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Removing the limitation to bike parks

I changed the limitation of the IMBA scale from "bike parks only" to "for mountain bike trails". This is deliberatly diverging from the original propsal. The IMBA scale was designed to classify all MTB trails regardless if they are located in a bike park or not. The scale used in mtb:scale is a legacy of the german "Singletrail Skala" (STS). The STS is fine to classify (alpine) hiking trails for MTB use leaning more towards the trial part of the sport ("Stolperbiken" for all the german speakers out there). It is not suitable to describe difficulty of current dedicated MTB trails (as primarily used with Trail Bikes and Enduros) . The STS is focus is on steepness and switchbacks. E.g: difficulty is defined if you have to perform stoppies over switchbacks, a situation which a more recent MTB trail will not have, even if it's an extremly diffcult trail.

The IMBA scales focuses much more on 1) trail width 2) height of (unavoidable) obstacles and gives clear indication of 3) maximum and average trail grades Opadeira (talk) 14:15, 21 April 2020 (UTC)

Since this was a discussed, approved tag which has been used in a particular way for several years, please make a new proposal (see Proposal process) if you want to make a major change to the definition, and discuss it on the Tagging mailing list. --Jeisenbe (talk) 07:20, 22 April 2020 (UTC)
Tangential to this we also need to say if mtb:scale:imba should only be set where the trail has a signposted or officially designated IMBA rating or if I'm able to make my own take on the IMBA scale would be. --Aharvey (talk) 08:45, 22 April 2020 (UTC)
The IMBA scale is not even translated to any other language besides English. Even on the OSM wiki there is no translation of it. But yes it definitely applies well to most purpose built mountainbike trails - if you like to foster the use go ahead and properly translate the IMBA scale first into more languages. And the STS is not focussing on just switchbacks or very steep trails. I see no advantage at all for natural trails to use IMBA scale over mtb:scale (STS). However it's true that mtb:scale is poorly adapted to purpose built mtb trails - IMBA scale is a bit better - however also not adapted to modern trailbuilding. For many things you will still have to take a guess into which IMBA difficulty this falls.--Extremecarver (talk) 10:22, 13 May 2020 (UTC)
Wouldn't this be a universal issue to all tags following established standards. -- Kovposch (talk) 21:18, 22 April 2020 (UTC)
I guess it would. It depends if the tag is defined as the assigned IMBA rating in which case we must map according to signposted IMBA rating, or if it's defined by the criteria for each rating then we can make an assessment independent of the officially designated IMBA scale and assign a value even when not signposted. Either way this page is not clear which is intended. --Aharvey (talk) 23:49, 22 April 2020 (UTC)

I agree with what user Opadeira is doing. The approved tags, mtb:scale, and mtb:scale:imba are poorly defined. They were proposed and discussed 11 years ago and probably not reviewed by anyone outside of Europe. Contributors are using common sense instead of the wiki. --Bradrh (talk) 15:34, 23 April 2020 (UTC)

I propose that the opening paragraph be changed to:

The Trail Difficulty Rating System shall be used for trails which are used by mountain bikes. For extremely steep trails, gradients greater than 20%, the mtb:scale may be more appropriate.

This key was never properly vetted and doesn't make sense as it stands. The imba scale was not created only for bike parks, and has been informally adopted by most mtb orgainizations and land managers for rating the trails in North America. Most maps show a green/blue/black/doubleBlack trail rating. The mtb:scale tag is the STS scale and appears to be relevant for extremely steep terrain and is not used in North America, and probably not much outside of Europe. I also think mtb:scale should be changed to mtb:scale:STS, but I don't want to fight that battle. --Bradrh (talk) 15:38, 9 May 2020 (UTC)

