cmh

I just picked up a used track bike and the previous owner said the chain might need a little more tension. So - what is the proper tension for a fixed gear? Tight as I can get it without binding? I also assume you can measure the chain and replace it at the same amount of wear as a geared bike (1/16 - 1/8" stretch over 12 inches). Is that correct?

Thanks for the help.

juvi-kyle

once you go slack, you will never go back...

RYAN INGERSOL

exactly. less tension=less friction.

chzman

high tension = unhappy bearings(and apparently a one tooth cog)

i like to guage tension by holding the rear wheel stationary and try moving the cranks back and forth, if you can feel a few mm of slack it should be loose enough to keep everything happy, and tight enough to prevent the chain from falling off.

genericbikedude

I tighten so there is no slack in the stand, but a few mm of slack while trackstanding.

11.4

You never want it loose enough that you could possibly derail the chain off the chainring. So test it when finished by using a wrench to push the chain over and see if you can get it to rise up and over a tooth -- even if it is too tight to drop off the chainring, under pressure this will be enough to snap a chain or cause some other variation on a thrown chain. Not pretty.

Other than that, don't run it too tight or it'll be noisy, wear fast, and be hard on the rest of your drive train. Generally speaking 1/2 to 3/4 inch up and down slop in the chain, measured between the cog and chainring, is quite acceptable. You won't gain much by adding more slack than that.

All this is when everything works. The problem is that many chainrings are anything but round, and then cranks have their tapers cut off center, so the problem gets compounded in the crankarm itself. Sometimes you can rotate the chainring to offset crank problems, but most of the time your problem is with the chainring. Turn the crankset with the chain mounted and tightened and you may have very little slack at one place, while 90 or 180 degrees away, you have a very slack chain. You may just have to compromise and find a tension that isn't too tight at any point, nor too slack at any point. If your chainring is horribly off, you should return it for an exchange, but honestly I have trouble finding a chainring that doesn't have this problem. Only the extra-fancy Sugino's seem to be free of problems. Most of my Dura Ace chainrings have the problem, along with Suntour Superbe's, Sugino 75's, and Campy's. Those TA chainrings (offered in both 130 and 144 BCD) can be really atrocious.

el twe

11.4 - WHO ARE YOU? You are such a wealth of knowledge and we are priviledged to have you on these hipster-bashing, bag-questioning boards. Muchos gracias, senor.

chzman

i always thought throwing or snapping a chain would be pretty.

spencer

i've done it twice on a downhill at a very high rpm......somehow im not dead.

sers

i spin the cranks while the chain is loose, and try to have the cranks generally spin that freely once i've gotten it tightened up. the chain usually has about 3/8" of slack at that point.

humancongereel

like 11.4 said. about a half inch of play. seems to do the trick.

cmh

Thanks for the help, everyone. I'll tighten her up a bit. I can't wait to hit the streets and see if this fixie thing is deserving of all the talk.

cmh

orbThorn

man i think my chain is way to tight..

bobdanger

my 1/50th of 1$- i let the shop do that stuff- true, im lazy and it costs a smidge more but i say let the pros do the pro stuff thats why theyre paid the big bucks- it gives me peace of mind not worrying abt if my wheel will slip or not- i have a speedlink so i never take the wheel off- makes cleaning the chain mad eazy; allz i do is the basic wash wipe down and lube and post-ride chain wipe- tension seems to be somewhere btwn a bit of play (snug to not so) throughout the chain except for where its tight for a second and then not.

ZachS

[rant on]

most commonly misspelled word on BF: G-A-U-G-E

[/rant]

skelly

slack.

thurstonboise

Just tight enough that I don't notice any play in the pedals. Amazingly enough it's 1/2" or so like everyone else recommends. If I can feel the chain tighten up when I change pressure on the pedals, the 15mm wrench comes out as soon as I stop.

nine

i am a recent convert to slack. it's true what they say about it.

Aeroplane

What do you do if you get a rear flat? Take it to the shop to reset the chain tension again?

Jerseysbest

Ah, finally some numbers to go by

jfmckenna

Yeah but numbers like that are too difficult to measure. I guess you could take a straight edge and a ruler perpendicular to it but it's kind of arbitray to say 1/2''. Best to go by feel. A test I like is to try to remove the chain off of the chain ring with my finger sort of like a front changer works on a geared bike, by rotating the cranks slowly and pushing the chain to the side. All teeth that come around should find the link and not come to the outside, then your good to go.

ZachS

no - takes it to the shop to reset the chain tension AND get the flat repaired.

rob3rto

Check out the bit about chain tension on Sheldon's site: https://www.sheldonbrown.com/fixed.html If you scroll even further down there's a pic of a finger tip cut off from getting stuck in the chain. Don't do that.