Please watch the 2017 Relentless Exposure 24Hr Race video to get feel for the riding at Nevis Range.
WEMBO, the World Endurance Mountain Bike Organisation, was formed in September 2011 to fill the void when there was no 2011 World Solo 24 Hour Mountain Bike Championship. Since 2011 the orginisation has gone from strength to strength.
WEMBO is a group of like-minded mountain bike clubs and promoters from around the world with vast experience in hosting 24 Hour Mountain Bike Races. They have agreed to stage annual World Solo 24 Hour Mountain Bike Championship events to ensure the future of the sport of Solo 24 Hour racing at the highest level and to meet the needs of the riders.
The WEMBO Vision
The WEMBO World Solo 24 Hour Mountain Bike Championships will provide true world-wide competition and be recognised by mountain bikers, spectators, the cycling industry and media as the pinnacle of the sport.
To create a predictable, regular and reliable set of quality world-wide events in which the World's best 24 hour mountain bikers can test themselves against each other at the highest level.
Fort William 2018
The Outdoor capital of the UK
No Fuss Events and Nevis Range are proud to be the hosts of the World Solo 24 Hour MTB Championship event for 2018. The event was last hosted here in 2014. You can watch the race video here and read the 2014 race report here.
The 24 hour race will start at 12 noon on Saturday the 20th of October 2018 and will run until 12 noon on Sunday. Riders will have until 1300 to complete the final lap. Please note that any rider returning after 1300 will not be counted.
The route will start from and finish at the Nevis Range complex, snaking and climbing up Aonach Mor and deep into Leanachan Forest and onto the world famous Witch’s Trail, World Champs and other amazing trails that make up the fantastic network within Leanachen forest. With at least half of the event taking place in the dark, the course has been designed to be ride-able for the full 24 hours regardless of weather conditions.
This is your opportunity to join the worlds very best endurance athletes for the a weekend of endurance mountain biking at one of the best venues that the UK has to offer. No Fuss Events have been successfully running the Relentless 24hr since October 2006 and have hosted WEMBO in 2014 we are therefore confident that the 2018 course will be one of the very best.
NB Every participant is allocated a 3m x 3m Pit area which is included in the entry price. Please note that pit areas will be allocated prior to arrival, if you would like to pit beside specific riders then please contact us at your earliest convienience.
If you would like a covered pit area, or a fully serviced pit area please purchase throughthe shop area of the website.
1 Fully Serviced Pits which Includes Flooring, Lights. Electricity, Table and Chairs £220
2 Covered Only £160
Pit Map Updated 30th April 2018
View Sheet Here
Please don't hesitate to contact us for any further info if required. [email protected]
0900 Course and pits open. No entry to pit spaces before 9am. Please obey the parking staff.
1000 Registration Opens
1600 Registration Closes
1800 Official Rider Brief (compulsory for riders and 1 helper). THIS WILL BE HELD AT THE PINEMARTIN CAFE AT NEVIS RANGE.
0600-1000 Parking/Pit set up. No vehicles will be allowed to enter the pits after 1000.
0730 Course open for practice
0800 - 1000 Registration for those unable to make it on Friday.
0800 - 1000 Collect race timing chips. SportIdent will be onsite at Nevis Range handing these out.
1000 Race Briefing for those unable to attend on Friday
1030 Course Closes for Practice
1140 Riders assemble at Start Line
1200 Race Start
1730 Compulsory to have lights fitted to start a lap
1200 Course closed, no more laps allowed to be started
1300 Official race end. Laps completed after this time will not be counted
1315 Provisional Results Published
1330 Presentations of Elite Winners
1900 All Categorories Presentations and Dinner - Moorings Hotel
1) How long will registration be open for?
The course has a capacity for around 600 riders, we don’t envisage that many entries but it would be great if there were. We would plan to keep registration open until about a fortnight before the race. All pit areas will be track side and we shall give regular updates on serviced pit availability.
2) What will the weather be like?
October is a great month for 24 hr races in the Scottish Highlands, whilst we cannot guarantee the weather there is a good chance it will be ok and there will not be any midgies. The weather in 2014 was amazing and we would love it if it were like that again, although we would recommend to plan for the worst.
3) Why is it so much more expensive than Relentless 24?
