caloso

Have you converted a vertical dropout bike to fixed or single speed without an eccentric hub or bottom bracket? Post it here.

How did you do it? Did you use Eric House's magic gear calculator? Did you use a half-link? Futz with various chainrings and cogs? Invoke some bad juju? Light a candle to Our Lady of Ghisallo?

Why did you do it? Are you a mechanical genius? Are you a cheap bastard? Did you just have too many spare parts cluttering your garage? Was it a drunken dare? Or just for the heck of it?

And pictures if you've got 'em. I know you do.

Cynikal 

I did it on an 97 stumpjumper MTB frame. Found it by luck, 44x16 worked perfectly. Fixed on a MTB is a blast...you can trackstand for days.

Landgolier

This shizz is mostly caused by people not wanting to file a frame. Filed frame + ground axle gets you in half link range pretty easily. I'll never get why people reeely reeely want some bike to be their fixed gear but don't want to actually commit to it. Get some old steel rig and center your chi on that first if you don't want to go all the way.

Bravo to people that nail it via gear futzing, though. We should put together a spreadsheet of frames and combos that work.

Cynikal 

There is an online calc somewhere (it's in my fav's at home). You just need to measure your chainstay and it will pump out compatible gears. Cool stuff. I'll post it later.

caloso

Do you mean this one? https://eehouse.org/fixin/

cabana 4 life

i have a 94 gt pantera 42 16. it was tight till the chain stretched. its my winter bike who cares

Cynikal 

Yup...that's the one. Glad I could help

46x17

There is this amazing guy Greg in SF who has a custom built Eisentrout specifically designed with vertical drops in order to "get all the extraneous crap off the bike". He knows his gear and only rides that so he had the frame built accordingly. If you have a copy of Short Bike Rides San Francisco he is the guy with the fix to be seen on two photographs.

RedDeMartini

It seems to be mostly a matter of luck and patience. The right combo of links, ring, cog and chainstay can do it, the hardest part is putting it together wrong and being honest to the fact that it too slack or too tight and that you will have to do it all over again. Too tight is better as it won't kill you, just use more oil.

drac_vamp

too tight will hurt bearings, no?

jamey

and destroy your drivetrain quicker.

taras0000

and slow you down and snap chains

caloso

So then, it could kill you.

humancongereel

yep. pretty much.

eddiebrannan

how is a track end extraneous?

Cynikal 

With vert dropouts tension will never be an issue. One less thing to think about. I'm assuming that is what he is talking about. Myself...I like options.

Kiecker

One thing that helps in using a "magic ratio" is to use a chain that already has some use so it doesn't stretch losing your tension.

46x17

In his world it is.

He is older than the average fixed rider and will do backwards figure eights around two posts while tying his shoes and ranting on the sprinter mentality, Lance, Trek, drop bars, etc.

He is a damn fine rider so if it works for him I am not going to argue.

Personally I see trackends being about as extraneous as paint, then again if you have been riding for 30+ years you probably know if you like trackends or not on your fix.

His dropouts actually have about 2 mm of back and forward adjustabiliy. The axle is all the way in the front when the chain is new and once it have been worn it it gets pull back 2 mm. "That is all that is necessary! If you need more your chain sucks!"

RedDeMartini

It seems to be mostly a matter of luck and patience. The right combo of links, ring, cog and chainstay can do it, the hardest part is putting it together wrong and being honest to the fact that it too slack or too tight and that you will have to do it all over again. Too tight is better as it won't kill you, just use more oil.

treechunk

I had a bike like that for a while. When I decided to replace my chain, I couldn't. My magic gearing was too magic or something. My chain continued to get worse until I ended up getting rid of that shizzie.


Buy an ENO.


End of story.

rvabiker

You say too tight won't kill you until that **** breaks as you are skidding downhill to a stoplight...

bianchiboy

I took a 1990 Bianchi campione with vertical dropouts and turned it into a fixed gear. The only thing I actually bought were spacers, and a rear sprocket. I used halflinks to get the right chain tension and I had to move the chainring a little bit closer to the frame. Besides the fact that a little bit of the chainring sometimes scrapes the frame due to torquing during rides, everything is nice. ppl look because they don't usually see a celeste colored bianchi campione as a ss :]

CoppellStereo

wonder how many broken chains there are doing it the magic way compared to using a tensioner/ebb/eh/etc.. because i know everytime ive done that, the chain would break after not too long, or maybe im a lot harder on my drivetrain than most people

adamkell

I like that a lot! If I ever, god forbid, require a winter bike, I'd like to build one like yours.

bianchiboy

That's happened to me before...but then again I was running the same chain that was on the bike when I bought it used. Since I've replaced with KMS chain, there's like a tiny bit of slack and I don't run a tensioner and it's fine.