Bb-un300 Square Tapered Bottom Bracket
Earn up to Rs. 55.50 cashback with Club House
Description
The Shimano BB-UN300 is a square taper bottom bracket built for everyday reliability. Whether you're grinding up the Western Ghats, commuting through Chennai's humid streets, or clocking training kilometres around Pune, a bottom bracket that resists moisture, dust, and grime is non-negotiable. At Rs. 1,110 with free delivery above Rs. 2,500, this is one of the most cost-effective drivetrain upgrades available at Cobbled Climbs.
Use Cases
Daily training. Reliable construction for repeat use.
Race day. Lightweight, stiff design for power transfer and aerodynamics.
Fit adjustment. Right stem length critical for comfortable bike fit.
Our Take
The BB-UN300 is the workhorse of Shimano's bottom bracket range — unfussy, durable, and widely compatible. For Indian riders dealing with monsoon humidity, red laterite dust on roads around Coorg and Ooty, and the general brutality of city riding, this unit holds up remarkably well. Grease-sealed cups keep water and grit out effectively. If your square taper BB is creaking or has play, this is the sensible, affordable fix to reach for first.
Sizing for Indian Riders
Bottom bracket sizing depends on shell width (typically 68mm for road frames, 73mm for MTB) and spindle length, which affects chainline. Check your frame's BB shell width before ordering — older Indian-market steel and aluminium frames often use 68mm English-thread shells. Spindle length should match your crankset's requirements. When unsure, bring your crank to a local shop or contact Cobbled Climbs for guidance.
Compatibility Notes
The BB-UN300 uses a square taper interface and English-thread (BSA) shell fitting. It is compatible with square taper cranksets across road and MTB applications. Not compatible with Hollowtech II, ISIS, or outboard bearing cranksets. Verify your shell thread standard (English vs Italian) before purchase. Professional installation is recommended for correct torque and long service life.
Pairs Well With
For a complete drivetrain refresh, consider pairing the BB-UN300 with a compatible square taper crankset, a quality wet-condition chain lubricant suited to Indian monsoon riding, a bottom bracket installation tool, and a chain wear checker to monitor drivetrain health over time.
Explore the full Shimano collection at Cobbled Climbs | Learn more at Shimano
Specifications
| Specification | Detail |
|---|---|
| Brand | Shimano |
| Product Type | Bottom Bracket |
| Shipped From | Mumbai, India |
Explore the full Shimano collection at Cobbled Climbs
Why buy from Cobbled Climbs
- 100% genuine — authorised Shimano retailer in India
- Free delivery on orders above Rs. 2,500
- Cash on delivery available nationwide
- 7-day easy returns
- Shipped from Mumbai
- Expert advice — built for Indian cycling conditions
Frequently Asked Questions
What is the Shimano BB-UN300 best used for?
The BB-UN300 is best suited to road, touring, commuter, and MTB bikes that use square taper cranksets. It is an excellent replacement unit for worn or creaking bottom brackets and works well on older steel and aluminium frames common across India. Its sealed cartridge design makes it a solid choice for year-round riding in Indian conditions.
How do I choose the right size BB-UN300 for my bike?
You need to match two dimensions: shell width (68mm for most road frames, 73mm for MTB) and spindle length (which must suit your crankset's chainline requirements). Check the stamping on your existing bottom bracket or your frame's specifications. If you are unsure, Cobbled Climbs' team can help you identify the correct size before you order.
Will the BB-UN300 hold up during Indian monsoons and 35°C+ heat?
Yes. The BB-UN300's grease-sealed cartridge bearings are designed to resist water ingress and contamination — a meaningful advantage during India's monsoon months in cities like Mumbai, Chennai, and Kolkata. Heat in the 35°C-plus range has minimal impact on a quality sealed cartridge BB. Periodic inspection after heavy monsoon riding is still recommended to catch any play early.
How does the BB-UN300 compare to a press-fit or threaded external bearing bottom bracket?
The BB-UN300 is a traditional square taper cartridge unit — simpler, lighter on the wallet, and easier to service than most press-fit designs. External bearing BBs like Shimano's Hollowtech II offer a stiffer interface for performance cranksets, but require compatible cranks. If your bike has a square taper crankset, the BB-UN300 is the more practical and cost-effective choice.
Is the Shimano BB-UN300 worth Rs. 1,110 in India, and what warranty does it include?
At Rs. 1,110, the BB-UN300 represents strong value — a creaking or worn bottom bracket saps power and worsens with neglect, making early replacement cost-effective. Shimano provides a standard manufacturer's warranty against defects. For warranty claims or service support in India, Cobbled Climbs can assist. Cash on delivery is available nationwide for added purchase confidence.
Why pay full price when loyalty pays back?
Club House rewards you for every purchase — up to 5% cashback, 100 bonus points to start, birthday rewards, and early access to limited drops. It’s our way of saying thanks for riding with us.
Shipping:
We ship all orders within 48 hours, excluding Sundays and public holidays. Delivery typically takes 3 to 5 days depending on your location.
Returns:
If your item arrives damaged, incorrect, or doesn’t fit, you may request a return within 7 days of delivery. Email us at support@cobbledclimbs.com with your order details. Items must be unused and returned in original packaging with all tags and labels intact.
Sale Item Guidelines:
Products purchased on sale are final sale and not eligible for return or exchange. Please double-check sizing, fit, and product details before purchasing.
Please note:
We follow a no money refund policy. Eligible returns are offered store credit or exchange only.
Crash Replacement
Easy Returns
Earn up to Rs. 55.50 cashback with Club House
Bb-un300 Square Tapered Bottom Bracket
Earn up to Rs. 55.50 cashback with Club House
Frequently Asked Questions
Does Cobbled Climbs ship Bb-un300 Square Tapered Bottom Bracket across India?
Is the Bb-un300 Square Tapered Bottom Bracket on Cobbled Climbs 100% authentic?
What is the return and exchange policy for Bb-un300 Square Tapered Bottom Bracket?
Is Bb-un300 Square Tapered Bottom Bracket currently in stock?
What payment methods are accepted?
Does Bb-un300 Square Tapered Bottom Bracket come with a manufacturer warranty?
How do I find the right size for Bb-un300 Square Tapered Bottom Bracket?
Can I get a price match if I find Bb-un300 Square Tapered Bottom Bracket cheaper elsewhere?
What We Reach For
When the ride calls, we don’t think twice. A jersey that’s made to move. A computer that knows the way. A care kit that keeps it all running smooth. These are the pieces we reach for — ride after ride.
