Mountain Biking - Pedaling problem

Yesterday, on my first trail ride, with the loki, the crank locked up and would not push forward no matter how hard I pushed. I would have to forcefully backpedal untill things loosened up so I could begin repedaling. And then it locks up again. i thought it was a messed up bottom bracket, but KonaRider said it was the chainline/tension causing the problem. So I go out this morning, I left it stuck from last night, and sure enough it was the chain. Damn, Kona is good at findin problems. It was really realllly stiff. i could barely pull it up or down. Kona what did you say I can do again? I have pix, but Im not sure what to look for. Is there a bit of a chain sag on here? If im in the 1-1 gears, I can do wheelies and everything is fine.

http://i7.photobucket.com/albums/y251/viperfx10/IMG_2383.jpg
http://i7.photobucket.com/albums/y251/viperfx10/IMG_2384.jpg
http://i7.photobucket.com/albums/y251/viperfx10/IMG_2385.jpg
^^that looks funny.

http://i7.photobucket.com/albums/y251/viperfx10/IMG_2386.jpg
^^to close??
http://i7.photobucket.com/albums/y251/viperfx10/IMG_2387.jpg
http://i7.photobucket.com/albums/y251/viperfx10/IMG_2388.jpg

I bet you the plastic disc behind the cassette is messing you up. It's most likely getting caught inbetween the largest cog and the spokes, siezing up the freewheel motion every once in a while.

If you have the correct tools, remove the cassette and then take off the plastic disc. If you don't have the right tools, you can try breaking it up- be creative, just don't damage anything else.

While you're at it, make sure you rear derailluer low limit screw is set correctly so you won't drop the chain off the largest cog. The purpose of that plastic disc is to keep the chain from getting tangled in your spokes, but with the derailluer setup properly you won't have to worry.

While you're at it, make sure you rear derailluer low limit screw is set correctly.
Where is that exactly?

Oh yeah KonaR, I fixed the brakes like ya said how.

your chain is too long, and I would not use the two smallest gears together.

But it only works with the two smallest gears. Consistant pedaling with the higher gears causes the lock up.

Where is that exactly?

The limit screws are 2 adjustment screws on the derailluer body. They are usually marked with "H" and "L" for the high-gear small cog and the low-gear large cog.

See http://www.parktool.com/repair/readhowto.asp?id=64

More than likely these screws are already set properly given that the bike is brand new and that these adjustment screws are not affected by cable stretch or any breaking-in kinda thing.

your chain is too long, and I would not use the two smallest gears together.

I second this. If your chain has any slack in the small chainring/small rear cog combo, it's too long. Although you should never use this combo anyways, it's good to be prepared when you shift into it absentmindedly or are in a race situation where you could care less.

You should have just enough chain to wrap around the large chainring/large cog combo without passing through the rear derailluer plus one extra link (one additional inch of chain.)

So I have to buy a chain breaker or something and use that first?

So I have to buy a chain breaker or something and use that first?

I still really think it is the plastic disc. Grab it and see if it has any movement when you try to pull it in every which direction. If it moves or has any play, that means it is no longer securely attached to the spokes. Basically, you don't want the plastic disc touching the cogs at all.

Gwhunt, I just got back from outside with it, and the plastic disc wont rotate as a complete circle...like it goes up and down at a certain point ( as if a hulahoop rotates on a person), and when the bikes upside down, and the wheel spins, I hear the plastic disk making more noise than the free wheel. You know yiou might be on to something!

Gwhunt, I just got back from outside with it, and the plastic disc wont rotate as a complete circle...like it goes up and down at a certain point ( as if a hulahoop rotates on a person), and when the bikes upside down, and the wheel spins, I hear the plastic disk making more noise than the free wheel. You know yiou might be on to something!

Yup, it's my favorite new bike problem. Take that sucka off of there! :p

Garg evil cheap looking plastic disk.

It's not the disk. If it were somehow catching on his chain, it wouldn't exhibit the problem in the lower cogs. Not to mention it looks fine in the picture.

Does it coast okay? Could it be a problem with the freehub?

I was looking at the plastic disk and it is beyond messed up. 2 of the 4 little clamps that hold to the hub are all bent and not even on it, one popped off and one is fine. Im trying to think of a way to get it off w/out taking it in. Ive tried a nail, a bush cutter, a xlarge hex wrench, but nothing would cut or scrap it off. Hm

I got it off, took the bike for a spin and it still locked up. After further analyis on the side of the road in the dark i believe it is the rear derailleur.

What chain do you have on there?

I've had a couple of recent problems with the SRAM PC-971 that came on my '06 Stumpjumper. The chain snapped twice (once on a ride just over an hour from where I live... that was frustrating) and the LBS replaced it outright with a new chain (same type). I considered upgrading to the 991 as it seems to get better reviews... no stiff links.

In my case, it was mildly similar where the pedals just sort of locked momentarily, but with the next push (not hard), the chain just went. POOF. No changing gears, no BIG hills, just a mild uphill after about 4-5 miles of riding.

shorten your chain and turn in that little screw on the der. that looks like it points right toward the dropout.. it will pivot the der. back a bit. Your guide pully is probably hitting the cogs.

A sram 8 speed.
I hope I don't mess somethin up if I try to adjust the H/L thing by myself.

leave the h/l alone, that only adjusts the outer limits of travel of the der. if the chain is not jumping into the spokes, or off the small cog toward the der., its fine.

Oh ok. Could this problem be the result of chain-sag?

Put a 9 speed chain on that thing.

It really looks like you have too long of a chain on it. If not, I'd blame the freehub. Try pedaling backwards and see what happens. If it doesn't want to move, and the chain builds up in one place, the freehub has probably had it. That's what happened to my brother's new STP 1. He had a new one put in free from warranty.

Put a 9 speed chain on that thing.
For real??

Well when the chain locks up, the bike cannot be moved backwards. I pulled the chain off the cog is was on, and the wheel could turn fine. I dont know how or especially where the chain gets lockup up at.