single speed rear brake

johnnypipe85

Hi there!
yesterday, on my way back from work something really sad happened,i'm still upset. i stripped the thread of the cog on my fixed gear bike when leaving the traffic lights at elephant&castle :shock:
so to get to work today i had to buy a freewheel cog for the other side of the hub.
i really didn't enjoy the commute today, it's not the same thing, but i guess i'll get used to it.

here's the question:
does going freewheel mean that i need to buy a rear brake? this is supposed to be the cheap, maintenance free bike that i wouldn't need to spend money on!

Jon

meagain

Legally, yes. In a worse-case scenario, only one brake could also have insurance implications.

johnnypipe85

thanks, it's annoying cause the bike only cost me £70, so a new brake will be half of that! I guess better safe than sorry!

meagain

"a freewheel cog for the other side of the hub"

While frowned upon by the purists (and the very strong, which may of course include you as you have stripped the other side!), no pracical reason why you cannot screw a fixed sprocket on the free (non-stepped thread) side. Bang it up TIGHT and unlikely to move.

Opinion only you understand.

SamWise72

What kind of bike is it? If you PM me your address, I'll package up an old Weinmann sidepull caliper and post it to you - pop it on, and Bob's your father's brother - no charge. I prefer two brakes even on a fixed gear.

ride_whenever

Presumably, if you put a fixed sprocket onto the freewheel side, you don't have a lockring, so you need a brake to account for the danger of it unscrewing?

SamWise72

You can use a BB lockring, but it's not threaded the opposite way to the cog, so it's risky. Best bet is to rotafixa the cog on there, also using locktite, do the same for the ring, and then run a brake too.

ride_whenever

rotafixa?

meagain

ride_whenever wrote:

rotafixa?

Perhaps it's short hand for a block of wood and an 'ammer?

SamWise72

Rotafixa:

http://204.73.203.34/fisso/eng/schpignone.htm

The best way to really torque a cog on.

meagain

Well, yes. Simpler is a serious chain wrench. I have one on same principle as this

http://www.machinemart.co.uk/shop/produ ... tive-tools

With an 18" 1/2" drive breaker bar (and if removing a seized sprocket a 2 foot tube as an extension, although the spokes might let go first) can tighten way beyond my ability to unscrew when (back) pedalling.

I agree that what usually pass for chain whips are pretty poor. Got mine for pulling bits off the old Landy!

SamWise72

I guess that's simpler, but I'm not sure whether it would be as powerful or not. What's nice about rotafixing is that you don't need any extra tools. I find my normal chain whip more than adequate, but then I don't have any suicide hubs, so getting it on with a king-kong grip is less important.

NorwegianBlue

When it comes to fixed cogs unscrewing when used without a reverse thread lockring there's a lot of "yes it will" "no it won't" discussion on internet forums. To add my 2p I've only ridden a bike like this once and the sprocket came loose in no time at all. It didn't unscrew, but it would have done had I not noticed that it felt a bit loose. If a reverse thread lockring wasn't necessary they wouldn't build them like that.

Thread locking compounds aren't intended to protect against large amounts of reverse torque. If they were you wouldn't be able to unscrew nuts that have been loctited on.

I have used one particularly dodgy fix in the past. A friend stripped his lockring thread and rather than have him scrap the wheel I fitted a sprocket. Drilled a hole right on the join between the sprocket and hub then tapped the hole to accept a small screw. Not perfect, but it lasted until the wheel wore out. This would probably work when fitting a sprocket to a freewheel thread as long as the hub body was thick enough at the thread.

When it comes to the legal position of two brakes the law in the UK is very clear on the subject. You must have front and rear brakes, a fixed cog doesn't count as a brake. So in the event of an insurance claim you would probably be in trouble if you didn't have a working rear brake fitted, even if the other party couldn't prove the lack of a brake had any bearing on the claim.

meagain

"When it comes to the legal position of two brakes the law in the UK is very clear on the subject. You must have front and rear brakes, a fixed cog doesn't count as a brake."

Sorry, but yes a fixed DOES count as an "independent means of retardation" to the rear wheel and therefore need only a front rim/disc brake.

The CTC's guidance is unequivocal AND accords with every interpretation of the Use Regulations that I have ever seen.

I however always use two on a fixed since an unfortunate event with which I will not bore readers again!

peejay78

i use one brake on fixed, because the brakes are always the last thing i fit when doing a build, and i can only usually afford one caliper/lever.

NorwegianBlue

meagain wrote:

"When it comes to the legal position of two brakes the law in the UK is very clear on the subject. You must have front and rear brakes, a fixed cog doesn't count as a brake."

Sorry, but yes a fixed DOES count as an "independent means of retardation" to the rear wheel and therefore need only a front rim/disc brake.

The CTC's guidance is unequivocal AND accords with every interpretation of the Use Regulations that I have ever seen.

Interestingly that completely disagrees with every accepted interpretation of "independent" when it comes to the parking brake on a car. In that case the means of application of the brake must be entirely independent of every other mechanical or hydraulic system. In which case, unless the CTC's interpretation has been tested in court I wouldn't rely on it. A car driver's insurance company would likely choose the interpretation of "independent" as applied to car breaking systems. A court may well take their side which would probably set a precedent. Where the law is open to interpretation, no interpretation means much until it has been tested in court.

Gareth