Mountain Bike Park

Design and Specifications

Rabbit Hill

Aberfoyle, Stirlingshire

Part of Loch Lomond and Trossachs NP

Document produced Bike Trosssachs with material supplied By:

Tom Durham, Collective Trax

Contents:

1. Project Overview

2. Track Construction Overview

3. Track Drainage

4. Track Signage

5. Enclosure Fencing

6.

Collective Trax – Background

Collective Trax was formed in 2012 as a trading division of Collective Training Ltd following an increased demand for help with developing mountain biking facilities. Run by Tom Durham, Collective Trax has completed several projects of different types including construction of large permanent facilities similar to this proposal for Bike Trossachs. Also portable modular bike tracks for schools and small scale tracks for young children.

Tom blends his insight from being a mountain bike guide and coach with his several years of experience as a ground worker to identify what type of facility is best for your situation. He prides himself on producing a design that will be inclusive, progressive and above all fun to ride.

As well as producing design documents such as this one he can also project manage the construction phase, ensuring that his designs are brought to life and give the best possible experience for the end users and the client.

As a founder member and chairperson of the Scottish Mountain Bike Consortium (SMBC), Tom can draw on a variety of skills from within the SMBC to provide complete facility solutions. Packages can include items such as signage, hire bikes and workshop, events organisation, etc all being possible components of your package.

1. Project Overview

Bike Trossachs, represented by Sandy Slater have asked for a design and construction specification to be produced for their bike park project at Rabbit Hill in Aberfoyle. This follows an initial consultation with Collective Trax and a subsequent community consultation carried out over approximately 3 months from November 2012 – February 2013.

Aberfoyle lies within the boundary of Loch Lomond and Trossachs National Park (LLTNP), along with the neighbouring community of Callander, the Aberfoyle community are looking to improve outdoor activity infrastructure for both the local community and visitors alike. Cycling forms a large part of the envisaged plan and Bike Trossachs are coordinating work on small scale projects in the area with the backing of LLTNP. (See LLTNP Outdoor Recreation Plan, sections: 2.9.5, 2.11.3, 3.5.1)

Within the local community of Aberfoyle there is already an active interest in all forms of cycling. Pupils at Aberfoyle Primary School have been taking part in Bike Ability training and a logical next step for them is to learn to ride off road as well in a safe and progressive environment. The proposed Rabbit Hill site sits adjacent to National Cycle Route 7 which currently runs from Carlisle to Inverness and links Aberfoyle and Callander, bringing many cycling tourists to the area.

1.1 Envisaged Track Description

The design of the track will be very important in ensuring that confident riders and novices will enjoy using it and want to return. With this in mind, a well surfaced and drained track is very important, as is a track that provides a fun ride; that can be proactively ridden as riders gain experience to increase the challenge and enjoyment. The proposed site at Rabbit Hill has two faces, sloping away from a central high point. This allows for different styles of track to be built on each side of the hill, increasing the capacity within a small area and allowing for a variety of different track types, providing a progression for the rider. For the purposes of this document, the two distinct areas will be labelled ‘East’ and ‘West’ to avoid confusion. Each area will have a 2 way access trail from the NCR 7 cycle path and there will be a two way linking trail between the two areas at the top of the hill approximately 40 metres in length.

A glossary of example Technical Trail Features (TTF’s) and other features is found at the end of this document.

1.1.1 East Area

Access to the East area will be from a specific bike park access point on NCR 7 adjacent to the existing informal footpath as shown in the example illustration below. This will feed into the uphill trail with a pinch point to control speed, and signage warning riders on the access trail to give way to those riding the blue trail or arriving from the Skills Area, all detailed below.

This area has a mostly constant gradient of approximately 10° with a steeper top section of approx 15°. It is a fairly wide slope approximately: W 40m x L 60m. There are a few mixed bushes and trees along the Northern perimeter bordering the cycle path NCR 7. At present there is an informal footpath trodden into the grass near the foot of the slope, represented by the dashed line in the illustration. The best solution for this project would be to re-locate this path further down the hill by 10m. This would give a much increased area for this part of the bike park, particularly the Skills Area detailed below, whilst keeping the foot path above the floodplain. When designing the layout of the bike park I have assumed that this is the case and the slope length is an average of 70m.

