Summary: Why this ring ?
In your Birelart brake pump, this ring is the main pivot point between the control lever and the thrust rod. Its function is twofold:
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Eliminate the game: It allows a "fat" movement without sidebeat. Without it, your brake pedal will have an unpleasant dead race ("blur" effect).
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Self-lubrication: Generally composed of sintered bronze impregnated with oil, it is designed to operate "dry" or with a minimum of lubricant, thus preventing the premature wear of the steel pivot axis against the aluminum of the lever.
- Technical specifications
| Feature |
Specification |
| Mark |
Birelart (original parts) |
| Inner diameter |
5 mm |
| Outdoor diameter |
7 mm |
| Total length |
7 mm |
| Type |
Flange (with collar) |
| Material |
Self-lubricating sintered bronze |
| Use |
Pivot brake pump lever |
- Mounting Tuto: Precision First All All
A 5x7x7 ring is fragile during installation. Never force.
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Housing cleaning: Before you place the new one, clean the bore in the lever with a cotton swab soaked in brake cleaner. It must not remain any trace of old dried grease.
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Verification of the axis: Pass your nail on the pin (pin) that crosses the ring. If it is marked, change it! A new ring on a striped axis will last two sessions.
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Setting up: The ring must enter with the thumb. If it strength, check that it is perfectly in the axis. Never use hammer, you would write the bronze.
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"Dry" or lightweight mounting: These rings are self-lubricating. Do not overload thick grease. A drop of fine oil type PTFE or Teflon is enough. The thick grease mixed with the track dust turns into abrasive paste that eats the ring in record time.
💡 Michel's trick
"It's a piece that we forget too often, and it is there that the braking feel is lost. The trick: If after a few outputs you feel again in your brake pedal, do not change the pump immediately. First inspect this ring. My Pro Council: Whenever you disassemble your pump for purge or revision, pass a dry cloth shot on this ring to remove black dust. If she shines, she is good. If it is matte and has scratches, replace it immediately: for the price of the room, it changes the life of your braking. "
❓ FAQ SEO (Frequently Asked Questions)
Q: Why does the ring have a "flange" (a flange) ?
A: The flange serves as a side stop. It prevents the ring from sliding through the lever hole and serves as friction spacer against the walls of the pump holder.
Q: Can I manufacture this copper or plastic ring ?
A: Especially not. The sintered bronze has specific properties of hardness and porosity to retain the lubricant. Plastic crash and pure copper would joke instantly against steel.
Q: Is it compatible with other brand brake pumps ?
A: Birelart uses standard dimensions, but the bore tolerance is specific. It is strongly recommended to use the original Birelart part to avoid any game.
✅ Ready for reassembly ?
Your braking is the most important system for your safety and performance. To finish your revision:
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[Nettoyant frein] (Essential to keep the pivot clean).
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[Goupille/Axe de pivot] (Check that it is not worn, otherwise the ring is useless).