Routes
- UA3 - mtb, network lcn, 39.4 km, ascent 752 m, descent 753 m
- UB Cup Drøbak - mtb crosscountry
- UB Cup Grønmo - mtb crosscountry, operator IF Frøy, 4.3 km, ascent 110 m, descent 118 m
- UB Cup Gullhaug - mtb crosscountry
- UB Cup Holmen - mtb crosscountry, 3.6 km, ascent 74 m, descent 74 m
- UB Cup Langsetløkka - mtb crosscountry
- UB Cup Lillomarka Arena - mtb crosscountry
- Über Aschberg nach Tschechien - mtb, network rcn, operator Bikewelt Schöneck
- Über das Aurachköpfl - mtb crosscountry
- Über den Eisenberg - mtb, network lcn, operator bike arena Sauerland
- Über die Pastorenwiese - mtb, network lcn, operator bike arena Sauerland, 14.4 km, ascent 453 m, descent 490 m
- Über die Steinhelle - mtb, network lcn, operator bike arena Sauerland, 21 km, ascent 724 m, descent 724 m
- Über Hillekopf & Junge Grimme - mtb crosscountry, network lcn, operator bike arena sauerland, 37.8 km, ascent 1143 m, descent 1140 m
- Übungsparcours - mtb
- Učka bike 7 - mtb, network mtb, operator Park prirode Učka
- Učka bike 8 - mtb, network mtb, operator Park prirode Učka
- Ude's Trail - mtb, 10.7 km, ascent 208 m, descent 714 m
- Údolím klopek - mtb, 0.1 km, ascent 0 m, descent 4 m
- Ugao - Artanda - mtb
- Ugga Dugga - mtb, 0.1 km, ascent 1 m, descent 0 m
- Uhelný vrch - mtb, network lcn, operator Kokořínské stezky z.s., 2.2 km, ascent 7 m, descent 165 m
- Uhlířská stopa - mtb, operator Areál Kouty, 6.6 km, ascent 63 m, descent 517 m
- Uhlířský důl - mtb, network lcn, operator Kokořínské stezky z.s., 3.2 km, ascent 3 m, descent 106 m
- Uhrehøje MTB - mtb, network lcn
- Ukryty Wąwóz - mtb, 1 km, ascent 3 m, descent 67 m
- Uli-Trail - mtb, network lcn, 0.4 km, ascent 0 m, descent 25 m
- Uliveta - mtb, network lwn, 1.1 km, ascent 2 m, descent 114 m
- Ulmizberg Trail - mtb allmountain, 3.5 km, ascent 9 m, descent 281 m
- Ulrichsteiner Panorama Runde - mtb, network rcn, operator Vogelsberg-Arena, 33.3 km, ascent 668 m, descent 664 m
- Ulstrup MTB Spor - mtb crosscountry
- Ultrabirken sykkel 2010 - mtb
- Ultrabirken sykkel 2011 - mtb
- Ulven - mtb crosscountry, 1.2 km, ascent 17 m, descent 12 m
- Um das Aurachköpfel über Schliersee - mtb
- Um das Soodener Bergland - mtb, operator Werratal Touristik
- Um den Kapuner - mtb, network lcn, 3.1 km, ascent 187 m, descent 33 m
- Um den Schliersberg über Miesbach - mtb crosscountry
- Umbrüggler Alm - mtb, network lcn, operator Land Tirol
- Umhauser Runde - mtb crosscountry, network lcn, 16.2 km, ascent 271 m, descent 273 m
- Ums Bichlach - mtb crosscountry, operator Tirol, 14.6 km, ascent 314 m, descent 313 m
- Ums Tal der 7 Mühlen - mtb, 30.4 km, ascent 719 m, descent 726 m
- Un Balcon sur le Pays de Brive - mtb, network lcn, 7.1 km, ascent 235 m, descent 233 m
- Un facile percorso con tutti gli alberi del Parco - mtb, network lcn, operator Parco Nazionale Foreste Casentinesi, 5 km, ascent 309 m, descent 340 m
- Un grandioso anello nell’Alto Bidente - mtb, network lcn, operator Parco Nazionale Foreste Casentinesi, 46.2 km, ascent 2263 m, descent 2263 m
- Un panoramico crinale tra Montoni e Rabbi - mtb, network lcn, operator Parco Nazionale Foreste Casentinesi, 31.1 km, ascent 1587 m, descent 1584 m
- Una facile salita, poi giù per la via dei Legni - mtb, network lcn, operator Parco Nazionale Foreste Casentinesi, 16.1 km, ascent 799 m, descent 730 m
- Unava coastal - mtb, network lcn, 7.9 km, ascent 54 m, descent 43 m
- Unava forest - mtb, 7.8 km, ascent 14 m, descent 38 m
- Unava trail - mtb, 3.2 km, ascent 16 m, descent 14 m
