Shimano BB-ES300 Bottom Bracket 73x121mm Hollow-Type
The Acera M3000 ES300 Octalink 73mm Bottom Bracket from Shimano is a splined bottom bracket for use with Shimano Octalink chainsets. It features a large oversized 22mm diameter hollow spindle that is made from cold forged chrome-moly pipe billet, which reduces weight and increases strength and rigidity. Thanks to the Octalink splined axle/crank arm interface you have a more rigid crank assembly compared to a square tapered spindle. The sealed cartridge bearing assembly runs on oversized ball bearings with maintenance-free, high efficiency rubber seals to keep dirt, mud and water out and keep you rolling for longer. Available in 73mm x 113mm, 118mm, 121mm or 126mm.
The Acera M3000 ES300 Octalink 73mm Bottom Bracket from Shimano is a splined bottom bracket for use with Shimano Octalink chainsets. It features a large oversized 22mm diameter hollow spindle that is made from cold forged chrome-moly pipe billet, which reduces weight and increases strength and rigidity. Thanks to the Octalink splined axle/crank arm interface you have a more rigid crank assembly compared to a square tapered spindle. The sealed cartridge bearing assembly runs on oversized ball bearings with maintenance-free, high efficiency rubber seals to keep dirt, mud and water out and keep you rolling for longer. Available in 73mm x 113mm, 118mm, 121mm or 126mm.
The Acera M3000 ES300 Octalink 73mm Bottom Bracket from Shimano is a splined bottom bracket for use with Shimano Octalink chainsets. It features a large oversized 22mm diameter hollow spindle that is made from cold forged chrome-moly pipe billet, which reduces weight and increases strength and rigidity. Thanks to the Octalink splined axle/crank arm interface you have a more rigid crank assembly compared to a square tapered spindle. The sealed cartridge bearing assembly runs on oversized ball bearings with maintenance-free, high efficiency rubber seals to keep dirt, mud and water out and keep you rolling for longer. Available in 73mm x 113mm, 118mm, 121mm or 126mm.
The Acera M3000 ES300 Octalink 73mm Bottom Bracket from Shimano is a splined bottom bracket for use with Shimano Octalink chainsets. It features a large oversized 22mm diameter hollow spindle that is made from cold forged chrome-moly pipe billet, which reduces weight and increases strength and rigidity. Thanks to the Octalink splined axle/crank arm interface you have a more rigid crank assembly compared to a square tapered spindle. The sealed cartridge bearing assembly runs on oversized ball bearings with maintenance-free, high efficiency rubber seals to keep dirt, mud and water out and keep you rolling for longer. Available in 73mm x 113mm, 118mm, 121mm or 126mm.
in 14 offers
The lowest price for Shimano BB-ES300 Bottom Bracket 73x121mm Hollow-Type right now is $22.99 at Bikebug, compared across 11 retailers.
The all-time low was $20.34 on 5 May 2025 — today's price is 13% above the lowest ever. That's a little above the best price we've seen.
Prices last updated 22 Apr 2026.
Last updated at 22/04/2026 12:30:51
Shimano Unisex's BBES300C21 Bike Parts, Other, One Size
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Shimano BB-ES300 Octalink Bottom Bracket 73x121mm Hollow Type
Delivery between 24–29 Apr $9.90
Shimano BB-ES300 Octalink Bottom Bracket 73x121mm Hollow Type
Delivery between 24–29 Apr $9.90
Shimano BB-ES300 73X121mm English Bottom Bracket | Bottom Brackets | Bicycle Superstore
Delivery $9.95
Shimano BB-ES300 Bottom Bracket 73x121mm Hollow
14-day returns
Shimano BB-ES300 Bottom Bracket 73x121mm Hollow
Delivery between 23–30 Apr $9.99
Shimano BB-ES300 Bottom Bracket (Hollow) — Octalink v2 / BSA / 73 x 121mm
Delivery between 27 Apr – 5 May $8
Shimano Shimano BB-ES300 Bottom Bracket 73x121mm Hollow-Type
Delivery $19.99
Shimano Bb-Es300 Bottom Bracket 73x121mm Hollow-Type
Delivery $12.50
Bottom Bracket Shimano Octalink BB-ES300 73x121mm
Delivery between 28 Apr – 4 May $12
originally posted on bikeinn.com
I got this bottom bracket when I upgraded my crankset to Shimano Claris. The original square tapered bottom bracket wasn't as stiff as this is. I would buy again if needed, but even after putting 2000k on it, it has not even creaked once. Thank you.