It is important that WEMBO has the look and feel of a World Championship event. The £10000 prize money has to come from somewhere, then there is and 12000 of infrastructure such a marquees and lighting units, Sportident air time system, media coverage support. Riders pit boards, crew T shirts, finishers mementos, none of which are supplied at R24.
4) What accommodation is available?
The Moorings Hotel is fully reserved for participants and guests, they will not open for other bookings until July. You can also find a full range of accommodation here.
5) Can we pit together with team mates etc.
Whilst we will not guarantee that you will be pitted all together we will do our very best to meet participant needs. The earlier you book and request it is more likely we will be able to assist.
6) Why is the destination known as the Outdoor Capital of the UK?
Outdoor Capital of the UK is Lochaber Chamber of Commerce’s tourism element promoting the tourism destination and adventure for all!
Under the Outdoor Capital brand the chamber membership collaboratively publicise, sponsor and promote the area as a tourism destination. The organisation produces official event programmes and guides which showcase all there is to see and do in the area. The Outdoor Capital of the UK website is the site to go to for local events and visitor accommodation, with an overall objective of developing local jobs and wealth and encouraging sustainable economic growth.
The organisation currently has a wide range of member businesses which range from accommodation, food and drink and activity providers to non-tourism focused businesses who support the aims of the Lochaber Chamber of Commerce and acknowledge that tourism is crucial to the local economy. Many of these businesses are SMEs and by pulling resources and working as a team the Lochaber Chamber of Commerce achieves the positive results that individually the members couldn’t otherwise reach.
7) Will there be a postal address where I can get my bike delivered?
We are currently working on this and will let you know once arrangements are finalized, we will also see if we can arrange for a post back service after the event.
8) Can we have an over 65 category?
We have now added this category, Please note that any category that has five or less riders will automatically be included into the category below.
Final course details will be released in the week leading up to the event. Below is a map of the 2017 24hr race course.
This is a list of entries for this event. If you think you should be here and you are not then let us know.
Solo Elite1) Kaitlyn Boyle - Kaitlyn Boyle
2) Gaia Ravaiolo - Gaia Ravaiolo
3) Team GORE / USE/Exposure / Sandy Wallace Cycles - Naomi Freireich
4) Cycle Works - Kate Penglase
5) Idworx Team - Jana Kalbertodt
6) Giusto Pro Records - Olena Novikova
7) De Pomeroy - Simon De Pomeroy
8) Team JMC/Pro Techniques Cycle Coaching - Tom Hodgkinson
9) Team JMC/Pro Techniques - Carl Salisbury
10) Croc Sports / RaaheCC - Matti Tahkola
11) Team Meget Tunge Ben - Kim Pliniussen
12) Team Meget Tunge Ben - Jesper Thomsen
13) IQ Chocolate/Fresh Air Experience - Jamie Shandley
14) X-bionic - lars braun
15) Hot Pursuit Cycles / Specialized UK - Max Suttie
16) RAF CA - Martin Pearson
17) Joachim Mendler Ultra Chiru Magura - Joachim Mendler
18) Taylor Lideen - Taylor Lideen
19) KRABCYCLES - Marek Vagner
20) KRABCYCLES - Tomas Vitvar
21) Ben Rayneau-Kirkhope - Ben Rayneau-Kirkhope
22) Eifel Cycling Team Northwave - Ingo Manteufel
Solo Singlespeed23) CAROLINA CASACUBERTA - CAROLINA CASACUBERTA
24) Gala CC - Torq/Exposure/Mt Zoom - Andrew Howett
25) justonbike - Justin Atkinson
26) Garage Bikes/InGear - Ben Houldsworth
27) I - Cycles - Neil Dingle
28) WWWa - Stephen Leighton
29) Socialtrack.co.uk - Neil Morrison
30) Islabikes - Steve Chapman
31) Wim Verheyen - Wim Verheyen
32) Sandy Wallace Cycles - David (Singlespeed) Glover
33) MARCAL FONT SOLA - MARCAL FONT SOLA
