Source
r/bikewrench•
SpacemanSpiffOCF

I'm trying to figure out the bottom bracket on my older road bike and thought I'd ask the experts.

I purchased the following bike around 4 years ago from a friend who didn't want to bring it back to Washington state from California after graduating from college.

2001 K2 105

BTW the Shimano 105 groupset is 5500 with a band on front derailleur.

I love this bike as it got me back into cycling even though now I only use it for commuting, grocery store runs, and bringing six packs of beer over to friends houses from time to time.

The bike still runs well enough and I maintain it along with my Tarmac SL4 but I haven't had to replace any components yet and unfortunately don't understand the bottom bracket standard which is listed as Shimano BB-ES70.

If I ever wanted to upgrade the groupset, which is starting to show its age, what would be compatible out of modern shimano groupsets? If I changed the rear wheel to a newer box section wheel along with a groupset upgrade could I go past 9 cogs on the rear cassette or does the frame limit me there?

Thanks

Posted Jan 14, 2015, 12:11 AM UTC · edited

110
FalseBuddha•

Your link is broken, but it looks life you were trying to link to a 2001 K2. I don't know anything about this bike specifically, but the brand was fairly low end and in that time period I can pretty much guarantee it has an English BB which is probably the most common BB standard in all of history. Every major manufacturer makes a BB that will fit your frame, you just need to match it to your cranks.

5
cleansoap•

IF the crankset is also 5500 series Shimano 105 than it is an Octalink-style bottom bracket. This is exactly like traditional square taper bottom brackets in that the spindle lives inside the bottom bracket shell and both the drive side and non-drive side crank arms bolt onto the spindle.

It is a cartridge-style bottom bracket which means that the entirety of the assembly (once crank arms are removed (with a special tool (which looks like and works like the square-taper variant but isn't because it has a larger (mushroom) head))) consisting of the spindle and the ball bearings AND the bearing races all come in a self-contained disposable tube (cartridge) which gets threaded into the bottom bracket shell (that one tube of your bike which faces side-to-side), again with a special tool).

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SpacemanSpiffOCFOP•

Thanks for the reply its a big help.

The crankset is 5500.

I looked closer at the bottom bracket and it is bc1.37 68 which fits what you and FalseBuddha have said so far.

removing the crank seems easy link

what tool/s do I need to remove the cartage after the crank is removed?

After that it seems I would just need an english cartrage to match whatever crank would replace it.

2
cleansoap•

A - Thanks for the gold.

B - The 5500 bottom bracket listed as shipping with that bike on the pedia link takes a BBT-22 or the cheaper BBT-32. That is probably the most common bottom bracket tool out there today as it is a 20-spline tool (you can count the interior splines of your existing bottom bracket to verify) also used for Shimano square taper bottom brackets and thus millions of bikes. Ask around amongst your friends or local cycling Facebook page, I lend mine out all the time.

C - Yes, you need an English threaded cartridge, but it needs to have an Octalink Version 1 (short splines) spindle if you're going to keep your current crankset. There is no reason not to get the Shimano 5500 part again.

You are going the right way looking at the Park Tool site, tons of good information there. Also see http://www.sheldonbrown.com/bbsize.html for images of Octalink V1 versus V2.

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pedroah•

If you upgrade, you'll only need a new rear hub if you intend to go 11 speed or more because the free hub body is a bit different. If you get 10 speed group, you can still use your current wheel. Though the current trend in rims is wider and deeper section rather than box shape. For example H Plus Son Archetype or Hed Belgium.

Newer Shimano cranksets typically use external bearing, branded as Shimano Hollowtech 2, so the bottom bracket comes in three pieces: 2 bearing cartridge that screws into each side of the frame, and a plastic tube that connects the two which I think is mostly for dirt and water protection. The axle is permanently pressed into the drive side crank. You'd need a different bottom bracket tool to work on these external cups.

Your RD will probably be fine for 10 speed, but you may end up havign to replace everything else. For Shimano 105 5700-series, Shimano changed the spacing of the chainrings but I don't know whether compensation for shifting the different amount of space is in the FD or shifter. The brake cable pull ratios, as I understand it, was also changed for 5700. Shimano 5700 is also the last good triple, IMO, that they made if you are still wanting a triple crank rather than compact double because they have 74/130mm bolt circle. The last of the Ultegra and Tiagra triples have the little ring attach to the middle ring rather than the arm.

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SpacemanSpiffOCFOP•

thanks for your time and the extra information.

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pedroah•

I forgot mention that Hollowtech 2 bottom bracket uses English thread so it works on your frame just fine if you choose to upgrade.

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AgentDaedalus•

Are you sure you want to upgrade just the components? This can prove to be very costly and sometimes it is better to just get an entirely new bike instead of replacing everything but the frame and fork.

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SpacemanSpiffOCFOP•

good point. Right now the bike is my beater bike and I just wanted to know what my options are should something need replacing sometime in the future without the added cost of a shop.

When / if it reaches a point where its either swap, upgrade, or trash the bike I wanted to not be forced to go the trash route from not knowing how to properly maintain the bike.

Now when that time comes I can weigh the options instead of just defaulting to trashing the bike.

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AgentDaedalus•

Could always give it to a friend or sell it too. :>

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