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single speed for a DH rig

atrokz

atrokz

Turbo Monkey
Mar 14, 2002
1,552
77
teedotohdot
Why would you want to do that? And more importantly, what gear would allow you to make a larger double, and still pedal to the lift?
 
saruti

saruti

Turbo Monkey
Oct 29, 2006
1,169
73
Israel
sorry but the link does not work
just go to the home page of this site
there is a "Zinger Singlespeed Tensioner - HEAVY DUTY "

do you know this tensioner? will it fit for DH?
 
HardtailHack

HardtailHack

used an iron once
Jan 20, 2009
6,742
5,631
There are some old guides that have the lower roller on a spring and it may be enough to to let you run SS. Roox rollercoaster or something rings a bell from years back and I thought Syncros had a more simply sprung lower jockey wheel.

I don't know of many spring loaded rear tensioners, but I imagine you could still snap it in a crash.
 
Gary

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,640
5,561
UK
Saruti - I assume you mean this thing



It's only £26 so why not just buy it and find out for yourself?

I reckon to run a flawless SS set-up on a DH bike you'd still need some amount of chain device up front and possibly a couple of guide plates either side of the sprocket. to achieve a completely taught chain through a rear tensioner alone would need a very stiff tension spring and I'm not even sure most mech hangers are beefy enough.. I'd also imagine the amount of tension needed to keep a chain taught on a DH bike would not be too good for the life of other components.

Talked about this loads with Monkeyfcker from here as he has been wanting to SS his sunday for ages.

I think SS in principal would work great for me but just can't see a completely reliable set-up being simple (or even very light) unless you have a frame design that lends itself to SS well (URT, Concentric BB pivot or jackshaft)
 
stoney

stoney

Part of the unwashed, middle-American horde
Jul 26, 2006
21,608
7,257
Colorado
Wait, you want to add a tensioner that is the same size as a rear mech? that makes no sense. Just get an X7 if you keep destroying them
 
Sandwich

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,069
5,980
borcester rhymes
I know of at least one person who switched to single speed using a similar setup. It worked for him for a while, but now he's switching back to gears. He never rode much to begin with. As a pure fun-bike, it makes great sense. I don't know if I would run one, it's essentially like a derailleur, and at that point you may as well have gears. If you have a concentric pivot or idler, that's a great reason to keep the bike SS.
 
xy9ine

xy9ine

Turbo Monkey
Mar 22, 2004
2,940
353
vancouver eastside
a few years ago i tried my tmx ss. neat in that it was dead quiet, but spinning out on the fast stuff & exploding knees on the slower gets old quickly. i swapped it back after a couple rides. ahh, i miss this old beast (whoa, look at the bar height; those were the days...):

 
gemini2k

gemini2k

Turbo Monkey
Jul 31, 2005
3,526
117
San Francisco
Use the search. We've posted a lot about this before. Long story short, use the YESS tensioner. 2:1 gear ratio for shuttle days (36:18), taller for resort days, say 36:14 or 2.5:1.
 
lamp

lamp

Monkey
Mar 21, 2008
210
0
The Joker said:
Wait, you want to add a tensioner that is the same size as a rear mech? that makes no sense. Just get an X7 if you keep destroying them
Click to expand...
Quick check to jenson reveals x.7 is $94 and an x.5 is $50.

I am currently running a singlespeed setup with a normal chainguide up front and beat LX derailleur in the rear. I have not had any chain retention issues.

I have one of these also, but have not installed yet:
 
descente

descente

Monkey
Jul 30, 2010
430
0
Sandy Eggo
i ran the alfine on my morewood ndiza as a single speed for a while. i had a hard time getting the b-tension right and had to mod the derailleur hanger to make it work with a 14t cog. if i remember right the alfine requires you run at least an 18 or 20t rear, and to get the ratio i wanted would have required a 40t or so front ring which i didn't want on a bike with 12.5" BB height. the high amount of tension eventually broke the hanger. it was ****ing sick while it lasted tho! no skipping, never missed a pedal stroke, and it was COMPLETELY silent no matter what you did.

i can tell just by looking at the yess tensioner that it will work no problem. had i been more patient, i should have gotten that tensioner.
 
manhattanprjkt83

manhattanprjkt83

Rusty Trombone
Jul 10, 2003
9,646
1,217
Nilbog
I am running my Transition TR250 singlespeed at the moment after smashing an x.9

Few thoughts:
- running an old rear mech but going to replace it with a paul melvin
- yes you need a chain guide up front
- 15/14 36t is a pretty good all around gear
- i rarely run out of gear w/ a 14t but dont race
- this is my dh/park bike only so i dont climb this
- bike is silent and problem free

I really like the setup and plan to keep it this way for here on out other than bigger trips. Heading to whistler next weekend and I will run gears there since we do rides outside of the park but for the local season i am all about SS.

good luck
 
monkeyfcuker

monkeyfcuker

Monkey
May 26, 2008
912
8
UK, Carlisle
As Gary said, I've thought about this for a while.

I have a Yess chain tensioner that I once tried to fit but (IMO) it just couldn't provide adequate tension while dealing with the chain growth issues. I never even bothered trying it out on the trail. I'd really like to try a decent single speed setup as I rarely if ever change gear on a run even when racing.

