masi61

I seem to have ruined the lower cartridge bearing on my Shimano Deore LX threaded 1" headset. I ride in the rain a lot and postponed maintenance for too long and I believe the individual bearing inside the cartridge cage rusted. I have flushed out all the dirt and rust (and water) that was in there, blew it all out with compressed air, flushed it some more in mineral spirits and blew it out a second time with compressed air. One of the bearings feels smooth. Unfortunately the questionable one is pretty notchy and grabby even though its now very clean.
Does anyone know of a source where I can get these shimano cartridge bearings? I would like to upgrade to the dura ace level of bearings if those are available for (anything approaching) a reasonable cost, say $50 for a set?
I hate to retire the current headset because of one worn cartridge bearing. I've heard that continually knocking the cups out of your frame and the crown off your fork race can cause elongation or wear, making future headset installs loose. Thanks for any guidance you might be able to provide on this subject.

HillRider

I think Shimano used the same type cartridge bearings in all of their cartridge bearing threaded 1" headsets. Hunt around at some older LBS's and see if they still have a Dura Ace, 105 (HP-5500) or Ultegra (HP-6500) headset in stock as these bearings should all work in your existing cups and crown race.

BTW, you can change a headset with no damage to the frame and fork if you use the proper tools and/or work carefully. It's not like you change headsets every 6 months. There are still new 1" threaded headsets available and if you can find an Ultegra HP-6500 sealed bearing headset, it is the class act of the type.

As a temporary expediant, switch your bearings around and put the top bearing in the lower race. The bottom bearing takes all of the load so using the better bearing there should smooth out the steering.

davidad

These will require a little more service but should work. https://www.mtnbikes.net/cartridgebearingfcomet1.aspx

masi61

Many thanks, HillRider - I will definitely put the smoother bearing on the bottom and also try to pack some fresh grease in there by using my microgrease gun and Rock-N-Roll Super Web grease. I checked one local bike shop today and they were not able to find any replacements in their Quality Bike Parts catalog. I am going to check a different bike shop tomorrow that has a account with Euro Asia imports and see if they carry the part. I'm not against replacing the headset and I already own all the correct tools, but I would prefer to replace bearings and I intend to pursue this some more because I know some supply house out there should carry these bearings for a reasonable sum. I have seen ads for bocabearing (not sure if I got the name right) and believe I saw where they carry replacement cartridge bearings for Suntour Superbe Pro hubs. If they carry these...you would think they also carry Shimano cartridge bearings too & maybe in ceramic too!

masi61

Thanks for the link Davidad - it looks like what I need but the lack of documentation makes buying one risky.

mechBgon

If your other options fall through, I did find a pair of Dura-Ace ones, new in the package. They're marked at $43.98 so $50 is about right with shipping. If you want those, drop me a PM.

masi61

Thanks for your time mechBgon. When you say you found some, are you saying they are in your shop (in you possession) or did you google them somewhere? I may be interested. I'll keep that in mind until I hear from LBS +/or Bocabearing tomorrow.

mechBgon

They're at the shop I work at. I set them aside in case you end up needing them. If I remember, I'll post the SKU tomorrow in case you can track down a set online for a good price.

davidad

They look just like the ones that are in Roy's bike. We pulled them and lubed them last Oct.
The DA bearings below are better because they are sealed, but still require some maintainence.

mechBgon

For the record, you're looking for HP-M740 (the Shimano part number and UPC code don't get any hits at Google). https://www.shopwiki.co.uk/Compaq-Shi...roducts/Compaq

masi61

thanks mechBgone for trying. Odd, but most of the google links to that part number are in British bike shops. Shimano should do a better job at listing the specifications for their bearings and allow ordinary people to be able to order replacements.

So Davidad - are you saying that the bearing that is listed at mountainbikes.net is serviceable but that the dura ace ones would be be the higher quality pair? I'm tempted to buy one of the cheapie bearings just to get on with this repair. But by the time I add shipping, I'm gonna maybe regret not sending a PM to mechBgone - Hmmm?

HillRider

Keep in mind that Shimano has been out of the headset business for many years. They never licensed Dia Compe's threadless designs and only made threaded headsets until they gave up entirely. Their web site's Tech Document section doesn't even list MTB headset parts lists any more and only shows now obsolete HP-6500 (Ultegra) and HP-7410 (Dura Ace) parts. Here are the diagrams and parts list for both of these:

https://techdocs.shimano.com/media/te...9830610601.pdf
https://techdocs.shimano.com/media/te...9830609006.pdf