125-200cc Chain Tension

Just bought a 2008 CR 125. Haven't yet picked up a service manual but will shortly. Noticed that the chain is really tight. Tighter than any other bike I ever owned. Is this normal? Do these bikes have a "tighter than most" chain? I can only only move this chain up and down a few millimeters. Like I said, I will be getting a service manual in the near future that I am sure will give me lots of info but was just wondering if any of you could offer a few quick nuggets of info. Thanks all

No base rule is about two fingers slack in the middle of chain.
Dont ride with tight chain will most likly break the thing.

Every time I get a new bike I compress the rear suspension (sometimes you have to take out a linkage bolt) to where the CS, swingarm pivot and rear axle are in line. This is the tightest point of the chain. Then I adjust the chain to have just a tiny bit of slack at this point. Then uncompress the suspension and put a permanent mark on the side of the mudguard the furthest you can lift the chain up, for a chain adjustment mark. Cam.

The best way to adjust any chain is to put your chest on the seat and reach down and grab the swingarm then compress the rear suspension until the front sprocket, the rear axle and the swingarm pivot are in a straight line. At that point the chain is as tight as it will get and should have a minimum of 20mm slack in it. I run mine a fuzz looser than that but that's my preference.

Ha ha, we posted the same basic procedure at the same time. A guy can get run over with good advise around here

when i was young i was shown this way as well..

agree with the above ways, but I run mine at about 40mm of movement in the middle of the chain, holding tape measure at the side then pushing it up as far as it will go, 50 mm gives clunky changes, then with 14 stone of me on bike the chain still has about a half inch or so of movement. Read too if you run chain to tight not only will it wear out, it could snap, roll up at high speed into the casing and crack them open or take your leg out, also wears out damages the output shaft bit that the front sprocket bolts onto

Manual states 1-2mm from the bottom end of the chain slider. That's all I do

I've always run mine on the loose side so it can digest sticks and trail trash without binding up.... good for a woods bike, maybe not so good for a motocross bike. I agree with gazmcfaza that 50mm starts making things clunky. I little loose won't hurt much but too tight will destroy things quickly.

Too loose might get cough by the rear tire (tire rub on a knobby tire is a different experience as a street one)

Robert-Jan