Ultrasonic cleaner for bike components
Practical guide: what to clean, what solution to use, how to run a cycle, and how to reuse/filter the solution.
TL;DR
- Default mix: 1 part Simple Green Pro HD : 10 parts hot water, 55 °C, 8 min.
- Rust: 5–10% citric acid, 50 °C, 10 min → baking-soda rinse → oil.
- Never use solvent-based degreasers (mineral spirits, brake cleaner, acetone, gasoline) — fire risk.
- Never ultrasonic sealed bearings, hydraulics, electronics, carbon, or painted/decal parts.
- Filter solution after each session with a $2 paint-strainer bag; reuse 3–10× before dumping.
- Re-lube everything immediately — ultrasonic strips all oil.
1. What to clean (and what NOT to clean)
✅ Good candidates
- Chains (pre-soak in degreaser first to keep the tank clean)
- Cassettes, chainrings, jockey wheels
- Derailleurs (remove pulley seals / b-tension spring if possible)
- Brake rotors (no pads — they’ll absorb solution and be ruined)
- Pedal bodies (after removing internal bearings)
- Small steel hardware: bolts, axle nuts, quick-releases
- Rusty steel parts (use the citric-acid recipe)
🚫 Do NOT ultrasonic
- Sealed cartridge bearings — solution gets past seals → ruined grease
- Suspension parts (forks, shocks, dropper posts)
- Electronics: Di2, AXS, eTap, smart sensors, head units
- Hydraulic brake calipers with seals/pistons assembled
- Carbon parts with bonded metal inserts
- Painted frames, decals, anything with adhesive graphics
2. Solutions
Recommended
| Solution | Best for | Dilution / temp | Notes |
|---|---|---|---|
| Hot water + dish soap (Dawn) | Light grime, default starter | 5–10 ml/L, 50–60 °C | Cheap, safe, low foam |
| Dedicated US degreaser (Elma Tec Clean A4, Branson EC, Crest Citrus) | Cassettes, chainrings, jockey wheels, derailleurs | 5–10% in water, 50–60 °C | Formulated for ultrasonic tanks — low foam, longest service life |
| Simple Green Pro HD / Crystal | Heavy grease | 1:10 to 1:20, 50–60 °C | Only “Pro HD” or “Crystal” on aluminum — regular Simple Green etches alu. Rinse thoroughly. |
| Sodium carbonate (washing soda) 1–3% | Cheap general degreasing, steel | 50–60 °C | Will dull/etch aluminum — keep cycles short or avoid on alu |
| Citric acid 5–10% | Rust removal, steel parts only | 50 °C | Never on aluminum or anodized. Neutralize with baking-soda rinse and oil immediately after |
| Isopropyl alcohol (≥90%) | Final degrease / chain prep before wax | Room temp, sealed jar | Flammable — sealed lid only, no heat. Use in a secondary glass jar inside a water-filled tank |
Can I use degreaser? — Yes, with caveats
- ✅ Water-based / citrus degreasers (Simple Green Pro HD, Finish Line Super Bike Wash, Muc-Off Drivetrain Cleaner, Pedro’s Pig Juice) — safe; work better in ultrasonic than by hand. Dilute per label (typically 1:5 to 1:20).
- 🚫 Solvent-based degreasers (mineral spirits, kerosene, Varsol, brake cleaner, acetone, gasoline, diesel) — DO NOT USE. Flash point too low; cavitation heats and aerosolizes them → fire / explosion risk. Chlorinated solvents can also attack the stainless tank.
- 🚫 Heavy-duty alkaline degreasers (Purple Power, engine degreaser, oven cleaner, pH ≥ 13) — etches aluminum and strips anodizing within minutes.
3. Running a cycle
Settings
- Temperature: 50–60 °C (sweet spot for cavitation; >70 °C reduces cavitation and accelerates alu etching).
- Time: 5–10 min for most parts; cassettes up to 15–20 min if heavily greased. Longer = more etching risk on aluminum.
- Degas fresh solution 5–10 min before loading parts (most tanks have a degas mode; otherwise just run empty).
Setup
- Fill tank with plain water + a drop of dish soap as the coupling fluid (protects the stainless tank).
- Put your actual cleaning solution in a secondary container (glass beaker, HDPE jar, or even a Ziploc bag) and suspend it in the tank. Lets you swap solutions without draining the tank.
- Pre-wipe heavy grease off parts with a rag — biggest single thing that extends solution life.
Recipes
Default drivetrain mix
- 1 part Simple Green Pro HD : 10 parts hot water
- 55 °C, 8 min
- Rinse → dry → re-lube
Rusty steel parts
- 5–10% citric acid in hot water
- 50 °C, 10 min
- Rinse → baking-soda water dip (neutralize) → rinse → blow dry → oil
Final chain degrease before waxing
- 90%+ IPA in a sealed glass jar, set inside a water-filled tank
- 3 min, no heat, lid on
- Air dry on a clean rag
After the cycle
- Rinse in clean hot water immediately → blow dry with compressed air or low-heat oven.
- Re-lube right away — ultrasonic strips ALL oil, including factory grease in bearings.
4. Reusing & filtering the solution
You can reuse a solution 3–20 cycles depending on type, and basic filtering extends life 2–5×. Bike drivetrain grime kills solutions fast (lots of grease + steel particles).
