Single Speed Conversion

[hdtvkss]

Gday,

ok seeing as the new cannondale arrives tomorrow im thinking its time i started the long awaited conversion to SS on my kona hard tail. before doing this though, i have a couple of things id like to know

given that the bike doesnt have horisontal drop outs, ill need to puchase somthing like a Surly singulator yes? from what i am aware this acts like the cage on a derailer and tensions the chain? are there any advs or disadvs to running one of these?

secondly, in order to get a good chain line, is it recommended to install a wider/smaller BB?

thirdly, what is a good ratio to start with? im not the worlds strongest rider ( hence why i want to build up my leg strenth on a SS) so im curious as to where to start?

 

[dunk]

Yes, you will need something like the Singleator, there are various versions around at all price points etc. The singleator will take up the slack in the chain to stop it falling off.

There wont be any need to change your bottom bracket, but you will nedd to adjust your chainline depending on what your doing with your rear wheel.

Ratios are another thing of trial and error, I generally run 34:19, but at the Highland Fling and 4 hour last week I ran 34:20.

I recommend you read the stuff on Sheldon Browns website:
http://sheldonbrown.com/singlespeed.html

Good Luck

 

[johnny]

You won't always need a chain tensioner. My Chase is the perfect length for a 32;14 ratio without the need of a tensioner. But if you do, I've always been completely satisfied by the DMR STS. It's tight, chunky and doesn't slip. I also think that 32:14 is an excellent ratio to ride (also dependent on the type of riding you will be doing) and SS will be NOWHERE NEAR as hard to ride as you first think. I thought I was in for a month or two of slaughter when I first started......I could not have been any more wrong!

Check out fortheriders.com, they used to sell a spacer kit with thin spacers that allowed you to get a straight chainline, they were about $15 from what I can remember. Couldn't see it at a quick glance just now, but fire off an email and I reckon they'll be able to help you out (best service I've ever had on the net by a country mile!).

 

[craigb]

i know ill piss someone off saying this but surly singulators are not the best thing to use they are ok to start off but if you wish to do it once and do it properly get an eccentric rear hub. they work a treat not as cheap as a chain tensioner but you wont have any probs with catching anything on a branch or log and riping it off. and you wont loose any power because its a straight chain line with no addons.

 

[aaron01]

personally I have heard the tensioners are a good half way if your not sure about the whole ss thing. As for gear ratios I'm using a 34/20 (Toowoomba) but if I'm not climbing the range I'll drop to a 34/14 or somewhere in between.

 

[FR Drew]

When I set up for single speed, I left the bottom bracket as it was, scrounged whatever spacers I could to get my chainline right and took care of tension using a Rennen Rollenlager which I purchased from www.phatmoosecycles.com (beware, website is a killer for those on dial-up).

The Rennen has 2 mounting points, one being the skewer for the rear wheel and the other being the derailleur mounting thread. I had to modify it by drilling a second pulley hole in order to give it enough throw to tension my Yeti ARC for 32:14 but it's fine in stock form for 32:16.

32:16 is as slow as a week of wet wednesdays on the flat tarmac but seems to suit the Canberra trails (Sparrow Hill and Mt Majura) pretty well. I've taken it up the road to the summit of Mt Stromlo as well and that's definitely do-able in 32:16 (although perhaps not a whole heap of fun).

 

[wombat]

The Rennen has 2 mounting points, one being the skewer for the rear wheel and the other being the derailleur mounting thread. I had to modify it by drilling a second pulley hole in order to give it enough throw to tension my Yeti ARC for 32:14 but it's fine in stock form for 32:16.

DMR's STS is basically a Rennen rip off. It's not as beefy, but that shouldn't be an issue for XC and trail use. Best bit is that it's about the cheapest tensioner around ( save for using an old derailluer or a jockey wheel and zip tie ).

I run one on my trials bike and it's been great, I love it because it tucks right up out of the way (I swapped the roller out for a jockey wheel to save weight and increase clearence). I've bashed it a bit on muffed up side hops (which happen a lot, due to me being crap) and no damage to it or my hanger.

The only reason I'd go for a sprung tensioner over a twin bolt, is if I was removing the wheel on a regular basis. I find that with the STS getting the wheel out without loosening the bolt is a real pain. Of course, you could probably avoid that if you set it up so that it exerted pressure downwards, instead of picking the chain up, but then you lose the clearence benefits.

Anyway, I hope that's of some help.

 

[scottmeister]

Don't go a surly tensioner, please. They have jack shit tension compared to good quality tensioners, and cost the same.

I run a Rohloff tensioner- it has dual metal jockey wheels, and fuck good tension. Cant fault it...and for $130, it's worth the dosh.

 

[wombat]

I run a Rohloff tensioner- it has dual metal jockey wheels, and fuck good tension. Cant fault it...and for $130, it's worth the dosh.

Where'd you score that from mate?

 

[johnny]

personally I have heard the tensioners are a good half way if your not sure about the whole ss thing.

What do you mean by that? You're either running gears or not and that's what determines SS, not whether you run a tensioner. Did I misunderstand what you were saying?

DMR STS!!

 

[Beena]

Where'd you score that from mate?

I know a little corner shop in Brunswick Street he may have scored it from...

Same place I got mine coincidentally! They do work very well, I'd say we sell more of them than any other tensioner - even at the price - they just work so much better than the $35 jobs.

 

[johnny]

Got a pic of it handy Beena?

 

[Pete J]

Whatever you do don't buy a DaBomb tensioner!!
They are cheap and nasty!
Am having problems with mine staying straight, it has quite a bit of lateral slop in it. It prefers to droop at an odd angle instead of at 90 degrees like it should.
And it gets worse under load too. Feels like it twists causing it to skip and jump.
I am probably going to replace it with an old derailleur.

 

[hdtvkss]

hay ya. thanks for all the replies. lots to think about there. given that ihave to hav the back wheel on and off all the time, i think a spring loaded tensioner is the way to go. so whats the talk about them being ineficient? is
that due to he pressure it puts on the chain line? it cant be THAT inefficient....

 

[craign]

You can always use an old derailleur to start with. Some people even cut the lower jockey wheel secion of the cage off, though I've never bothered myself.

For spacing the rear sprocket for a good chain line just go get a bunch of old cassette spacer from the LBS.

 

[johnny]

DO NOT get a surly copy tensioner. I don't know anyone who has used one for more than half an hour. They break just looking at them!

 

[aaron01]

What I meant Jonny is that if he isn't sure weather he will stick with the ss then this is a safe half way point where you can easily change back to gears without spending a small fortune, I guess it was a bit poorly worded

 

[Bjern Fita]

good advice here. Surly knock-off tensioners are absolutely crap, Surly original's are only marginally better. Steer clear. (If I haven't dissuaded you, I have one of each available to buy for cheap if you're still keen).

There's a couple of posts on mtbr.com about the 'floating ring' method of tensioning. Some guys are using a spare ring in between the ring at the cranks and the cog at the back to achieve tension on the chain. Have a search, it looks pretty cool but I've got no idea how practical the idea is in the real world (although some guys claim it works perfectly).

I reckon a Rennen (or knock-off) would be your best bet.

 

[Beena]

Got a pic of it handy Beena?

Certainly do, pic attached.

They retail for $130.

 

[johnny]

Wow, have a go at that little fella! Pretty interesting concept for SS, look forward to seeing one in action (or action pics, nudge nudge, ).