On a flip-flop hub, how much difference in gearing is typical? Feasible?
 

So I'm thinking of going ss/fixed, and and I'm thinking of 46/17 on the fixed side, but on the freewheel side as a bailout gear how much bigger can I go before I run out of dropout? 19? 21? I'm sorry if this a dumb question...

My wheels all seem to have a 3-tooth difference between sides, but my dropouts are perfectly happy with a 6-tooth difference.

it depends on how long your trackends or dropouts are. i run a 14 and a 16 on my bianchi without a problem.

Put a master link on your chain, carry another master attached to a few regular links in your flat kit and you can have as much difference as you want.

i asked about the dual masterlink a while ago:

http://www.bikeforums.net/showthread...ual+masterlink

in the end, i decided to just have one chain without the masterlinks. ymmv.

I don't follow the bail out gear on the flip side of the hub.
In my theory if you only have the one cog that is what you are going to ride. Uphill, downhill on the flats , in the wind. It doesn't matter. If you have a gear to switch.....well that is going to mess with your mind. You are always going to be thinking ( tis too tough better use the bail out).

Well thats just how I feel.

Tony

what tony said.

(i might feel a bit differently for touring though).

It makes perfect sense in my head - I run the small cog for pavement and the larger one for dirt. Same deal with the flip-flop freewheel hub.

my dropouts are like those 80s type of dropouts--ie slightly horizontal, about half of the length of classic Campagnolo dropouts... it affords a 3-teeth difference on the cogs... ONLY if the extremes of the cog fit on the extremes of the dropout... ie if 17t is centered on the dropouts.. i can run 16 and 18

I understand if the bike is dual function. If I had to tug my kids in the trailer using the same bike as my daily ride then I would want different gearing. There is no way I can pull them around in the gear I use everyday .... well I can but it's no fun.

So one ratio for dirt and one for pavement sounds good to me.

I just do it with a different bike.


Tony

I've heard of SS'ers using the fixed side as their bailout more than the other way around. And it makes sense, if you take their concept of bailout. Ride the freewheel exclusively, if it blows up just flip the wheel and you can still ride home.

I have a three tooth difference with no problems. I run 49-18 for the street but when at the track I flip over to 49x15. So, in essence I'm not running a bail-out gear, but rather a street gear and a track gear.

As for dropouts, I have the 49x18 set up right at the very beginning so it's got a tight clearance and when I switch to the 15, it goes in the middle of the dropout. I could probably drop another two teeth and be towards the end of the dropouts. This would be for a Soma frame.

Thanks for all the info, it really helps. As far as my motivation, I'm (seriously) considering a flip-flop set up because I ain't never done this one-gear thang before, so it's a little bit of FUD* responsible for wanting the freehub. Go figure...





*Fear, Uncertainty, and Doubt

I have a flip-flop hub, but I don't have a flop on it. I haven't put a freewheel on it yet. So far, I haven't really had the need to. You could always do that... :p

It sounds like you actually know some people who will actually flip the rear mid-ride if they come across something to difficult for their gearing. Is this correct?

According to Sheldon Brown, Adding/Subtracting a tooth will move your axel 1/8". Adding/subtracing a link, will move 1/2". So do some math, measure your dropouts and you'll have your answer

guh. I knew there was some reference/rule of thumb, but I didn't find it on Sheldon's site. Guess I was too busy playing with the gear calculator. Thanks--

Why not build another wheel with a sturmey 3-speed hub? They have the same OLD as a track hub. Just get a long piece of housing, some zip ties or elec tape, an old clamp-on chainstay cable guide, and jimmy the shifeter onto your bars and voila--you have a 3speed track bike. You can swap as you please.

You'll probably start all the hipsters thinking that planetary gears are the next cool thing, and that maybe mesh hats and tight tshirts are on the way out.

sigh