Popping my fixie cherry

[lewis1641]

If you run your chainline as inboard as possible you can use a ghost gear to tension a fixie with vertical dropouts.

A 'Ghost' gear is a chainring whose teeth engage with the chain but otherwise is in no way attached to the bike.

The chainline needs to be inboard because the chainring needs to be able to be adjusted one tooth at a time backward toward the rear sprocket until tension is achieved without colliding with the chainstay. The chainring needs to be bigger than the rear sprocket in order to engage the chain and not touch the rear sprocket.

The whole thing looks really smart as you roll along. Recently I did 4 laps of the Strathpuffer lite course on my SS mtb with this arrangement of tensioner with no problems

and it looks completely awesome too.

http://www.youtube.com/watch?v=Rlse9h74Q8Y

just make sure chainline is bang on.

 

[oldave]

Altho' I have retired from them (I live at the top of a hill and as I got older the gear I needed to get UP it was too low for anywhere else) i rode a good few '000 miles on quite a few different fixeds. I used to ride some with just a front brake. After I'd had a brake fail - luckily on a bike that DID have two - I never again relied on just ONE. If the lever that sheared off had been my only one I'd have at best been badly injured.

All you need to know (and more) is on Fixed FAQs which I think can be found on wiki: it was put together by the old Fixed Community off what is now bikeradar when the fad was in it's renaissance period a few years ago.

I first rode fixed in about 1963....but then I'm OLDave.

It's great fun - enjoy!

 

[trickylad]

Maybe ss is the right option then. Does the tensioner just alleviate the infinite calibrations that a fixie needs?

Anyone got any educational pics of the options above? Would certainly help as i work through this.

Would the option of a sprocket bolted to a rear disc hub still work for ss as well as fixed?

 

[PIGEON]

A single speed would be much easier to build with the parts you already have, you'll just need one of your cassette sprockets and some spacers to take up the space where the rest of the cassette would normally sit.

(lots of narrow spacers allow you to get a perfect chain line)

With a single speed setup you will be able to run a chain tensioner, or you could just use your old rear mech for this purpose.

Single speed is definitely the more economical option as you won't need a new hub. With your vertical dropouts, if you want to go fixed, the most practical option would be an eccentric hub like the one eastcoaststeve posted, because that has a built-in chain tensioning mechanism, but they are much more expensive than a simple track hub off eBay.
The riding experience of a single speed is very different from a fixed gear though.

 

[PIGEON]

Would the option of a sprocket bolted to a rear disc hub still work for ss as well as fixed?

It would probably work if you get a rear hub with a cassette body on one side and a disc mount on the other side, with a single sprockets and spacers on the cassette side and a bolt on fixed cog on the other. That way you'd be able to turn the wheel around to switch from fixed to ss.

But if you want to go that route it's probably better to buy a purpose built "flip flop" hub with a track cog and lockring on one side and a freewheel with built-in coasting mechanism on the other:

 

[oldave]

"It would probably work if you get a rear hub with a cassette body on one side and a disc mount on the other side, with a single sprockets and spacers on the cassette side and a bolt on fixed cog on the other. That way you'd be able to turn the wheel around to switch from fixed to ss."

Yes, but wouldn't solve the vertical d'outs problem.

The Eno eccentric hub is a fine if pricey bit of kit, but the latest version is unfortunately disc mount/fixed rather than the original fixed/free configuration.

Having built/adapted many fixeds I am firmly of the view that the only sensible (and ultimately most economically viable) route is to start with the right drop outs!

 

[f1fan111]

i run a SS setup on my marin and i use a casette hub with space kit. Supposedly you can actually do it to a freehub but i am not sure how :?: never tried fixie i do at one point though.

I am actually buildiing up another SS bike using a 98 DMR Trailstar at the moment

 

[oldave]

i run a SS setup on my marin and i use a casette hub with space kit. Supposedly you can actually do it to a freehub but i am not sure how :?: never tried fixie i do at one point though.

I am actually buildiing up another SS bike using a 98 DMR Trailstar at the moment

A fixed/free (I believe flip flop is the current term!) simply takes a single screw on free wheel on the free side. Whether or not one needs a specific FIXED (two threads as above) hub is debateable. Many consider that a fixed sprocket banged up TIGHT on a free wheel hub will suffice.

 

[ekiborter]

[Whether or not one needs a specific FIXED (two threads as above) hub is debateable. Many consider that a fixed sprocket banged up TIGHT on a free wheel hub will suffice.

Many consider pulling out before ejaculation a reliable method of birth control..........


which it is........ until it isn't.
:roll:

 

[oldave]

Well... many consider running a fixed sprocket without a lock ring even on a fixed hub which WILL take one is on balance safer. It takes a considerable amount of force - beyond most mortals - to shift a sprocket once it has been torqued down under a few miles use - take it up the steepest hills you can manage a few times!

If the legs of Hoy and running without brakes/skid stopping for fun, then yes, a "proper" hub and lock ring. Otherwise not in practice a problem IMO/E.