originally posted on pushys.com.au
Very happy with quick supply of this item. Also the price is extremely cheap. As i fixed a bike for a friend who is doing it tough. Quality isn't and issue as it is Shimano
originally posted on ebay.com
This BB is what one needs to gear up their MTB with road bike crank to fit in standard 73mm English 30 threaded shell. This BB pushes the drive side crank just enough out to clear the frame to be able to fit road crank Octalibk v2 style on a mountain bike frame. Now I have 53/39T with 11-32 cassette mtb (2x10soeed) that I use as a commuter and can still granny up steep hills and then get up to 48 mph on the other side. Chain line is fine, few mm (about 3) that were necessary to push the drive side out and clear the frame translate in to within tolerance angle at the rear end for smooth shifting and no rubbing.
| BB Type | Octalink |
| Structure | Standard |
| Shell diameter | BSA (BC 1.37) |
| Mounting | screwed |
Shimano Unisex's BBES300C21 Bike Parts, Other, One Size
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Shimano BB-ES300 Octalink Bottom Bracket 73x121mm Hollow Type
Delivery between 24–29 Apr $9.90
Shimano BB-ES300 Octalink Bottom Bracket 73x121mm Hollow Type
Delivery between 24–29 Apr $9.90
Shimano BB-ES300 73X121mm English Bottom Bracket | Bottom Brackets | Bicycle Superstore
Delivery $9.95
Shimano BB-ES300 Bottom Bracket 73x121mm Hollow
14-day returns
I got this bottom bracket when I upgraded my crankset to Shimano Claris. The original square tapered bottom bracket wasn't as stiff as this is. I would buy again if needed, but even after putting 2000k on it, it has not even creaked once. Thank you.
Very happy with quick supply of this item. Also the price is extremely cheap. As i fixed a bike for a friend who is doing it tough. Quality isn't and issue as it is Shimano
This BB is what one needs to gear up their MTB with road bike crank to fit in standard 73mm English 30 threaded shell. This BB pushes the drive side crank just enough out to clear the frame to be able to fit road crank Octalibk v2 style on a mountain bike frame. Now I have 53/39T with 11-32 cassette mtb (2x10soeed) that I use as a commuter and can still granny up steep hills and then get up to 48 mph on the other side. Chain line is fine, few mm (about 3) that were necessary to push the drive side out and clear the frame translate in to within tolerance angle at the rear end for smooth shifting and no rubbing.
This is a hard one to review because although the product is good and fairly cheap, it just isn't as robust as I would like. That said I'm a hard rider so wear things out quickly. My wife manages twice to three times the life on the same part.Anyway it's a quick and easy fix if you have the tools and it's maintenance free once fitted so overall I give 4 out of 5 stars because I'd like them to last slightly longer for me.
Typical good quality Shimano product. Fitted perfectly straight out of the box. No fitting instructions but its pretty straightforward as long as you have the correct tool. Just remember that on one side there is a left handed thread.
Not many choices available for the old octalink drivetrain. Expect shimano’s usual levels of quality, but yet to see how much abuse this can take. Shipping was fast, price was good. No complaints!
Purchased as a direct replacement for Shimano ES-51 of similar size. Perfect fit.t
so this is the replacement bottom bracket for es70, since it's no longer made. the previous model was a little heavier than the current but feels to be better made. es300 has a plastic cover on the crank side that can, over time get exposed to salt, cold, heat which will eventually wear down the plastic and allow things to get in. personally, they should've just kept the same design and not worry about any future wear and tear.
I bught this part for a vintage Italian bike restoration but I didn't know that the bottom bracket would not fit my crankarms. Would like to return.
Good part,very quick to sort any problems out. Reliable trader.
| BB Type | Octalink |
| Structure | Standard |
| Shell diameter | BSA (BC 1.37) |
| Mounting | screwed |