I also agree with suggestions by Opadeira and Bradrh. There may be users who review this wiki and decide not to apply an IMBA rating tag even if this system is widely used in their region (not just in bike parks). Because of the wiki, they may instead opt to apply the mtb:scale tag even though they are unfamiliar with this rating system and it isn't used in their region. Ideally, the tagging system would be changed to encourage users to apply the rating system used in their region rather than attempting to conform to a system (STS) which isn't very applicable for common trails anyway. So I would also prefer mtb:scale:STS in place of mtb:scale, but an overhaul like this seams unlikely at this point. Also, the IMBA system seems to be widely used in Australia, and a slight variant of it (Kennett Brothers rating) is used in New Zealand. --FevetS (talk) 15:05, 10 May 2020 (UTC)
I support thesuggestion to change the opening paragraph. Also I can confirm for Europe that IMBA is the most common standard for classification of trails. I'd support the adaption of IMBA for mtb:scale. Opadeira (talk) 06:10, 11 May 2020 (UTC)
I have not seen anywhere in the Alps that IMBA is used as a reference for rating mtb trails. Bikeparks do label their trails like skislopes - but each park has it's own rating criteria - and a lot is marketing based - trying to show that everyone can have fun and challenge. A black trail in non mountainous regions would often not even be a red trail in a bikepark of Switzerland or France.. Yes mtb:scale is more complicated - but it has to because it tries to be objective and not subjective.--Extremecarver (talk) 10:02, 13 May 2020 (UTC)
I strongly disagree. The suggestion of Bradrh to limit mtb:scale to "extremely steep trails, gradients greater than 20%" to my impression is more or less arbitrary. According to taginfo mtb:scale and mtb:scale:imba are used worldwide with a similar distribution, where mtb:scale with more than 500k entries is about 15 times more commonly used than mtb:scale:imba. The change to a widely used definition would have to be discussed and agreed on a broader scale like on the Tagging mailing list as already mentioned above by Jeisenbe. IMHO mtb:scale:imba should only be used if purposely build manmade elements like berms or jumps exist and not on generic, "natural" paths. --geow (talk) 09:53, 12 May 2020 (UTC)
It was discussed on the tagging mailing list April 22. I didn't see any comments from Geow. The last comment was mine and no one disagreed. 20% is arbitrary, I put that in because the wiki for mtb:scale mentions mentions 40% as if that is realistic. There is no rational reason for mtb:scale:IMBA to be limited to a man made trail.--Bradrh (talk) 16:09, 12 May 2020 (UTC)
Well, the discussion on the tagging list was not that specific, to sum it up: There were 7 posts total, from 5 participants. You have changed your mind from deprecate mtb:scale:imba to replace mtb:scale by mtb:scale imba. I would not consider the contributions of the other 4 participants as a vote for a justified change of the definition of mtb:scale. But I think we agree that mtb:scale:imba should be used for all officially signposted or designated IMBA-trails or trails with corresponding features. There are certainly trails where it makes sense to use both systems in combination. And in the Alps where I mainly cycle and map, it is definitely necessary not to forget mtb:scale:uphill. --geow (talk) 21:23, 12 May 2020 (UTC)
I see and accept your point about mtb:scale beeing more used than mtb:scale:imba and agree with you that we should not "jettison" mtb:scale. But I suggest that mtb:scale:imba should not be limited to "officially signposted" trails, much less for IMBA-trails only (which would limit mtb:scale:imba to the US only). It should be used for all trails (natural or purpose-built) where MTBs are used. There are many unofficcial MTB trails with no signposts at all that should be accounted for in OSM (especially in the Alps, e.g: Austria where I map). Opadeira (talk) 07:38, 13 May 2020 (UTC)
Yes I did change my mind, the best solution would be one scale, like the IMBA scale. The trails in North American are almost universally rated Green/Blue, etc like ski areas, by a local club or the land manager. The next best solution, since we're not starting from scratch and the STS scale has a lot of history here, is to use the IMBA scale appropriately. The uphill difficulty can be determined from the grade & the imba scale, it's redundant.
The discussion was on the tag list, and was also here. There are 3 in favor, you seem to be the only one opposed. You seem to be agreeing now, are you going to revert your revert? I'm not going to get into a wiki edit war. I'd like to see some logic in this tag, but OSM is inferior to other tools currently out there for mtb trail difficulty rating & it will never catch up until there is a redesign & dumping the worthless STS scale. Even though mtn biking has been my main hobby for many years, & I think OSM is important and worth contributing too, this piece is so messed up & isn't that important to me that I won't spend any more time on it.
PS: I mainly cycle and map in the Rocky Mtns, where the mtn biking is much better than it is in the Alps :) --Bradrh (talk) 02:28, 13 May 2020 (UTC)
I agree. The STS scale provides little to no information about trails for current state of mountainbiking. It's a reason why sites like trailforks are much more predominant in mountainbiking. Opadeira (talk) 07:54, 13 May 2020 (UTC)
As one of the original creators of the mtb:scale and mtb:scale:uphill - I strongly disagree to make mtb:scale:imba the default. Besides mtbiking all over Europe - I have also been mtbiking in USA and Canada. I agree that the STS based mtb:scale is not that easy to understand - but it is way more objective and applicable to all kind of trails. And yes a simple blue/red/black system would be appealing to many people - but this would end up the same as with skislopes - in a really subjective system where each country or area has it's own definition of what is what. In Europe very few people have any idea about how to apply IMBA scale. Your rant is completely out of scale. Many people will disagree that mtbiking in US or Canada is any better than in Europe or in the Alps (have fun in your enclaves/refugee camps as you cannot just bike where you like - even worse than in Austria). And OSM will always be inferior to specialised databases because it is more complicated and objectivity makes it hard to showcase good trails. So Strava or Trailforks will have a big edge here - because OSM cannot use data like they do. That is the same for automobile use. OSM is not designed to compete with google maps in any way. However OSM is still needed for Strava or Trailforks to provide a base. You cannot just change mtb:scale to something new - it is widely used and any change will only cause confusion. I do agree that since mtb:scale was written - many things related to mtbiking have changed. So in Europe bikeparks, flowtrails and any kind of purpose built trails for mtbiking have become a lot more widespread - and yes mtb:scale has no reference to berms, to jumps, to north shore elements or other purpose build features. If you want people to grade according to IMBA scale - then lobby editors to include a preset. the key does not matter much. --Extremecarver (talk) 10:02, 13 May 2020 (UTC)
My comment about rcky mtns vs alps was meant as a joke --Bradrh (talk) 18:33, 13 May 2020 (UTC)

