wroomwroomoops

I have a TH Industries BB. I really like this BB, so I decided to replace the bearings. On the bearings, you can clearly see "6002RS"

ok

So I order two pairs of 6002 2RS (only those were listed) bearings. Theoretically, they should be compatible. They just came in the mail, each of them in it's very own little cardboard box, on which "6002 2RS" is stamped.

ok..

I open one of the boxes and compare the bearing, still wraped in airtight plastic bag, with the bearing from the BB (I was a bit apprehensive because of the RS vs. 2RS issue). Well, whatdayaknow, they are NOT compatible! The new bearings are narrower (shallower) and have a larger diameter. The diameter difference is about 1mm! The narrower width is not a great deal, but the larger diameter makes them unusable!

So, , livid from rage, I check the product code on the new bearings, and it is 6002 RS !!!! WTF!? These should be exactly the same kind of bearings as in the BB! They should be identical!!


So what's going on here? I have 6002 RS in the BB, I received 6002 RS in the mail - and they are different!

How can I even order correct bearings, after this shocking experience? Confidence is lost forever...

San Rensho 

Go to an industrial bearing dealer with your old bearing. They will more than likely have one that is exactly the same. Be sure to tell them what its for or they may try to sell you an expensive very high speed, high load bearing.

phoebeisis

Hmmm,
Reread the little numbers on the original bearings. The stuff after the 1st 4 numbers doesn't matter so much. A 3 can look like a 2, 5 look like 6's etc. Wipe them clean, and use a magnifying glass.
6002 is 15 32 9

6003 is 17 35 10
6902 15 28 7
6903 17 30 7
There is a mistake somewhere. Carefully remeasure your original bearings- .040"= 1mm. It will tell you what you have.
Luck,
Charlie

wroomwroomoops

Thanks man, those numbers are useful. I measured the original 6002RS, and I get 16 31 10. But the new 6002RS has the same dimensions, as you cite there.

And to demonstrate that the original bearing has 6002RS on:

ryder47

I've been working for bearing distributors for years and the dimensions given by "phoebeisis" are correct. However, your 16x31x10 makes me cringe and I would ask you to actually measure the crank where the bearings ride and the housing where the bearings sit. It isn't unreasonable for the bearings dimensions to be worn and serves as a confirmation of the measurements of the old bearing. This is what I would do if you brought these to my counter.

Also wouldn't be the first time a special bearing with standard seals used to close them up and 16x31x11 is very, very special. Standard 6002 could be machined to 16x31, but then make it a millimeter wider . . . that's a lot of work, keeping in mind that the overwhelming vast majority of "specials" are variations of standards.

The only 16mm bore bearing I can think of at the moment is a 6202 "special", however that measures 16x35x11 (standard 6202 is 15x35x11).

jemoryl

You do realize that TH BBs are quite inexpensive? Biketoolsetc.com has a variety for about $24 ea.; maybe you can save yourself some grief by replacing the entire thing.

wroomwroomoops

The "problem" with you Americans is, you go to a webshop, see a bottom bracket you like, see that it's only $24 and then wonder why does that "bozo" (that would be me) ***** about some bearings when he can have the whole BB for a couple dozen bux.

But you forget that I might not live in the USA, and that BB would end up costing me $50 or $55!

Moreover, the bearings in question cost $2-3 each, and are so small that they can be sent in an envelope, making shipping expenses an order of magnitude smaller.

EDIT: Biketoolsetc.com doesn't even ship outside the USA and Canada

TO11MTM

wroomwroomoops:

I think I might have one of these BBs at the missus house. Want me to double-check the measurements on a fresh BB to see if they really are that off?

wroomwroomoops

Yes, if you have the time, please do so. I am really curious. Mine is "BB 7420ST".

TO11MTM

K, it won't be till later when she gets outta work, but I'll let you know when I do.

jemoryl

Sorry, didn't notice that you are in Finland. Didn't mean that you should try to purchase from biketoolsetc.com, but just using it as a pricing example. So I guess a TH BB is not cheap in your country?
Yeah, as others have suggested, take the whole thing to a bearing house (apologies in advance if they don't have these in Finland!).

TO11MTM

That's a good question indeed, are there bearing houses in Suomen Tasavalta? Did I even get that right, I'm pretty cruddy at Finnish despite studying it for a while. I'm still stuck in a position unable to check what bearings my bracket in question uses... In the meantime you might want to give one a call if you got a place. That said I think you might be up a creek as it were, I've got a feeling TH Might have gotten these bearings 'extra special' if you know what I mean... Not that it would make a whole lot of sense to do so but I have seen weirder things in the bike industry.

wroomwroomoops

And I don't dispute them, for a single second.

16 mm exactly.

wroomwroomoops

Well, it's formally correct (it means Finnish republic), but wrong in this, as in most contexts - you wouldn't say "federation of the United States of America" in any but the most legalistic contexts. Just say Suomi.

I am not even sure what a bearing house is?

