7

I have a Speedo Duomatic that has been stuck in one gear the last 10 years. Probably because of too much lube in the wrong places. Now is the time to fix this. Everything is clean and I'm ready to put lube in the right places.

How should I lubricate to make sure it doesn't get stuck again?

enter image description here


I've planned to lubricate like this:

  1. Brake flaps gets oil.
  2. Brake drum gets a thin coating of grease.
  3. Bearings and parts that spin on the axle get moderate amount of grease.

I suspect the small plastic ring with a metal pin on it should not be greased (even though it spins on the axle)?

6

A couple of months ago I did this exact overhaul and it has been running super smooth ever since. Can't comment on the longevity yet but here is the logic:

Bearings: standard bearing grease, oil is too thin and will result in increased bearing wear.

Brakes: "Bremsmantelfett" (brake grease) from Hanseline. Here you can probably get away with normal grease, but if you do a lot of braking (eg. hilly area) the grease can heat up and harden, so the more heat resistant the better. Don't grease the braking surfaces of course.

Gears: oil, this area is well contained so no chance of the oil running away and oil makes the gears change smoother.

Pawls: oil, you can also use grease or a mixture but be careful not to apply too much grease underneath them or they can stick down. Give them a good test before and make sure they are really springy.

Other mechanisms: grease oil mix, oil can run away and get places you don't want (brakes) but grease can be prone to hardening. A sticky oil can also work here.

Not sure about the plastic ring you mention but if it rubs against something wipe a bit of grease on it. In general anything that should slide should have some sort of grease or oil on it and choose oil vs grease based on how well it needs to stay put.

| improve this answer | |
  • 1
    Nice answer! "Don't grease the braking surfaces of course" -- yes, that was my first thought too, but after having consulted my bike shop I put a thin layer of grease on the brake drum. This makes the breaks go in and out of action very smooth and with no squeaking, and I can still lock the wheel by back-pedalling. I doesn't seem to affect the operation of the drum brake negatively. – PetaspeedBeaver Dec 11 '16 at 21:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.