Building a singlespeed



Kimberley Luoto

New Member
May 13, 2012
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I have a '93 Cannondale MTB that I'd like to convert to a single speed......maybe a fixie (still learning all these terms). I've been looking at You Tube. Any suggestions would be most appreciated!!

Kimberley in PDX
 
I converted my Trek 4500 over to single speed last year. I purchased a DMR single speed kit that comes with spacers, a new rear gear, and a chain tensioner. Surly also makes nice single speed kits. For your crank you have some options. If your chain rings are removable, you can get rid of 2 and attach the middle one with BMX style bolts. My crank had the chain rings riveted on, so I got a different crank. You'll need a new chain as well like a 9 speed chain or similar. For mountain biking I would start with a 2:1 gear ratio, such as a 16 tooth rear gear paired with a 32 tooth chain ring. If you are going to commute you can up that ratio a bit depending on the terrain.
 
FYI. In addition to the fore mentioned conversion kits which allow you to use a Freehub-type rear hub in a Single Speed bike, SURLY makes FLIP-FLOP rear hubs with 135mm spacing ... a good place to start. The flanges are wider apart & that means that the cog wlll be further away from the bike's centerline which means that the chainring can be located on the outer shoulder of a MTB crank's spider. My recollection is that they are about $80.

REAL makes a 135mm Single Speed hub which has a disc rotor mount on the other side.

The WHITE INDUSTRIES ENO hub allows you to avoid the problem of adjusting the chain tension, but it is fairly expensive (over $100 ... a whopping $140+ comes to mind as the MSRP) ... it is available with as a traditional Flip-Flop hub OR with their own "mounting system" on the other side which is really designed for a matching Fixed cog & presumably a disc rotor adapter ... and, maybe, they have some with other "disc" mounts, now).

There are probably other 135mm Single Speed rear hub options ...

... INCLUDING bolting a 16t-or-larger (?) "cog" onto a FRONT disc hub & replacing the standard axle with a SOLID AXLE + necessary spacers.

If you are using a ROAD crankset, then it seems that you can use most run-of-the-mill Freewheel type rear hubs after you center it & add the additional spaceers on a solid axle OR you can use a standard Flip-Flop "Track" rear hub designed for frames with 120mm rear spacing.

You can use a "half-link" to adjust the chain tension ...

BTW. Apparently, you cannot use most chain tensioners with a Fixed "Track" cog. I'm not sure why.

"Track" cogs & SS Freewheels are available with 1/8" (Track) & 3/32" (Road) width teeth.

FWIW. I recommend ACS Freeheels .
 
alfeng said:
BTW....... Apparently, you cannot use most chain tensioners with a Fixed "Track" cog. I'm not sure why...... .....FWIW. I recommend ACS Freeheels .
It's because when you put pressure in a reverse direction, as when slowing down or stopping using your rear wheel and tension on the drivetrain, you are making the LOWER run of chain attempt to straighten out fully! Just as the top run of chain in a normally pedaled bicycle is straight and unencombered with any tensioning device, reverse pedalling with such a device present will generally attempt to RIP IT OFF your bike as it tries to strighten out the chain run! :angry: Also FWIW,.......i recommend the White Industries "Trials" version of their freewheel. About the strongest and best made out there,.....so not the cheapest. As i recall it has 6 pawls and 72 points of engagement, and with a heavier outer chromoly steel body than their regular version. One nice thing about this freewheel is you can get back on tensioning the rear wheel with VERY little movement of your crank coming off a coast! As close to the "instantanious" fixed gear hookup as you will find on a freewheel! Another benefit i like is that the freewheel is rather noisy with all those pawls and points of engagement, so others on the road or trail can usually hear you coming! I don't even bother mounting a bell to alert others of my approach with this freewheel,..... simply stop pedaling! Otherwise, while you are pedalling,....you are in "Stealth Mode"! :cool: (NOTE: I know this is an older thread,....but i'm sure others might have wondered about this also. Rather than someone trying it and getting injured (or worse yet hurting your "baby" :crying: ),....i thought i would explain why it's not going to work.)
 
Quote: Originally Posted by joejeweler .


It's because when you put pressure in a reverse direction, as when slowing down or stopping using your rear wheel and tension on the drivetrain, you are making the LOWER run of chain attempt to straighten out fully!

Just as the top run of chain in a normally pedaled bicycle is straight and unencombered with any tensioning device, reverse pedalling with such a device present will generally attempt to RIP IT OFF your bike as it tries to strighten out the chain run!
angry.png



Also FWIW,.......i recommend the White Industries "Trials" version of their freewheel. About the strongest and best made out there,.....so not the cheapest. As i recall it has 6 pawls and 72 points of engagement, and with a heavier outer chromoly steel body than their regular version.

One nice thing about this freewheel is you can get back on tensioning the rear wheel with VERY little movement of your crank coming off a coast! As close to the "instantanious" fixed gear hookup as you will find on a freewheel!

Another benefit i like is that the freewheel is rather noisy with all those pawls and points of engagement, so others on the road or trail can usually hear you coming! I don't even bother mounting a bell to alert others of my approach with this freewheel,..... simply stop pedaling!

Otherwise, while you are pedalling,....you are in "Stealth Mode"!
cool.png


(NOTE: I know this is an older thread,....but i'm sure others might have wondered about this also. Rather than someone trying it and getting injured (or worse yet hurting your "baby"
crying.png
),....i thought i would explain why it's not going to work.)


Yes. That's true if the pulley wheel is attached to a stationary tab ...

THAT type of tensioner is comparatively rare, now ...

But, I think that most of the readily available tensioners are spring loaded, so when the chain tries to straighten, the arm will simply pivot downward, accordingly ...

So, AFAIK, the "warning" is no longer applicable in most cases.