random gear set up

uglypoo

Just a quick thread to find out if anyone has tried just running a front mech and two gears on a commuter bike with a single ring on the back...
My ride to work is pritty flat and dull with two good hills on it. I've been riding a mountain bike with the whole 27 gears and found i only need the biggest and a smaller one for the climb and could do without the rest (less maintanance/lighter/etc)
Apart from chain tension i can't imagine any problems just wondering if people have experience.

cheers bigears

lost_in_thought

I think you'd have trouble with your chainline, wouldn't you? I've always been told it's important...

You could achieve the same effect by simply breaking your rear derailleur...

neil_sheehan2000

I don't think chainline would be a massive issue if the one cog you had on the back was in the middle of where your cassette used to be, but chain tension would be a pretty large problem. I'm struggling to see how you would get away with not having a rear deraileur (if that is what you're suggesting)- I suppose you could just fix it in place so you wouldn't need a cable or shifter (bit of a bodge though).

Are you proposing to use the biggest and smallest rings a the front as well, and getting rid of the middle one? Cos I don't think your front deraileur would like that at all either (the difference in the number of teeth would be too big).

uglypoo

my overal plan is to go for a single speed rear wheel (dmr revolver stolen from an old jump bike)and use the middle and outer chainrings at the front, probably a 32 and 44 tooth (46/48 if i can get away with it).
i spend 4 miles of the commute going along an fairly flat dirt track in the biggest gear i have then drop down just befor work for two on road climbs... my legs are too puney for a big ring climb but 27 gears seem a bit ott

neil_sheehan2000

Ah, fair enough. As above, bear in mind the chainline issue though (can you choose where you put the single ring at the back?). What are you using to tension the chain? I'm no expert but I'm not sure whether your usual single-speed chain tensioner will take up that much slack. (Though, to be honest, I haven't got a clue...)

Aidy

Get a HammerSchmidt!

That would be all kinds of awesome

Jehannum

You might find a compact chainring for the front gives you what you want: 34/50.

Do the limit screws on the current rear changer have enough travel to hold it in one gear all the time? Or could this be acheived by replacing them with longer screws? This would be easily reversible if you wanted the gears back in the future. Then it's optional whether you remove the shifters, cables etc... Not a lot of weight saving, I'll admit.

J.

whyamihere

It can be done. You'll need to run a locked out rear mech to provide chain tension.

biondino

If you're running a rear mech you can try this newfangled "gears" thing too!

always_tyred

What would be gained by this setup? Are you proposing to go fixed gear? If not, the only mechanical feature you woud be omitting is the front shifter and the cassette. I reckon you'll save about 200g.

Given the hassle, and the fact that in any event you would have to use a normal chain (not a ss/fixed chain) is this a useful project?

uglypoo

valid points allround guys... cheers for the ideas. weight saving would be minimal but every bit counts when you're a lazy bugger like me.

Looked at that HammerSchmidt thing, damn good idea but not cheap but would be the perfect option.

Original plan was to cut maintanace and cut cost of replacing parts (time for a drivetrain overhaul anyway) and i just liked the no maintainance of my old jump bike but i really need more than one gear

any ideas how to get over the chainline problem?do spacers on the chain rings work or is it time to start measuring up for a new bb?

love you all

fossyant

Buy a FIXED !