ddeand 

I just took apart the headset on an older project bike, and I'm a little stumped as to how to best grease the headset bearings. The headset is a Dura Ace 7410 from 1995, and it looks like the bearings might be sealed. I don't want to ruin the thin rubber bearing cover to get to the actual bearings, but I need to get some grease in there before I put things back together. Can I do that? This is what they look like:

McBTC

ddeand 

Thanks!

MarcusT

Didn't watch the attached video, but just using a utility knife, carefully remove the seal. clean, grease and replace the seal (undamaged)

sweeks

Not a bad video. However, as it's relatively easy to remove the (plastic) seals, I would recommend removing the seals on both sides and cleaning the bearing before re-greasing it. Just adding grease will extend the life of the bearing, as the video says, but removing any dirt or abrasive wear products will do a better job.
Steve

Andrew R Stewart 

And when you pull the seals take a peak at the ball sizes. Note how small they are. Know that load capicity is geometricly related to the ball diameter (and only linearly related to ball count). For some perspective then check out the "classic" loose ball (and often called "unsealed") ball sizes.


Regardless of ball count or size all bearings like periodic cleaning and relubing. Andy.

brian3069

The bearings appear to be the same as the ones used in the 600 Ultegra 6500 headset. The 6500 headset has regular bearings sealed inside a case. The silver ring is a clip that holds it together, pry the clip off with a small screw driver. The case will separate in half. Inside there are caged bearings that can be serviced or replaced.

HillRider

This may be correct but I've had wonderful service and longevity with sealed cartridge bearing headsets, typically far better than loose ball types, probably because they are indeed sealed.

I have a Chris King headset with over 40,000 miles that is a glass smooth and free of play as the day it was new and a couple of FSA headsets that gave over 30,000 miles of nearly maintenance free service.

Loose ball headsets, even with a full compliment of balls (no retainers), reasonable periodic maintenance and proper adjustment have never lasted that long.

Andrew R Stewart 

Dave- I don't dispute your experience. I, too, have a few King headsets in use and find them to work well for a long time. But the headset pictured is a far cry from the material grade that King uses.


I will say that our experience reflects that we take care of our stuff. I see far too many bearings that are roached from over loaded initial adjustment, from a lack of maintenance as the lube is washed out with age/rain/wind (like at 75mph on a car rack) and from poor reassembly. Hence my comments are directed at the bulk of the public who have only a little knowledge at best. Andy

AnkleWork

+1
I anticipate the development of external BBs with large full compliment caged bearings and fine preload control. Will require excellent sealing.

ddeand 

Got it done! Thanks for all the info - I appreciate the help.

Dave Mayer

These are the best headsets ever made. False brinelling is the #1 killer of road bike headsets, and the brilliant Shimano design largely eliminated this.

You can pay big bucks for some bling boutique headset, but they are all inferior to the Dura-Ace / Ultegra /600 headsets of the era.

The Shimano cartridges can indeed be serviced - starting by carefully cracking the metal retaining ring and then pulling the two halves of the bearing apart. Note about 20 small balls held with a plastic retainer.

The retainer can be discarded and the bearing filled with a greater number of balls: a good thing. So if the bearing races are pitted, resulting in indexed steering, then filling the carts with a greater number of balls will completely refresh/restore them.

Smooth as new, and no indexing. Trust me: I've done this.

HillRider

I agree that those Shimano cartridge bearing headsets were far superior to most of their contemporaries. I had the Ultegra version on one bike and it outlasted its Tange loose ball predecessor by a factor of 4.

However, they were never made in threadless form. Once the "Aheadset" type of threadless headsets caught on, Shimano abandoned the headset market.

Dave Mayer

They were superior to all of their contemporaries.

There are some options for using these threadless. The quick approach is to use the bottom parts of the Shimano headset only, and mix with threadless-specific top parts.

A more innovative approach is to apply a Dremel tool to the top threaded cap for a few minutes to convert it to threadless. You'll also need a conical -shaped shim that comes stock with threadless headsets.

Note that Shimano headsets came in both 1" and 1 1/8" sizes.

HillRider

Yeah, that Dremel (or a lathe) conversion was done by pro team mechanics to let them use the Shimano, their teams equipment sponsor, headsets on their bike's threadless forks. It was a jury rig but it worked.

They were also available in 1-1/8" threaded form but cataloged as MTB components as Deore XT, etc.