Mountain Bike Reviews Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
1,715 Posts
Discussion Starter · #1 ·


something cool to think about: rollercoasters are ALL gravity fed. but they are not "down"hill all the time. you have ups and downs the whole way.

Roller Coaster Simulator:
https://www.funderstanding.com/coaster

The cars on a typical roller coaster are not self-powered. Instead, a standard full circuit coaster is pulled up with a chain or cable along the lift hill to the first peak of the coaster track. The potential energy accumulated by the rise in height is transferred to kinetic energy as the cars race down the first downward slope. Kinetic energy is then converted back into potential energy as the train moves up again to the second peak. This hill is necessarily lower, as some mechanical energy is lost to friction.

Not all rides feature a lift hill, however. The train may be set into motion by a launch mechanism such as a flywheel launch, linear induction motors, linear synchronous motors, hydraulic launch, compressed air launch or drive tire. Such launched coasters are capable of reaching higher speeds in a shorter length of track than those featuring a conventional lift hill. Some roller coasters move back and forth along the same section of track; these are known as shuttles and usually run the circuit once with riders moving forwards and then backwards through the same course.

A properly designed ride under good conditions will have enough kinetic, or moving, energy to complete the entire course, at the end of which brakes bring the train to a complete stop and it is pushed into the station. A brake run at the end of the circuit is the most common method of bringing the roller coaster ride to a stop. One notable exception is a powered roller coaster. These rides, instead of being powered by gravity, use one or more motors in the cars to propel the trains along the course.
https://en.wikipedia.org/wiki/Roller_coaster

Roller Coaster Simulator
https://www.funderstanding.com/coaster
 

·
Registered
Joined
·
351 Posts
Provided that attention is paid to issues such as water runoff to prevent fall line erosion, and the track is suitably designed so as to prevent the need for braking coming into the turns this sort of track is totally viable.

From what I've seen A-Line at Whistler is largely along these lines is it not?
 

·
Registered
Joined
·
1,715 Posts
Discussion Starter · #3 ·
Fullrange Drew said:
Provided that attention is paid to issues such as water runoff to prevent fall line erosion, and the track is suitably designed so as to prevent the need for braking coming into the turns this sort of track is totally viable.

From what I've seen A-Line at Whistler is largely along these lines is it not?
yeah for sure..... i realize my post may have gotten a big "duh" response..........

obviously DH trails have declines and banked turns/berms.........

i was more interested in how much "up" gradient action you can get just using gravity and pumping.... i have already built up-gradient rollers and up-gradient jumps, so i know it works.

when you only have small rolling hills to work with, rather than mountainsides... there are some different challenges....

. . . . anyway . . . .
 

·
Registered
Joined
·
374 Posts
It's just giant grade reversals, but you would want some mini ones to help with drainage. I supose the true roller coaster effect works best on smooth dirt. Where I live smooth dirt attracts horses and cattle, then it's not smooth anymore. Running the trail through rock gardens makes a great cattle guard.
 

·
Justin Vander Pol
Joined
·
1,720 Posts
That kind of what we're trying to do on the xc loops at Duthie Hill Park, outside of Seattle. We really wanted to maximize vert since there's only about 125' total elevation change, highest point to lowest point.

It essentially means that our trails are designed so that advanced riders don't often have to use their brakes. If a section is fast, send them back up the hill, via a fast corner, maybe one that has a berm. It's a fun design concept to play with, but not really rocket science.

The hard part really is drainage, since you need to try even harder than normal to avoid bottom turns. 2/3 of the terrain and soils in the park make this a reasonable task. The other 1/3 of the park is a lot of work due to poorly draining soils and/or lack of slope.
 

·
Justin Vander Pol
Joined
·
1,720 Posts
To add to this concept, there's the design element of making a loop trail (start/stop at the same elevation) feel like it has more descending than climbing.

There's a couple ways to do this, depending on the terrain. For us, it means having the climbs a bit steeper and shorter, say ranging from 6-12%, and having the descents shallower (3-6%) and longer.

There are a lot of other variables that go into this that a good trail designer instinctively knows. It would be a fun exercise to try and create a written guide to quantify some of the elements that go into designing "good" trail of various styles. The IMBA Trail Solutions books is good at the basics of drainage and layout, but you could write a whole other book on designing various styles of singletrack.

The thing that would make this really hard is that there are many different types of totally kickass trails. I guess that is why trail design is so bloody fun.
 

·
local trails rider
Joined
·
12,300 Posts
Coasting uphill can be really fun. Got a few small spots where I can, as long as I get a good start on the downslope.

The trail is practically straight at the bottoms of those. One is on the side of a ridge. A couple of others look like what the British call "bomb holes". These are remnants of the latest Ice Age: a chunk of ice got stuck and was covered with sand, gravel, etc. Then the ice melted. The ground drains well in those areas too.
 

·
Zach Attack
Joined
·
174 Posts
We have been working on elements like these. One of the things that we do is rough flag line the route at around 5% and then come in (after corridor approval) and pin in our flowy course. This allows for a purposeful rate of decline or climb that can be buried in a variety of grade reversals that range between 12" min. vt grade difference to 5 feet or more depending on side slope for drainage.
 

·
IMBA Canada
Joined
·
844 Posts
I love the "rollercoaster" feel of a trail... Check this short section out on the top of our newsletter:

http://www.adsvmq.org/forum/viewtopic.php?t=5192

We designed it 3 years ago. That short section is a lot of fun and with proper berms, it feels like you're riding fast... but the ups and downs make it feel a lot longer... there is a "up" at the end where i always here the "clunk-clunk" mechanism as i go up... and as you reach the top at almost zero speed, one last sharp turn downhill takes you back to max. momentum.

That feeling came even more true after my first visit at the 18rd in Fruita. It's all about flow and rollercoaster in that area.

I'd love to see more exemples of this!
 

·
local trails rider
Joined
·
12,300 Posts
Whatever you have at the bottoms, make it so that you don't have to slow down there.
 
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top