Question: Convert my old hardtail to Singlespeed?

[rhizopogon]

Just curious! How hard would it be to make my 95 Stumpy hardtail a SS?

Hey man!
It's easy and I would love to help you.





Best case you need:

1. Cog - A SingleSpeed Specific cog won't flex and has tall teeth to prevent throwing the chain on climbs or sprinting. Never use a cassette cog from a shifting bike - it is designed to throw the chain!

Approx Retail Prices:
$ Stamped steel ~$5 many sizes to choose from
$$ Surly Stainless steel, Endless ~$30 pretty much every size




2. Tensioner - You need a way to get the chain tight enough so that it won't fall off. Since you took off the derailleur, the device that previously performed that function, you'll need something to take its place. That something is a Chain Tensioner**. Generally speaking, its best to adjust the tensioner so that it pushes "up" on the chain. This effectively wraps more chain around the cog. Not to be confused with BMX style tensioners, or tugnuts.

Approx Retail Prices:
$ DMR, generic ~$20-$25 many sources, some good, some poor.
$$ Surly, Soulcraft, Rennen ~$50 - $75 other brands in this range too
**(Note: Other options are not discussed here)



3. Spacer Kit - These spacers line the cog up with the middle chainring. They hold it in place tightly when the cassette lockring is tightened down. A small yet vital part. Think of it like a chainring bolt: tiny and worthless, but absolutely nessesary.
$ Generic spacers: there are a lot of them! Same inside dia. as a BB shell 1.37", so you can use all your old XTR HollowtechII BB spacers for your singlespeed! maybe $10 or so.
$$ Rennen, Endless, Soulcraft... etc etc. Many to choose from. $20-$50






Worst Case you need:
1. Cog
2. Tensioner
3. Spacer Kit
4. Chain - (your chain is too worn)
5. Chainring - (your chainring is too worn)
6. Chainring bolts or bashguard - (need something to take up the space from only running one ring or shorter chainring bolts)
7. New Brake Levers - (if you have the combination shifter/brake levers )

If you are Really Unlucky:
1. You will have to buy everything above, plus cranks and maybe even BB! - (because you have the one-piece style chainring crankset with a wornout middle ring or if your older 5 bolt 110BCD crankset is limiting your gearing choices. )

However, you will probably be able to get away with "best case" or best+levers, since a '95 Stumpy probably came with XT 5 bolt cranks, or Specialized Strongarms, either of which would work fine.

More questions?

[Dirt]

Good write-up.

The one thing that I'd add is that going with a cog that has a wide base to it will protect your freehub body a little better than some of the more inexpensive stamped steel cogs. Surly, endless, king and others make cogs that have a base that is 3mm wide instead of about 1mm wide. That spreads the force of the cog over a larger area on the freehub body and it helps prevent the cog from making grooves in the freehub body.

I've used the Endess cogs (about $30) and had no trouble with them at all. They're a snug fit, which is good.

Good luck.

Pete

[Pinoy Rider]

Looks like I'll need a new chain and chain ring(Drivetrain is an 8 spd that is 12 years old, shifts just as good as my new bike). Cranks are LX 170mm 5 arm. Will I want to run a little longer crank arms for torque or can I get away with my current cranks.

[drevil]

Looks like I'll need a new chain and chain ring(Drivetrain is an 8 spd that is 12 years old, shifts just as good as my new bike). Cranks are LX 170mm 5 arm. Will I want to run a little longer crank arms for torque or can I get away with my current cranks.
Run those cranks for now. Just use a slightly lighter gear.

[rhizopogon]

Looks like I'll need a new chain and chain ring(Drivetrain is an 8 spd that is 12 years old, shifts just as good as my new bike). Cranks are LX 170mm 5 arm. Will I want to run a little longer crank arms for torque or can I get away with my current cranks.

Yes! The crankarm question:

Crank length does little to increase the amount of mechanical advantage that you have. For a 5mm difference, there is a 0.9% difference in mechanical advantage. Basically nothing.

However, crank length is proportional to your leg length. Running the right (ie. short) length crank makes it easier to spin at high cadence, something you will more than likely be doing on your SS.

So yeah, Ricky (of course) is right.

[rhizopogon]

Agreed. Good point.

However, most converts will most likely NOT have super high end hubs with aluminum freehub bodies. Most people will have a steel freehub body that will work just fine with the cheap, stamped steel cogs.

A wide base cog also can pose problems for some spacer kits.

Good write-up.

The one thing that I'd add is that going with a cog that has a wide base to it will protect your freehub body a little better than some of the more inexpensive stamped steel cogs. Surly, endless, king and others make cogs that have a base that is 3mm wide instead of about 1mm wide. That spreads the force of the cog over a larger area on the freehub body and it helps prevent the cog from making grooves in the freehub body.

I've used the Endess cogs (about $30) and had no trouble with them at all. They're a snug fit, which is good.

Good luck.

Pete

[Dirt]

Agreed. Good point.

However, most converts will most likely NOT have super high end hubs with aluminum freehub bodies. Most people will have a steel freehub body that will work just fine with the cheap, stamped steel cogs.

A wide base cog also can pose problems for some spacer kits.

Good points. For normal sized humans, you're right.

I'm a big boy. For clydes like me, I'd still suggest using a wide based cog. The Endless Fibanaci spacers work well. They are alittle more expensive.

Pete

[halfinch]

I'm a big boy. For clydes like me, I'd still suggest using a wide based cog. The Endless Fibanaci spacers work well. They are alittle more expensive.

