Exhaust Pipe Assembly (Header / Bend Pipe) for Royal Enfield Thunderbird 350 bs4 (UCE) – RLX00101/B

Royal Enfield RLX00101/B is the genuine OEM exhaust pipe assembly (front/header/bend pipe) used on the Thunderbird 350 platform. This is the pipe section that routes exhaust gases from the cylinder head toward the silencer/mid-joint. If your pipe is cracked at the flange, dented from bottom hits, rusted through, or leaking at the head joint (ticking sound, soot marks), replacing the header with the correct OEM routing restores factory alignment, sealing and stress-free mounting.

Customers also search this part as exhaust header pipe, bend pipe, front pipe, downpipe, header assembly, and in workshops as “exhaust bend” or “front pipe”. OEM matters here because incorrect bend angles can cause silencer misalignment, vibration, premature gasket leaks, and contact with chassis/footrest mounts.

Before you buy: confirm your bike is a Thunderbird 350 (UCE) and match the pipe shape + flange style with your existing unit (share a clear photo if unsure).

Key Features

• Genuine Royal Enfield part: RLX00101/B
• Correct OEM routing and bend geometry for stress-free exhaust fitment
• Fixes header cracks, dents, rust perforation, and exhaust-leak “ticking” at the head
• Helps restore stock mounting alignment (reduces vibration/rattle from misfit pipes)
• Designed to seal correctly with the proper exhaust gasket at the cylinder head
• Ideal when replacing a silencer kit and your original header is weak/damaged
• Compatible only where the Royal Enfield parts catalog matches RLX00101/B (see table)

Compatibility Table 

Variants

No variants.

FAQs

Q1 (Fitment): How do I confirm RLX00101/B fits my Thunderbird 350?

Match three things: (1) your bike is a Royal Enfield Thunderbird 350 (UCE), (2) your old pipe’s flange shape/bolt spacing matches, and (3) the bend route is the same (clear side photo). If you want “zero wrong order”, share a photo of the old pipe from the head flange to the first mounting point before dispatch.

Q2 (Fitment): Will this fit Thunderbird 350X / BS4 Thunderbird 350?

Only For Thunderbird 350 bs4 which has no oxygen sensor. (Check Part Number)

Q3 (Comparison): Genuine OEM vs local/aftermarket bend pipe—what’s the real difference?

Aftermarket pipes often differ in bend angle, flange thickness, and bracket alignment, which can cause silencer misfit, vibration cracks and gasket leaks. OEM is made to the original geometry so it bolts up without forcing or “jugaad” spacers.

Q4 (Installation): Any precautions while installing an exhaust header pipe?

Install with a fresh exhaust gasket if needed, tighten head nuts evenly, and re-check after a heat cycle. Avoid forcing the silencer alignment—fit the header first, then mid/silencer. Do not pressure-wash directly at joints until fully cooled.

Q5 (Symptoms): What problems does this pipe solve?

Exhaust leak/ticking at the head, soot marks near the flange, cracked/dented header, rust perforation, and silencer alignment issues caused by a bent pipe.

Q6 (Returns-prevention): What should I send to confirm before shipping?

Send (1) your bike model + year (or VIN last 6 digits), and (2) clear photos of your old pipe (head flange + full side route). This prevents ordering the wrong Thunderbird variant or confusing it with Classic/Bullet/Electra pipes.