Jump to content

Bike bottom brackets: square tapered, Octalink, BSA / MegaExo, Pressfit, BB30 / PF30. Shimano


Recommended Posts

  • 10 months later...

Deput post - Hello!!

Thanks for the video - I watched with interest but length is a factor nobody seems to commit to - perhaps a good video topic I am sure several struggle with this!


I am building an XC bike for my 11yo girl from new and as-new re-purposed parts, and my plans are for 

TWITTER frame (26 or 27.5 compatible), bottom bracket width is 68mm, threaded


SLX 1x11 (11-42) / SLX shifter and mech

26" Shimano M15 wheels (for now)  Ardent/Ikon

Toseek bars/stem/post

Shimano M395 brakes

Basic velo saddle

all above fixed


Variables are the crank (choice here) and bottom bracket (yet to buy);

Shimano Octolink (3x stripped and given a 34t or 36t ali single ring) - this needs an octolink BB


Truvative 1x (steel 38t removed, 34tor 36t ali single ring) - this needs a square taper BB


Finding the balance in theory for the correct BB lengths has me concerned - as real low gears are likely to be rarely used but irritating if slipping off back-pedaling, high gears more likely to be used (9/10/11) on trips.   Use for the bike would be cycle paths, gentle trails, some climbs, much flat as I am trying to build my youngest daughter's interest in cycling!


Personally tending towards octo/113mm, but inexperienced with 1x.  Any experienced tips welcome!


Hopeful - Graz


btw - this will replace a small frame GT Avalanche 2 (14kg), sweet child bike but heavy...




Edited by Graz
missed a bit : )
Link to comment
Share on other sites

  • 2 months later...
  • Administrators
On 10/23/2018 at 2:02 AM, Graz said:

34t or 36t

I would start with the chainrings, Graz. I've been riding the 32T chainrings with 10-50T cassette so far. Are you sure 1x drivetrain with 34 or 36T will be OK for you daughter? Otherwise, the Octalink should be a bit lighter and just more up-to-date BB.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...