Singlespeed For Bike Park

sittingduck · Nov 23, 2007

I hate derailers. If you can do it, go for it. I'm not sure how much chain growth you're going to have with the BR, you might need some sore of tensioner to keep from snapping or dropping your chain.

w00dy · Nov 23, 2007

MP, lets talk gear inches.

I'll spell it out for those reading along who might not know:
front sprocket size / rear sprocket size X wheel size = gear inches
Standard BMX gearing (44/16x20) is 55 gear inches.

I have the FQ set up at 57 gear inches and I think it's perfect.
I can (barely) make it up the climb just before Tempest at Diablo, and I never really spin out with it. If I'm going that fast I'm just hanging on, not trying to speed up. For lift access runs I love it. Nice neutral gear for cranking at a jump or getting in that last pedal kick before a drop.

I love how simple the bars look with just brakes. Back to my roots...

ROTFLMAO · Nov 23, 2007

I don't think a singleator will allow enough room for the chain stretch. You'll need this. And I think it's a great idea.

With the conversion the pully will push the chain down but the upper pully will hold the chain wrap tightly on the rear cog.

Buy it here

ire · Nov 23, 2007

I'd say go for it. I'd be inclined to run a bigger gear and walk more.....nothing would suck more than not being able to get the speed to hit stuff

ire · Nov 23, 2007

manhattanprjkt83 said:
this is my only reservation, i like riding the north shore stuff alot too though so it is going to be tough to find a happy medium...

32 - ???? any suggestions? **** maybe i could run bmx micro gearing for more clearance!!!!

You know what I would do? I would go to places you like to ride (with a der on your bike) and try different gears, write them down, how you liked them, and then make a descision based on this info.

ROTFLMAO · Nov 23, 2007

Run a SS conversion kit on a normal rear hub. 32x16 would be a common gear to start out with. Pick up some extra cogs, if you know you're going to be climbing put on an 18, if your going to be screaming DH throw a 14 on there. you leave some options for yourself that way.

ROTFLMAO · Nov 23, 2007

It might work but you'd have to set it up with a ton of chain slack probably in the "push down" config which would cause some skipping of the chain. Just get the Yess tensioner, it was designed to be used on FS bikes and will keep the chain nice and tight on the rear cog.

w00dy · Nov 23, 2007

Don't spend the cash for a conversion kit. I always just take apart and restack old cassettes.
What I like to do is run the gear I want in between two spacers and stack two larger cogs on the outside of that. It makes kind of a ghetto chain guide.
If you're using a spring loaded tensioner you could set up two of these sandwiches on your freehub and switch between them manually. If done right, your chainline shouldn't suffer too bad. I'd recommend a 16 and a 15.

CHOP · Nov 23, 2007

w00dy said:
Don't spend the cash for a conversion kit. I always just take apart and restack old cassettes.
What I like to do is run the gear I want in between two spacers and stack two larger cogs on the outside of that. It makes kind of a ghetto chain guide.
If you're using a spring loaded tensioner you could set up two of these sandwiches on your freehub and switch between them manually. If done right, your chainline shouldn't suffer too bad. I'd recommend a 16 and a 15.

I was getting ready to ask if you could put 2 different size gears on the back and switch back and forth with your hand.

oscerthegrouch · Nov 26, 2007

If your going to be pointing down hill I would say to use a 32/14 I run a 36/16 on my DJ rig and if I point her down hill I will be spinning way to fast. Since you are using this for DH trails you might want to consider a harder gear ratio so you can pick up speed when needed without having to pedal to fast.

mandown · Nov 29, 2007

i'd try to hunt down one of these
http://www.rohloff.de/en/products/speedhub/dh_chain_tensioner/index.html

gackrider24 · Nov 29, 2007

this past season my shifter pod ****ted out on me at diablo one day so i just ripped the thing off and locked the rear derailer into one of the higher midrange gears and ran it for the rest of the season. It made me faster in sections where i would usually rely on my lower gears. I wanted to build up a single speed bottle rocket after i saw the transition double set up with a single speed i thought it was a sweet idea
as far as chain tensioners go for the yess pro tensioner that was desinged for a full suspension

not to mention youll probably shave some weight if u care

turkishprison · Dec 12, 2007

Bill,
here is a pick of a rocket with that yess chain tensioner. looks like a winner. I found it on mtbr in the transition forum.

ROTFLMAO · Dec 12, 2007

Ha that's mine. It's also in this forum. I'm going to do some more adjusting of the tensioner. I think I can pivot the upper portion rearward in the slot and remove another link in the chain. The key is getting the chain as short as possible without having it limit the travel at the top of the stroke or causing the arm attached to the lower pulley to hit the chainstay. It runs really well as you see it here but there may be room for improvement. I might grab a half link chain to allow for finer adjustment.

turkishprison · Dec 13, 2007

ROTFLMAO said:
Ha that's mine. It's also in this forum. I'm going to do some more adjusting of the tensioner. I think I can pivot the upper portion rearward in the slot and remove another link in the chain. The key is getting the chain as short as possible without having it limit the travel at the top of the stroke or causing the arm attached to the lower pulley to hit the chainstay. It runs really well as you see it here but there may be room for improvement. I might grab a half link chain to allow for finer adjustment.

yeah i ganked em from you mtbr post.

ROTFLMAO · Dec 13, 2007

It's all good. I like having a famous bike LOL.

Greyhound · Dec 14, 2007

This is a friend of mines B'Rocket. He used some heavier springs in his tensioner which keeps everything super-quiet and smooth.

sittingduck · Dec 14, 2007

That's so freakin' cool.... I think I might do it to my session 77. Derailers are tools of satan designed to drive us crazy.

rm raider · Dec 14, 2007

Question about SS gearing. 2:1 (32x16) with 24 in. wheel. Would it pedal the same as 26 in. wheel. If not, what gearing would be similar to 32x16 for 24 in.

w00dy · Dec 16, 2007

rm raider said:
Question about SS gearing. 2:1 (32x16) with 24 in. wheel. Would it pedal the same as 26 in. wheel. If not, what gearing would be similar to 32x16 for 24 in.

No, it would pedal differently, my first post in this thread has a pretty in depth description of how to figure this out.

ROTFLMAO · Dec 17, 2007

rm raider said:
Question about SS gearing. 2:1 (32x16) with 24 in. wheel. Would it pedal the same as 26 in. wheel. If not, what gearing would be similar to 32x16 for 24 in.

32x14 or 32x15 would be closest as far as gear inches goes

rm raider · Dec 17, 2007

Now I understand gear inches.
Thankyou Woody and Rot.

Singlespeed For Bike Park

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