Just a reminder for newer fixed riders.
I’ve only recently learned how to slow down my bike without the use of brakes.
Doing this puts a lot of stress on the wheels, chain, cranks and pedals.
Yesterday I was looking over my bike and found my new Truvativ cranks had loosened off quite considerably and could have come off anytime! They were installed by a LBS.
Chain has stretched significantly and needs a link taken out.
That doesn’t sound right at all…
^ really?
Well it is slacker now than when I put it on…
I’ll check with my LBS and find out the brand etc.
Thanks
This has happened to me.
I got one of these…
http://www.kmcchain.us/kmcproduct.asp?pid=4866&bsid=54&ssid=667
note that it says it’s stretch proof :roll:
you sure you haven’t pulled the rear wheel forward? that’s what happened to me when i rode a poorly installed rear wheel. it hadn’t been installed anywhere near tight enough.
^ no because I was taking the wheel off and on over the weekend and it goes much further back in the rear lugs than it did two weeks ago before I could slow down without using brakes
I’d put money on the chain not being stretched.
Like Jams said your wheel has probably moved forward. If your chain had stretched enough to require taking out a link to make it short enough it’s not going to fit around the profile of the teeth on your chainring or cog.
^ ok that makes sense
I’ll check it out. Thanks.
When you’re riding, you don’t notice the crank arm flopping about?!
^ it wasn’t ‘flopping about’ but yeah I take your point!
Which truvativ cranks are you running, are they for ISIS spline? Some are notorious for loosening, while others need some rides (and subsequent tightening) to ‘seat in’ properly.
As for chain stretch, a little is normal. But a whole links worth of stretch on a 100 link chain (i.e. 1% stretch) would be an indication to get a new chain.
I run Truvativ Omnium Track Cranks…
http://store.citygrounds.com/store/product/2160/Sram-Truvativ-Omnium-GXP-Crankset-165mm/
I’ll check the chain stretch. I’d have a few beers and might not have been that good on the end of a spanner. :roll:
These cranks are awesome, I have 2 sets and not had any trouble.
The 8mm allen key on left hand crank on the omniums needs to be torqued to 50 Nm. That’s pretty darn tight and I think you’d stuggle to get to that if you are just using a little allen key. Take them back and ask them to use a torque wrench. What is your LBS?
Also, the BB cups should be torqued to 37 Nm.
This.
Holland Park Cycles 
:?
Another thought is to check the rollers on your chain. I had a cheap chain that threw a few rollers which caused slack points in the chain. To get a good chain tension I had to tighten the chain more which led to more rollers getting thrown as the chain went slack where the missing rollers were meant to be, then over-tight when there were rollers to engage the cog and chainring (similar to the kind of effect you get with an out-of-round chainring). It was probably when it was over-tight that the rollers got broken. This problem led to a significant movement in the rear wheel position over time and a lot of chain noise! Only after the second re-tighten did I realise that there were rollers missing and I promptly replaced the chain!
^ ok thank you
yeh how do you fix the left crank arm coming loose. mines just started doing it recently, annoying creaking noise and then it loosens off. ive tried tightening the allen key bolt as tight as itll go, but it seems to be loosening quicker and quicker now
:?