Rear-Axle Bias Control
Designed to pair with a front BBK or OE setup while letting you tune front-to-rear bias through pad compound and rotor diameter.
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Description
Circuit Racing TR41 Rear Wheel 4-Piston Big Brake KitRacing Series Circuit Rear Axle 4 Piston TR41 Circuit Racing Rear 4 Piston Big Brake Kit The TTSPORT Circuit Racing TR41 is a rear axle 4 piston big brake kit built for circuit work, time attack, and endurance use. A monoblock forged caliper, two piece floating or fixed rotors, and a track tuned pad window give you a predictable pedal lap after lap, with serviceable hardware designed for a real pit workflow. Why Builders Choose the TR41 Rear brake
Racing Series · Circuit · Rear Axle · 4-Piston
TR41 Circuit Racing Rear 4-Piston Big Brake Kit
The TTSPORT Circuit Racing TR41 is a rear-axle 4-piston big brake kit built for circuit work, time attack, and endurance use. A monoblock forged caliper, two-piece floating-or-fixed rotors, and a track-tuned pad window give you a predictable pedal lap after lap, with serviceable hardware designed for a real pit workflow.
Why Builders Choose the TR41
Rear brake torque controls rotation, trail-braking attitude, and ABS/electronic stability behavior. The TR41 rear caliper uses a 31.8 mm / 36 mm staggered piston layout, 4-piston architecture, and 36.12 cm² piston area per caliper so initial bite stays linear and the rear axle does not over-grab as pads heat up.
Monoblock Forged Caliper
Monoblock forged aluminum body gives high stiffness and low pedal compliance under repeated heavy braking.
Racing Piston Package
Racing pistons without dust boots are designed for high pad and caliper temperatures plus quick teardown service.
Two-Piece Rotor Platform
Two-piece rotors in Ø330 or Ø345 mm × 28 mm internally vented construction help shed heat between corners.
Track Pad Windows
Choose 0–600 °C standard pads for sprint and HPDE work, or 0–750 °C Option B pads for endurance and back-to-back sessions.
Pit-Friendly Serviceability
Open-back pad access, replaceable friction rings, stainless braided lines, and required bedding-in support a real pit workflow.
Technical Specifications & Kit Options
| Brake Caliper | ||||
|---|---|---|---|---|
| Series | Racing Series — Circuit | |||
| Model / Application | TR41 | |||
| Axle Position | Rear | |||
| Piston Count | 4-piston | |||
| Piston Type | Racing pistons, no dust boots | |||
| Piston Diameter | 31.8 mm × 2 / 36 mm × 2 | |||
| Total Piston Area | 36.12 cm² per caliper | |||
| Caliper Dimensions | 284 mm × 152.8 mm × 75 mm | |||
| Construction | Monoblock forged aluminum | |||
| Net Weight | 2.50 kg per caliper, without pads | |||
| Finish | Nickel-plated | |||
| Custom Color | Not available on this caliper | |||
| Caliper Mount | Radial mount with vehicle-specific caliper brackets | |||
| Recommended Wheel Size | 17 in or larger | |||
| Recommended Rotor Size | Ø330–345 mm × 28 mm | |||
| Brake Rotor Options | ||||
| Configuration | Standard 330 mm | Standard 345 mm | Option B 330 mm | Option B 345 mm |
| Rotor Material | Heat-treated high-carbon cast iron | Heat-treated high-carbon cast iron | Racing-grade heat-treated high-carbon cast iron | Racing-grade heat-treated high-carbon cast iron |
| Rotor Dimensions | Ø330 mm × 28 mm | Ø345 mm × 28 mm | Ø330 mm × 28 mm | Ø345 mm × 28 mm |
| Construction | Two-piece, internally vented | Two-piece, internally vented | Two-piece, internally vented | Two-piece, internally vented |
| Rotor Hat | Application-specific alloy hat | Application-specific alloy hat | Application-specific alloy hat | Application-specific alloy hat |
| Mounting | Fixed or floating, size and application dependent | Fixed or floating, size and application dependent | Fixed or floating, size and application dependent | Fixed or floating, size and application dependent |
| Directional Design | Left/right specific | Left/right specific | Left/right specific | Left/right specific |