Pete


endless makes a nice cog. i've found that it can be finicky to place on some freehubs. surly also makes a nice wide cog. prices are similiar.

[Dirt]

endless makes a nice cog. i've found that it can be finicky to place on some freehubs. surly also makes a nice wide cog. prices are similiar.

Yup! They're great. They'll probably last longer too since they are steel and the Endess are aluminum.

I realy like Endless' spacers though because they give you the freedom to space your cog in 1mm increments depending on what your chain line is. They also give pretty easy to follow instructions for how to figure out the right spacing of the cog on your freehub body.

I'm sure there are other spacer sets and cogs that work very well. Those are the ones that I have worked with and am pretty happy with.

Pete

[rhizopogon]

Good points. For normal sized humans, you're right.

I'm a big boy. For clydes like me, I'd still suggest using a wide based cog. The Endless Fibanaci spacers work well. They are alittle more expensive.

Pete

Clyde or not, regular skinny steel cogs on regular steel freehubs are plenty strong. Think of the amount of torque a 34T cog on a shifting bike makes! Far more than any singlespeeder could dream of making using any "normal" SS gearing, yet the skinny, single steel cog doesn't damage the freehub body.

[wrench177]

Clyde or not, regular skinny steel cogs on regular steel freehubs are plenty strong. Think of the amount of torque a 34T cog on a shifting bike makes! Far more than any singlespeeder could dream of making using any "normal" SS gearing, yet the skinny, single steel cog doesn't damage the freehub body.
I, to, think for the time being a nice inexpensive stamped cog will be fine. I've been running those cheap ones on my bike for well over a year and my freehub shows no sign of damage.

As for the chain tensioner, my vote goes for the Soulcraft. It costs a bit more than the others, but it blows everything else away in terms of design and function. Save money on the cogs and put it towards the Soulcraft tensioner. It doesn't use spring tension and works great in either push up or pull down configurations.

[ride_clyde]

Clyde or not, regular skinny steel cogs on regular steel freehubs are plenty strong. Think of the amount of torque a 34T cog on a shifting bike makes! Far more than any singlespeeder could dream of making using any "normal" SS gearing, yet the skinny, single steel cog doesn't damage the freehub body.


Hmm don't know about that. I rode a steel stamped 16t cog on my SS conversion (which happens to be a '95 stumpy just like the title post) that I use only for bike polo on a total flat surface other than dog crap and the occasional ride over the ball, mallet or other player. It started to dig into the freehub (oops it was a ti - XTR freehub!) so i replaced it with a surly 17t. No diggin' now other than the sweet new gear and the perfect fit withought the singleator.

[Dirt]

Clyde or not, regular skinny steel cogs on regular steel freehubs are plenty strong. Think of the amount of torque a 34T cog on a shifting bike makes! Far more than any singlespeeder could dream of making using any "normal" SS gearing, yet the skinny, single steel cog doesn't damage the freehub body.

It isn't worth arguing over. I know that many, many people haven't had trouble with with narrow cogs on steel freehub bodies. That means it is good enough for the vast majority of people. Over the years I have had a problem with them and I've worked on a few people's bikes that also had trouble. I thought it was worth mentioning that if, for a few $ more, a wide-based cog could be purchased that it might be wise to do so.

[ride_clyde]

But i really want to argue.

Not really. My advice is to just do it, then start figuring out what you need or want to upgrade. For all of the "simplicity" of ss there are a lot of choices and considerations. It really is ironic how many technical SS questions there are compared to geared.

Long live choice!

[Dirt]

But i really want to argue.

Not really. My advice is to just do it, then start figuring out what you need or want to upgrade. For all of the "simplicity" of ss there are a lot of choices and considerations. It really is ironic how many technical SS questions there are compared to geared.

Long live choice!

Part of the reason for the technical questions is that people who start with SS riding often coble together their SS by converting (I prefer the term "un-neutering" ;) ) a geared bike. People with relatively little mechanical experience feel (rightly so) that they are capable of doing this sort of thing rather than taking it to a shop. They ask questions accordingly. Thus the influx of technical questions. That's my take on it. Ask me later and I'll come up with another answer. It depends on which of my personalities is typing at the moment.

I'm sure we can find better things to argue about. We could go over to LittleTommy's thread about making his SS into a 1x9 and have a religious discussion. Over on that thread the cycling gods are telling him to keep it an SS, Buddha is telling him to run 32x18 gear ratio, and the Flying Spaghetti Monster is promising a never-ending flow of malt beverage in the afterlife.

Now THAT is something truly worthy of a good argument.

Love,

Pete

[micky]

You can get a single speed kit, buy a cheap chain, remove the little ring (I use the big ring as a bash guard, who cares if it gets damaged now) and put the parts together.

This could be done for less than $35.00



http://www.performancebike.com/shop/Profile.cfm?SKU=23062&item=50-6550&slitrk=search&slisearch=true

[rednow]

I just got one of these from Perf. It works great. I was about to buy the Surly Tensioner and SS kit until I saw this. Strange that its basically the same thing surly gives at a much lower cost.

[Dirt]

Much lower cost. Click on the link and it shows it is on sale for $22.

[halfinch]

I just got one of these from Perf. It works great. I was about to buy the Surly Tensioner and SS kit until I saw this. Strange that its basically the same thing surly gives at a much lower cost.

if it's a pyramid tensioner or a similar knock off, i've found the don't hold up as well and fail quickly. positive note, if it has three holes through it to "shave weight" you can use zip ties to maintain tension for short periods.