The main track in this area will be a flowing trail of approximately 250m metres (including return trail) which will wind its way down the hill, making as much of the space as possible. Using the Forestry Commission’s cross country trail grading system, this trail will be graded as ‘Blue’. In simple terms, this means that a novice will enjoy riding the track and progressing their skills while even an expert mountain biker will enjoy the fun ride. The trail will feature a series of bermed corners, grade reversals and rollers, and will rarely be flat. This encourages a proactive riding style and helps to build a solid foundation in mountain biking skills whilst ensuring a fun and engaging ride for everyone, regardless of skill level.

At the end of the trail a berm will direct riders onto the return trail at the junction with the access point from NCR 7. This return trail climbs back up the Northerly side of the slope and will have some optional technical sections such as an exposed rock section and rock causeway to challenge riders and provide interest on the way up.

On the Southern side of the slope a Skills Area will be accessed from either the fourth corner of the blue trail or via an exposed rock section leading from the start/finish area. It will feature various progressive TTFs in isolation allowing riders to practice specific skills and build confidence on a feature before moving to the next, more challenging one. As well as exposed rock sections, features will include progressive drops, skinnies, and some small table top jumps. The skills park will be graded for difficulty using the Forestry Commission’s ‘Orange Lozenge’ grading system for bike parks and will have a total trail length of approximately 200 metres.

1.1.1 Track Layout Illustration – East Area

1.1.2 West Area

Access to the West area will be from a specific bike park access point on NCR 7 adjacent to the existing footpath as shown in the illustration below. This will feed into the return ‘uphill’ trail as detailed below with a pinch point and signage warning riders on the access trail to give way to those riding the jump line.

The West area has a steeper gradient of approximately 19° at the top end of the slope, gradually decreasing to a flat area at the foot of the hill. The existing footpath winds up the hill to a viewpoint so use of this slope is restricted to an area mostly below the footpath. Following the community consultation carried out by Bike Trossachs, it was felt that the option of re-routing the footpath to allow a greater area should be discounted as it is a popular path in everyday use.

This area will have a jump line of approximately 150 metres (including return trail) to challenge more experienced riders and, like the Skills Area, will also use the Forestry Commission’s ‘Orange Lozenge’ grading system for bike parks. From the start area, the jump line will start with a Step Down feature with a steep landing leading into a Step Up jump. This will land riders in a berm and following that, two tabletop jumps in succession. Each jump will have a medium and hard option allowing for smaller or larger jumps with both options being roll-able to allow less experienced riders to practice safely. Experienced riders will still be challenged and encouraged to progress through the hard set which will give significant air time.

At the end of the jump line a berm will feed riders into the return trail, leading back to the start area. This return trail will have a short steep section approximately 10m long which some riders may choose to push their bikes up. If ground conditions allow due to the proximity of the bedrock, a switchback climb could be utilised here to lessen the gradient. This has been shown in the illustration. A short ‘push up’ section is quite a common occurrence for a jump trail and is not likely to discourage riders in any way, indeed dirt jump specific mountain bikes are not usually ridden uphill at all.

1.1.2 West Area Illustration

2. Track Construction - Overview

All the tracks together will be a total of approximately 735m long including all return routes, access routes and central linking section. This also includes approximately 200m of track in the various sections of the Skills Area.

The track will be cambered to aid drainage and surfaced with a 10mm layer of Whinstone dust. After proper compaction at the construction phase, this dust will further percolate into the track sub base over time and form a hard wearing and sustainable surface that can be ridden in most weathers and for the majority of the year.

The main trail width should be 1-1.2m. TTF’s and corners will tend to have a wider track surface to allow novice riders room to negotiate them easily, while optional more challenging TTF’s will tend to have a narrower width of between 0.6-0.8m.

The track will roll and undulate around corners and over bumps and other features. The design intends to enhance the existing terrain to make it more interesting for the rider while still appearing to be a natural part of the landscape as much as possible.

