Since I'm doing a restoration on my 93 Hardrock, can and should I put a modern sealed bottom bracket in

I am guessing a 93 already is sealed. Maybe you want to decide on internal or external bearings.

If you are doing restoration I wouldn't change the BB. If it's serviceable I prefer the originals.

Not really sure of its age but its got caged ball bearing BB. pre restoration pic. Any guess on the year?

The parts spec seems similar to my 92 hardrock, which btw has a cup and cone bb that I still use, and works well. I did switch out the seatpost from a straight post with steel clamp to a modern alloy one-piece kalloy.

Think I'm going to stick with the original BB, paint is not going to be original though. Current state.

That looks really good. I'd say keep the original cup and cone bottom bracket if it isn't pitted. How did you repair the top tube ding?

I'd absolutely upgrade the Bottom Bracket
the one you've got is the cheaper style, with nuts instead of bolts on the ends.
and caged bearings are terrible; to make room for a cage they use fewer bearings (9 instead of 11), which decreases lifespan.
it's also common for the cage to deform and end up wedging the balls.

also would get a modern lower profile crankset on there.
The spider on that old style extends out way too far and snags my heels when pedaling. YMMV


at the very least, replace the cages with loose packed balls. fresh set of 11 per side, 1/4" balls

A small amount of spot putty

Stock crank is already done (too much time into it not to use it) but I think I will upgrade to the 11 balls, thanks for the tip! FYI this is my first bike restore BTW

Great improvements, liking the pedals, what is your paint type/brand? I have a frame that needs a resto.

Why stick with the original bottom bracket, especially if it is a loose bearing BB? This isn't a "restoration" since you've painted the frame. Assuming a loose bearing BB, there's no sense in keeping a bottom bracket that needs constant maintenance. There was nothing about loose bearing BBs that was or is superior. A cartridge bearing bottom bracket works better, lasts longer, is easier to work on...requires no extra work or adjustment to intstall... and doesn't need constant attention.

And a cartridge bearing BB will last about 10 times as long as a loose bearing BB like this one. No one but you will know that it wasn't "original".

If the races are ok you could reuse the bb, but a sealed Sq. drive will last longer with no maintenance. My two shimanos have over 20,000 miles each.

All paint used is Rustoleum rattlecan, wetsanded between each coat, currently waiting on clearcoat to completely cure before final polish. I started this paint process in mid October, patience is the key here! Frame was completely sandblasted prior to paint.

So which cartridge BB will bolt right in if I decide to go that route?

Depends on the crank, but this should help: Sheldon Brown's Bottom Bracket Size Database

And yeah, the Hardrocks were on the lower tier of Spesh's lineup, so there's nothing to be gained by keeping it original. I prefer the simplicity of threaded cartridge BBs, $30 and they'll last a million miles*

*may not actually be a million

Anyone with English threading. AKA 1.375" X 24 tpi (threads per inch). For the existing crank, the only issue would be the length of the spindle. But you should be able to measure the existing spindle and get that length.

A Shimano UN55 is the model number. They are dirt cheap even when paying full retail at your local LBS.

Cool thanks, grabbing the calipers!

A loose bearing bottom bracket doesn't need "constant maintenance;" it only needs routine maintenance. And with routine maintenance, usually no more often than annually, and often less, it can last for decades. What makes them "superior" to cartridges is that they are not single-use, disposable items.

Egads! Well you've done a fine job with it.
Personally I'd never have the patience, I'd rather just pay an auto shop to power coat and be done with it.

"Routine maintenance" is the same as "constant maintenance". If you have service the bottom bracket once a year, that's once a year more than you have to service cartridge bearing bottom bracket.

As for lasting "decades" that's not been my experience with loose bearing bottom brackets. Even with higher end "sealed" loose bearing bottom brackets (the "seal" is an o-ring around the spindle), they never lasted "decades". Cartridge bearing bottom brackets, on the other hand, can last for decades with no maintenance at all. Yes, they are a disposable but if you have one for 20 years, I'd say you've gotten you money's worth out of it.

Back in the bad old days of mountain biking, loose bearing bottom brackets had to be taken apart much more often than once a year and they were often had pitted spindles and occasionally pitted cups. The bottom bracket...along with the headset...was the most fiddly and commonly replaced part on early mountain bikes. It felt like we had to by headsets by the gross and bottom bracket spindles by the dozen.

I've never worn out a cartridge bearing bottom bracket of any flavor. I've had dozens of them and they have all met their demise because of upgraditis rather than because they have worn out. The (supposedly) fragile external bottom bracket on my commuter bike has around 17,000 miles on it now and is still going strong...without out any fiddling.

Finally, I volunteer at a bike co-op and have had the opportunity to see thousands of bikes over several years of volunteering. Loose bearing bottom brackets are often pitted and worn while I seldom see a cartridge bearing bottom bracket that has worn out. Maybe one a year, at most.

So, if by "single-use, disposable items" you mean something that doesn't need maintenance, is easy to install and can be ridden until nearly the end of time, then, yes, cartridge bottom brackets are "single use" items. It's just that it takes roughly forever to reach the end of the "single use".

I did have to replace the BB on my 2012 Giant Escape so I already have the BB tool, so cartridge it is!

You're doing an excellent job for a first restoration. Very involved. Love the color too.

However, I would also go with a sealed square taper BB cartridge.

Would replacing a cartridge bearing bottom bracket every couple years also be "constant maintenance?" I've replaced plenty of cartridges at that service interval on customers' bikes over the years. Granted, some high quality cartridges can last far longer, but the same can be said for high quality loose-bearing bottom brackets. I've had the same Campagnolo Nuovo Record bottom bracket in one of my bike since 1981 and it's still going strong with maintenance only every five years or so.

Based on my own cartridge bottom bracket replacement rate and on the replacement rate for my co-op where we see every kind of bike possible in every kind of condition possible, I'd say that you are way overestimating the replacement interval of cartridge bearing BBs. The cheapest Shimano or even the cheapest Shimano knockoff lasts much longer than 2 years in my experience, even under heavy useage.

And, while high quality loose bearing bottom brackets can last quite a while, those are rarities. Most loose bearing bottom brackets are very poor quality to start with. I'm somewhat surprised that DEW21's has a loose bearing bottom bracket at all. I bought a 1990 HardRock new and I'm reasonable certain that it had a cartridge bearing BB