Solo Under 2334) Basecamp Bikes/Merida Bicycles U.K. - Kyle Beattie
Solo 23 - 2935) Pull The Udder One - Tom Archer
36) R.O.T racing - Alex Flinn
37) Jordan Butler - Jordan Butler
Solo 30 - 3438) Eye Of The Cider. - Alex Taylor
39) Tredz.co.uk - David Bowkett
40) Team JMC (Gobby) - David Gobby
41) www.solosride.be - Elias Van Hoeydonck
42) RibapedalBikeShop/VictoryEndurance - Filipe Matos
43) Evans Cycles - Nick Owen
Solo 35 - 3944) FIZO Cycling - Gwynn Le Maitre
45) Team JMC/M.FORTEracing - James (Ticker) Whittaker
46) Geelong Mountain Bike Club (GMBC) - Kelvin Little
47) Penguin pirates - Stefan Hodgetts
48) Fat Power - Euan Patrick
49) Seb fatteux barbu - Sebastien dupont
50) KTM UK FACTORY MTB TEAM - Lee Monks
51) WWWSO - Steve Gates
52) Team JMC - Alex Watts
53) MÓKÓTÓBIKES/ +NUTRIÇÃO/ COLIPNEUS/KEINO - Rui Damião
54) pedalon.co.uk #TORQFuelled - David Carr
Solo 40 - 4455) Niner Bikes NZ/Bike Otago - Ronel Cook
56) SoloYOLO - Julie Baird
57) Pigeon Pie - Peter Boyd
58) croux24 - Cedric ROUX
59) Cyclehighlands Scotland - Scott Sutherland-Thomson
60) Hayfield Hub - Jamie Bell
61) Complete Cycle Works - Plymouth - JAMIE WARD
62) Bike IN Tierras Altas - Enrico Miracoli
63) Huw Thomas - Huw Thomas
64) TeamJMC - Darren Hall
65) Chain Brain - Kevin Skidmore
Solo 45 - 4966) Bike City - Carole Welch
67) iCycles - Mike Hancock
68) Centralian Records Management - John Pyper
69) Team Ben the Bike Tech - Stuart Cornell
70) Hardies Bikes Melrose - Scott Ramsay
71) Team JMC/Steely Eyed Clothing - Richie Scott
72) DHB Sport - Rob Lee
73) Team Nod - Nod Nelson
Solo 50 - 5474) SoloYOLO - Laurie Simonson
75) Cannock Chase Cycle Centre - Peter Nadin
76) Team JMC - Keith Kitchen
77) Team Scumo999 Isle of Man. - Gary Kirby
78) Kommando 8. August - Martin Staiger
79) Rock and Road - Kenny Young
80) le gars de la Yaute - olivier bertrand
81) Neil Scott - Neil Scott
82) Team PRONGHORN RACING - Jens Aagaard
83) LUDOVIC BRAULT OXYGENE PSA - LUDOVIC BRAULT
84) manchester tri club - steve clayton
Solo 55 - 5985) creasingmatrix.com / Bikestyle IOM - Adrian Beale
86) Oakey Creek Racing - Michael Hawley
87) Pine Creek Racing - Mark Wood
88) Patoche04 - Patrick GOUARD
89) Santa Cruz Bicyles - Exposure Lights - USE - John Pitchers
90) AAA Racing - peter selkrig
91) Ben Thomas Coaching - Julian Paphitis
Solo 60 - 6492) Epicyclo Bike Walking Club - Brian MacLeod
93) Full Measure - Kern Reynolds
94) The Bike Shop Calgary - Dennis Smaggus
95) Gregor Grant - Gregor Grant
The Race Organisers, the Chief Commissaire, or the Race Director reserves the right to change any rules and regulations at any time to provide fair and safe riding conditions. Riders will be required to sight a copy of the final rules and regulations at event registration. After event registration closes, any changes to rules and regulations will be announced at a race briefing.
If there is a rule dispute, the English language version of the rules will be used to decide the outcome.
Riders and helpers must obey the directions of Race Officials at all times.
If a qualified international commissaire is appointed by the Race Organisers as the Chief Commissaire, they will have absolute authority in ruling on infringements, having taken advice from the organisers, race director, medical staff, time-keepers and course marshals. The Chief Commissaire may impose penalties ranging from a warning, a fine, removal of a lap through to disqualification. The Chief Commissaire’s decisions are final and cannot be appealed.
In the absence of a qualified international commissaire appointed by the Race Organisers, the functions of the Chief Commissaire will be performed by the Race Director with the same level of authority.
The nominal time for race start is 1200 on Saturday.
Depending on entry numbers, the Elite categories may start first, followed by the age-group and single speed categories 10 to 15 minutes later. The official start time for the 24 hour period will be from when the Elite categories start.
