Need help? We are open M-F 8-4 Central
Product Description:
The Tange LN‑3912 is a high‑quality sealed‑cartridge bottom bracket designed for 73mm English‑threaded frames. With a 118mm square‑taper spindle and durable sealed bearings, it’s an ideal replacement for MTB and road bikes using JIS‑standard square‑taper cranksets. Smooth rotation, long service life, and classic Tange reliability make this a dependable upgrade for any build.
These bottom brackets are brand new OEM, never installed, never used, and not in retail packaging.
Sale includes the bottom bracket only.
Key Features:
• Brand: Tange
• Model: LN‑3912
• Shell Width: 73mm
• Spindle Length: 118mm
• Spindle Type: Square Taper (JIS‑compatible)
• Thread Type: BSA / English 1.37 × 24t
• Material: Steel and alloy
• Color: Silver
• Weight: ~334g
• Condition: New OEM, never installed
• Includes: Bottom bracket only
• Country of Origin: Japan
• MSRP: $29.99
Fitment Details:
• Fits 73mm English‑threaded bottom bracket shells
• Compatible with square‑taper cranksets (JIS standard)
• Suitable for MTB, road, hybrid, and touring bikes
• Sealed‑cartridge design for low maintenance and long‑term durability
Performance Features:
• Smooth sealed bearings for consistent rotation
• Durable construction for long service life
• Reliable OEM quality from Tange
• Ideal for refreshing older bikes or completing new builds
Condition Notes
While working on bicycles is not difficult, an improperly assembled / tuned bicycle can lead to damage to the bicycle or injury to you. We recommend that you have a qualified mechanic install components and service your bicycle.
Brakes - It is not uncommon that new hydraulic brakes would required bleeding. While not difficult for a qualified mechanic it is very easy to introduce air into the lines. We strongly recommend you have a qualified mechanic bleed your brakes if necessary.
Wheels - It is not uncommon that a new wheel may require some minor truing and if equipped bearing cone adjustment.
Suspension - Shocks are not easily serviced outside a shop setting. Any adjustment beyond rebound and sag should be done by a shop. Quick note on lockout function, it will not become rigid, it will however be very stiff.
NOTE: STRIPPED THREADS IN CRANKS AND PEDALS ARE DUE TO THOSE COMPONENTS NOT BEING PROPERLY TIGHTENED. STRIPPED THREADS DUE TO IMPROPER ASSEMBLY / MAINTENANCE ARE NOT COVERED BY WARRANTY.
- Some items we sell qualify for the Manufacture warranty, most do not. Generally items in retail packaging can qualify, OE items do not. While we do not extend any warranty we will offer a refund on items that fail in the first 30 days.
- While working on bicycles is not difficult, an improperly assembled / tuned bicycle can lead to damage to the bicycle or injury to you. We recommend that you have a qualified mechanic install components and service your bicycle.
- Brakes - It is not uncommon that new hydraulic brakes would required bleeding. While not difficult for a qualified mechanic it is very easy to introduce air into the lines. We strongly recommend you have a qualified mechanic bleed your brakes if necessary. Bleeding brakes is not covered by warranty.
- Wheels - It is not uncommon that a new wheel may require some minor truing and if equipped, bearing cone adjustment. Minor wheel truing and cone adjustment are not covered by warranty.
- Suspension - Shocks are not easily serviced outside a shop setting. Any adjustment beyond rebound and sag should be done by a shop. Quick note on lockout function, it will not become rigid, it will however be very stiff. We will not replace a shock that does not become "rigid "when locked out if equipped.
NOTE: STRIPPED THREADS IN CRANKS AND PEDALS ARE DUE TO THOSE COMPONENTS NOT BEING PROPERLY TIGHTENED. STRIPPED THREADS DUE TO IMPROPER ASSEMBLY / MAINTENANCE ARE NOT COVERED BY WARRANTY.
- Rates - please see shipping tab at the top of the description for expedited options.
- AK, HI, APO/FPO - Shipping to these locations is a global on / off function. Due to the varied nature of our product mix and the impact of DIM weight we are not able to ship to these locations.
- Please see the Shipping and Payments tab
- Please see the Shipping and Payments tab
- We prefer email. We answer email M-F. Please use the ask a question link at the bottom of the description or the ask seller a question link at the top of the page. We strive to answer all email within 1 business day.
- We are open M-F 8-4 Central. Sorry we are no longer allowed to list our phone number, please use the "Find Contact Information" form.
- We respect your privacy. We only collect the information needed to receive your payment and ship your order. We do collect your phone number in the checkout in order to assist the carrier if there is a problem at delivery. We will not sell your information to anyone.
- Where do you get your stuff? - Trade secret.
- Why do you use your own UPC and not the MFG's UPC? - Using our own UPC's gives us greater influence on the description. Because many of our parts are OE they either do not have a MFG UPC or may differ slightly on what is included. Using a MFG UPC can cause our description to be overridden by a catalog description that may not match what we are selling. Additionally many manufactures use UPC's that start with a 4. Those are not necessarily unique numbers and are not always valid as unique product identifiers outside a store setting.
- You say over and over to have a qualified mechanic work on my bike. What if I want to do my own work? - Not a problem, most repairs are easy and do not require special tools. There are several great instructional resources out there. Just be aware as a novice it will take you longer and components damaged due to improper installation are not covered by warranty.
- Can I pick up my item to save shipping? - Yes, but we are in the sticks. Our closest Starbucks is 30 minutes away. We do ask that you contact us first so we can pull your order. With drive time and gas not many people realize a savings.
Our History
Before disc brakes, before V-brakes, before suspension forks, around the time the first index shifters that actually worked and the first production mountain bikes hit your LBS, Ben Gibbs started Bennett’s Cycle in St. Louis Park, MN. In the late ‘90’s he sold that shop and started experimenting with online sales. Ben started selling on eBay in ’99, back in the day when your default user ID was your email address. If you wanted to get fancy you could change that to your website URL. That ID (can’t put the name here because it included a URL) was one of the first to exceed 100,000 positive feedbacks.
Our Business Philosophy
Move as many parts as possible without it being a pain. Just keeping it real. Pulling that off is a bit easier said than done. In order to do that we strive to deliver value to our customers by sourcing quality products at prices that make you ask is that for real? We commit to being honest and fair in our transactions with customers and suppliers. If a dispute arises, if we are at fault, admit it early. We are committed to providing a work environment that recognizes the unique value of each of our employees. And recognize that work, while it consumes much or our time, is only a part of who we are and by being welcoming and accommodating when life spills in. The only slightly unreasonable thing we ask of them is to stay out of our parking spots.
Where we are:
Crosslake Sales
Crosslake, MN 56442
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