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Public-images-osm logo.svg mtb:scale:imba
A classification scheme for the difficulty of specifically designed trails for mountainbiking. Edit this description in the wiki page. Edit this description in the data item.
Group: properties
Used on these elements
may be used on nodesmay be used on waysshould not be used on areasshould not be used on relations (except multipolygon relations)
Useful combination
Status: approvedPage for proposal

The Trail Difficulty Rating System shall be used for mountain bike trails which are specifically designed and designated for mountain biking, to be found in "Bikeparks", for example. For "natural" trails it is advised to use mtb:scale=* and mtb:scale:uphill=* instead.

mtb:scale:imba=0 to 4.
0 refers to Easiest (white circle), 1 is Easy (green circle), 2 is More Difficult (blue square), 3 is Very Difficult (black diamond), and 4 is Extremely Difficult (double black diamond).

IMBA Trail Difficulty Rating System
Tag / Category Trail width Tread Surface Average Grade Maximum Grade Unavoidable obstacles Unavoidable bridges Technical Trail Features Other
⚪ Easiest (White Circle)
1.8m (72") or more Hardened or surfaced < 5% Max 10% None None None No obstacles
🟢 Easy (Green Circle)
0.9m (36") or more Firm and stable 5% or less Max 15% 5 cm (2") tall or less 0.9m (36") or wider None Avoidable obstacles may be present
🟦 More difficult (Blue Square)
0.6m (24") or more Mostly stable with some variability 10% or less Max 15% or greater 20 cm (8") or less 0.6m (24") or wider 0.6m (24") high or less, width is >1/2 height Avoidable obstacles may be present
◆ Very difficult (Black Diamond)
0.3m (12") or more Widely variable 15% or less Max 15% or greater 38 cm (15") or less 0.6m (24") or wider 1.2m (48") high or less, width is < 1/2 height May include loose rocks, short sections may exceed criteria
◆◆ Extremely difficult (Double Black Diamond)
0.15m (6") or more Widely variable and unpredictable 20% or more max 15% or greater 38 cm (15") or less 0.6m (24") or narrower 1.2m (48") high or less, width is < 1/2 height May include loose rocks, many sections may exceed criteria
More specific tags width=* surface=*, tracktype=* incline=* incline=* smoothness=* bridge=* + width=* bridge=* + width=* n/a

IMBA Trail Difficulty Rating System.jpg

Graphics reused with permission from IMBA. Updated original found here.