Additional TTF’s that are added to the track to further enhance the experience will be constructed from natural stone or rot resistant timber such as Larch. With some additional landscaping these will form part of the track, again looking as natural as possible.

It is important to understand that the finished track on a project like this will often differ from the initial design’s layout; flexibility is required in order to ensure the track flows properly for the rider. This can only be done during the construction phase as the track evolves and requires an experienced trail designer to understand how the track will be ridden. This is especially pertinent on this project as the site has a very mixed depth of soil with bedrock very close to the surface in some areas. Given these considerations it is important that a generous contingency budget is included by prospective contractors in order to accommodate this flexibility.

The majority of the initial track shaping can be carried out by an experienced excavator operator in a 360 degree tracked machine with a tilt/rotate bucket. This type of bucket is essential to in order to minimise labour and time. An operator who has experience of this type of project is also essential. A 5T excavator has been suggested in the Bill of Quantity but is important to note the restrictions, caused by the bridge on NCR 7, to <2 metres track width of any plant used.

Technical Trail Features to be Included (see glossary, section 14):

· Berms

· Rollers

· Grade reversals

· Drop offs

· Technical Rock Climb

· Rock Causeway

· Pinch Points

· Skinny

2.1 Strip and Fill Construction

Strip and Fill construction is suitable for flatter sections of trail or where the trail follows the gradient of a slope. Any organic soil will be stripped out to a depth of approximately 100mm, forming a tray along the identified track route. This will then be rebuilt with a 150mm layer of type 1 stone sub base and a ‘wearing course’ of 10mm whinstone dust, leaving the finished surface approx 50mm above the existing ground level.

Soil removed when forming the tray can be retained and reinstated at either side of the track forming side batters with an angle of <45°. These should then be covered with suitable topsoil and reseeded with appropriate vegetation.

See specification in section 13

2.2 Strip and Fill Construction, Example Illustration

2.3 Bench Cut Construction

Bench cut construction will need to be used where the track traverses a slope. In this method of construction, a bench is cut into the slope with a cross fall downhill of approx. 5% to aid drainage. A tray can then dug from within the bench or formed with removed material on the lower side of the track. The chosen method of forming the required tray will depend on the gradient of the slope.

This tray will then be filled with 150mm type 1 stone sub base and a wearing course of 10mm whinstone dust. It is important that the uphill batter is graded to an angle of <50deg and re-seeded with appropriate vegetation to avoid erosion onto the track surface.

2.4 Bench Cut Example Illustration

2.5 Geotextile Membrane

It would be advisable to lay a Geotextile membrane as a first layer to prevent the track sinking into the ground over time and becoming boggy on the lower lying access routes. A Geotextile Membrane will also prevent grass growing up through the track over time as the wild grass on the site has deep roots.

2.6 Technical Trail Feature Construction

TTF’s such as berms, rollers and tabletops are built in much the same way as the main track surface. The basic shape will be formed of suitable ‘asdug’ subsoil and type 1 stone sub base laid on top. The whinstone dust wearing course will be 10-20mm on TTFs to allow for detailed shaping and ensuring the finished surface rolls as it should.

The subsoil on site has a good amount of grit and mineral content and should be suitable for forming the basic shape of the TTF’s. Borrow pits can be utilised if needed for extra material and may be required for forming the table top jumps in the West Area. Borrow pits must be refilled with stripped turf or topsoil before the construction is completed.

See TTF Glossary, section 14 for illustrations of each of the features listed below.

Berms are banked corners which allow the rider to travel at a greater speed around a set radius than a flat corner by allowing the rider to lean their bike into the corner and increasing the grip their tyres have on the ground. They are also very useful for novice riders as they help to ‘guide’ them in the correct direction at a slower speed.

They are concave in the banking, with a maximum angle of around 50° at the top. On a track of this type they will be a maximum of approximately 1 metre high and should have a constant radius curve. Careful consideration needs to be given to drainage at each berm to ensure that water doesn’t collect on the track surface.

