Mongoose Legion

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Release Year
Wheel Size
Number of Gears
Gearing Type
34.0 lb
Brake Type
Frame Material

Summary of Reviews

We have read all expert and user reviews on the Mongoose Legion. In summary, this is what cyclists think.

9 reasons to buy

  • The L100 has a full chromoly frame. Dropouts may be Hi-Ten steel.
  • Clearance allowed for at least 2.5” tires.
  • On the L18, brake-levers were apparently adjustable for smaller hands.
  • Freestyle models feature gyro brakes to allow for handlebar spins.
  • The L100 struck some owners as being lightweight.
  • Reviewers admired the burgundy color.
  • For more mechanically-minded buyers, assembly was easy.
  • Shorter top-tube lengths suited smaller riders, while still using 20” wheels.
  • The ‘female’ front hub on L100s is the correct width for the fork and allows pegs to be attached.

20 reasons not to buy

  • Generic instructions cover three models, confusing some buyers.
  • At this price-point, unsealed rear-wheel hubs on the L100 disappointed.
  • One-piece cranks on L18s are not up to real tricks and jumps.
  • Chain tension was often too tight.
  • Undergreased bottom-brackets, headsets, hubs and axles… disappointed.
  • On L18s, bottom-brackets were a cheap bearing-and-race design and tended to grind.
  • Welding errors included a top-tube that wasn’t centered!
  • Legions only have one brake, which is fine for trick-riders but not for kids.
  • Cheap U-Brakes were difficult to adjust and showed underwhelming stopping power.
  • Brake cables were often too short and sometimes snapped, causing accidents.
  • Rims are painted on lowest-end models, limiting braking power.
  • On the L100, rim seams are pinned not welded, compromising strength.
  • Tires are tough to change on the Xposure rims.
  • The KMC chain broke on a large number of occasions, sometimes on first rides.
  • Pegs needed specialist long-sockets to attach or remove.
  • Missing parts occurred, including handlebars and saddles!
  • On a few occasions, rear hubs disintegrated within a few weeks use.
  • An expert noted sloppy welds, on forks, rear dropouts and elsewhere.
  • One expert deemed pedals to be ‘pure garbage’ for trick use.
  • On the 2018 L100, the headset is non-standard and not easily replaced or repaired.

Bottom line

This BMX comes in a range of models. Only the L500 is somewhat suitable for larger riders and tricks. Prospective buyers should be warned about heavy use of the L100 and lower-end models, even for beginners. At least, not without replacing a number of parts. Owners should be aware that the Legion needed standard adjustments required on an internet buy. But in addition, some buyers found that hubs, bottom-brackets and headsets also needed to be disassembled and regreased from new. Be safe, take your new BMX to your LBS and have a pro mechanic make it AOK. Trick riders said it felt ‘clumsy’ on vert ramps and skate parks. Regular chain breakage and break cable snappage was concerning, especially since these faults caused a number of accidents involving children, according to parent reviews. Legion, or lesion?

Expert Reviews

0/100 based on 0 rated expert reviews
Douglas Thompson

Mongoose Legion L100 In-Depth Review

Keep in mind that these parts are not to be trusted for long-term use… I can say that this would be a pretty good purchase if you were just trying to go for the frame because it’s 100% chromoly…

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Douglas Thompson

How Much Abuse Can a Mongoose Take? L100

I just broke my chain… it’s probably the weakest part. We do have some sprocket damage as well.

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Douglas Thompson

Detailed Mongoose Legion L100 Review 2017 vs 2018

Just about everything feels, is and looks higher quality on the 2018 model. One of the best quality bikes you can get for this price range. The hardware on the rear axle seems to be lower quality.

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User Ratings

74/100 based on 980 ratings
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Bike Comparison

Mongoose Legion in comparison to averages

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