# 1990 Trek 800 BB size?



## hallin222 (Oct 13, 2005)

I'm attempting my 1st singlespeed project out of a free Trek 800 that I found on Craigslist.

See SS forum thread here:

http://forums.mtbr.com/showthread.php?t=204669

It looks like the BB is toast and I'll be needing a new (or functioning used) one. How do I know what size I need? I've looked on that Vintage Trek site and didn't find it yet.

Better yet, does anyone here have one (along w/ some 3-piece cranks) that they'd like to sell or trade?

Thanks,

Ian


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## bikerboy (Jan 13, 2004)

Ian,

That bike is going to have a 68mm bottom bracket shell, standard english threads. The spindle width depends on the crankset you are using. You will most likely be fine with a spindle length of 110mm wide or more.

I should still have the bottom bracket out of my Kona which was removed when the bike was new. If it hasn't been moved by our chronic house cleaner (Brandon) I still know where it is. You can have it if you like. Its just a cheapie cup and cone unit, not a cartridge bearing model, but it does the job. Come by Tuesday since I will be working. I am sure I am the only one who knows about that thing.


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## hallin222 (Oct 13, 2005)

Hey, thanks, man. That's awesome! I really appreciate the help. The ones I took out this morning was just a simple 'cup and cone, loose bearnig system' too. It basically crumbled in my hands.

Am I going to need a special tool to remove the non-drive side adjustable cup that sits just under the outer lockring? It's got those 6 or 8 pin hols it it that require a 'pin spaner'(?).

Also, is your old Kona BB a square taper also? As you know I'm on the lookout for some used 3-piece cranks so I can get my middle ring down to a more off-road friendly 32 teeth rather than the 38 that are on the one-piece unit it has now. I just want to know what to look for regarding crank type. I keep looking for some 180mm's but they seem pretty rare in the used market.

Thanks to you, and a few other folks out there, this may be a pretty neat little ride when I'm done. I'll make sure to bring it by when I'm finished.

Ian


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## bikerboy (Jan 13, 2004)

It actually uses a cartridge BB tool like the Shimano BBs, but is still makes use of a lockring. They call a "semi-cartridge" unit, basically a nice euphamism for cup and cone. It installs the exact same way as a cup and cone, just with the cartridge tool. Its a square taper.

Oh, by the way, I spotted a used Truvativ Firex square taper crankset at the shop. I will have to ask James whether or not it is for sale.


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## hallin222 (Oct 13, 2005)

bikerboy said:


> It actually uses a cartridge BB tool like the Shimano BBs, but is still makes use of a lockring. They call a "semi-cartridge" unit, basically a nice euphamism for cup and cone. It installs the exact same way as a cup and cone, just with the cartridge tool. Its a square taper.
> 
> Oh, by the way, I spotted a used Truvativ Firex square taper crankset at the shop. I will have to ask James whether or not it is for sale.


Cool. Please do. See you Tuesday!


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