MudPie

The question: Is standard bike grease (Park or Bontrager brand) good enough or shall I use high temp auto disc brake grease for rebuilding bicycle coaster brakes? And what is the consequence of not using a high temp grease?

Recently I refurbished two 20" kids bikes with Bendix coaster brakes from the 70s. I haven't rebuilt a coaster brake in years and found the actual Bendix service instructions on line. They call for "high temperature" grease slathered on the innards of the coaster brake. I talked myself into thinking kids would not stress the internals to a high temperature, since they're not likely to go that fast and they don't weigh much (not much kinetic energy). Plus I'm guessing the video games compete for the kids' attention, and I don't expect them to ride them much.

Now, I have two adult beach cruiser bikes I'm refurbing for a friend. I plan to tear the coaster brakes apart, clean and lube.

veganbikes

If it were me I would use a high temp grease especially if the hubs are going to get used. If not I wouldn't worry about it. However since the hubs probably won't see service much I would make them as good as possible.

This is my ideal for a coaster brake hub if I needed or wanted a coaster brake hub.: Souped up coaster brake hub ? MON?

79pmooney

I've never opened a coaster brake and haven't owned one for some 60 years. I have no idea what the grease actually does on those hubs. But, something I have thought about a lot is - what if someone takes that hub and rides down ... (Day 2 of Cycle Oregon, 2016 for example.) Or the wheelchair hub I dreamed up 30 years ago that could be taken into wilderness a wheelchair could never get to before. That hub failing? Maybe someone notices the guy never returned, maybe not. Do I want that on my conscience?

Andrew R Stewart 

My usual go to for years was common auto axle bearing grease. But having done so many coaster brake overhauls I find the kind of grease to be low on the list of importance. Un worn parts set to good adjustments with plenty of grease was more the issue.

Back in the day we would set the bearing pre load to a slightly loose amount, just like SA AW hubs of the era. Andy

FBinNY 

It depends on your weight and riding conditions.

For typical use by adults or youths on f as irly level terrain, any grease will do.

However, if your heavier, or there are long and/or steep grades involved then you'll want a high temp grease.

FWIW when I first started in the b bike industry, I had occasion to talk to an engineer at one of the last companies still making coaster brakes in the USA. One of their design tests involved a 300#+ employee, and a long steep hill nearby. He'd drag the brake all the way down to heat the hub until it glowed.

Bill Kapaun

Was his name Rudolph

MudPie

Yeah, I agree. For peace of mind, I'll use high temp auto disc brake grease. The stuff isn't expensive and much cheaper than the tube of Park or Bontrager grease I usually buy. A 1 lb tub of auto grease is under $10. It's just a bit messier to dispense. In general, I don't seem to use much grease these days with sealed-this and sealed-that components. A 4 ounce tube of grease lasts me years. 4X that for a 1 lb tub.

Duragrouch

Yeah I think for cheap coaster brakes, standard auto wheel bearing grease should be good, a good quality one typically has a 500 F degree "drop point", the temp at which it liquifies and runs.

Something not cheap, like a Shimano Rollerbrake in an Internal Gear Hub, these have roller cams pushing out the brake shoes, and the hub is expensive, so I would try to determine what Shimano specifies; It could be wheel bearing grease, or could be a silicone grease.

grumpus

According to the legend of the Repack Run it just vaporises and makes for an interesting ride.

Duragrouch

I still have a pale green tube of Phil grease that I bought with my first good bike in 1989, still some in the tube, I use auto wheel bearing grease now, I think it's better, and the last few years use green marine (boat) wheel bearing grease, as the extensive website for Aaron's Bike Repair (specializing in IGH service) swears by the stuff, especially in the rain. It's a different chemical base, but I don't know exactly how it works. A camper and trailer supply place in town carried it. First ordered off amazon, said green marine, opened the can, was normal grease, I sent back. As with most good greases, a tub of the stuff was about the same price as a small tube of "bike" grease. But the green stuff does not specify a drop point. For anything high temp, I'd use the 500 F auto grease. EDIT: I sit corrected, the green marine grease also says 500 F and meets an ASTM spec.

79pmooney

Those guys were young, crazy and immortal. I'll stick to my high temp grease to send mere mortal folk down.

smd4

White lithium worked perfectly fine for us.

Duragrouch

Back in the day, my dad (an engineer) said "There is sliding contact grease, and rolling contact grease." Sliding he used black lithium (like for steering linkage), rolling he used "long-fiber" (no actual fibers, it describes the appearance as you scoop out a bit of it) grease (for wheel bearings). Now, I buy a tub of grease, and it indicates it's good for everything. White lithium, I perceive as a bit "cleaner", comes in spray form, nice for door hinges that are visible.