Front brake question

[MalcW]

Hi

My neighbour has just bought a 1950s Model 18 with a full width hub front brake. When he uses it, the lever tends to tighten up - i.e. on the first pull there is a normal amount of slack in the cable; on a subsequent pull during the same braking period the cable feels tight. After stopping and pulling away again, it's back to normal, until the next time. Yet the brake seems to still work the same, and it isn't getting hot. I would have thought that if the shoes were sticking on, the cable would feel more slack, not less. I've had the brake out and it all seems OK, and the brake plate is centred correctly.

Any thoughts?

Malc

[alanengineer]

Drop the wheel out and have a look. A quicky job, but if nothing else its piece of mind knowing to know whats happening to an important part of the bike

[SPRIDDLER]

I'm not completely clear as to what you mean by 'tight' but it might help to discover whether it's caused by the cable jamming (e.g. it has a broken strand) or it's the gubbins inside the drum that is sticking, so disconnect the cable and operate the brake lever to see if it is still 'tight', then (still with the cable disconnected) try operating the brake by the lever at the brake backplate.
If the shoe lining is well worn it may be that the cam that spreads the shoes isn't returning fully to its 'at rest' position when the handlebar lever is released.
BTW - it's probably irrelevant to the issue but if the '50's' bike is pre '54 it would originally have had a single-sided front drum not a full width.

[MalcW]

Hi

Thanks for your thoughts so far. We did drop the wheel out and remove the brake plate, and everything looked clean and as it should, with decent, quite new looking riveted linings, chamfered at the leading edges. Good idea about disconnecting the cable and trying both cable and lever separately.

Spriddler, I think it's a '54 bike. It has a full width hub, but slightly different in shape to that on my '60 bike. mine has the ribs around the hub slightly raised, whereas his has the ribs flat across the drum. Also, mine has the brake actuating lever at the top, behind the fork leg; his is at the bottom. The brake retaining arm looks the same on both.

Cheers,

Malc

[g80csp11]

i did have a front brake that was sticking , turned out to be lack of grease on the actuating spindle through brake plate , eventually i had to stop in a tesco car park and drop out wheel and oil the spindle as i could not find anywhere on a sunday evening with a grease gun with the old point applicator
1 hour later back on the road . all fixed .
Job made worse as the 67 P11 does not have a center stand

the other ting to check is the lever pivot ive seen those too tight in the past to point of sticking

when you find the solution , let everyone know !

[Duncan]

Hi Malc, could it be that your neighbour is experiencing the AMC "design feature" that when adjusting the free play in the brake cable on the centre stand or stationary it appears to tighten up in use, I normally run my brake levers with quite a bit of free play when stationary as this "self adjusts" when on the move. I think this is more apparent with non standard or longer cable routes.

[MalcW]

Hi Malc, could it be that your neighbour is experiencing the AMC "design feature" that when adjusting the free play in the brake cable on the centre stand or stationary it appears to tighten up in use, I normally run my brake levers with quite a bit of free play when stationary as this "self adjusts" when on the move. I think this is more apparent with non standard or longer cable routes.

Hi Duncan

Interesting. I haven't come across that, but it certainly fits the description of what's happening.

Thanks,

Malc