine was too powerful for the chassis, but don't recall any issues with seizing.

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Re: 1925 Sunbeam 500 Model 101
« Reply #3 on: 10.08. 2022 16:30 »
What a shame that Sunbeam  were not given the prominance they deserved by BSA  , the S7/8  still have a faithful following but to round it off with a scooter that had a reputation of seizing at the drop of a hat ,says a lot about BSA's management.

Was a shame; but it was also a shame that they were rather gutless, had some quirky problems (rear worm-drive arrangement notably), leaked a lot of oil, and cost a small fortune. Weren't built at Small Heath either. The effort post-war to resurrect the idea that The Sunbeam was for Gentlemen (which was the Marston view of his bicycles back before Noah started shaving) failed to resonate with a market in which the younger sector wanted grins per mile with performance, and the older bit was migrating to staid four-wheelers - all under conditions of austerity that would make us tremble (even today). Have to be honest and say I don't care for the S versions much, but I think the pre-BSA bikes, under ICI's and then briefly AMC's ownership, were beautiful. Best paint jobs ever on a production machine? Must be close - Mr Marston started life as a 'japanner' and was very picky.
Never played with one of the scooters - nor indeed any other scooter.

This from gaukmotors.co.uk:

The S models were manufactured from 1946 to 1956. There were three: the S7, S8 and S7 Deluxe. All three were very expensive but with only modest performance which resulted in low sales.

The unusual engine layout was the S7's notable feature with an engine and drive similar to that of a car. The engine was a longitudinally mounted inline vertical OHC 500 cc twin with coil ignition and wet sump lubrication which, though a dry clutch, drove a shaft drive to the rear wheel. The inline engine made this technologically feasible (flat-twin "boxer" engines on BMW motorcycles had already used shaft drives). Unlike BMW, who sensibly specified a bevel gear crown-&-pinion drive to the rear wheel, Sunbeam used worm gearing with a bronze spiral gear; by reputation the soft bronze gave rapid wear of drive components.

The original S7 was produced from 1946 to 1948. In 1949, the sportier S8, with standard-sized wheels rather than the fat tyres of the S7, and BSA type front forks, was produced. The S7 design was improved and then sold as the S7 Deluxe. The original S7 was available only in black, whereas the standard colours for the S8 were "Polychromatic Grey" or black. The S7 Deluxe came in either "Mist Green" or black. If sold abroad then BSA would supply the Sunbeam in almost any colour that BSA used. Although the early S7 was not a good seller or mechanically very sound, it is the most sought after and commands a premium over the S7 Deluxe and the S8.

When Sunbeam production came to an end, BSA sold the remaining stock of parts to Stewart Engineering, and this company is now the sole supplier of spares for post-war Sunbeam motorcycles.
Bill

Offline Topdad

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Re: 1925 Sunbeam 500 Model 101
« Reply #4 on: 11.08. 2022 09:20 »
Rex, take my word for it they did ,when in 1969 I worked in liverpool for the main BSA/Tri dealer ,Cundle mtrs after working for Horsman's who were main "retail"BSA/Tri dealers about a mile away , I found to my disgust a b asement full of those things ,well at least 25 plus similar mopeds (??) first job ,sell this lot , workshop said scrap'em as the costs of getting running would outway any sales .Sales prevailed I went off on saturday night and thank god found the showrooms floor had given way smashing the bloody things to bits ,off the hook. I was told by the workshop manager that the first ones were ok ish but then a spec was changed the barrel should have been coated in something ,can't remember, but the bean counters had had there way and plain iron was the way they came out and they siezed. If you got one running the buggers were fastand someone raced a special with one of there engines ,my opinion hasn't changed ...crap
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Offline RDfella

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Re: 1925 Sunbeam 500 Model 101
« Reply #5 on: 11.08. 2022 11:03 »
For years I lusted after an S7 in mist green. Different but beautiful too. I seem to recall BSA decided to emasculate the engine power as a means of getting the transmission to last. Shame they didn't modify the transmission instead, although I think vibration was another issue.
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Online Greybeard

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Re: 1925 Sunbeam 500 Model 101
« Reply #6 on: 11.08. 2022 16:53 »
As a boy I was also in love with the S7 Sunbeam; it was so very different to any other British motorcycle. 👍 They all seemed to be Mist Green.
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Re: 1925 Sunbeam 500 Model 101
« Reply #7 on: 11.08. 2022 21:20 »
G'day Fellas.
I remember as a kid a friend's father had a S7 motor under his bench. We thought of putting it in a gokart. Never did get there.
Cheers
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Online Rex

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Re: 1925 Sunbeam 500 Model 101
« Reply #8 on: 12.08. 2022 08:23 »
Sunbeam used worm gearing with a bronze spiral gear; by reputation the soft bronze gave rapid wear of drive components.

One of the many "bad reps" the poor old S series still have to suffer all these years later. The supposed problem was solved many years ago just by using the correct oil in the rear drive.
Biggest problem of the bike was the sheer weight of it, although marketing an expensive bike post-war as a "Gentleman's machine" was not a good move either as it surely must have been a non-existent market.
They're nice bikes (I had one until very recently) but having just the one spares supplier can mean expensive and/or OOS parts waits.

Offline Topdad

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Re: 1925 Sunbeam 500 Model 101
« Reply #9 on: 12.08. 2022 11:47 »
This will break your heart Rex, back in 1966 and  newly licenced to kill motorbikes by stupidity,  my best mate wanted a bike ,any bike but bigger than 250 ,so an outfit was the ideal solution . Igot asked to run him up to formby and money exchanged hands ,can't have been much  cos whe didn't have much? Anyway condition of sale was that he tokk "all of the spares " as well .We filled the sidecar with sunbeam bits ,large lumps of engines at least 3 of those massive dynamos  etc ,bike duely performed well and after parking up all spares were put in his mums lock upand duly forgotten about ! Bike ran like a clock for a couple of mths ,boredom set in and one on arriving at his house I found him balls deep in the bike ,he'd decided to do a decoke why I'll never know , like a demented dervisher bits were flying ,slight exageration  but not by much , all over and after much grunting the head was loose ,he hadn't realised it was ohc so chain still attached another half hour and some how that freed and he was able to clean and grind ,much sweat was created and tempers flared as i was only there watching khaving only just started to dable with my A10,over the whole weekend he laboured and put all together, such requirements as timing forgotten after all he'd not moved the engine (?) moving the outfit about 2 feet in gear hadn't been noticed til later , any way it , of course it wouldn't go ,I towed it ,etc still no life eventually light stopped play ,the outfit stayed there for 2 mths and he sold it for next to nothing .2 yrs later Mums moving and suddenly all these bike bits , she threw the lot in the bin ,what a shame also taught me one undeniable fact "don't try to fix something that isn't broken "   
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Online Greybeard

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Re: 1925 Sunbeam 500 Model 101
« Reply #10 on: 12.08. 2022 13:45 »
TD,
That scenario must have been repeated frequently when old bikes were worth very little.
Greybeard (Neil)
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Offline sean

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Re: 1925 Sunbeam 500 Model 101
« Reply #11 on: 12.08. 2022 15:07 »
as some of you are Sunbeam enthusiasts does anyone know what year and model this  one is  ?
it was my uncles in the Uk .