Rod Brake Adjustment

[clarion]

I have recently acquired a rod-braked roadster. It's lovely, but the brakes are rather vague. Could anyone give me advice on how to optimise the braking for best effect? i.e. How can I stop downhill in the wet?

 

[bobg]

If only.... As has been said on here before " a bit vague" is often the best you'll get ... however
There are a number of possibilities that will go some small way to improve the brakes on roller lever (rod) brakes
1. Because the braking surface is on the inside and not the edge of the chrome or steel or stainless steel rims, they are very prone to judder if the rim is in even the slightest bit eccentric so that can resolved by getting them trued. Bike shops can easily true run out ( buckled) rims but egg shaped ones take a bit more skill.
2. In earlier models of the roadster, the clamp that attached to the front forks into which the "horseshoe" shaped brake mount was fitted was of a better construction and made more substantially to minimise judder but I think these were discontinued in the 40's.
3 The small clamp with the slot or hole in it that bolts to the front forks has to be very accurately placed so that then the brake blocks impact exactly on the correct inner part of the rim to maximise braking. It is often necessary to file the blocks to fit the profile of the rim. The original blocks were often made with leather composition inserts at the braking surface for improved wet braking, these are available but you may need to hunt for them.
4 The rear braking is far inferior in my experience. The clamps that bolt to the chainstays neverseem to fit at the necessary angle to allow the "horse shoe " fitting and therefore the brake block to line up fully with the profile of the inner rim of the wheel,,, which is why ( usually) the blocks on it are only worn over 1/2 their width" Getting both th front and rear brake clamps in exactly the right position and angle is half the battle along with correct leather insert blocks and ( (sometimes ) a bit of manual bending of the horseshoe clamp (again to ensure the blocks run properly along the profle of the rim. I suppose tht has been oft said before still applies, start braking bout 25 yards before you need to stop!! I have the original Raleigh booklet which details the braking system set up and how to adjust it, I'd be happy to loan it to you.
BTW in order to set up the rear brakes properly, you'll need to remove the chaincase, the front prises off like the lid of a paint tin and there is a bolt accessible between the arms of the chainwheel. Its a bastard to get back without the chain clanking, this is often because the chainwheel is slightly off true so check it before refitting. Chain tension is also critical too.
Good luck

 

[wheres_my_beard]

In setting up some brakes on an old post office bike, I found the brakes were really poor if there was any slack in the mechanical connections in the rods, especially where the lever connects with the first vertical rod in front of the headset. Once I managed to get the play out of the system I was pleasantly surprised by how much more predictable and effective both the front and back brake were, even if the brake pad was not sitting fully inside the rims.

1. Ensure you have a good spring to return the lever, this is the only tension pulling the pad back away from the rim.
2. There is a small nipple in here on the end of the slim rod going down to 3. I found that jamming a slim screw driver into the hole pushed the slim rod down and made sure that rod was pushed down as far as possible so that there was no play when the nut below was tighthened.
3. Tighten this nut as much as possible, once you have got no slack or give in the rod fitting inside it.
4. Adjust the clamp around the fork that holds the small rod sticking out from just under the brake pad to set the pad to come inwards as it gets pulled upwards. I found having these as high as possible worked for me.

Also, adjust the brake pad so that when it connects with the rim, it connects as squarely as possible.

Not all of my brake pads connect with the rim, but as they have worn more material is in contact and I have fairly good braking power.

Post some pics, it might help.

 

[raindog]

In setting up some brakes on an old post office bike, I found the brakes were really poor if there was any slack in the mechanical connections in the rods, especially where the lever connects with the first vertical rod in front of the headset. Once I managed to get the play out of the system I was pleasantly surprised by how much more predictable and effective both the front and back brake were......

+1
There's alot of 'lost energy' through all the different linkages, especially on the rear brake. Also, adjust the blocks as close to the rims as you can get away with or leverage efficiency will be lost with the levers almost touching the bars. They're fiddly to set up, in fact, they're a pain in the neck, but once done and the blocks are "bedded-in" to the rims they are surprisingly powerful.
As to braking in the wet - good luck.

 

[clarion]

This is all good advice, thanks. I noticed that the brake lever has a lot of travel before activating the rod, because it's quite loose in the pivot. Not badly so - just design issues that that gets magnified. I'll play with tightening everything up. I think one of the rods is a bit bent, which won't help. The wheels already seem very round, so that's not a problem.

Need to go have a play. Now, where would be a good place to get spares?

 

[bobg]

http://oldbiketrader.co.uk are good. BTW Good advice about slack linkages, I should have mentioned that!
I think Beard's PO bike is a Pashley, the brake lever return spring on those seems a bit more efficient that the ones on Raleighs.

If you need bits and can't track any down I may have some. just shout.

Bob

 

[Davidc]

Brings back distant memories - my "Small Ladies" Humber, that I rode from age 7 to 11 had those brakes, and if memory serves me correctly the best they ever got was 'a bit vague'.

When I got my next bike the single pivot, cable operated calipers, with rubber blocks on a steel rim seemed incredibly powerful even in the wet!!!

As above, good luck.

 

[tyred]

They are hassle to set up but should be fine (in the dry at least) when set up and will work for many years without input if they're not disturbed.

Make sure your spokes aren't too loose as the rim will try to pull upwards and don't be afraid to bend and hammer things around to get it right. The pads need to both hit the rim at the same time. They don't self equalise like side pull calipers. Also, on some designs, there is an extra piece which offsets the pads from the stirrup on the front. If you have this, ensure the pads are behind the stirrup close to the front edge of the fork blades. If it's fitted the other way around, the rim will push the pads away.

Put a drop of oil on each pivot, this is import, especially for the back brake and use proper oil like engine oil, not WD40 and make sure you have little or no play at each part of the linkage.