Honda Grom, Must Have Mods that Make a Real Difference
The Honda Grom, also known as MSX125, is one of the most modded bikes in the world. It is light, simple, and bulletproof, which makes upgrades fun and affordable. This guide lists the mods that give the best return in feel, safety, and style. Each section includes what to look for, ballpark costs in AUD, and direct links to relevant parts on DriftnDrive so you can build your setup fast.
1. Exhaust, sound and response
Why it matters: a quality slip on or full system reduces weight and sharpens throttle feel. The Grom platform is sensitive to fueling changes, so plan your tune if you also change intake parts.
What to look for
- Removable baffle for sound control on long rides and at events
- Clear fitment for MSX125, 2014 to 2020, and 2021 onwards are different generations
- Stainless or titanium construction, quality welds, hardware that will not rust
Typical cost: 300 to 1,000 AUD depending on brand and whether it is a full system.
Shop related: Zard Exhausts and other brands in store.
2. Suspension, forks and shock
Why it matters: the stock fork and shock are soft. Better springs or a cartridge kit, plus a quality rear shock, give real control on rough streets and in tight corners.
What to look for
- Spring rates that match rider weight and cargo, heavier riders need stiffer springs
- Adjustable damping if possible, rebound and compression help with mid corner stability
- Fresh fork oil and a fork service if the bike is not new
Typical cost: fork springs and oil 200 to 400 AUD, cartridge kits 600 to 1,200 AUD, rear shocks 450 to 1,200 AUD.
3. Tail tidy and lighting
Why it matters: a tidy rear cleans up the look and keeps the plate secure. Choose a kit with a plate light and correct indicator mounting to stay compliant on road.
What to look for
- ADR friendly plate angle and LED plate light
- Robust brackets, weatherproof connectors, no sharp edges
- Indicator resistors or a relay if you fit LED signals
Shop related: Tail Tidys collection, plus Puig Thin LED Indicators.
4. Brakes, lines and pads
Why it matters: better feel equals more confidence. Braided lines reduce expansion, quality pads give bite and consistency. A fresh rotor helps if the old one is worn or warped.
What to look for
- Stainless braided lines and brake fluid with a high boiling point
- Pad compounds that balance bite with rotor life
- Correct rotor fitment for your model year and ABS status
Typical cost: pads 80 to 200 AUD, lines 150 to 250 AUD, rotor 120 to 250 AUD.
Shop related: MetalGear Grom front rotor.
5. Intake, filter and airbox tips
Why it matters: intake changes pair with an exhaust for better response. On small engines, filter and airbox design have a big effect on low end torque, so avoid extreme cuts unless you plan to tune.
What to look for
- High flow filter with proper sealing, do not over oil foam filters
- Heat shielding around the intake path if you ride in hot traffic
- Clear guidance from the manufacturer on whether a tune is required
6. ECU tune and fueling
Why it matters: once you open up intake or exhaust, a tune keeps fueling in the safe zone and smooths throttle transitions. The result is better rideability and reliability.
What to look for
- Tunes that specifically list MSX125 generation and mods
- Reversible maps or piggyback controllers if you want to switch setups
- Support for closed loop adjustments where available
7. Gearing and driveline
Why it matters: a small change in sprockets can make the Grom feel quicker around town. Shorter gearing helps acceleration, taller gearing can lower cruising rpm. Match chain length to sprocket choices.
What to look for
- Steel sprockets for durability on commuters, aluminium for show builds
- Quality O ring chain, correct pitch and links
- Speedometer correction if your ECU allows it
8. Controls, bars and pegs
Why it matters: better leverage and grip improve confidence. Adjustable levers set reach correctly, rearsets and pegs increase ground clearance, tank grips reduce arm pump.
What to look for
- Lever span adjustment and solid machining
- Pegs with aggressive knurling or rubber inserts for comfort
- Rearsets that keep hardware tucked and secure
Shop related: Puig Sport Footpegs that list the MSX125 in fitment, plus lever kits in store.
9. Crash protection that actually works
Why it matters: tip overs happen. Sliders and axle protectors keep the damage minor. Case covers protect engine covers that are expensive to replace.
What to look for
- Frame sliders with solid mounts that slide rather than catch
- Axle sliders for fork and swingarm protection
- Case covers that clear your exhaust and do not rub plastics
10. Comfort, visibility and style
Why it matters: the best Grom is the one you want to ride every day. Seats, grips, mirrors, and small screens improve comfort and visibility. Lighting upgrades boost safety.
What to look for
- Seat foam that supports longer rides without adding too much height
- Compact mirrors and mirror block offs for track days
- Screen protectors that stop cluster scratches and glare
Shop related: MSX125 2021 plus screen protector, and for earlier bikes a Puig fender extender for 2014 to 2015.
Buyer check table
| Upgrade | Why it matters | What to look for | Typical cost, AUD | Install difficulty |
|---|---|---|---|---|
| Exhaust | Lighter weight and better response | Removable baffle, clear Grom fitment, stainless or titanium | 300 to 1,000 | Easy to medium |
| Suspension | Control, comfort, and tyre life | Matched springs, service history, adjustable shock | 200 to 1,200 | Medium |
| Tail tidy | Clean look and secure plate | ADR friendly angle, LED plate light, indicator spacing | 80 to 250 | Easy |
| Brakes | Consistent stopping and lever feel | Braided lines, quality pads, correct rotor | 200 to 500 | Easy |
| Intake | Pairs with exhaust for response | High flow filter, good seal, tune advice | 60 to 200 | Easy |
| ECU tune | Smoother fueling and reliability | Model specific maps, reversible options | 200 to 600 | Medium |
| Gearing | Faster feel or lower cruise rpm | Correct chain length and pitch, speedo correction | 120 to 250 | Medium |
| Controls and pegs | Better leverage and grip | Adjustable levers, aggressive knurling, secure mounts | 100 to 350 | Easy |
| Crash protection | Saves plastics and covers in a tip over | Solid mounts, axle sliders, case covers | 150 to 400 | Easy |
| Comfort and visibility | Ride more with less fatigue | Seat foam, compact mirrors, cluster protection | 50 to 250 | Easy |
Pre ride setup checklist
- Torque check bars, pegs, calipers, and axle nuts
- Set chain slack, lube, and alignment
- Bleed fresh brake fluid, verify lever feel
- Check tyre pressures cold, then verify after a short ride
- Verify plate light and indicators after a tail tidy install
- If tuned, save a stock map backup in case you need to revert
Frequently asked questions
- Which year is my Grom, and do parts fit across generations
- Early MSX125 models are 2014 to 2020, the new shape started in 2021. Always check that parts list your exact year.
- Will I lose reliability with an exhaust and intake
- No if you tune correctly. Keep filters clean, use quality fuel, and follow service intervals.
- Is a big bore kit worth it for commuting
- Only if you also improve suspension and brakes. Torque is great, however comfort and control matter more day to day.
- What small mods give daily comfort
- Seat foam, grips, mirrors, and a screen protector reduce fatigue and glare on longer rides.
Shop the essentials
Browse parts that match this guide, then filter by Honda MSX125 or Grom where required.
- Search, Honda Grom parts
- Tail Tidys
- Exhausts
- Front brake rotor for Grom ABS
- Footpegs and controls
- Screen protector, 2021 plus Grom
- Fender extender, 2014 to 2015
Swap in direct product links for any new Grom specific items you list. Keep ADR notes near lighting and plate gear.