TO11MTM

Ahh. Yeah, I kept running into that issue with the book I was using to teach myself... it's geared waaaay too much towards 'proper' Finnish. Main thing that discouraged me, Every time I practiced I ran into sounding like some overly formal tard.

A bearing house is basically a place that sells just about every sort of bearing imaginable. They vary in terms of accessibility depending on where you are; For instance numerous automotive manufacturers and suppliers of automotive components operate in my area of the united states and as such places use lots of industrial machinery I have my pick of shops that carry bearings... Your best bet is to look up 'bearings' in a phone book / directory and if you find a place located at/near an industrial area, you're probably in business.

Once you get to one, typically you can specify your country of origin. Preferences vary, but typically most people in the machining world say china is the lowest quality, and German/swiss the highest. USA and Japan are somewhere in the middle, and Taiwan somewhere on the lower end.

TO11MTM

Did a search... might want to try these places:

K R A F T M E K Helsinki, Finland
www.kraftmek.com
Laakeri-Center Helsinki, Finland
www.laakeri-center.fi

Tampereen Laakerikeskus Tampere, Finland
Supplier Details | www.tampereenlaakerikeskus.fi

wroomwroomoops

I must tell you about a huge difference between Finland (and most other EU countries) and the USA: while in the USA the consumer has incredible power, and is, in facgt, taken good care of, in Finland you have the impression that you, as an individual, are ****. Yep; I like Finland for many reasons, but in this quite imortant respect, USA is way ahead.
Two examples: I am into antique book conservation and collecting, and was looking for ways to combat foxing. Since I'm quite good at chemistry and academic research, I found out that sodium borohydride could stop and even reverse some of the damage done by foxing. So my quest to purchase a small amount of NaBH4. How naiive I was. I found NO ****ing way to get hold of the blasted substance. Sure, if I was a company (and not a looked-down-on individual), I could have gotten a free sample even. But as a simple Joe, no way. Wanna know the funny thing? Finland houses one of the largest NaBH4 producers in the world!
Second example: another thing I liked to collect, were vintage computers. I needed 4 fasteners with a certain anglosaxon threading and diameter, in order to close the case of a NorthStar Horizon. I found several companies that either import or produce them. I had the clerk in one of them tell me openly "we have those fasteners, but can't sell them to you - we only sell to companies".

So, the bearing house as you describe it, seems the kind of place that would simply spit on my money and send me away.

It's in cases like this, that I have a huge amount of resentment towards EU, and a huge appreciation and respect for the USA - where you can buy online a 50 kV Tesla transformer with iridium electrodes, if you want. Or a decommissioned nuclear missile silos. Or anything. And noone is going to spit on your money just because you're an individual and not a company.

<rant off>

JanMM

Decommissioned nuclear missile silo...............hmmmmm..............never worry about tornadoes again.............................

wroomwroomoops

Those first two companies don't sell to people, just to companies. I don't know about the third, their website seems to be down/unregistered (I have found the same link with my own search, and you did write it down correctly, but the website itself is shot).

Anyhow, you can find a lot of companies that specialize in mechanical engineering parts/supplies (did you know that the largest diesel engine in the world was recently built in Finland?) here, but they are all apparently "too important" to sell to individuals.

ryder47

Then this bearing in these dimensions (16x31x10) is a very, very special bearing made for a specific application, either for bottom brackets made by TH, or TH came across this bearing from another very specific application. At this point your choices are rather limited to either procuring the bearings from TH directly (or a distributor of) or buy a new BB.

wroomwroomoops

I only wish they didn't mark them as 6002RS.

TO11MTM

Hahahaha... I'm reminded of the old Batman movie.

"Selling a pre atomic era naval surplus submarine to someone who doesn't even leave their full address?"

I have a BB 7420 in my small, sweatshop-worker-like hands right now and am looking it over. I'll have to find a way to measure it here at home but if it helps at all (Although I doubt it at this point) it's marked similar.... "TH Industries" "KNK 6002 RS" My guess is KNK was the company that made the cap... although logically speaking they probably made the bearings too, I doubt TH bought the bearings from someone else and just happened to slap KNK covers on them...

That said there's a dark side to all the consumer power, it causes some problems in industries. For example I used to work in PC sales. Unfortunately all that 'consumer power' makes stores all too eager to offer the 'best price' because lots of people see 'best price' as 'best value...' and as a result there are Online webstores that happen to do enough volume to order straight from the manufacturer, and sell to the average consumer a product for what the shop normally BUYS it for. It's actually pretty crappy because lots of these companys never would have gotten off the ground if it weren't for the small mom and pop shops who took a chance on them.

TO11MTM

And lo, on the 8th day.... God created Calipers.... and forgot to give Drew a set.

...
I'll have to measure the BB at work tomorry.

Soil_Sampler

It does not look like KNK makes 6000 series bearings? KNK, likely sub-contracted to another bearing mfg.

https://www.knkbearing.com/products.html
https://www.alibaba.com/company/16993.html

Soil_Sampler

https://www.allproducts.com/tbea/th/01bb-7420.html