SJK

Does anyone know what effectual difference the viscosity of different greases will have on items such as your hubs, headsets or bottom brackets? The reason I ask is I recently repacked my hubs with Lubrimatic Marine bearing grease. This grease is definitely thicker than the Shimano grease that was originally in there. I believe everything is adjusted properly as there is very (almost none) little play in the hubs until I have them in tightened with the QR. However, I believe they are not spinning as long as they used to with the small amount of thin grease that was in there. Don’t flame me here but – will this slow me down (not that it matter)? Does thicker grease have any real effect over long term rides in terms of energy consumption? Do most of you like the low viscosity thin stuff because it makes your wheels spin faster?

sydney

You could put light oil in the hubs and they would spin longer.Long term durability would probably be an issue.Since I'm not out to set the mile record,I'm fine with waterproof marine bearing grease. And yes, it is thicker than the green shimano goat snot.I use to use white lithium.It got too runny during hot summers in the Texas panhandle.

Applehead57

I've heard that you should pay attention to the temperature range that your oil is formulated for. Bikes don't generate as much heat as boats/automobiles, so a lighter oil would probably work better. I don't know what weight works best (if that's the right gauge). Probably any good grease would work and not cause damage. I agree that a very light oil would likely not last as long as a heavier oil/grease.

Doctor Morbius

I recently repacked several hubs with Shimano's Spin Doctor goat snot. Next time I'm going to use marine grease. One of the more respected LBSes in town recommends Finish Line Teflon Grease. However, if you do annual hub maintenance, marine grease is probably fine. It does an excellent job at repelling H2O and it's cheap.

I don't think I would entertain gear oil or lithium grease for hubs. Not unless one plans very frequent maintenance.

supcom

If your hubs spin freely (not binding or hard to turn) and are adjusted correctly, then you are fine. Any difference in friction is going to be insignificant and will make no difference in your speed.

Avalanche325

You should not use oil in hubs, you should use grease. The big differance is that grease stays, mostly, where you put it. Oil will not. It will all go to the outside when the wheel is spinning and not lubricate the cones properly.

Greases have ratings for temperature, pressure, water resistance, etc. Technically, a low temperature (allows the lubricant out of the matrix at lower pressure), low pressure (breaks down the matrix at a lower pressure) grease should be used. Remember, as it warms from use, it will get thinner.

However, in the real world, you are not going to see much differance.

PS. You should have a little play in the bearings when not clamped in the QR. When you clamp down, THEN, you should have almost no play. If you have no play at all when not clamped, they are adjusted too tight.

phantomcow2

Marine grease is good stuff for bearings. BIcycle specific grease is a waste of money if you ask me. You may notice more resistance if you spin whatever with your fingers, but there wont be any difference when your rolling

spinbackle

Can I repack my hubs with Jif peanut butter? I'm going to set the new record for the hour. Is Jif any better than say...Peter Pan or Skippy? Where can I obtain viscosity ratings for these lubricants? Any help would be appreciated.

Doctor Morbius

4 out of 5 Mothers choose Jiff when repacking their hubs.

SJK

Thanks. That is how I have them – with ever (and I mean ever) so slight play off the bike and “no wiggle” when I put them back on with the QR’s.

This does make me wonder what Shimano is putting in their hubs. It looks like some kind of thin mucus. Now I see why so many people repack them right off.

Rowan

I used to think the same, and repacked hubs with copious quantities of grease. Hmmm, no. All it does is allow the lubricant to seep from the carrier and out through the seals, which in turn provides an avenue in for grit and stuff.

Way back when I was financially poor, my grease gun was a plastic cake-icer with the smallest tip. Same principle as a greasegun. I still use it. I put a smear around the cup to keep the balls in place, put another smear around the top of the balls and reassemble. On the road (touring) I use a small squeeze bottle (eyedrop bottle) to do the same job.

I believe the balls don't need huge dollops of grease to remain lubricated and do their job efficiently. However, maybe just slightly more than the Shimano factory may apply.

But I might be wrong, and could stand corrected.

SJK

You may able to find the viscosity ratings on their respective packages.

supcom

Avoid the crunchy varieties.

baxtefer

what's wrong with lithium?
just curious....

Doctor Morbius

Some have complained about it melting and oozing in high heat conditions, as in a Texas summer.

baxtefer

ahhh, so not a problem for me.

Raiyn

Not at all. I use the marine grease on my own hubs.

gcbbike

I've found several viscosities of marine grease. which one are you guys talking about?

noglider 

It makes no difference. Use whatever lasts until your next overhaul. You can use oil if you keep replenishing it. Most people can't remember which is what makes it unsuitable.

Lawrence08648

Just go out and buy a synthetic bike grease such as Pedros and you don't have to worry about viscosity or water and the wheels will spin faster.

FBinNY 

The marine grade grease you used is just about perfect for your hubs. Higher stiffness increases resistance to water washout, and improves hot performance (though bike bearings don't get hot, the way car bearings do), but increases the parasitic (viscous) drag.

You may feel variation in grease drag with various greases, and an unloaded wheel may slow to a stop sooner, but these are very small forces compared to the total forces involved in a loaded bike moving through air. Also newly greased bearings always feel stiffer until the balls push most of the grease off to the side, and this same hub will feel looser next week.

Either way, bearing drag is probably well less than 1% of the total drag on the bike and declines as a percentage with higher speed, so reducing the 1% by another 10-20% to 0.8% isn't going to mean very much in the scheme of things.