Ondra VLK Custom - KTM 500 EXC

Product reviewed

A custom KTM 500 EXC built by Ondra VLK (also described as “KTM’s ambassador” and a Czech traveler). The video is a “custom show” explaining what was changed to make the bike suitable for long-distance home enduro / rally-style riding—including riding through rough terrain (e.g., Morocco) and planned riding in Georgia.

Key features & modifications mentioned

Purpose-built for off-road / long-distance enduro + travel

• Built for terrain riding where weight, reliability, and engine behavior matter most.

Weight focus

• Ondra emphasizes that small weight differences are very noticeable.
• Changes aim to keep the bike stable and manageable.

Cush drive / rosette modification (driveline behavior)

• The build uses a rear-wheel “cush drive / cush drive-like” setup: a rubber/solid coupling approach between the drive components and rear wheel.
• Ondra chose to save money versus buying a full cush-drive system by installing a New Zealand-sourced sprung rosette.
• Purpose: it simulates cush drive behavior and reduces road jerking, especially at lower speeds.
• Described as not pretty, but effective at “calming” drivetrain impacts/vibrations.

Suspension upgrade

• Uses higher-end components for the shock system (notably VP/Pro-level setup):
  • Cartridges and shocks from an Explorer Pro-type setup (VP “X Pro” rear shocks also mentioned).
• Cost-conscious choice: Ondra replaced fork internals, not the entire fork.
• Tuning process:
  • Adjusted with a suspension expert (Tomáš), then fine-tuned “by feel.”
  • General tuning advice:
    • Tighten more when riding fast
    • Loosen when riding heavier / under different conditions

Fuel tank upgrades (major part of the build)

• Stock tank:
  • About 8.5–8.7 L
  • Consumption estimate: roughly 5–6 L (per rider’s estimate)
• First attempt:
  • A 15 L Acerbis tank, which Ondra says noticeably changes handling / center of gravity
  • He describes the behavior as “terrible” compared to the current setup
• Current/selected tank:
  • A Dakar-style multi-part tank (visually/behaviorally compared to 790/690 Dakar)
  • Claimed capacity: approximately ~20 L (“they say 21”)
  • Packaging/fit: weight is kept lower/closer to the bike, improving stability
  • Installation described as plug-and-play, with hoses/cables included and neat access
    • He claims you can access/adjust connections without removing the whole tank (by removing screws)
• Handling impact:
  • Ondra notes the bike becomes more stable and less “restless” at slower speeds
  • He removed the 15 L tank and says the difference was immediately noticeable

Engine service approach / longevity expectations

• Ondra’s view: the engine doesn’t need much work if treated properly (avoid sustained full-throttle misuse).
• Service interval discussion:
  • A “standard” reference mentioned: about 15 engine hours
  • Ondra argues that number fits hard full-throttle riding more than his real use
  • He prefers planning based on kilometers and practical conditions
• He modified the clutch/basket area (including references such as Federal Performance, and larger clutch basket/cover parts).
• Replacement rhythm:
  • He references changing items roughly around 2000 km
• Travel practicality:
  • In Morocco, he rode very long distances (around ~2800 km mentioned) and wasn’t worried about maintenance barriers due to access, tools, and practicality

Air filter / intake access

• Airbox is described as accessible and still usable “despite the tank.”
• Foam filtration elements mentioned (including a dust-catching/pre-filter style layer).
• Oil/foam setup referenced, with quick replacement claimed within ~10 seconds.

Cooling / overheating

• Ondra claims the XC/EXC platforms are built for tough terrain:
  • Fan + sufficient water capacity
• He contrasts with 690 models, which he says overheat more often.
• Fan is said to activate during harder rides/conditions.

Handguards / bar flexibility debate

• Ondra uses VP-style spring clamps / shock-related flex components (related to flexibility/absorption benefits).
• For handguards/grip guards:
  • He believes many designs make bars feel too stiff/solid
  • He prefers setups that allow handlebar flex so impacts are absorbed more naturally.

Cockpit / rally navigation

• Carbon/aftermarket tower mentioned, attributed to a “plug and play” style installation.
• Garmin navigation:
  • Uses OS Maps, saved routes, and GPX transfers
  • Primarily helps avoid getting lost in heavy fog / nowhere
  • He avoids relying on many handlebar controls (wants fewer buttons)

Tires

• No single “best tire” for everything; choices depend on ride type.
• For travel he recommends Michelin Tracker, praising price/performance.

Pros (as stated)

• Engine reliability / toughness, suited for “built to withstand nonsense.”
• Longevity-oriented setup: minimal engine work if ridden properly.
• Much improved stability from the chosen Dakar-style tank (lower center of gravity vs 15L Acerbis).
• Better low-speed driveline feel due to the cush-drive-like rosette (less road “jerk”).
• Suspension upgrades significantly improve rough-rock handling.
• Travel practicality:
  • Maintenance can be done on the road (e.g., clutch/gear-related parts)
  • Navigation helps prevent wrong turns in poor visibility
• Plug-and-play install for the tank and electronics integration (as described).