Rollers are low rolling bumps in the track which a rider can use to generate speed by pushing their bike over and down each roller. They are not designed to be jumps; rather they encourage the rider to actively ride their bike instead of just being a passenger. They will range from 200-400mm high and be 3-4 metres long.

Table Top Jumps are constructed in the same way as rollers, but are larger with a flat ‘table’ surface which riders can roll over if necessary but aim to leave the ground and clear the table. They have a steep ‘upslope’ and longer landing slope with a shallower gradient. Depending on the grade of the jumps they can be anything from 5 – 15 metres long in total.

Grade Reversals are where the trail flows up and down whilst traversing a slope. These are fun features to ride and also help a track to drain properly by encouraging water to collect at low points where it can be channelled away.

2.6 Technical Trail Feature Construction cont.

TTFs on the track including the Drop Off, Pinch Points, Technical Rock Climb and Rock Causeway will involve bedding imported rocks into the track and forming the surface around them, or stripping away organic material to expose bedrock below where appropriate. Any imported rocks need to have at least 30% of their mass buried in the track and the surrounding sub base and wearing course needs to be carefully compacted by hand to ensure that the rock is secure.

The Drop Off features in the Skills Park will have large square edged rocks forming a lip over which riders can choose to roll. They will have the option of rolling over slowly or carrying more speed and dropping off where both wheels land simultaneously. The smaller of these features can also be ridden in reverse during a coaching session to practice the skill of negotiating a rock step up.

Pinch Points are obstacles set to narrow the width of the trail by approximately two thirds and force the rider to control their speed. On this track they will be formed of imported boulders embedded in track. Crucially they will be embedded so they cannot be ridden over like the other features and at least 30% of their mass must be below the surface. Multiple pinch points may be used in succession if necessary.

The construction of the Technical Rock Sections will involve stripping all organic material away to expose the bedrock underneath to form a challenging surface for the rider to negotiate. The finished surface will be a similar width to the main track and may have several ride-able ‘lines’ or routes across it. These features can also be ridden in reverse during a coaching session to provide numerous optional challenges

Similar to a Technical Rock Climb, a Rock Causeway will involve embedding numerous large, flat boulders into the track alongside each other to form a challenging surface for the rider to negotiate. The finished surface will be narrower than the main track and will only have a single ride-able ‘line’ or route across it. Typically used to cross a marshy area of ground, this feature can also be ridden in reverse during a coaching session to add another option for riders.

A Skinny is a narrow section of raised timber, often made from slicing a tree trunk along its length or building a wooden frame with a narrow decking out of treated timber. Skinnies are made increasingly difficult by raising them off the ground or setting them at angles to form slopes or bends. Depending on their size and mass they can be fixed to posts in the ground to prevent them from moving although using trunks generally means this is unnecessary. Larch is generally advised as a low maintenance timber that does not rot in contact with the ground.

3. Track Drainage

The majority of this track is set on a slope so drainage should happen naturally, aided by a cross fall on the track surface of not more than 5% where bench cut, and a cambered surface where the ground is flatter. No ditches should be dug adjacent to the track as this is a potential risk for riders. Rather ‘French’ style drains filled with single size gravel or collection pits with large boulders can be used on the inside of bermed corners and at the bottom of grade reversals, where water will naturally collect. Twin walled 6” pipes can then transport excess water under the track to where it can soak away naturally. Where the track traverses adjacent to another section, the drainage may need to transport water under both sections. However as there isn’t a large hillside above the track, it is not envisaged that large amounts of water will need to be diverted.

Drainage will need to be installed as a minimum in the areas indicated in the drawing 3.1 and 3.2 below.

3.1 Drainage Plan East Area

3.2 Drainage Plan West Area

4. Bike Track Signage

Each track will have a main interpretation panel near the start of the access route, located with a good view of the track so users can identify with what they see on the panel. Further interpretation panels should be located at the start of each trail with individual TTF identity/grading signs used in the Skills Area to help riders choose the most suitable features for them

4.1 Main interpretation panels to include:

· Map of route - showing: route(s) and TTF options, route grades, ride direction, lengths, potential hazards.

· MTB ‘Is this for you’ grading information panel, to include XC grading / Bike Park grading advice as appropriate.

