Hello all. I was thinking of taking up a project but need an opinion on whether or not this is even possible. And before I drag it out to a LBS to have them laugh and try to sell me something else, I decided to ask you guys. Okay, I have a 2010 Trek Soho S and was wondering if its even possible to hang a rear derailleur on this bike. That would probably be the main issue if I were to try (and maybe cassette fitting?). I just have love for this bike but I want some gears. I know I could just buy a bike off the internet for cheap or whatever but that's no fun! Let me know what y'all think!

I believe that you can by derrailleur hangers that fit slotted dropouts so that part is possible. But if it's a dedicated SS then the dropout spacing will be too narrow to allow fitting a geared wheel by enough that it will be a serious factor.

Finally there's LOTS of great riding bikes out there that will feel just as good as this one. And given all the things you have going against you on this conversion I'd just keep this one and enjoy it for what it is or sell it to finance a geared ride.

If the spacing is wide enough, switching to an IGH would be a better way to go.

+1

The advantages of an IGH would be clean looks, compatibility with frame, gears, and a fairly wide range of options as to how many gears you want.

Cheers

Thats a good idea. Duh. Never thought of that. Gotta do some research on those. I would still like to know if i can put a derailleur on. Im not sure if its a dedicated frame or not. It kinda just looks like a generic MTB frame minus cable guides. Of course that may be another problem.

If you are SET on having a derailleur, how about a front one? A double crankset will give you twice the gears. With an IGH on the back, you could be in business!

No go. He'd still need a RD to be able to cope with the chain slack needed to be able external gears. He COULD fit a a geared crank(like the Schlumpf) but it'd be prohibitively expensive.

As already stated, an adapter claw, or a low-end RD with an integrated hanger will let you do just that.

About 30 seconds with a ruler or a tape measure should sort that out.

Well, the basic frame is such a successful design that there are a lot of bikes that looks pretty much like any other bike.

Not really. There are plenty of MTB riders who run cable sheaths all the way from shifter to RD to get better protection against mud and dirt. Use plenty of zip ties and functionally there's no problem.
Besides, a bit of searching will show you that there are cable stops and mounting brackets available for after market installation. They go on a bit like hose clamps and work just fine. Not quite as elegant though, unless you go for the chromed ones.

My bad. I forgot about the chain length difference for two sizes of rings.

There's no doubt at all that this is a dedicated single speed frame. The horizontal dropouts with no derraileur hanger is a dead giveaway for that fact even without the added evidence of the lack of shifter cable stop points.

Hey thanks for all the replies. You guys are full of info. But I just bought a frame off ebay so I can build a bike that IS possible! Thanks again!

FWIW, Schlumpf Cranksets have a Planetary gear in them to create a second ratio, with out a front derailleur

His Speed Drive is 1.6X in overdrive mode,
there are 2 - 2.5X cranks .. 1, overdrive 'high speed drive'
and reduction gear 'Mountain Drive'

I got the latter for my Brompton, with an AW3 hub .. 15t cog on the hub in a 349 sized wheel

so, in low range, I have 3 more gear ratios.

oh, and you can reduce the width of many IGhubs , just take off some added Nuts on the left end of the axle, My Folding bike has a 117 wide over lock nut distance..

So not prying the dropouts out to fit a 135 hub can me avoided.

Folks have used a Sachs (SRAM?) Duomatic, a kick back shift 2 speed hub, and a Schlumpf crank to have 4 ratios,
and still no shifting cables.

some current SRAM IG hubs use a shifting 'klickbox' at the hub which is a continuous cable in housing all the way from the handlebar control , no fittings needed , just zip-tie the housing to the frame.