Removing "this applies for instance to North Shore"

I suggest to remove the addition of "this applies for instance to North Shore" in the sentence "The Trail Difficulty Rating System shall be used for bikeparks, this applies for instance to North Shore" It's nonsenical. Opadeira (talk) 14:15, 21 April 2020 (UTC)

I believe "North Shore" is a local mountain bike park / trail system which was known to the creator of the proposal, but you are right that it doesn't make sense for a global definition. Feel free to remove it, or alternatively add examples from around the world in a separate place, later in the article. --Jeisenbe (talk) 07:18, 22 April 2020 (UTC)
Agreed, it adds to confusion for a global tagging scheme as most people in the world won't know what this means or is talking about. --Aharvey (talk) 08:42, 22 April 2020 (UTC)
North Shore referred to North Shore style elements - not to Vancouver North Shore. But yes - removing it is okay. --Extremecarver (talk) 10:02, 13 May 2020 (UTC)

removing " It is adapted to MTB trails with artificial obstacles."

I suggest to remove the sentence "It is adapted to MTB trails with artificial obstacles". As the IMBA rating is not adapted to MTB trails with artificial obstacles Opadeira (talk) 14:15, 21 April 2020 (UTC)

This was part of the original proposal and has been part of the definition for several years. --Jeisenbe (talk) 07:20, 22 April 2020 (UTC)
It is also widely ignored. His suggestion makes sense. --Bradrh (talk) 15:35, 23 April 2020 (UTC)
I think it should be changed to it is adapted to purpose built mtb trails. Because the IMBA scale is really unusable when it comes to rating hiking trails. The amount of people mtbiking in North America vs Europe is pretty small. In USA/Canada you mainly bike on purpose built trails - and actually I've never felt the need for a map there anyhow - because everything is signposted. On the other hand you usually cannot even ride in national parks (e.g. Yellowstone) and hiking trails are off limit. Also in the US riding on hiking trails the current mtb:scale is much better adapted than the IMBA scale - it's just that in most parts of the US you simply cannot ride on hiking trails.--Extremecarver (talk) 10:02, 13 May 2020 (UTC)
I disagree. I think the IMBA scale is highly suitable to classify hiking trails for MTB use Opadeira (talk) 10:27, 14 May 2020 (UTC)
Extremecarver, what you are saying is simply not true. Mountain biking is not allowed national parks in the US, but most trails in other areas (e.g. national forests, state or county parks) are multi-use. IMBA is the common mountain biking difficulty rating on these multi-use trails, even if they are not purpose built for mountain biking and contain no artificial obstacles. --FevetS (talk) 18:41, 17 May 2020 (UTC)

Problems of IMBA scale

While I understand many people may prefer this over the STS based mtb:scale - there are many problems.

1. Width - does not say much about difficulty at all - as long as you can't fall down. Not clear how this is meant.
2. Gradient - different values, but on it's own it is pretty useless.
3. While IMBA focuses more on obstacles - especially in North America it's usually always possible to circumvent the obstacles/jumps/drops. The rating in bikeparks is usually based on the (often manmade) obstacles even though you can avoid them. This is actually a bigger problem for the IMBA scale then the mtb:scale. In the mtb:scale we assumed to base the difficulty on the easiest line without leaving the trail (e.g. shortcutting bends) - in the IMBA rating it is usually based on the standard line (whatever that is) but never on a "chickenway".
4. No translation into any languages other than English
5. Unavoidable bridges - I don't understand what the authors meant by this. It can only be assumed to be about north shore elements - however it does not say anything about the height of bridges. In reality the rating in bikeparks will be based on a combination of width of the element and height. Many easy lines have already low height elements that are less than 600mm wide.
6. Avoidable Elements may be present. This phrase is on any level except easiest. Doesn't make sense. It should be the opposite to write for easiest - no obstacles instead.
7. Does not include any other man made features but obstacles (undefined), bridges (strangely defined) and a strange definition of unavoidable obstacles (what is a drop?).
8. It is not based on any skillset that you need to know to master a trail - even though in most places the actual rating will reflect it.

