December 12, 2013 / Posted in Repair tips / By bikesonrobson / Leave comment

Tech Tip #1: Chain tension

Well it’s winter in the northern hemisphere right now so I decided to make a new tech tips section where I will be covering everything from basic and advanced mechanical work to tips on buying new or used bikes. Hope you enjoy the information, thanks for reading.

Tech Tip #1:

Chain Tension (fixed/singlespeed)

 

Tool list:

(1) 15mm box end wrench, socket, or like tool (1) rag….and some coffee

15mm box end

15mm Box end

 

Proper chain tension is much more important than people think, especially if your bike is set up fixed. Improper chain tension can cause parts to wear faster, unnecessary force on your knees, and an increased possibility of a broken chain. But don’t worry, checking and adjusting these things are easier than getting your long johns under your skinny jeans (my ongoing winter battle).

 

First of all you need to get your rear wheel off the ground, if you have a stand this is the time to use it, if not just flip your bike upside down.

 

Checking tension:

 

Checking tension is the same for both fixed and free set-ups but the tension they work at efficiently can be different. Start by grabbing your chain and give it a shake up and down to see if you do infact need to adjust your chain. I keep mine tight enough that it won’t sag under its own weight but it will still have 2-5mm of up and down play, with a freewheel you can get away with a slightly lower tension. Another thing to keep in mind while you are checking is most chainrings, cranksets, freewheels, and cogs and a margin of error and you will most likely have a spot in your drive train that is a bit tighter than everything else, this is the spot I adjust my tension around so I don’t end up with an extra tight spot.(warning: this can also be caused by poor adjustment or a myriad of other issues, if you have what seems like a very bad tight/loose spot it’s best to get it looked at.)

Checking tension - Poor

Checking tension – Poor

 

Checking tension - Good

Checking tension – Good

Adjustment:

Remember that tight spot in your chain? Now find that and set your cranks and wheels up to it. I like to do what I refer to as “walking” my wheel into place. I do this for a number of reasons, it allows for a very precise tension adjustment and for you to easily center your wheel in the rear triangle without the use of chain tensioners……ewwww. Start with your drive side nut, loosen it off and place your free hand on your non-drive chainstay while pressing that side of your wheel with your thumb until the chain is at the desired tension, tighten that nut moderately now. repeat the same process on the other side*. If everything is lined up at this point you can tighten both axle nuts to 34 nM.  Look, I know that is a bit specific soooo….. as tight as you can get it with a 15mm stubby wrench without hurting your hand, or pretty tight with a regular 9” 15mm wrench will do for a less technical answer. If your wheel hasn’t slipped on you in the past you probably have been doing a pretty good job on the force.

"Walking" the wheel

“walking” the wheel into place. Thumb on the Non-drive side

*Note: This process may have to be repeated 2 or 3 times in order to get your wheel on center with proper tension.*

As always, if you have any issues with anything on your bike feel free to give us a call at the shop and we can help you through it.

Now get out and ride your nice tight chain.