Solution lifespan (bike drivetrain use)
| Solution | Typical reuses | When to dump |
|---|---|---|
| Dish soap + water | 2–4 | Looks like coffee, foam collapses |
| Simple Green Pro HD (diluted) | 3–6 | Grease floats instead of emulsifying |
| Dedicated US degreaser (Elma/Branson/Crest) | 8–20 | Per spec — usually until heavily loaded |
| Citric acid 5–10% | 1–3 (steel only) | Fizzing stops, turns yellow/orange |
| Washing soda 1–3% | 3–5 | Greasy film, soap scum |
| Isopropyl alcohol (final rinse) | 2–4 | Visibly dirty or water-contaminated |
Dump it when: cavitation sounds duller, foam won’t break, or parts come out streaky.
Filtering — three tiers
Tier 1 — Settle + skim (free, ~30 min, ~70% of solids)
- Let solution sit 30 min to overnight in a tall narrow container (taller = faster separation).
- Three layers form: top = oil film, middle = clean solution, bottom = sludge + swarf.
- Skim the top with a paper towel laid flat (wicks oil up) or an oil-only spill pad.
- Decant the middle into a clean jug; stop 1–2 cm above the sludge.
Tier 2 — Paper or bag filter (~$2, 5 min, ~95% of solids)
- Paint strainer bag (best): 5 µm or 1 µm bags at Canadian Tire / Home Depot / auto parts (Trimaco, 3M, generic; ~$2 for 2-pack). Stretch over jug mouth with elastic, pour through.
- Coffee filter + funnel: #4 cone in a kitchen funnel. Pre-warm solution to ~40 °C or it clogs immediately. ~500 ml per filter.
- Improvised: 200+ mesh stainless kitchen strainer lined with paper towel.
Tier 3 — Magnetic + two-jug settling (shop setup, best long-term)
- Stick a strong neodymium magnet (~1”) on the outside of your storage jug — pulls ferrous swarf (chain/cassette particles) to the wall. Wipe magnet area clean periodically.
- Use a two-jug system: “dirty” jug for spent solution, “clean” jug for filtered. Pour into “dirty” after each session, settle overnight, filter top 80% into “clean” next day.
What filtering will NOT fix
- Emulsified grease bound to surfactant (cloudy solution that won’t separate) → chemically spent; dump.
- pH drift (citric acid neutralized by rust, alkaline cleaners losing strength) → dump and remix.
- Sub-micron abrasive grit.
Filter kit (~$10, lasts months)
| Item | Where | ~Cost |
|---|---|---|
| Paint strainer bags 5 µm (2-pack) | Auto parts / paint section | $2 |
| Kitchen funnel 5”+ | Dollar store | $2 |
| Two HDPE jugs (clean + dirty) | Reuse laundry detergent jugs | $0 |
| Oil-absorbent pad / bilge sock | Auto parts | $3–5 |
| Neodymium magnet ~1” | Hardware, Lee Valley, Amazon | $3–8 |
| Coffee filters (backup) | Grocery | $2 |
End-of-session workflow
- Remove parts, rinse, set aside.
- Pour tank contents into the “dirty” jug.
- Wipe the tank dry; refill with plain water + drop of soap for next session’s coupling fluid.
- Once the dirty jug has settled (≥30 min, ideally overnight):
- Skim top oil layer with paper towel.
- Pour through paint-strainer bag + funnel into the “clean” jug.
- Stop 1–2 cm before the sludge; rinse the sludge into trash or the HHW container.
- Solution is ready to reuse next session.
Two-stage wash strategy (extends premium-degreaser life)
- Stage 1: cheap dish-soap mix for bulk grime (dump frequently).
- Stage 2: dedicated degreaser for the final clean (lasts much longer because parts are already mostly clean).
5. Storage & disposal
Storage between sessions
- Opaque HDPE jugs with tight lids (laundry detergent jugs work great). Label with solution type + date.
- Away from heat, freezing, sunlight.
- Citric acid can grow mold after a few weeks — refrigerate, refresh with more citric acid powder, or just mix fresh (it’s cheap).
- IPA only in sealed glass — evaporates fast.
Disposal (when finally spent)
- Soapy water / water-based degreaser: small amounts down a utility sink with lots of running water (most CA municipalities accept this). Larger or heavily contaminated → household hazardous waste depot.
- Citric acid: neutralize with baking soda until fizzing stops (~pH 7), then down the drain.
- IPA: small amounts evaporate outdoors safely; larger → HHW depot.
- Never pour drivetrain wash water into storm drains or onto soil — contains heavy metals (zinc, lead from chain wear) and emulsified petroleum grease.
Waterloo region: see HHW disposal - Waterloo — free drop-off at 925 Erb St W (Gate 2, Waterloo) or 201 Savage Dr (Cambridge), Mon–Sat 7 am–6 pm. Max 25 L per container, must be labeled, no glass.
Tank maintenance
- Drain and refill the coupling fluid every few sessions or when visibly dirty.
- Wipe the tank dry between sessions — standing water + minerals will pit stainless over time.
- Use distilled water for the tank if your tap water is hard.
- Never run the unit dry — kills the transducers.
6. Safety quick-list
- No flammable solvents in the tank — ever
- Lid on whenever heat or volatile chemicals are involved
- Gloves + eye pro for citric acid, alkaline degreasers, IPA
- Ventilate the room — even “safe” degreasers off-gas when heated
- Never run the unit dry