The ranking of riders within categories, the assignment of race numbers, and their position on the start grid is at the sole discretion of the WEMBO.
Riders should be prepared to start with a short “Le-Mans” run to an area where their helpers are holding their bikes from behind barricades. No personnel other than riders are allowed on this part of the course. Riders must wear their bike helmets during the Le-Mans run. Depending on entry numbers and the layout of the event centre, a riding start (traditional XCO start method) may be used. The final decision on the start method is advised to the riders at the race brief.
The race finishes for all categories 24 hours from the official start time of the Elite Category. At that point, the course will be closed and no more riders will be allowed to commence a lap. This time is measured at the race finish line.
Any rider who completes 1 lap will appear in the results as a finisher.
A lap which is commenced before the 24 hours have elapsed, but is completed after 24 hours and before 25 hours, will be counted towards the rider’s results. A lap completed after 25 hours of race time will not be counted towards the rider’s results.
The minimum age for entering the event is 18. A rider's age is calculated on 31 December of the year that the race is held. Rider's entering age categories will be required to produce a photo ID at registration showing date of birth at registration.
A rider can only enter one category in the race.
Printed start lists will be displayed at Registration and will also be available online. A start list will be published at the close of Registration on the Friday before the race, and will be available at the Race Brief. Riders have 30 minutes after conclusion of the Race Brief to advise the Race Director of any changes. After that time, no changes to the starting list, by rider or category, are permitted.
Pausing or Abandoning the Race
The race may be paused or abandoned due to extreme weather, emergencies or any other reason decided by the organiser or Chief Commissaire. If the race is paused, all riders must complete the lap they are on and their time and laps will be recorded. If the race is then abandoned, that will determine the final placings. If the race is resumed at a later time, then the riders will be started on their lap in a staggered start method, so that each rider has the same time off the bike due to the pause and there is no unfair advantage gained. Riders who were in the pit row when the race was paused, will be started with the first rider when the race is resumed.
There will be no refunds or other considerations if the race is paused or abandoned.
Within each category, the rider who has completed the most laps is the winner. For riders on the same number of laps, the rider who has completed them in the shortest total race time will receive the higher placing.
The WEMBO World Champion title will only be awarded to the winners of the Elite Category (Male and Female) even if a rider from another age or single-speed category comes in ahead of them. The Elite categories are open to all riders aged 18 and above.
Progress results will be published at regular intervals throughout the race. The method will be advised by the race organiser leading up to the race and in the rider brief.
Provisional final results will be published at 1415 on Sunday. There is then a 15 minute period open for protests. If no protests are received, or on completion of the protest hearings, final results will be published.
A protest must be submitted as soon as possible after the alleged offence. The final time for submission of protests is 15 minutes after the provisional results are posted after the race finishes. Protest must be accompanied by a $50 / 40 Euro / 30GBP protest fee, which will be refunded if the protest is upheld.
Protests can only be submitted by riders, registered rider helpers or event staff.
Protest forms will be available during the race from the Race Director.
The Elite Male and Female winners will be presented to the crowd and media at the event at 1430 on Sunday. The official presentations and awards ceremony/dinner for all categories will be held on Sunday evening at 1900. Podium riders must be present in order to receive their prizes unless they are prevented by a medical condition authorised by the event medical staff.
The winners of the Elite Male and Female categories are required to be available for media interviews and to sign jerseys for sponsors and organisers.
Bikes and Equipment
Your bike must conform to the UCI general rules for mountain bike racing.
You are allowed to use any number of spare/replacement bikes in the race and you will be provided with 2 copies of your bike numbers at registration. Bike changes can only be made in the Solo Rider pit area. A rider cannot exchange bikes with another rider while on the course.
Single Speed category riders are permitted to have a different gear ratio on their spare bike(s).
26”, 29” or 650B mountain bike wheels and mountain bikes are the only style of bikes/equipment to be ridden in the race. No other type of bike is allowed, including flat bar road bikes or touring bikes with road type bars. Expressly forbidden are road and cyclo-cross bikes and unicycles. The minimum tyre width allowed is 1.6”. Front suspension is recommended but not compulsory. Bar ends are allowed but only on the ends of the bar. Triathlon style aero-bars are forbidden.
