Dumonde Tech Freehub Grease and Oil
We learned our lesson when we gummed up a freehub with grease, costing us a stage race. It suddenly couldn't engage, we couldn't get a wheel in time. Race over. A friend learned when his freehub was screeching as he coasted out his door after servicing his rear wheel. In these situations, it took frantic web searches and anxious telephone calls before the problem was diagnosed. Then, with a little work and the proper lubricant, the problem was solved—though our sticky freehub was never quite the same again.
Freehubs are nothing the average cyclist wants to service until he has to. Being proactive with bike components is always a good idea, but hard to live up to. And taking apart a rear hub always looks like a complicated, unpleasant task. Luckily, component manufacturers have taken note (ease of assembly cuts down time for them, too), and most new hubs are pretty easy to service. Most seem to come apart fairly quickly, often with two hex wrenches, with the exception of Shimano's cup-and-cone hubs, which not only do you need multiple wrenches, something to catch the loose ball bearings, but a 10mm Allen wrench to get the freehub body off (14mm for XTR). Here's a guide to pulling freehub bodies from Park Tool.
Most freehubs have pawls, and for most pawls you want oil. Mavic officially recommends their own oil, which is a 10 weight (10w) mineral oil. Other manufacturers typically recommend a light weight oil—we've heard TriFlow from some, Phil Wood Tenacious oil, bore oil, sewing machine oil. Zipp uses a light grease. The idea is something thin that coats metal surfaces to protect the metal without being thick enough to limit the action of the pawls, and also not so thick as it will get sticky in the cold. We've used 3-in-1 oil as well, and it seems to run out of the pawls and subsequently we've been told it doesn't really work well as a lubricant in this application.
Dumonde Tech has been making lubes for bicycles and motor sports since 1985. We've tested out their chain lubes before (Regular and Lite and, Bio-Green) and generally like their stuff. Since we've never been totally confident in our choice of freehub lubes, we were interested in checking out their venture into the freehub.
They make two freehub lubes, a Freehub Oil and a Freehub Grease. The oil is for just about all pawl mechanism-based freehubs. It's designed to leave a thin film on the moving parts, enough to keep them moving, enough to prevent them from rusting, but not so much as to have parts get sticky. Pawl-equipped freehubs include: 3T, American Classic (and those that use AC innards), Easton, Formula, Hed, Mavic, Reynolds, Shimano, SRAM, and Zipp.
The grease is for freehubs that work with a ratchet plate or clutch mechanism. Freehubs that utilize grease include: Campagnolo/Fulcrum, DT/Swiss (and those that use DT/Swiss innards), Chris King, Hadley, Industry 9 (they also are developing a hub that will need freehub oil), Stan's, White Industries, and WTB.
We sampled both. Most of our wheels take oil. Take the freehub apart, clean out the old gunk, apply the new oil. Quantity is hard to figure: Dumonde suggests checking with manufacturers, but our experience is they aren't good at describing a quantity. Our typical mode is to get everything clean and dry first, put a little on to certain areas, spread it around with our finger, and then add a little more, spread again, until everything seems to have a light coating, and then add a little more on the toothed components be it the hub body or the freehub. We performed this maintenance on three regularly-used wheels, two for road, one for cyclocross. The clicking sound of freewheeling was a little bit louder, but there appeared to be a bit less friction between the pawls and the freehub. We observed this both when riding no-legged and when working on the bike in our stand.
We thought that we had one hub that needed grease, a Ritchey hub, as that was what the folks at Dumonde recommended. After cleaning it, putting a coat of light grease, and reinstalling, the wheel didn't coast. The problem was that because our Ritchey is fairly old, it uses American Classic-style six-pawl mechanism and not the DT/Swiss ratchet system that newer Ritchey hubs use. We cleaned out the pieces, oiled lightly, reinstalled, and it has been great ever since.
After over six weeks of use, the oil is holding up well. We've been in several downpours on the road and there is no noticeable change in action in terms of what we can hear or see. We don't know if the wheels will hold up through the winter without servicing, but, on the good side, we have the oil at the read for when it does. And according to Dumonde, it remains liquid until -40 degrees Fahrenheit. Since this product will mostly be sitting in your toolbox and will take a long time to use up, Dumonde suggests trying the oil on brake pivots and cables, uses we haven't tried yet.
Whether or not you pull for Dumonde Tech Freehub Oil or Freehub Grease, you should have some kind of freehub lube at the ready for when you service your hub.