So it's actual objectivity is really really low. Much lower than mtb:scale. It's advantage is that it includes verbal notes like easiest, easy, more difficult, very difficult and extremely difficult. There was a discussion when creating mtb:scale to do so as well - however it was agreed to drop it - because it is just subjective and not objective. Actually applying IMBA scale to bikepark trails / manmade trails would put even some easy ones into the extremely difficult section. Not having objectivity makes it easier to relate to and adaptable. It is against OSM philosophy of mapping what's on the ground/objective criteria however. For a bikepark / a region / a trailcenter - I agree it is more useful to classify ways based on easy to very difficult - and just have some experienced people classify the ways into these categories. For OSM however we need a set of objective rules - that can be applied globally - and IMBA scale really fails here. I do agree that mtb:scale is lacking - and should be improved. We should use videos plus photos to describe the difficulty. We need to decide/clarify what objective we use when we rate a purpose built MTB trail - do we base the rating on the obstacles or on the chickenline. There is a big conflict here - if you can avoid any difficult places (this is common) - then rating the chickenway will be detrimental to everyone looking for fun on that trail. On the other hand if we rate it accordingly to the normal line including jumps, drops and so on, and someone uses the map for getting from A to B, he may decide against using this way but could have done so if we rate it accordingly to the chickenline.

On the other hand we should create a new tag to describe purpose built difficulties - like north shore elements, drops, obstacles, wallrides and so on - based on the common line choice - and maybe a warning tag if very dangerous places cannot be avoided (e.g. a gap/roadgap that is part of the line without a chickenway - this usually doesn't exist in North America due to liability - but does exist in Europe in some places). However who would actually use that tag? In bikeparks we don't need a map - OSM can hardly enter the data so that a purpose built map based on a lot of common knowledge but less objective criteria for rating - can be replaced. My ideal would be - add some clarification to the mtb:scale. Include some short videos showing trails from 0-5. Don't include anything purpose built into it and always base it on the chickenline (except if we start micromapping and also map the chickenway too). Then improve on the IMBA scale including bikepark features/ manmade features - clarify the rating is relative ot the area and not in general. Clarify that the rating is never based on the chickenway but always based on the most common line (e.g. one huge drop/jump in a difficult line -that 80-90% of users avoid - should not put this way into extremely difficult, but a feature 50% of bikers clear - should be) and clearly state this to be an additional rating. mtb:scale should continue to be the main system for classifying "hiking trails" used for mtbiking - the new scale on the other hand should be for purpose built mtb trails.--Extremecarver (talk) 11:44, 13 May 2020 (UTC)