· Clear list of all routes and their grades, general explanation of ‘optional Technical Trail Features’ (these will be signed on the track)

· Emergency information for the panel location

· Safe cycle code, based on FCS Forest Cycle code and tailored to situation – i.e. logging trucks irrelevant

· Any further information such as Bike Trossachs information/contacts, funding information etc.

4.2.1 East Area Track signs

Annotation

Location

Description

A

East Area Interpretation panel

As listed above

B

Entry to Blue trail

Swooping Descent -> Rollers and berms

(XC Blue)

C

Entry to bedrock descent leading to Skills Area

Medium Technical descent on exposed rock

(Orange Lozenge 2 dots)

D

Trail Split

Entry to Skills Area / continuation of blue XC trail

E

Skills Area option

Easy Technical descent on exposed rock

(Orange Lozenge 1 / 2 dots tbc)

F

Optional TTF - Easy Drop

Easy Drop

(Orange Lozenge 1 dot)

G

Optional TTF – Medium Drop

Medium Drop

(Orange Lozenge 2 dots)

H

Optional TTF – Hard Drop

Hard Drop

(Orange Lozenge 3 dots)

I

Optional TTF – Boardwalks

Difficulty tbc by Bike Trossachs – envisaged easy/medium/hard

Mixed Boardwalks

(Orange Lozenge as appropriate)

J

Optional TTF – Easy Tabletop Jumps

Easy Table Tops

(Orange Lozenge 1 dot)

K

Optional TTF – Technical Rock Climb

Difficulty tbc, envisaged Blue

Technical Rock Climb

(XC Grade Blue – tbc)

L

Optional TTF – Technical Rock Climb

Difficulty tbc, envisaged Red

Technical Rock Climb

(XC Grade Red – tbc)

M

End of return Trail

Finish / No Entry

(2 signs, one post)

N

Trial Junction

No Entry

O

Trail Junction

No Entry / Give Way & ride direction

(3 Signs, one post)

4.2.2 East Area Track Signage Plan

4.3.1 West Area Track Signs

Annotation

Location

Description

P

West Area Interpretation panel

As listed above

Q

Entry to Jump Line

Orange Lozenge 2 & 3 dots – Medium and Hard

R

End of return trail

No Entry

S

Trail junction

Give Way to riders on Jump Line

4.3.2 West Area Track Signage Plan

5. Enclosure Fencing

The whole site will need to be fenced off securely with Heras type fencing for the duration of the construction phase to ensure the safety of the general public in the area. 420m of fencing has been allowed for this and the main contractor will be able to advise on costs for this. Further fencing will need to be used to separate the access route from the public as well on NCR 7 and around a stockpiling area in the public car park. These should require 150m together.

It is suggested that the Bike Park is fenced off once built with a low impact fence to prevent dogs and cyclists coming into contact with each other. This will also help to ensure the safety of the public as it will leave no doubt as to where each party is supposed to be when accessing the bike park or multi use public paths. Each access point should include a self closing gate with suitable latch to allow easy access for riders. There should also be an access point at the top of the hill adjacent to the viewpoint with a similar gate.

The planning authority will need to make the final decision as to whether they feel fencing the site will be visually suitable and should be consulted as to their opinion on this as soon as possible. They may also stipulate what type of fencing they would like to be used. A similar perimeter to that used during construction would give approximately 420m of fencing.

6 Maintenance

A facility like this proposed bike park requires regular maintenance and this should be taken into account in the initial costing of the project. It is suggested that as a minimum, 10% of the total build cost is budgeted for maintenance over the first 5 years. The key to good maintenance is a ‘little and often’ approach, where regular checks identify potential problems early. This allows for them to be dealt with before becoming a hazard to riders and inevitably incurring more cost.

As this is a community club led project, all responsibility for continued maintenance will lie with Bike Trossachs as the client and facility manager. There are plans in place for developing a group of ‘Trail Fairies’ by training them up in trail maintenance and engaging other groups such as school pupils to help.

Appendix - Construction Details

Strip and Fill

Bench Cut

Roller Construction

Berm Construction