I'm interested to try a single speed setup again with the Yess tensioner with guide plates either side of the rear sprocket in the style of the old MRP chain tensioners if you get me.

For what it's worth the Yess tensioner is a fair bit smaller than a short cage rea mech and a fair bit more out of the way.
 
manhattanprjkt83

manhattanprjkt83

Rusty Trombone
Jul 10, 2003
9,646
1,217
Nilbog
did you try just running a derailleur that was pulled mid tight? That with an e.13 lg1+ is bomber haven't dropped a chain once all season and great tension.
 
T

trib

not worthy of a Rux.
Jun 22, 2009
1,479
421
There is a guy on these boards who runs an orange Patriot or 22x bike single speed.

His set up is e.13 front device with rotated forward and the lower arm of a derailleur mounted on the bottom roller which then provides ample amounts of chain for when the bike is at full compression but means there is nothing to break off the rear. Seems to work well for him. Will post pics If I stumble across them
 
juanbeegas

juanbeegas

Monkey
May 6, 2008
355
2
Singapore
monkeyfcuker said:
I have a Yess chain tensioner that I once tried to fit but (IMO) it just couldn't provide adequate tension while dealing with the chain growth issues.
Click to expand...
Was it the ETR-D? You can adjust chainline and tension on that model. Probably the best tensioner you could use on a full suspension frame, in my opinion. Couple that up with a proper chain guide up front and you should have a pretty bomb proof single speed set up for DH...
 
Kanye West

Kanye West

220# bag of hacktastic
Aug 31, 2006
3,741
473
Been running my DH bike in SS form for 3 years now and have no desire to change, except for racing. For riding resorts and shuttle trails and generally really nasty stuff that normally likes to steal my derailleur, it's golden.

The sideways profile on these is sorta similar to a derailleur, but the sideways clearance is the large benefit.
 
monkeyfcuker

monkeyfcuker

Monkey
May 26, 2008
912
8
UK, Carlisle
juanbeegas said:
Was it the ETR-D? You can adjust chainline and tension on that model. Probably the best tensioner you could use on a full suspension frame, in my opinion. Couple that up with a proper chain guide up front and you should have a pretty bomb proof single speed set up for DH...
Click to expand...

Yeah I believe it's that model. Again it was just my opininon but the thing just couldn't provide necessary tension throughout the bikes travel for my liking. I got bored of adjusting the thing and sacked it off.
 
gemini2k

gemini2k

Turbo Monkey
Jul 31, 2005
3,526
117
San Francisco
monkeyfcuker said:
Yeah I believe it's that model. Again it was just my opininon but the thing just couldn't provide necessary tension throughout the bikes travel for my liking. I got bored of adjusting the thing and sacked it off.
Click to expand...
I think I've been experiencing a similar problem with mine. I'm not ready to give up on it though. Sometimes the chain will fall off the lower pulley cog in between the guide plates and the lower tension cog. I have it as tight as it can go while still allowing for sufficient chain growth. I haven't talked to the YESS guys yet about it though. In the past though their CS has been AMAZING. I can't stress that enough, awesome guys.
 
monkeyfcuker

monkeyfcuker

Monkey
May 26, 2008
912
8
UK, Carlisle
I think if you sandwiched the cassette cog in between two guide plates and had them almost touching the smooth roller it would be sweet, the tension reqd wouldn't be half as much, something I wanna try sometime.
 
tartosuc

tartosuc

Monkey
Feb 9, 2004
202
0
montreal
monkeyfcuker said:
I think if you sandwiched the cassette cog in between two guide plates and had them almost touching the smooth roller it would be sweet, the tension reqd wouldn't be half as much, something I wanna try sometime.
Click to expand...
thats what i did, combined with the yess tensionner, works very well.
I still have the mrp chain guide up front.

The two guide plate are just cogs that i grinded down the theeth.

i'm running 38-18 right now. i bit tough on the flat sections but perfect for 95% of what i'm running.

it is setup on a Canfield jedi, due to the pulley, the bike does not have much chain growt
 

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Bikael Molton

Bikael Molton

goofy for life
Jun 9, 2003
4,023
1,154
El Lay
Saw a dude at Whistler running a similar set-up on his Sunday.

I have what I believe is a problematic technique: shifting too much. I've been considering trying SS on my DH bike for a time, just to break me of this habit.
 
rocketmatt17

rocketmatt17

Monkey
Sep 10, 2007
270
0
Yes it works great on a jedi, You can keep the chain super tight which keeps the mech out of the way. I used a hammerschmidt up front and loved it! I only threw one chain all season which was due to a twig getting stuck in th rear cog. I left 3 rear cogs on so i could just change them by hand until i could decide which size I wanted to use. With the yess tensioner there is enough play and adjustment to do so. I ran a 24/38 hammer up front and a 12 in the rear
 
descente

descente

Monkey
Jul 30, 2010
430
0
Sandy Eggo
if thats anything like a surly (which it looks to be) it won't provide near enough tension. you really need a double roller to get proper wrap around the rear cog AND be able to accomodate chain growth.
 
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