Horizontal drop outs - a must ?

RedAende

Would like a single speed with flip flop hub.

I have an old Mercian 531 road frame with standard drop outs i.e. about 1" long and at 45" angle.

Can I use a single speed wheel or do I need a frame with horizontal drop outs ?

Thanks.

peejay78

you can do it with forward facing dropou,ts as long as you have enough room to tension the chain. .

chainline is a bit more tricky. should be fine, just a bit of bodging.

rustychisel

should be okay. Depending on chain length and sprocket choice you need about 3~4mm adjustment room, then vroooooom.

Big Red S

If you're wanting singlespeed with a frewheel, not a fixed wheel, then you can do it on completely vertical dropouts, you just need a chain tensioner.

RedAende

thanks for the replies so far, so I can ride single speed,

but what about fixed ?

peejay78

yes, you can.

chain tensioners look really nasty.

the ferry

ok apols for this.
Are you saying that you can still ride fixed WITHOUT the traditional horizontal drop outs?

nicklouse

well i would not like running a fixed on a tensioner.

dont forget half links.

rustychisel

Yes you can. Using a half link, careful calculation etc.

http://www.fixedgeargallery.com/2005/ap ... heaton.htm

peejay78

"magic gear"

puddleduck

forgive the newbie question but would you need to change the hub when converting a geared road bike to a fixed without using a chain tensioner?

rustychisel: lovely bike, i have a 2002 ocr3 which i'm thinking about converting to a fixed. I've had a look at the "fixmeup" calculator, and measured the chainstay length to give me a suitable list of gear ratios. Is this what you did?

I'm a complete newbie when it comes to this stuff, been reading as much fixed related topics as i can!

rustychisel

ANY FRAME which allows you to get the right chain tension can be made fixed. Some are just harder than others... you really need about 3~4mm adjustment space, which is a little impossible with single position vertical dropouts. But yes, you can do it, and it's a bodge.

Hi Puddleduck, thanks for the comments. The Giant is nice to ride, but it's changed substantially since then (drop bars, new front wheel, seatpost, saddle, cranks).

The rear hub needs to be either a track hub or an old road hub with threads for a freewheel (screw on), often known as a 'suicide hub', because the fixed cog CAN unscrew if improperly installed or you treat it roughly... etc

I used the chain length calculator and opted for 42 x16 to give me the right gear, with a 1/2 link in the chain. Because the tension is too tight I also had to file the dropouts slightly - Sheldon Brown suggests a couple of other options. But yes, it's a bodge, it works okay, but it's not ideal. If the frame is valuable, you're not too sure about how to proceed, or you might convert it back to geared, then something like the ENO hub is definitely the best way forward. Expensive though.

If you don't mind fiddling along and trying things out, don't be afraid to experiment though. It's only a bike. Build it and ride it carefully until you know what it can do.

steverile

No problem running fixed in 'old style' semi-horizontal drop-outs. An inch long gives you plenty to tension the chain and experiment with different gear ratios. Same for freewheel, no need for a tensioner. But don't try and run fixed with a tensioner - it'll end badly

RedAende

Big Al my local wheel building guru has measured up the frame.

120mm traditional "campag" style drop outs (old 5 speed frame we think) so the wheel building has commenced with a flip flop hub.

Fitted a new headset yesterday and going to attack some rust with hammerite so should be on the road/canal this saturday for a minimal budget.

For those with short vertical drop outs White industries EON hub is the option, though expensive £120 vs £20 for a run of the mill flip flop. I looked at one and is a beautiful piece of precision engineering though dont think it would agree with scottish salt and rain.

RedAende

Thats me completed my first 30 miler on towpath.

New wheel, new chain & 42 & 18 cogs, cycle cross brake levers, result.

Was surprised at how quiet the whole thing is, total silence when cycling through the countryside on the towpath. (or is it just that derauleurs make a hell of a racket?)

Probably fit a freewheel on other side of flip-flop but at the moment getting used to riding fixed.

andyp

RedAende wrote:

For those with short vertical drop outs White industries EON hub is the option, though expensive £120 vs £20 for a run of the mill flip flop. I looked at one and is a beautiful piece of precision engineering though dont think it would agree with scottish salt and rain.

I probably could have got away with a normal fixed hub on my fixed conversion but went for the White Industries ENO hub in the end. It hasn't had much in the way of bad weather yet this winter but it's held up well so far. It feels very smooth too.