Shiumano UN100 Bottom bracket. New of 2021 is Shimanos UN100 Bottom bracket. Cost competitive construction while maintaining SHIMANO quality and performance. JIS Square taper. THE THREADS ARE ONLY PLASTIC, IF YOU FIT IT AT AN ANGLE AND CROSS THREAD IT YOU RUN THE RISK OF STRIPPING THE THREADS, PERMANANTLY DAMAGING THE PRODUCT AND THE BOTTOM BRACKET COMING LOOSE WHILE RIDING.
