Author Topic: External bearing bottom bracket options  (Read 1878 times)

Blah

  • Not sure where I'm going
External bearing bottom bracket options
« on: 04 October, 2010, 09:52:33 am »
I'm looking to buy a compact 9 speed chainset. This discounted Shimano R600 seems a good candidate.

I have no idea which cups to buy though. I'm slowly entering external BB cups world, on most bikes I'm still on octalink. I'm assuming the 5600 ones should do.

I understand I will also need a tool. There's a discounted Pedros one, but there's a six and and eight notch version. Baffled.

This is obviously all part of a big ploy to confuse me and to make sure I don't attempt any of this myself.




Re: External bearing bottom bracket options
« Reply #1 on: 04 October, 2010, 10:01:28 am »
You need the 8 notch one - the 6 is for Dura Ace and XTR Octalink.

You also need the little plastic Shimano tool for preloading the bottom bracket bearings, or an integrated tool like a Park BBT-9 or this cheap one:

X-Tools BB Tool Hollowtech II | Buy Online | ChainReactionCycles.com

The Park website is pretty good:

Park Tool Website

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: External bearing bottom bracket options
« Reply #2 on: 04 October, 2010, 11:19:00 am »
Unusual to see the chainset sold without the BB cups included.  They're all much of a muchness IMO - I've got 105 cups on a MTB triple and probably vice versa.  You'll probably also need a selection of BB spacers, 1mm and 1.5mm, also available from SJS.
when you're dead you're done, so let the good times roll

Blah

  • Not sure where I'm going
Re: External bearing bottom bracket options
« Reply #3 on: 04 October, 2010, 11:30:32 am »
Unusual to see the chainset sold without the BB cups included.  They're all much of a muchness IMO - I've got 105 cups on a MTB triple and probably vice versa.  You'll probably also need a selection of BB spacers, 1mm and 1.5mm, also available from SJS.

Aha, something else to throw into the mix! Now, I've actually got some of these, but how would I know I need them? Are they do with the Q factor?

Chris N

Re: External bearing bottom bracket options
« Reply #4 on: 04 October, 2010, 11:51:23 am »
Yes, but more to do with chainline.  MTBs generally come with 68 or 73mm BB shells, so the MTB Hollowtech II cups come with spacers to adjust the chainline for different setups.  You probably won't need to do that on a road double.

Blah

  • Not sure where I'm going
Re: External bearing bottom bracket options
« Reply #5 on: 04 October, 2010, 12:04:25 pm »
Lovely, thank you very much!

Ready to order now...

Blah

  • Not sure where I'm going
Re: External bearing bottom bracket options
« Reply #6 on: 11 October, 2010, 10:47:03 am »
You need the 8 notch one - the 6 is for Dura Ace and XTR Octalink.

Hmm. Opening the box, the 8 notch tool definitely does NOT fit. It's the 16 notch I need.

I'll go with the Park tool I think :-)

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: External bearing bottom bracket options
« Reply #7 on: 11 October, 2010, 11:41:51 am »
You'll know if you need the spacers, because the assembly simply won't work without them (if they're needed - if you see what I mean!).  Its usually when fitting a MTB chainset to a road frame.  With that combination at worst you can end up with rather more spacer than is healthy, but the good news is that the bearings don't have to be fitted very tight (nothing like as tight as the cups on a traditional cup-an-cone BB), so stripping shouldn't be a concern.
when you're dead you're done, so let the good times roll

Re: External bearing bottom bracket options
« Reply #8 on: 11 October, 2010, 03:21:52 pm »
You need the 8 notch one - the 6 is for Dura Ace and XTR Octalink.

Hmm. Opening the box, the 8 notch tool definitely does NOT fit. It's the 16 notch I need.

I'll go with the Park tool I think :-)

Yep the Park tool is excellent: Park Tool BB Install Spanner & Tool HollowTech II | Buy Online | ChainReactionCycles.com

If you were closer I could lend you mine (Somerset if any good)

You'll know if you need the spacers, because the assembly simply won't work without them (if they're needed - if you see what I mean!).  Its usually when fitting a MTB chainset to a road frame.  With that combination at worst you can end up with rather more spacer than is healthy, but the good news is that the bearings don't have to be fitted very tight (nothing like as tight as the cups on a traditional cup-an-cone BB), so stripping shouldn't be a concern.

On a road bike you will not need spacers, the triple set up has one to give clearance, the mtb bottom brackets however are built to do both 68 and 73 shell so come with 3 spacers as required.


tiermat

  • According to Jane, I'm a Unisex SpaceAdmin
Re: External bearing bottom bracket options
« Reply #9 on: 11 October, 2010, 03:26:18 pm »
Note, if fitting a Shimano TRIPLE chainset a spacer is needed on the non-drive side, but for a double or compact a spacer is not.

Quite why only for the triple, and not the doubles, know not I, and please please ask not how I know thus...
I feel like Captain Kirk, on a brand new planet every day, a little like King Kong on top of the Empire State

Re: External bearing bottom bracket options
« Reply #10 on: 11 October, 2010, 03:48:13 pm »
Note, if fitting a Shimano TRIPLE chainset a spacer is needed on the non-drive side, but for a double or compact a spacer is not.

Quite why only for the triple, and not the doubles, know not I, and please please ask not how I know thus...

Because the axle is a fraction longer to allow room for the inner ring.

tiermat

  • According to Jane, I'm a Unisex SpaceAdmin
Re: External bearing bottom bracket options
« Reply #11 on: 11 October, 2010, 03:58:29 pm »
Note, if fitting a Shimano TRIPLE chainset a spacer is needed on the non-drive side, but for a double or compact a spacer is not.

Quite why only for the triple, and not the doubles, know not I, and please please ask not how I know thus...

Because the axle is a fraction longer to allow room for the inner ring.

OK, I get that, but why have the spacer on the NDS then?
I feel like Captain Kirk, on a brand new planet every day, a little like King Kong on top of the Empire State

Re: External bearing bottom bracket options
« Reply #12 on: 11 October, 2010, 03:59:34 pm »
Note, if fitting a Shimano TRIPLE chainset a spacer is needed on the non-drive side, but for a double or compact a spacer is not.

Quite why only for the triple, and not the doubles, know not I, and please please ask not how I know thus...

Because the axle is a fraction longer to allow room for the inner ring.

OK, I get that, but why have the spacer on the NDS then?

To keep the chainline correct I guess.