DannyPants

Hello everybody, this is my first post here!

I am building my first road bike to commute around my college campus, and I can't decide between building a fixed gear or building a 5-7 speed (I've pretty much determined that 5-7 gears is all I will need.) I really want to try a fixed gear for flatter rides, but I also want to be able to switch to a derailer system for days when I ride places that are more hilly (I figure it will be easiest for me to just have two chains, one short for the fixed and one long for the derailer.) Also, just to make things clearer, I will only have one chain ring up front.

I've been looking everywhere, and does a rear wheel exist that will allow me to have a fixed gear on one side and the a 5-7 gear cassette on the other side? I have seen flip/flop hubs that have a fixed gear, and then a freewheel on the other side, but I want to have multiple gears on the other side. I wondering if something like this is even possible, or if I should just buy two separate rear wheels. Thanks for the help!

operator

no

Doctor Who

Unless you like pouring money into an overly-complicated bike project, you might as well buy two bikes: one being a fixed gear, the other geared.

You could also buy something such as a Surly Long Haul Trucker or a 'cross bike with sliding dropouts and go back and forth between fixed/geared, but even then, that's more trouble than it's worth.

EivlEvo

Oh boy.

You should post this in ss/fg 1st of all and then take the flaming as welcoming.

You could THEORETICALLY run a flip flop and thread a 5-7 speed FREEWHEEL onto it but you would have to have a frame with the proper spacing and if you were running fixed on one side and a freewheel on the other side you would have a derailler anyways so what would be the point? Not to mention... when you ran it fixed your chainline would be a disaster (most likely)

What I would suggest...

1. Goto Sheldon Browns website and read read read.
2. Get yourself some cheap POS with horizontal or semi horizontal drops.
3. Get a flip flop hub and run it fixed on one side and single speed on the other side. You can gear up by 1 or 2 teeth on the single speed side so that if you REALLY can't get up a hill or something you can flip it and go.

If you were going to build a geared bike to commute... I would just buy some cheap pos (used not new... a used POS is most likely an actual "real" bike instead of some wal-mart crap) and use that as is.

Welcome...

Don't leave if the fixed gear / single speed guys trash you.

DannyPants

Thanks for the replies. I figured that must be the case that such a hub does not exist. I actually just bought a Surly Cross Check frame on ebay yesterday, I'm excited!

It doesn't seem like too much trouble to me to simply swap the rear wheel and chain when wanting to switch from fixed to geared, that's only a 5 min job or less I figure. And if I only had one chainring up front couldn't I align it so it would work pretty well with fixed and geared? And would I have to take the derailer off when I use the fixed gear, would it be in the way?

Oh, and basically the point of trying to find a wheel like this is because it would be like having two bikes in one, much cheaper than having to buy 2 separate bikes.

EivlEvo

Yes you'd have 2 bikes in one but its sort of like redundancy.

I mean... I have my "racing bike" which I will ALMOST never ride anywhere except for training and racing purposes. I also have my fixedgear that I use to commute. It has flip flop. I only use the fixed side. In fact... I don't even have it setup for ss.

You could just build a single or fixed and get a gear ratio that is optimum for your type of commute.

The derailler wouldn't be in the way, but you would have to disassemble the chain every time you wanted to swap between geared and fixed.

As far as chainline, you'll most likely be screwed. Chainline variances are largely adjusted on a "converted bike" by using 1. spacers on the rear freehub, which would mean that you would have to change your cassette/single gear everytime you wanted to switch. or 2. by the dishing on the rear wheel and the spacing inside the rear triangle. If you have a wheel built for a flipflop it is built to run single speed on the freehub side, and fixed gear on the fixed side. Either way... thats 1 gear on each side. Stacking a cassette in there would require you to redish that wheel. Otherwise... ur screwed.

The Cross check is a sick frame. It uses the "Gnot rite" spacing for the rear which means you could squeeze it to run a road cassette or stretch it to run an MTB cassette.

I think you're not understanding why your idea is very dangerous though.

mascher

2 speed fixed cog from Surly, the dingle:



2 speed White Ind. Eno freewheel



2 speed crankset e.g.




Of course those eno freewheels cost about the same as a pair of Zipps, and the Dingle is twice as much as a regular cog... but Sheldon would probably approve.

EivlEvo

Those dingles are for the pugsly. I don't think you would be able to run them on a standard spaced hub.

Could be wrong.

Pugsly will run 2 gears on either side of its hub on the front and the rear.

26" x 4" will do that for ya.

operator

Yeah let's ignore the fact that he specifically said 7 gears

brianappleby

i don't think chains are really meant to be taken on and off like wheels.

You have a geared bike already? How hilly is your area? The elegance of a fixed gear bike is its simplicity. Just try it fixed. If that doesn't work, sell the parts and start over. Chances are that you'll end up riding the bike in one mode most of the time anyway.

Nullius

Get an ISO disk hub, and bolt a fixed cog where the disk-rotor would go. A modern hub would be set up for 8 speeds or higher, but if you're really set on 7 you can use a 2.5mm spacer. Get a bike with horizontal dropouts, and either two chains, or a chain with two masterlinks, and you'll be set.

mascher

But, but... I posted big pictures and had almost no content!

I would go with a one speed, but if I was going to use two speed "singlespeed" stuff I would totally use the cross-chaining combos with a double in the front and have 8 gears, which I guess is still not 5-7.

But I wouldn't use any of this stuff, I'd go one gear in an urban area or college town.

explody pup

I think the project would be more hassle than it's worth. But if you're set on it, you should look into an internally geared hub with a disc brake mount like the Shimano Alfine and the Sram i-Motion and mounting a cog on the brake side. It might take some ingenuity to match the chainline from the freewheel side to the disc brake side. If you keep the two cogs within a couple teeth of each other, you won't have to change chains when you want to go from freewheel to fixed.

mascher

I think that might be the only way to go about it that's reasonable, if there can be any sensible way to do this at all. That hub makes me want to do it too.

MarkSch

You can definitely do this, but you are probably going to need to look for some old-time (late 80s, early 90s) parts.

Way back when 7 speed cogsets were the norm, you threaded the entire cogset / freewheel assembly onto the hub. My old Mavic Comete disc wheel came with a fixed gear adapter that you could thread onto the same hub, allowing you to use the disk either in 7 speed mode on the road, or fixed gear on the track....still have it...it's up in the attic.

As an aside, this disk also has little holes around the periphery into which you can put weights....to get that flywheel effect....

SSSOOO....you could look for an older wheelset with a thread-on 7 speed freewheel (friction or old time index shifting) and look for a fixed gear adapter.

Mark

Approx01

just take that 7 speed cassette and jam some rocks and mud up in it

oh maybe you can find an old rusted cassette and wheel for free!