None of the advantages (still need both mechs, or the chain will be too long in the small/too short on the big, chain line won't be perfect either) of SS, but a less useful range than a 1x10, can't think why it's not popular...

If you use a cassette rear wheel with spacers, you can run two sprockets on the back and two chainrings - get the combination right (basically same number of teeth total) and you can swap the chain between the inner/outer sets of gears and it'll work.

If you've been silly and got a SS specific rear wheel then this obviously won't work (unless it's a SS cassette version).

go for twingle/dingle speed - 2 front/2 back and if you get the ratios right the chain length is right for both.

Its doable if you use a springed tensioner to take up the slack chain.

problem with dingle you cant change on the fly.

You could do what they do with brompton SL2s, two sprockets in the rear and a rear mech as a tensioner/2 spd shifter.

Nice oldskool thumbshifter on the bars, short cage road mech on the back with the stops wound all the way in either side (maybe need to swap out the screws for longer ones to restrict the pantograph travel enough), two groove amada sprockets and some cassette spacers. Set the chain banjo string tight on largest sprocket.

If you go with a WI double freewheel and a WI double-double ring, you'll get 2 ratios which use the same chainlength.

[url= http://farm3.static.flickr.com/2442/3571025018_c90a63c06a_b.jp g" target="_blank">http://farm3.static.flickr.com/2442/3571025018_c90a63c06a_b.jp g"/> [/img][/url]
[url= http://www.flickr.com/photos/singlespeed-pimp/3571025018/ ]White Industries Double Double[/url] by [url= http://www.flickr.com/people/singlespeed-pimp/ ]Singlespeed Pimp[/url], on Flickr

As said above, it's easy to do with either a 'proper' [url= http://www.wiggle.co.uk/surly-dingle-track-sprockets/?dest=1&curr=gbp&lang=en&utm_source=google&utm_medium=base&utm_campaign=products ]Dingle[/url] or with sprockets giving the same chain length eg. 36/14 to 32/18

I tried for winter commuting on my HT as it was uphill to work and downhill home. I couldn't get the tensioner to pick up enough slack (even with a dual jockey wheel tensioner) as the difference between the 2 front rings was too big (think it was 22-34), so I would have needed a new front ring, at which point I gave up. Either that or use a real rear mech.

In the end I left on the front mech and just used the bigger ring and went to work slower, and put gears back on in April. Hoping to get out more this winter so may try again now I know what the problem is/was.

I did do it for a while - it worked but imperfectly. I went full S/S for a bit but have now built with a Sturmer Archer 3 speed internal hub.

I have an Inbred with slots and a regular freehub with 18T and 13T running to a 32T front.
I run the 13T on the road and move the wheel forward for the 18T when offroad.
The 18T is in the perfect chainline, 13T 1 space displaced.
Takes under 1 minute to change over.
I use a normal steel skewer QR and it seems to be OK on the 13T road setting without needing the chaintugs, which are set for the 18T.
So, no tensioner and extra weight/complexity.
Simples.

So... you feel the need to change the gear ratio while pedaling? If only we lived in a world where there was some method of doing this simply and cheaply

Maybe one day eh..... I live in hope

OH **** ME!!!!! I'VE JUST THOUGHT OF SOMETHING!!!!!!!!

[img] [/img]

😉

The Alfine tensioner takes up a fair bit of slack. Have considered doing this on my CX bike (one gear for tarmac, one for dirt) but haven't actually done it.

Okay Dok"a"y Bikists.. Mucho thanks for your non flaming opinions to my most humble of questioneeee.

Having read your thought's/dones/have dones/won't erm,dones, I've decided to bin this little fag packet idea of mine and toss it right over into the bin of choice, which today is non recycled bin (because I'm a rebel in disguise)

And sin of all sins, enter the wardrobe marked "world of 1x9, welcome, please wipe your nose upon entering"

Cheers chaps

you could use a hammersmidt to do the job up front without needing anything at the back? Might meet your needs

ScienceOfficer runs a twingle with an EBB.

If you want to use a tensioner, get one like the DMR which allows you to adjust the left-right position of the jockey wheel. Then you can change which pair of rings you are using.

If you are using slotted dropouts or an EBB you wont have this problem.

dingle or 1x? are the best options.

depends whether you want to change on the fly or not.

IMO.

you could use a hammersmidt to do the job up front without needing anything at the back? Might meet your needs

Not good. Your more 'normal' gear is the higher Hammerschmidt gear and is very draggy. The lower gear for climbing the hills is the non-draggy one, so it just becomes a royal PITA.

http://www.bikerumor.com/2010/09/09/review-truvativ-hammerschmidt-a/

[url= http://www.sturmey-archer.com/products/hubs/cid/7 ]Problem Solved... [/url]

I built a single speed, my knees hated it. Adding a Sturmey 3spd hub has made it tolerable. Cheap, bomb-proof, still uses the 1/8" chain in a straight line. On the other hand - it's a bit heavy, and is a bike that absolutely no-one will ever admire. If you used a Hammerschmidt it would be pretty much the same, except for the lack of admiration bit. Oh - and the cheapness.

a bike that absolutely no-one will ever admire.

Surely a "Theft proofing" Bonus for a commuter bike though?

ScienceOfficer runs a twingle with an EBB.

Not actually correct. I run as the OP describes, with a Rolhoff tensioner. Really, I use it as a single speed. My second front ring is a granny, which I refer to as my 'cheater ring' and is there for big days when I'm spent and my legs can't handle the 2:1 gear.

I've used it about twice, and shift manually by physically moving the chain to the other ring by hand. It runs fine like this.

Anyone get a.dingle.to work ok?

I tried it but needed a tensoner

Pauls melvin will let you run a souble up front and singlespeed rear. I have used one on a few SS conversions including full sus ones. I think it'll work better (or ones that are similar) because it has two jockey wheels so holds the chain better.

Orange built a P7 a couple of year similar to this:

[url= http://www.flickr.com/photos/thebicycleescape/3594421663/ ]Dingle-speed[/url]

OK so you adjust the tensioner position by hand when you switch between the different chain rings. Neat!

I ran an alfine with twin rings and an alfine tensioner, it coped no probs with a 14T difference at the front, ran an 8spd chain.

OK so you adjust the tensioner position by hand when you switch between the different chain rings. Neat!

I'm not sure if thats aimed at me buzz, but, no, I only need to shove the chain across to the smaller ring. The rolhof tensioner is a two wheel affair with a strong enough spring with enough range to cover at 22 to 32 range. Its easy and painless and has the benefit of the tensioner automatically taking up chain slack too. Its never dropped in this configuration either.