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

115MM 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 - 85MM 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 NEED FOR REAMING.

115MM HEAD TUBE ESTIMATE WEIGHT 171 GRAMS

SKU - TBE-HT-42-52-R20-115