THIS 4130 MACHINED HEAD TUBE IS MADE TO EXCEPT IS42 UPPER AND IS52 LOWER HEAD SET INTEGRATED BEARING. USING VARIOUS HEAD SETS TO WORK WITH 1-1/8 OR TAPERED 1-1/8 TO 1-1/2 STEER TUBE

180MM LENGTH +.5/-0

UPPER HEAD TUBE IS 45MM OD AT RACE , TOP HEAD TUBE TO END OF UPPER RADIUS 8MM LONG

LOWER HEAD TUBE IS 55MM OD AT RACE , BOTTOM OF HEAD TUBE TO END OF BEGIN 20MM RADIUS 22MM

CENTER TUBE SECTION 42MM OD - 140MM LENGTH

MAIN TUBE CENTER SECTION IS 1.5MM WALL THICKNESS

RACE ID ARE MACHINED FOR IS42 UPPER AND IS52 LOWER. HEAD SET WILL DROP IN PRE WELD/BRAZE . POST WELD/BRAZE BEST PRACTICE WILL BE TO REAM RACES FOR DISTORTION. USING ALUMINUM OR BRASS HEATSINK WILL GREATLY REDUCED DISTORTION AND REAMING.

10MM HEAD TUBE ESTIMATE WEIGHT 241 GRAMS

SKU - TBE-HT-42-52-R20-180