- Uncle Tom's - mtb, network lcn, 2.6 km, ascent 55 m, descent 10 m
- Undalslund MTB - mtb, 8.5 km, ascent 78 m, descent 83 m
- Undefined - mtb freeride, 7.4 km, ascent 35 m, descent 35 m
- Under liften - mtb, 1 km, ascent 0 m, descent 127 m
- Underworld - mtb, 1 km, ascent 3 m, descent 5 m
- Underworld - mtb, 4.2 km, ascent 20 m, descent 28 m
- Unnamed - mtb, operator US:AR:Bentonville, 1 km, ascent 34 m, descent 18 m
- Unnamed - mtb, operator US:AR:Bentonville, 0.2 km, ascent 16 m, descent 0 m
- Unter der Haube - mtb, operator Fremdenverkehrsgemeinschaft Schwäbischer Wald e.V., 30.4 km, ascent 780 m, descent 782 m
- Unterberghorn - mtb crosscountry, operator Tirol
- Unterer 3-Stundenweg - mtb, operator Wienerwald Tourismus, 3.2 km, ascent 122 m, descent 118 m
- Unterer Family Trail - mtb, operator 3Länder Enduro Trails, 1.5 km, ascent 3 m, descent 154 m
- Unterer Grund - mtb crosscountry
- Unterer Hofwald - mtb, network rcn, operator Tirol, 1.1 km, ascent 10 m, descent 88 m
- Unterer Roan-Trail - mtb, operator WienerWaldTrails
- Unterer Schöneben Trail - mtb, 1.6 km, ascent 0 m, descent 285 m
- Unterer Spin Trail - mtb, network lcn, 2.7 km, ascent 0 m, descent 281 m
- Unterkürnach - mtb, network lcn, 0.3 km, ascent 2 m, descent 4 m
- Unterspinrunde - mtb, network lcn, operator Tirol, 19.7 km, ascent 722 m, descent 727 m
- Untertal-Runde - mtb, operator Land Tirol
- Unterwandalm-Karseggalm-Breitenebenalm - mtb, network lcn, 2.7 km, ascent 69 m, descent 225 m
- Unterwiesenalm - mtb crosscountry, operator Tirol, 2.8 km, ascent 236 m, descent 26 m
- Up - mtb, 0.5 km, ascent 10 m, descent 3 m
- Up & Over - mtb, 0.6 km, ascent 22 m, descent 25 m
- Up and Doune - mtb, network lcn, 0.9 km, ascent 37 m, descent 9 m
- Up Hill Both Ways - mtb, network lcn
- Up Hill Both Ways Alternate North - mtb, network lcn, 1.5 km, ascent 34 m, descent 33 m
- Up River - mtb, 0.8 km, ascent 15 m, descent 61 m
- Up Thunder dome - mtb, network lcn
- Up to Stew - mtb, 1.8 km, ascent 62 m, descent 20 m
- Uphill - mtb, network lcn, operator Nyakas Enduro Trails, 1.1 km, ascent 81 m, descent 1 m
- Uphill Access - mtb uphill
- Uphill Flowtrail by Focus Bikes - mtb, network lcn, operator Familienarena Bucklige Welt-Wechselland, 4.7 km, ascent 489 m, descent 75 m
- Uphill Track - mtb allmountain, 4.3 km, ascent 1 m, descent 118 m
- Uphill-Trail - mtb, network lcn, 1.2 km, ascent 35 m, descent 1 m
- Uphill-Trail - mtb, network lwn, operator Radlager MTB Trails, 1.3 km, ascent 111 m, descent 2 m
- Upland Dörfer Tour - mtb crosscountry, network lcn, operator bike arena Sauerland
- Uppeldad - mtb crosscountry, network lcn, operator Sundsvalls kommun
- Upper Blair Witch Trail - mtb crosscountry, 2.1 km, ascent 32 m, descent 53 m
- Upper Blue Heron - mtb, network lcn, operator Noquemanon Trail Network, 2.8 km, ascent 25 m, descent 21 m
- Upper Boundary - mtb freeride, 0.4 km, ascent 0 m, descent 75 m
- Upper Boundary - mtb freeride, 0.3 km, ascent 0 m, descent 73 m
- Upper Buckle Trail - mtb, 1.7 km, ascent 39 m, descent 6 m
- Upper Butte Loop #4093.1 - mtb, 19.5 km, ascent 392 m, descent 318 m
- Upper Crippler - mtb downhill, 0.7 km, ascent 0 m, descent 164 m
- Upper Cut Trail - mtb allmountain
- Upper Digger - mtb freeride, 0.3 km, ascent 51 m, descent 0 m
- Upper Green Loop - mtb
- Upper Griffen - mtb downhill, 0.5 km, ascent 47 m, descent 0 m
- Upper GRR - mtb, 1.3 km, ascent 70 m, descent 27 m
- Upper Harbor - mtb, 0.1 km, ascent 0 m, descent 0 m