[Basurablanca]

Hi all,

Looking for a little advice on a single chain ring set up for cross racing.
Specifically:

What size chain ring?
Is a chain guard mandatory? Chain guide?
Cassette cog range?
Anything else I've left out?

Thanks in advance!
Bruce

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[Basurablanca]

Just found this thread which answers most of my questions: Thread (http://www.bikeforums.net/showthread.php?t=47604)

Apologies for the unnecessary thread. I'll still take any advice, however!

Thanks,
Bruce

[jeff williams]

I run a 38T Blackspire non-ramped chainring. I think a 39 is about as large as you can go.
Triple spyders are best as the mid ring mount puts the chainline straight (or close.)

A bashring is a good idea, I made one from my x-tra 46T ring. I run a lower chain tensioner, this really quiets the bike jumping, an upper tensioner is required IF you intend to jump while in high gears. Generally I just gear down to deal with, with xc racing full on, I'd get an guide system.

I really like the lack of derailler front, no noise and I got to remove shifter, 1 and 1/2 rings, derailler, cable...nice, I had a hell of a time getting the bike down to 22 lbs.

My rear is 12-28, 7spd. I have a 10T cog for the rear when 1 build an 8 spd rear. 10-38 @ 100 rpm is just under 30 mph.
I did notice a bit of drive change upping the front from 36-38T.
the ratio is 2-1 front T to rear.

Heavy DH and freeride monocog (?, making up terms here) tend to go less teeth, 34,32. I find mine perfect as upping 2 teeth put my chain up one cog so I run on my 4th cog mostly and I don't run outta teeth rear (12-38 is 24.5 mph @ 100rpm.)

I might bail on an exteme hill, going 28-38, but not often, my chain tensioner wraps my chain over 4-5 more teeth and I'd swear I have more torque on the hills.

If you grind up a bashring, some blunt teeth are great for getting off logs and rocks.

>jef.

[jeff williams]

http://www.johnhenrybikes.com/catalog.asp?whichpage=&search=&mode=price&category=34&subcategory=0&item=1657

Just nasty, just 280 bones.

[jfmckenna]

I run a 38T Blackspire non-ramped chainring. I think a 39 is about as large as you can go.
Triple spyders are best as the mid ring mount puts the chainline straight (or close.)

A bashring is a good idea, I made one from my x-tra 46T ring. I run a lower chain tensioner, this really quiets the bike jumping, an upper tensioner is required IF you intend to jump while in high gears. Generally I just gear down to deal with.

I really like the lack of derailler front, no noise and I got to remove shifter, 1 and 1/2 rings, derailler, cable...nice, I had a hell of a time getting the bike down to 22 lbs.

My rear is 12-28, 7spd. I have a 10T cog for the rear when 1 build an 8 spd rear. 10-38 @ 100 rpm is just under 30 mph.
I did notice a bit of drive change upping the front from 36-38T.
the ratio is 2-1 front T to rear.

Heavy DH and freeride monocog (?, making up terms here) tend to go less teeth, 34,32. I find mine perfect as upping 2 teeth put my chain up one cog so I run on my 4th cog mostly and I don't run outta teeth rear (12-38 is 25mph @ 100rpm.)

I might bail on an exteme hill, going 28-38, but not often, my chain tensioner wraps my chain over 4-5 more teeth and I'd swear I have more torque on the hills.

Monocogs are cool. If you grind up a bashring, some blunt teeth are great for getting off logs and rocks.

>jef.


Jeff do you have any pics of this set up?

[jeff williams]

Check back later today, i'll ride out to get some pics snapped.
I built the tensioner I run as well, it's a simple lower rubber wheel guide that pushes the chain from the underside onto the chairing.
I made it with 16mm motion film projector parts, I'm on my second arm\ anchor system.

[jeff williams]

Jeff do you have any pics of this set up?

sorry, the computer with the file was without op.

The anchor bolt shaft is 3mm wall and ground concave to fit the chain stay.

[jeff williams]

Ya! got a new photo emailed>

[jfmckenna]

HaHa nice dice!

Pretty clever set up.

[jeff williams]

Thanks, I had too many other upgrades, single dad- no $.
Replaces say $200+ store gear, works o.k.
I'll get a pro built one, or ripoff a better design, I need some better metal working tools or cash.