Falling apart underneath me

pangolin

Was riding in this morning on the fixie. Halfway down the hill in the middle of Richmond Park I notice I am able to freewheel. This alarmed me. On closer inspection I found the rear cog had unscrewed itself completely, and the chain had fallen off the chainring as a result.

This happened to anyone else?

Wasn't a big problem, I had a spanner in my pack so put it back together and stood on the pedals a few times to tighten it up again. Do people tighten these more than you can just by pedalling? I was nervous about braking using the pedals for the rest of the journey!

veronese68

Shouldn't you have a locknut to stop that happening?

spasypaddy

yeah why havent you got a lock nut?

im destroying road bike parts bit by bit, slowly but surely im running out of working bikes...

nicklouse

pangolin wrote:

Do people tighten these more than you can just by pedalling? I was nervous about braking using the pedals for the rest of the journey!

mine is held on by 6 bolts so not worried.

Greg T

pangolin wrote:

Do people tighten these more than you can just by pedalling? I was nervous about braking using the pedals for the rest of the journey!

There should be a locknut with a reversing thread holding it on... been a while since I messed around with my cogs but there are two sides to a flip flop hub, one with a lock nut threading thing and one without for a freewheel.. .

Also God gave you brakes to slow you down... leg braking is considered a bad thing by many..

TommyEss

If you are going to use the rear sprocket for braking then you need a lockring - and if you are only running a front brake then you need a lockring to comply legally as well as sensibly. Frankly I am surprised it has taken this long for the problem to expose itself - I'd count yourself lucky and buy a lockring pronto - they're under a tenner.

pangolin

Well this explains things.

I have 2 brakes btw. Off to get a lockring!

TommyEss

Hah! I had the same thing but thankfully(!?) on the velodrome - I was slowing down to stop on the barrier prior to a race excercise, and suddenly freewheeled.

Just check your hub as well - a lot are flip flop with only one side reverse threaded to take the lockring - make sure your sprocket is on the correct side - and check that when then sprocket is fully tightened (using a chainwhip not pedalling force) that you have some exposed reverse thread protruding - that's where the lockring will sit. You'll need a lockring tightener to get that on - you might already have one for your bottom bracket. I would expect on a Charge you've got a pretty standard thread pattern as well (there are a couple of more exotic flavours of lockring threading, but I would be very very very surprised if you had that on an off the sheld bike like the Charge - but may be worth a quick email or phone call to Charge to check)

Kieran_Burns

I have to admit, it would take considerably less than a close inspection to notice a chain had come off... there are clues.

pangolin

Greg T wrote:

Also God gave you brakes to slow you down... leg braking is considered a bad thing by many..

Why is this? I considered it a plus as every time I braked this way was a bit less wear on my rims / pads. I wasn't doing it exclusively though, I use both brakes too.

Anyway, a lock nut has been purchased for the princely sum of £2. I can controversially leg brake and trackstand to my hearts content once again.

TommyEss

I think there's a difference between braking to a stop and merely backing off and slowing down using pedals alone. I actually found that slowing slightly in traffic etc was very intuitive on my fixed wheel, but when I had to perform an emergency stop, it'd be brakes all the way (although I often found I'd intuitively stopped pedalling and was actually skidding the rear when it was wet/greasy!)

FWIW - Lord Sheldon of Brown tells us the quickest possible way to stop is the front brake to the point just before it locks (good luck finding that exact point - maybe wind it down a couple of notches!!)

Hard braking with your legs alone will put an immense load on your knees, hence not really recommended. As I've said, backing off, effectively not putting in any active push down on the pedals, lets you suck energy out of the bike through leg resistance - but slowing from 20 to 15 over a number of metres is very different to pulling an emergency stop/skid stop with your legs alone.

pangolin

Ah I see. Cool well that's what I do using just legs, so I shall continue!