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PostPosted: Sat Nov 28, 2009 2:11 pm 
Dirt Disciple

Joined: Mon Nov 24, 2008 11:17 am
Posts: 10
A preliminary search has found a few snippets of info but nothing comprehensive on a bike I've just acquired. The bike is a Trevor Jarvis Flying Gate - I have its provenance and know that it was bought as a frame and forks only from Trevor in late 1982/early 1983 - so the owner obviously built it up himself (or his LBS)

What is foxing me is the gears - it has :

1 a Sturmey Archer 5 speed hub with "S5.2" stamped on it, together 83 - 2 (the shell is the engraved style, not the printed on lettering) with 2 sprockets and chain pulling thing for the changer on both sides of the axle

2 a Suntour derailleur that, obviously, shifts the chain from one sprocket to the other

There is a dual lever attached to the stem - the LH side lever connects to the changer on the left side of the axle; the RH side lever connects to the Suntour. There is also a Sturmey Archer trigger that connects to the RH side of the axle.

So, I assume that if the hub is a 5 speed, then the bike is a 10 speed.

What is also odd is that the hub has a separate alloy flange bolted to it. It's like a giant allow washer that is bolted, with small bolts, through alternate spoke holes on the hub flange - and has a set of spoke holes on its outer edge - and the wheel is laced as normal with short-ish spokes. I've never seen anything like it before - the flange is odd, the only possible reasons I can think of are that a) the wheel could be stiffer with shorter spokes, or b) it makes changing a broken spoke a lot easier (esp the sprocket side)

I've posted a few pictures on my website at : http://www.beewee.org.uk/index.php?opti ... Itemid=106

I'd really appreciate some thoughts on what it's all about ... and my decision has to be made on whether to abandon all this hub stuff and fit conventional cassette/mechs when I refurb it over the winter.

Rob


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PostPosted: Sat Nov 28, 2009 3:32 pm 
Gold Trader
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Joined: Sun Jun 22, 2008 1:38 pm
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Location: OZ
Presumably the sprocket(s) on the rear are made by Cyclo - they made two and three speed converters up until the early 90's

I had the privilege of touring their factory in Perry Barr in the early 90's- wish i had bought a lot of the odd stuff :-)

You can in fact fit an old (1930's/40's) threaded sprocket driver to an old S5 hub and screw a multispeed freewheel on there..........

I think you're probably right re the hub flanges in that this was done to enable easy changing of spokes. in addition the steel hub shells were notorious for breaking modern spokes due to the shell being thinner that the spoke bend. The thicker alloy plates would get round this problem also

I have a replica Gate made in the early 90's which can be found in the "reader's road bikes" section- altho the maker is unknown- it's definitely NOT a Jarvis :-)

Andy


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PostPosted: Sat Nov 28, 2009 4:08 pm 
Dirt Disciple

Joined: Mon Nov 24, 2008 11:17 am
Posts: 10
fatfixie wrote:
Presumably the sprocket(s) on the rear are made by Cyclo - they made two and three speed converters up until the early 90's

I had the privilege of touring their factory in Perry Barr in the early 90's- wish i had bought a lot of the odd stuff :-)

You can in fact fit an old (1930's/40's) threaded sprocket driver to an old S5 hub and screw a multispeed freewheel on there..........

I think you're probably right re the hub flanges in that this was done to enable easy changing of spokes. in addition the steel hub shells were notorious for breaking modern spokes due to the shell being thinner that the spoke bend. The thicker alloy plates would get round this problem also

I have a replica Gate made in the early 90's which can be found in the "reader's road bikes" section- altho the maker is unknown- it's definitely NOT a Jarvis :-)

Andy


Just looked at your bike ... I can see why Trevor says it isn't one of his - it looks from the photo as if the wheelbase is the same as a conventional bike (i.e. the seat tube if continued to the BB would allow a rear wheel to fit) rather than the Flying Gate concept of a shortened wheelbase created by the vertical tube and the rear wheel extending forward of the seat tube alignment.

I've been digging around on the net and have had some answers on another forum ... I think I'm going to ditch all the hub stuff and fit conventional cassette, derailleurs etc when I do the refurb ... it's not as if the bike was built with the hub gears.

Rob


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PostPosted: Sat Nov 28, 2009 5:25 pm 
King of the Skip Monkeys
King of the Skip Monkeys
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Joined: Wed Nov 07, 2007 4:34 pm
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Location: Moomin Valley
look up chris667, he's your Sturmey man


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PostPosted: Sat Nov 28, 2009 7:24 pm 
Old School Grand Master
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Location: Lost in Translation
"Hybrid gearing" (hub gears combined with derailleurs) always had a following among British bike-tinkerers, and Cyclo (among others) made parts to make the job simpler. In the late eighties there was even an adapter on the market (the "Dacon converter") that would allow three Shimano Uniglide sprockets to be mounted on a Sturmey hub.

The S5/2 was a decent hub. It's basically two three-speeds in one can: a medium range and a wide range. The left hand lever shifts between the two. Middle gear is direct drive, and common to both, hence five different gears.

I haven't seen those big add-on flanges on a Sturmey hub before, but it used to be fairly common to rivet big flanges onto a small-flange hub body. You see it fairly often on French touring bikes of the fifties and sixties. Some people claim it makes a stiffer wheel, and it certainly makes it easier to replace broken drive-side spokes. fatfixie's got a point about spoke breakages being more common with the thin steel flanges. People used to pack out the spoke elbows with brass washers to reduce flexing at that point. Sturmey also produced an alloy-shelled model of the S5/2.


Last edited by one-eyed_jim on Sun Nov 29, 2009 6:25 am, edited 1 time in total.

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PostPosted: Sun Nov 29, 2009 1:03 am 
Gold Trader
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Joined: Sun Jun 22, 2008 1:38 pm
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My gate replica does have a short wheelbase- i have compared it with a friend's Jarvis replica and it's a pretty faithful copy.

The pic is not accurate- the seat tube would rub nicely on the rear tyre if it was continued....................

Would be a shame if you didn't use the S5 hybrid system- maybe fit to another frame (good excuse to buy another bike :wink: )

Andy


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PostPosted: Sun Nov 29, 2009 10:16 am 
Dirt Disciple

Joined: Mon Nov 24, 2008 11:17 am
Posts: 10
fatfixie wrote:
My gate replica does have a short wheelbase- i have compared it with a friend's Jarvis replica and it's a pretty faithful copy.

The pic is not accurate- the seat tube would rub nicely on the rear tyre if it was continued....................

Would be a shame if you didn't use the S5 hybrid system- maybe fit to another frame (good excuse to buy another bike :wink: )

Andy


.... NO - I've got 15 already!!!!!!!!!

Rob


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PostPosted: Sun Nov 29, 2009 12:23 pm 
Gold Trader
Gold Trader

Joined: Sun Jun 22, 2008 1:38 pm
Posts: 1439
Location: OZ
Only 15.............- i wish i had only 15 :D


Andy


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