| Face Pattern | Curved Slot / Grain Slot / Wave Slot / Drilled & Slotted | Curved Slot / Grain Slot / Wave Slot / Drilled & Slotted | Wave Slot | Wave Slot |
| Best Use | HPDE, sprint, club race | Heavier chassis, longer sessions | Time attack, endurance heat soak | Endurance, heavy GT, back-to-back stints |
| Brake Pad Options | ||||
| Pad Option | Standard | Option B | ||
| Compatible Rotors | Iron / steel only | Iron / steel only | ||
| Operating Temperature Range | 0–600 °C | 0–750 °C | ||
| Average Friction Coefficient | μ ≈ 0.38 | μ ≈ 0.45 | ||
| Recommended Use | HPDE, sprint, club racing, rear-axle setups behind a hot front BBK | Endurance, time attack, heavy chassis, aggressive front pad combinations | ||
| Lines, Brackets & Service | ||||
| Brake Line Construction | Three-layer reinforced | |||
| Brake Line Material | PTFE liner / SUS304 braid / PVC sheath | |||
| Caliper Brackets | Vehicle-specific radial caliper brackets | |||
| Rotor Hats | Application-specific alloy rotor hats | |||
| Wheel Clearance | 17 in or larger wheel; final clearance depends on wheel barrel and spoke profile | |||
| Bedding-In Procedure | Required before track use | |||
Caliper finish: Nickel-plated. Custom color is not available on this caliper. Final clearance depends on wheel barrel, spoke profile, rear knuckle, hub location, rotor hat offset, and bracket geometry.
Package List
Calipers ×2
2 × TR41 rear monoblock forged 4-piston calipers, nickel-plated finish.
Brake Pads
Brake pads for both rear calipers, selected from standard 0–600 °C or Option B 0–750 °C pad window.
Brake Rotors ×2
2 × two-piece internally vented rear rotors, Ø330 or Ø345 mm × 28 mm, left/right specific.
Caliper Brackets ×2
Vehicle-specific radial caliper brackets for correct rear caliper alignment on the supported rear knuckle.
Rotor Hats ×2
Application-specific alloy rotor hats matched to rear hub location and rotor offset.
Brake Hoses ×2
Stainless braided rear brake lines with PTFE liner, SUS304 braid, and PVC sheath.
The Bespoke Engineering Process
Every TR41 rear circuit racing system is engineered around the vehicle’s rear knuckle, hub location, rotor hat offset, wheel barrel, spoke clearance, brake line routing, and rear brake bias target. The goal is not a generic universal fit; the goal is a rear brake package that works with your chassis geometry and gives the driver repeatable pedal behavior lap after lap.
1. Technical Consultation
We review the chassis, rear suspension and knuckle setup, competition use, target rear brake behavior, wheel package, tire package, front brake pairing, ABS / electronic stability behavior, and whether the car uses OEM or custom rear uprights.
2. Data Submission
For OEM knuckles, provide vehicle information and detailed wheel specifications. For custom knuckles, provide CAD files, technical drawings, hub-face data, rotor mounting information, or accurate mounting-point measurements so the bracket and rotor-hat package can be evaluated correctly.
3. Engineering Review & Approval
TTSPORT reviews the submitted data, confirms the vehicle-specific radial caliper bracket, rotor hat offset, brake line approach, and required fitment details for approval before manufacturing begins.
If you are unsure whether your wheel, rear knuckle, rotor offset, or brake line layout is suitable, Contact us before ordering so the engineering team can review the build details.
Installation & Break-In
- TR41 rear kits ship with vehicle-specific radial caliper brackets and brake-line fittings.
- If your chassis is not a standard catalog application, send hub face, rotor mounting, wheel clearance, rear knuckle, and line-routing details to the engineering team before production.
- For custom subframes, swapped rear knuckles, motorsport hub conversions, or non-OE rotor offsets, bracket geometry and line routing must be validated before manufacturing.
- Open-back pad access allows pad changes without removing the caliper.
- Two-piece rotor design allows friction ring replacement while retaining the alloy hat.
- Bedding-in procedure is required before first hot lap or track use.