I agree that the STS has value to classify (alpine) hiking trails and we should use it for this. The problem with STS is it contains little to no usable information about MTB trail difficulty. Take a look at the UCI World Cup Downhill tracks (e.g: Maribor, Mt. St. Anne etc.) or Stages from the Enduro World Series (e.g: Finale Ligure) ore even XCO (e.g: Nove Mesto). They are very difficult trails. But because of the total absence of any switchbacks, tight corners and lack of gradient most of them would just about make it STS S2. Still I would discourage any beginner to tackle Mt. St. Anne DH Track. IMBA would (correctly) classify it at Level 4/difficult/black diamond or 5/very difficult/double black diamond. It's becasue the scale was built for MTB trails.
Also I don't understand the relevance of "purpose built" obstacles/trails or not. A hard rock garden ending in a 2m drop is going to be of a certain difficulty, no matter if it was created using north shores or by including natural features of the landscape. A trail will provide a certain difficulty, no matter if it was built top to bottom or just "grew" into being a MTB trail.
As I experience it, because of the lack of applicability to MTB trails, the current use of mtb:scale in praxis is using only (!) the qualitative definitions (e.g: easiest, difficult etc.) and not the full STS definition. Opadeira (talk) 10:40, 14 May 2020 (UTC)
The thing is - there is some sort of rating that is widely used - and it's similar to IMBA scale. However it's not defined and varies from place to place or region to region. If you read through the IMBA scale - it is also not at all adapted to current mtbiking trails. Right now subjectively rating a trail works out much better than using either STS or IMBA - and if you drop the steepness part then actually STS is still more applicable. I would lobby for a completely new scale - that is a little less objective, and rather based on subjective difficulty - and maybe use well known trails as example for the rating. There is however of course on problem remaining - and that is skillset. I know many skilled DH riders - who will excel on jumps and drops, or very steep straight lines, they fail to get through tight corners however, they cannot right exposed or very loose steep trails and so on. Basically mtb:scale=4 & 5 they cannot ride it. On the other hand I know many skilled riders who excel on tight trails, who have no problems with really steep stuff, not afraid of riding super exposed stuff (easy via ferrata) - but will not go over any drop higher 1m, no jump over 3-4m and so on. Very different mindset and focus. For less skilled riders this separation is even bigger. So I would maybe diverge the scale from level 3-5 separating into bikepark scale and natural scale (with difficult DH tracks like Champery or Nordkette Innsbruck somehow in between). If you strictly follow the IMBA rules - the rating of trails will not reflect the current rating. (BTW - besides doing a lot of vertriding I am also a certified Freeride bikepark guide - so I do know my shit about biking and used to theory behind it. From that standpoint the IMBA rating sheet really sucks, and STS is outdated and too focussed on hiking trails. With common sense both are okay - but not good. And a 2m drop in a bikepark is not comparable to a 2m drop on a natural trail. First in a bikepark you know it has been made for it, the runout is long enough, the landing is okay, and so on. There are very very few 2m drops on normal trails that are rideable at all. Often a 1m drop becomes impossible - because you cannot look at the drop ignoring the surrounding. And that is a problem that any scale that focuses on features will face. If you ever ride a bikepark in Canada or US-e..g Whistler - with decent skills you can just ride down anything without ever footwalking it. Dangerous features are even roped of and only open for events. Things are built very safely. In european parks on blacks/doubleblacks this is not so true anymore (e.g. some dangerous gaps), and on natural trails you will have to walk things many times - find a line, thing about safe exits and so on. Same as with indoor climbing vs outdoor rockclimbing (especially if the route outdoors is not popular or known) --Extremecarver (talk) 10:47, 14 May 2020 (UTC)
"I would lobby for a completely new scale - that is a little less objective, and rather based on subjective difficulty" I think this makes the most sense, or tweaking one of the current keys this way. I view this IMBA key as basically this. It's impossible to rate all mtb trails objectively. We should adopt the green/blue/etc ratings that are already widespread, and we do not need to reinvent anything. Local mtb clubs have already rated their local trails, or there are crowd sourced ratings from popular apps. I don't see any value added to having a different tag for natural vs bike parks. It's subjective and will be different depending on the locale. That's just the way it is. --Bradrh (talk) 01:49, 15 May 2020 (UTC)
Assuming the same run-in and -out difficulty a feature (e.g: drop) is most definetly comparable from natural to purpose built (e.g: bikepark). In your example you assume different difficulties a priori. In interesting coincidence one of the place you list as "I have contributed to", namely Anninger, Moedling, features a perfectly natural 2.5 meter drop with an ideal run-in and runout setup (48.06846,16.24017). Opadeira (talk) 11:51, 14 May 2020 (UTC)
The thing is - usually outside of bikeparks run in and run out are much worse. On the Anninger - where is the good 2.5m drop? I know exactly one - Jump down from the Husarentempel into the flat. I only know of one rider who did that on a DH bike and that was really sketchy. that is basically a 2.5m drop to flat - and you can't do it high speed, because the run out is like 10m long only. But it doesn't really matter - both IMBA and STS only describe features on their own - not in succession. That is a real problem.--Extremecarver (talk) 12:02, 14 May 2020 (UTC)
I provided the exact coordinates (not Husarentempel).
My point about irrelevance of "purpose built" to natural still stands. Opadeira (talk) 12:24, 14 May 2020 (UTC)

Rewording "mountain bike trails which which are specifically designed and designated for mountain biking"

I propose to change the above mentioned sentence to "trails which which are primarily used for mountain biking". It would make the tag applicable to MTB-trails without taking into account how they were created (as there are many MTB trails that are not purpose built, but are still MTB trails).

I support this amendment. At least in North America, IMBA is the commonly used designation of mountain biking difficulty on multi-use trails, not just purpose built trails. One only needs to look at popular mountain biking websites such as Trailforks or MTBproject to see that this is the case. --FevetS (talk) 13:45, 18 May 2020 (UTC)
I support this also. --Bradrh (talk) 14:14, 18 May 2020 (UTC)