International Standards approved bicycle helmets must be worn at all times while riding a bike during competition and practice. The following helmets are accepted: AS/NZ 2063, ANSI Z90.4, SNELL B or N Series, ASTM F-1447, CAN/CSA-D113.2-M, US CPSC standard for bicycle helmets, European CEN standard EN1078. Failure to meet this requirement may result in immediate disqualification from the event. Damaged helmets must be replaced. Skate style helmets are not approved for this race. The mounting bracket for a helmet-mounted camera must not compromise the structure of the helmet. For example, it can be attached by straps, velcro or glue - but it cannot be bolted to the helmet.
Attaching Your Bike Number Plate
Attach your bike number to the front of your bike using at least 3 ties, securely fastening it to the handle bar and ensuring that can be easily seen from the front. Your number should be in front of the brake cables and not wrapped around any part of the bike.
The number cannot be altered, obscured, cut or de-faced.
Each rider will receive 2 front number plates and 2 smaller rear number plates. The rear number plate can be attached to either the rider’s clothing/backback or the bike but it must be visible from behind.
Elite, Age-Group and Single Speed category riders will each have specific number-ranges and colours to permit easy identification on course.
At night, you must have a red rear flashing light, a white front light minimum 5W halogen equivalent, plus a spare white light (this can be a second front light, head lamp or a small torch). You will be advised during the race briefing what time you must have lights fitted, and your helpers will be reminded throughout Saturday afternoon by public address announcements and signage in the helper area.
Please note that because of the different locations around the world, the period of twilight may not be as long as you are used to in your home country.
Carrying Items During the Race
iPods or other musical playing devices are not permitted for riders while on course.
Riders are permitted to carry mobile phones or 2-way radios on course, but these must not use earpieces, and the riders must stop and pull off the course when they are using them.
Riders are allowed to wear helmet cameras, fitted either to their helmet, body or bike, in practice and during the race. The mounting bracket for a helmet-mounted camera must not compromise the structure of the helmet. For example, it can be attached by straps, velcro or glue - but it cannot be bolted to the helmet.
Riders need to be prepared for drug testing by the national anti-doping agency of the host country of the race. Chaperones and escorts will be provided by the organizer. The top 10 men and top 5 women can expect to be tested however additional riders may be chosen at the sole discretion of the national anti-doping agency. The race numbers of riders to be tested will be published on a board at the finish line from 1200 to 1415 on Sunday. If a selected rider does not present for testing, they will be disqualified.
The course will be marked by arrows, signs and bunting/tape. Riders must follow the course and it is the sole responsibility of the rider to stay on the course.
A rider who leaves the course for any reason must return to that same point on the course to resume a lap.
While on course you must keep going in the direction of the course. If you have a mechanical problem, you cannot retrace your path to get to an assistance area. If you do so, that lap will be not be counted.
The Solo Pit Row Area
The Solo Pit Row Area is part of the course. All riders must pass through it every lap. It will be designed so that all riders travel the same distance to go through it. Each rider will be allocated a 3m x 3m space where they can place their own support tent or hire a tent from the organisers. All tent fittings, including ropes and pegs, must be within the allocated area. Access to the Solo Pit Row Area is by pass, which will only be given to riders, helpers (maximum 3 per rider), officials and media.
The rider can only receive assistance from their helpers inside or directly in front of their allocated pit area, keeping the course clear. There will be a 1.5 metre "clear zone" in front of each 3m x 3m Solo Pit Row area. This must be kept clear of tents and other items. If a rider needs to stop to collect any items, or to have work done on their bike, then they must pull off the course in the Solo Pit Row area and into this clear zone. Riders must not stop on the course in the Solo Pit Row and obstruct other riders.
All Solo 24Hr riders must have nominated a helper who will be at the race site and who can be contacted by mobile phone (provision of this information is part of your online entry). One helper can support a maximum of 3 riders. A helper must not assist a rider, other than their own, in the solo pit area. A helper must not interfere or obstruct another rider, or hinder the provision of support to another rider.
When in the Solo Pit area, helpers must be stationary while providing support to riders who are moving. For example, they must be standing still while holding a bottle for their rider to pick up as they ride past (normal XCO Feed-Zone rules).
The rider is responsible for the actions of their helper(s) during the race. The actions of a helper, including verbal abuse of another rider, may result in penalties being applied to their rider.