Cons (as stated)

• Cost
  • The tank/build is described as extremely expensive (including an import price remark such as “ridiculously expensive”).
  • The build is “out of love,” not budget-minded.
• Rosette/cush-drive solution isn’t aesthetically perfect (functional, but “not pretty”).
• Tradeoffs in suspension/controls/handguards:
  • Some handguards can reduce handlebar compliance and make impacts feel harsher.
• Weight impact depends on comparison
  • He repeatedly notes weight changes are noticeable, though he still favors the final outcome.

Comparisons mentioned

• Acerbis 15 L vs current Dakar-style tank
  • Acerbis is criticized for worse center of gravity and more troublesome handling in heavier terrain.
  • Dakar-style tank improves stability and ride behavior.
• KTM 690 vs EXC/500
  • Ondra says 690s overheat more often than the EXC/500 platform.
• Competitor/value discussions (indirect)
  • Mentions broader comparisons (e.g., CF Moto based on KTM tech ideas, general pricing talk), but suggests direct financial comparisons (especially for “€80–90k class” machines) don’t really work.
• Early debate mentioned:
  • AEP/KTMC/Husqvarna were discussed in context of Morocco debates, but the review focus remains the KTM 500 EXC.

Numerical values / ratings mentioned

• Engine service concept:
  • About ~15 hours (but he argues it’s for hard full-throttle use)
• Oil/consumable reference:
  • ~1.2–1.3 L mentioned (as presented in context of liters; not fully consistent in subtitles)
• Maintenance cadence:
  • Around ~2000 km for clutch/basket-related replacement approach
• Fuel:
  • Stock tank: ~8.5–8.7 L
  • Stock consumption: ~5–6 L
  • Tried tank: 15 L Acerbis
  • Current tank: ~20–21 L (“20 when filled dry new”; “they say 21”)
• Total bike weight (with full tanks):
  • Roughly ~125 kg (“plus or minus 125”)
  • Compared to roughly ~170 in another referenced build category (e.g., “AEP 170” mentioned; exact reference unclear)
• Bike price commentary:
  • “around 450k” (currency unclear)
  • Mentions ready-made rally kits might be 600+ (currency/units unclear)

Unique points mentioned (consolidated)

1. Ondra VLK built a custom KTM 500 EXC for travel enduro.
2. Emphasis on progression to the ~5 kg EXC class (prior bike/weight evolution mentioned).
3. Prioritizes weight, reliability, and engine behavior.
4. Longevity philosophy: engine is fine with proper use; not for constant abuse.
5. Uses a cush-drive-like rosette solution to fix low-speed driveline jerk while controlling cost.
6. Suspension uses VP/Explorer Pro-level cartridges and X Pro-type shocks; fork internals swapped for savings.
7. Suspension tuning with Tomáš, then rider fine-tuning.
8. Range planning concept mentioned (e.g., 10L default and 40L structure mentioned via True North Motos).
9. Ergonomics/fit concerns with tank geometry for shorter leg positioning; knee/leg placement matters.
10. Seat comfort approach: foam/gel for “crossings.”
11. Engine servicing: claims the engine doesn’t need much work; replace based on practical needs.
12. Clutch basket/cover upgraded (Federal Performance referenced) including dirt-catching improvements.
13. Fuel capacity/consumption comparisons across multiple tank options.
14. Dakar-style tank improves stability by shifting weight distribution lower.
15. Current tank capacity approx 20–21 L, compared directly to the 15 L Acerbis handling difference.
16. Tank install described as plug-and-play, with access for servicing via screws instead of full removal.
17. Cooling philosophy: EXC built for tough terrain; fan support; 690s reportedly worse.
18. Intake/filter access described, including quick air filter replacement and filtration approach.
19. Handlebar behavior: some protective setups make bars too stiff; Ondra prefers flexibility.
20. Cockpit tower: low carbon tower; concerns about height/fit over terrain/jumps.
21. Electronics: Garmin navigation with OS Maps and GPX route transfer; route guidance helps in fog.
22. Tires: no universal winner; Michelin Tracker recommended for travel.
23. Total full-tank weight around 125 kg; weight changes are “noticeably” felt.
24. Plans for a second bike and swapping parts later (modularity mindset).

Speakers / roles

• Ondra VLK: main builder/rider; provides most technical and subjective details (engine, suspension, tank/rosette, navigation, tires, ergonomics).
• Biker Boys Garage host / interviewer: asks questions and adds comparisons/observations with less technical depth.

Overall verdict / recommendation

The video presents Ondra’s custom KTM 500 EXC as a highly capable travel/enduro rally-style build, prioritizing reliability, improved handling via a carefully chosen Dakar-style tank, and careful driveline + suspension tuning. The biggest downsides are high cost and a few compromises (such as a functional but “not pretty” cush-drive-like rosette solution).

Recommendation: Yes—if you want a long-distance off-road KTM 500 platform and are willing to invest in targeted upgrades rather than buying a single one-size-fits-all rally kit.