Technical Q&A with Lennard Zinn: Wheels, grease, oil and a chunk of chain
By Lennard Zinn
KGS Bikes technical writer
This report filed August 29, 2006
Are these a problem?
Dear Lennard,
I use the Fulcrum Racing 1 wheels with a Shimano drive train, though I have a titanium (11-25) cassette made by Cycle Dynamics. The freehub body is grooved by each of the cogs (see attached photo). My bike shop says this is a normal consequence of using a cassette with individual cogs. I don't buy it. I think it is the result of the softer material (aluminum) used in this free hub body. My other wheels, with steel free hub bodies, are not grooved. My drive train makes a periodic, soft noise that I have not been able to eliminate, and I fear it may be related to the slight looseness of the cogs. Is this grooving typical for aluminum free hub bodies?
Kurt
Dear Kurt,
Grooving like this is typical of aluminum freehub bodies with separate cogs. The aluminum cog carriers on present-day cassettes are a great step forward from this perspective. This problem is also another reason why Shimano went to much deeper spline valleys for its 10-speed freehubs than it had used for 7, 8, and 9 speeds, on which it used either steel or titanium for the freehub body. But other manufacturers made aluminum freehub bodies compatible with Shimano cogs, and what you are experiencing is typical with them. The first few cogs are still loose even on cassettes with aluminum cog carriers on the larger cogs, and they would still dig into the shallow splines of 9-speed aluminum freehub bodies, making them hard to remove.
Lennard
The case of grease v. oil
Dear Lennard,
I have a rear wheel with the new Shimano 10-speed hub, and after 1500 miles it began creaking terribly during climbs. I disassembled the freehub body, cleaned out the old grease, and reassembled it using a small amount of Pedro's Syn Grease to lubricate the pawls. The creaking is gone but now the ratcheting sound of the freewheel is louder than before. I miss my formerly quiet freewheel. I am afraid that adding more grease to the freewheel might cause the pawls to slip under a heavy load. What is the recommended lubricant for the freewheel mechanism? In an earlier column you recommended Mavic mineral oil, but wouldn't that make the freewheel ratcheting even louder?
Derek
Dear Derek,
You're right to be concerned about grease. Never put grease in a freehub, except perhaps ones without standard pawls, like an American Classic or a Hügi (DT) with a star ratchet. You are asking to land on your nose. Just use light oil. Yes, the clicks will be loud.
Lennard
Dear Lennard,
Hello. I recently rebuilt my Kysrium SL rear hub and used a light coating of DT 'special hub grease' (a red-colored grease that smells like icy-hot). The wheel began making a noise and the bike shop sent it to Mavic to diagnose and fix the problem. According to the bike shop, Mavic told them that grease (regardless of thickness) can't be used and mineral oil should be used on the pawls. I have never heard of this before, except Chris King's recommendation of using a thin oil (Phil Tenacious Oil or Shimano Hydro Spit) for extreme cold weather riding. Should mineral oil specifically be used in Kysrium SL rear hubs?
Adam
Dear Adam,
Yes, only use mineral oil or the pawls will stick and not lock up the freehub. You can hurt yourself badly standing on the pedals if the freehub slips.
Lennard
Old wheel - will it work with my new cogs?
Dear Lennard,
I am currently building up a project bike (04 Klein QProXX frameset) and I have purchased an American Classic 1420 wheelset (2003 vintage). I seem to be getting conflicting info on whether those wheels will be Dura-Ace 10 compatible; are they?
Dan
Answer from American Classic:
Our wheels with the Shimano spline are Shimano 9 or 10 compatible! We also have a Campy spline that's Campy 9 or 10 compatible.
Ellen Kast
American Classic
Getting it in line
Lennard,
In their tech manual Shimano lists the chainline of their XTR,XT,LX cranks as 50mm. The chainline listed for XTR hubs, however, is 44.75mm. How important is perfect chainline? I know that Co-Motion makes a touring bike (a single) that uses 145mm rear axle spacing. A King or DT hub spaced at 145 should give better chainline. Are there any drawbacks to building a single bike with wide spacing? One advantage of a wide hub would be a dishless rear wheel.
Ben
Dear Ben,
It's usually not a problem using the wider crank with the narrower rear. The only drawback to the wider rear hub, as long as you are already using the wide crank, is incompatibility with standard wheels, chainstay-crank clearance, and the need for a custom frame. You are right; the wheel is stronger. This is seen often on downhill bikes for that reason.
Lennard
Hey, what ever happened to....
Dear Lennard,
I have been curious about what has happened to the Power Pedals from Norway. They looked very promising, and I used them for several years until I hurt my ITB and went back to regular pedals. I was convinced that I got more power out when using them. My main problem with them was the somewhat larger Q factor seemed to cause me problems. You wrote an enthusiastic article about them and I was wondering if you were still using them.
Mark
Dear Mark,
No, I have not used them in years. The company never was fully funded and could not gain the traction it needed to get over the marketing hump. The engine behind the marketing, Ole Aspaas (now deceased), left the company, and there was never an audible peep out of Power Pedals on this side of the pond after that.
The pedals were promising but heavy and clunky. More cycles of product development might have created a more refined product that might have sold well.
Lennard
It's not the wheel, it's the motion
Dear Lennard,
I've noticed the top jockey wheel on my road and MB derailleurs get pretty stiff if I don't dab some oil on the seals from time to top. That doesn't seem to happen to the bottom jockey. I've seen sealed replacement bearings for sale, but both jockeys are fixed - there is a top specific jockey that moves like the Shimano. Is that important - to have that lateral movement in the top jockey?
Steve
Dear Steve,
Yes, Shimano's "Centeron" lateral movement of the upper jockey wheel is critical for it to work well and always line up properly under the cog. Some other derailleur manufacturers have no upper jockey lateral play, but for Shimano, it's a must.
Lennard
Finally, regarding problems with 10-speed chains, I received this:
This just goes to show that progress can sometimes be the greatest step backwards you can take. Everyday riders do not need ten speeds. Ten speed chains that are liable to break when you are out behind God's back is not progress.
Eight speeds is enough for any weekend warrior.
Terry
KGS Bikes technical writer Lennard Zinn is a frame builder (www.zinncycles.com)
a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides "Zinn and the Art of Mountain Bike Maintenance" and "Zinn and the Art of Road Bike Maintenance" as well as "Zinn's Cycling Primer: Maintenance Tips and Skill Building for Cyclists."
Zinn's KGSBikes.com column is devoted to addressing readers' technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn (veloqna@comcast.net) Zinn's column appears regularly here on KGSBikes.com.
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