Depending on the length of the lap and number of riders entered, the organisers may provide neutral feed and mechanical support zones on the course. Helper(s) can take items to these zones and leave them there for their riders to collect.
If a neutral mechanical support zone is provided, then the rider can conduct work on their bike in that zone but they cannot receive assistance from their helper(s) or other non-riding personnel.
If a neutral feed/drink zone is provided, then the rider may stop and collect items from that area. Helper(s) can be at the area but cannot pass items to riders nor make physical contact with riders.
The location and type of neutral zones will appear on course maps and be briefed at the rider brief.
Mechanical assistance during the race (repair and material) can be provided from other riders entered in the race while on-course however there is no obligation on a rider to help another rider. Outside assistance on-course from helpers or spectators is not permitted.
The Solo Rider pit area is the only area where riders can receive mechanical assistance from their supporters and non-riding personnel. Helpers may remove bikes from the Solo Rider pit area for servicing at the race facilities, then return them to the pit area.
If you have a mechanical problem and continue to walk your bike along the course to the end of the lap, then that lap will be counted. If you shortcut the course to return to the start or are assisted back to the start, then that lap will not be counted and you must commence a new lap from the start when you are ready.
Withdrawing From the Race
A rider may withdraw from the race at any time. If they choose to withdraw, they must notify the event staff at the timing tent. A rider who withdraws is not allowed to rejoin or resume the race. They must remove their race numbers and cannot ride on the course for the remainder of the event. If they have completed at least one lap, they will be awarded a race result.
Taking an Extended Rest Break
If a rider wishes to take an extended rest (more than 1 hour off the course) before resuming the race, the rider or their helper must advise the timing staff so that lost-rider procedures are not instigated when they fail to come through timing at the expected time. There is no requirement to advise the timing staff when they resume the race.
Medical Assessment and Assistance
General first aid care during the race is provided by members of the official medical services, from the moment riders enter the starting area until they leave the finishing area. Interventions during the race can only be carried out in a stationery position. Riders must dismount from their bikes to receive medical assistance.
If you are injured and assisted back to the event centre, then your lap will not count. Following treatment, the Chief Commissaire will make a decision on whether you are allowed to continue the race, based on available medical advice. The Chief Commissaire’s decision is final and non-appealable.
The Chief Commissaire may remove a rider from the course for assessment if in the Chief Commissaire's opinion the rider is showing signs of extreme fatigue or other condition which may be detrimental to the rider or to other riders in the race. Following medical assessment, the Chief Commissaire will either:
allow the rider to resume racing,
mandate a rest period before the rider can resume the race, or
withdraw the rider from the race.
This decision is the sole responsibility of the Chief Commissaire and is non-appealable. There will be no compensation for the rider for the time taken for the assessment process.
Drafting / Collusion
Riders are not permitted to draft from or be drafted by a rider of the opposite sex.
Riders who break the drafting rules will receive one warning from the Chief Commissaire. One lap will be removed from their race tally for each subsequent warning they receive during the race.
A rider cannot enter the race with the purpose of helping another rider. For example, if a rider rode 3 laps then took a 10 hour rest, then resumed the race but was ruled to be drafting, pacing or assisting a rider who had been riding continuously, then both riders would be disqualified.
Right-of-Way, Passing and Being Passed
A rider walking their bike must give way to a rider who is riding. If you are walking your bike, make sure you leave plenty of open track for the other riders.
The rider being overtaken has right-of-way (unless they are walking their bike) until the overtaking rider is past and clear by one bike length.
If you want to pass the rider in front on single track, call out “TRACK”.
When the rider in front feels it is safe to pass, they will pull over to one side and call “PASS”. They may also call out “ON MY LEFT / ON MY RIGHT”.
Let the rider in front know what you are doing by calling “ON YOUR LEFT / ON YOUR RIGHT”. If there will be more than one rider passing, let the rider in front know that as you pass them by calling, for example, “TWO MORE COMING THROUGH”.
If you do not make this call, the rider in front will assume you have decided not to pass and will return to the centre of the track.
The rider in front is under no obligation to let you pass, but slower riders and lapped riders should not delay faster riders unless it is unsafe to let them pass. Remember, if you are the overtaking rider, the conditions you feel are safe may not be considered safe by the rider you want to overtake. They may be less experienced than you, or they may have seen something on the track that you have not.
Overtaking is not allowed on bridges or constructed ramps.