running a single chainring

[nicmarsh]

I have a 531 frame, circa 1956. I am slowly gathering parts to get it back on the road and get a feel for the bike before considering further restoration.

So at this moment in time it is not going to be 'period correct' but I do wish to make nods in that direction where desirable and affordable. So I have 27 x 1/14 alloy wheelset in place. I intend to run a 5 spd freewheel and would like to run a single chainring. 5 speed, just what I grew up on!

I assume it would have had a single chainring when new, there is one braze on for a shift lever. I also assume that chain-set would have been steel.

QUESTION BEING: If I buy a used chain-set that currently has inner and outer rings can I use the cranks and simply put a single, maybe new, chainring on? I have been looking at 49D's to give a period feel though they aren't always affordable! More 70's something like Sugino Maxi cost less but obviously are intended for two chainrings; could I run these as a single chainring? I have noticed a new single crank-set FSA gimondi which may prove a better option.

Any views?

[thirdcrank]

There are plenty of chainsets around intended for a single ring: ie virtually everything intended for hub gears and everything for track racing.

The main thing to be aware of is that a lot of older singles (and probably some current ones) are 1/8" width while a 5 speed derailleur needs 3/32".

PS Have a look at stuff for what are now known as "fixies." What some of us call fixed wheel, which is enjoying something of a revival.

[531colin]

£20 for an alloy cotterless?.....not period correct, but cheap enough to compensate? http://www.spacycles.co.uk/products.php?plid=m2b0s109p2188

[thirdcrank]

531colin's link reminds me that as well as "fixie" we now have "single speed." From your POV, no difference, as you will be running a 5 speed freewheel, but if you need to look further, it's another search term you can use. But check the width before buying.

[bobc]

I've been using single chainrings on 'dual chainring' crank/spiders for a few years now. The only problem is that the 4 or 5 bolts you get with the dual will be too long & wil tighten upon themselves while leaving the chainring loose. Nil desperandum, it's a simple grind/file to fix or shorter screws/nuts can be obtained

[garibeet]

You can actually get shorter bolts just for this purpose, all my bikes are single chain ring.
http://www.evanscycles.com/products/id/ ... wwod61UAeQ
There you go, 10 second search, second hit. The inter web is useful sometimes

[CJ]

Single ring sounds simple but can bring unexpected problems. Back in the day, even derailleur chains were 'full bush' and relatively rigid. The shifting breakthrough came with the Sedisport split-bush design, that has been continuously improved so that modern chains skip between sprockets and fall off a chainring (onto the chainring below if there is one) with the lightest off prodding. Nowadays all chains are split bush - even single-speed and hub-gear chains!

You will not find a full-bush derailleur chain without paying silly money for a rare surviving item of old stock, and will have to get the chainline spot-on to avoid the chain falling off at the slightest provocation.

It will be simpler - and result in a more useful bicycle - to fit a double anyway, complete with its useful chain re-railleur device!

[pioneer]

Nic, it might be worth taking a look at the stuff in Velosolo in London. I ride mainly singlespeed and fixed wheel and get most of my bits there.

[nicmarsh]

Thanks all for replies. I certainly will ensure will only be looking at 3/32 chain. Its a pretty frame, nervex lugs, Youngs of Lewisham, so cosmetics become an issue too!

Still not sure what I'll do though...... I have been ebay bidding on various Stronglight and Sugino cranksets and will probably keep looking in that department at the moment, though seems like it might be easier to just go out and buy new with a retro look. May work better too?

[sreten]

Hi,

If you have a frame and then build it up to a bike it will certainly
cost you a lot more than a new bike with a similar frame, unless
you source all parts used and cheap, that is the way of things.

Conversely if you have an eye for used high quality stuff going
cheap you can build a high spec bike, still won't be cheap, but
cheap for all the bits, if the frame is is worth the effort.

rgds, sreten.

[Grumbleweed]

The 49D is a good choice for single chain ring applications.
Plus you can normally pick them up for 20 quid at bike jumbles and usually in very good condition.

[pliptrot]

For the dedicated follower of fashion the SRAM corporation seem dedicated to peddling single ring chainsets. They started a year or so ago with their single ring x11 on the back "system", and are now pushing the same design at cyclocross. The design remains inelegant - the chain angle from a single ring up front across a wide cassette at the back can never be a good idea. But the idea seems to be gaining ground. Good idea, marketing gimmick, daft idea? What do you think?

[nicmarsh]

The 49D is a good choice for single chain ring applications.
Plus you can normally pick them up for 20 quid at bike jumbles and usually in very good condition.

Yes 49D would be my first choice, but not seen any for twenty quid yet!

[CJ]

For the dedicated follower of fashion the SRAM corporation seem dedicated to peddling single ring chainsets. They started a year or so ago with their single ring x11 on the back "system", and are now pushing the same design at cyclocross. The design remains inelegant - the chain angle from a single ring up front across a wide cassette at the back can never be a good idea. But the idea seems to be gaining ground. Good idea, marketing gimmick, daft idea? What do you think?

Interesting to note that they've had to develop 'thick and thin' chainrings to keep those promiscuous chains in place. Thick and thin refers to the teeth, to mesh more tightly with outer and inner links respectively, so the chain can't flex sideways so much - after the point of engagement at least. It seems to work really well - but adds to the cost of machining.

If you ask nicely and cross their palm with gold, Middleburn will probably make you a thick and thin chainring for some other bolt circle (like 5-pin) than those catered for by Sram or the other big boys in the playground.

[garibeet]

Wow, I must be really unlucky running single chainrings, of the 4 bikes that I have including one that runs a 6 speed cassette(shortened xt 9sp) I have yet to drop a chain at all. Unusual it seems given the tenant of this thread seems to be that it is inevitable..... What could I be doing wrong?