Frequently Asked Questions
Is the TR41 a front or rear caliper?
The TR41 in this listing is a rear-axle 4-piston caliper, sized and valved for rear brake balance on a balanced race car. It is intended to pair with a matching front BBK or a properly biased OE front setup.
What rotor size and wheel size do I need?
The TR41 rear caliper accepts Ø330 mm or Ø345 mm × 28 mm two-piece rotors and requires a 17-inch or larger wheel. Final clearance depends on wheel barrel and spoke profile.
Which pad compound should I run?
For HPDE, sprint, and most club racing, the standard 0–600 °C compound with average μ 0.38 gives a stable rear bias. For endurance, time attack, or heavy chassis where rear pads see higher heat, choose the 0–750 °C Option B compound with average μ 0.45.
Can I change the caliper color?
No. The TR41 ships in a nickel-plated finish only. Custom color is not offered on this caliper.
Does it fit my car out of the box?
The kit uses radial-mount brackets and brake-line fittings made for each application. Confirm your exact chassis with us before ordering. For non-catalog or custom builds, our engineering team will validate bracket geometry and line routing.
Is bedding-in required?
Yes. A proper bedding-in procedure is required before track use to transfer pad material evenly to the rotor and stabilize friction. Follow the included procedure before your first hot session.
Ready to spec your TR41 rear racing system?
Need help speccing rear bias, pad compound, rotor size, rotor hat offset, or a custom bracket for the TR41?
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.8 ★★★★★
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Product Reviews
★★★★★ 5
delightful read
Format: Kindle
What a delightful read. The characters are awesome, the plot was so good, I loved it. I was intrigued and it kept me wanting more. Told in multiple pov, the book sucks you in and doesn’t let go. I cannot wait to read the next book.
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Reviewed in the United States on January 30, 2025
★★★★★ 4
not bad
Format: Kindle
I loved the plot of this book. The characters just didn’t have a lot of depth. The connections and “love” just weren’t communicated very well in the writing. The author didn’t write the sweet psycho trope very well at all either. Lachlan was just a mess of a character.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 17, 2023
★★★★★ 5
A Beta Worth Rooting For
Format: Kindle
In Spare, Violet Fox flips the omegaverse on its head, giving us a Beta heroine determined to make her mark. Joining the Beta Trials to support her sick father, she's thrown into a pack that doesn't want her, especially the possessive Alphas.
But here's the twist: their sweet Omega turns out to be her scent match. Cue the angst, forbidden tension, and a slow-burn romance that will make your heart ache in the best way.
Violet Fox delivers an emotional, refreshing take on the genre, proving Betas aren't "spares." They're stars.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 10, 2025
★★★★★ 5
Beta, Alpha, Omega oh my!
Format: Kindle
Omegas are precious and given to Alphas & their packs... but the Betas want in too. To this end, the Beta government is rolling out its trial of assigning a Beta to each Alpha-Omega pack. But forcing a Beta into a pack where they are not wanted will not end well... Of course, no one expected the Omega to fall for the assigned Beta. Great read and cliffhanger
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 15, 2025
★★★★★ 3
A familiar story, just with…..less.
Format: Kindle
So, as other reviewers make clear, this is very similar to Pack Darling and The Beta. It’s much closer aligned with The Beta, in plot and maybe more like Pack Darling with characters.
That being said, I don’t hate this…..but it wasn’t great either. It’s both books mentioned but just….less. Less angst, less emotion, less feeling. The plot feels very half fleshed out, and the “bad guy” feels underwhelming. I didn’t really feel any real emotions from and of the male leads, except maybe Oliver. The others fell sorta flat for me. And Mika makes herself out to be this big bad ass straight outta training and then we never see it from here again with the one fitting room incident as the exception.
SPOILER:
The whole, “Oh, I’m actually probably an Omega, but I don’t wanna be but I do actually wanna be but no one can ever know my secret that I do nothing to hide “ thing fell so flat. She never commutes to believing she was secretly an omega, but also mentions her “secret” a lot. It just felt so manufactured.
I’m intrigued enough to read part 2 and see how the author closes everything out, but this is not one I’ll recommend or ever come back to.
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Reviewed in the United States on February 13, 2024
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