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Thread: Bermology

  1. #1

    Default Bermology

    Does the Illiniwek berm tighten its curvature quickly at the end?

    The Jubilee berm is easy to ride and has never induced a crash for this aged, balance-challenged rider.

    The wood berm at Illiniwek, the third from the top, has been crashed on hard a couple times and less severely a few more times.

    Patrick Tibbits

  2. #2
    Join Date
    Sep 2012
    Location
    United States
    Posts
    574

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    Actually I ride illinwek berms without issues anymore . sbp berm (final one mainly) for me is a pain and I've ridden it a lot. Either having a kicker while off camber or trying to transition on the exit messes me up.

    Drew gave me some help on learning them faster.

    Problem with illinwek from what I know is cross between going too high at too low of a speed and not leaning properly with the angle of the berm. Some bikes (like fat bikes) are more prone to climb up the berms if not leaned hard enough and not expecting it. I know that from experience

    The final berm there is one where you go in high and come out low.

    I know drew had posted a chart showing about where you should be on height into the berms vs your speed.

    The biggest problem for me was mental, can't over think it. Just like small bermed corners in the dirt, just a lot bigger so you can go faster.

    Sent from my SM-T350 using Tapatalk

  3. #3
    Join Date
    Nov 2008
    Location
    Hampton, IL
    Board Position
    Trail Steward - Illiniwek; Web Director
    Posts
    1,833

    Default

    The IFP wood berms are all constant radius but #1 (the biggest) and #3 drop about 5' of elevation and riders will gain speed through them (about +4mph). This effectively makes them feel like a tightening radius turn. #3 is the most challenging because the elevation drop is the greatest/quickest and it's radius is also the tightest of the three at 12'. To account for the increased speed as you ride through berm #3, the bike needs to be leaned an additional 10-15 degrees by the exit of the corner to maintain the turn.

    The IFP wood berms are a totally different animal than the SBP wood berms and they can't be ridden the same way. Curved face berms force riders into a specific line based on speed alone. Riders can't do much steering correction once committed to the turn so setting up for it properly is key.

    Flat plank berms with shallow bank angle, like the SBP berm bridge, allow much more flexibility of line choice. The berm bridge is also a larger radius (19-22') and much wider (4'). I think the bank angle is around 35 degrees also.

    If a rider gets too high on the IFP berms without leaning, the front tire can lose traction resulting in a highside crash over the bike. This can also cause a fall over the top of the berm. From what I've seen, not leaning enough and trying to ride too high on the berm is almost always why people crash on them. The key is leaning the bike into the berm so the tires are perpendicular to the curved deck.



    This is an example of a poor line. The front tire is trying to climb over the berm and is at a very steep angle to the deck (a low traction state). Rider is not leaning enough into the berm. Also notice the tires are at two different heights on the berm and if you draw a line connecting the contact patches, they don't point through the turn.



    This is a good line example. Bike is leaned so tires are perpendicular to the planks (maximum traction state), rider is positioned about half way up the bank, and the tires are at the same height and a line through the contact patches follows a "level" path through the berm.




    I posted this diagram a while ago showing the theoretical speeds for IFP berm #1 in this thread: Tips for Riding the New South Loop Wood Berms Angles and speeds will be a little different for berms #2 & #3 than shown in this diagram, but the general idea is the same: Lean the bike!
    Last edited by DH001; 06-17-2017 at 05:43 AM.

  4. #4

    Default

    Thanx, Berminator,

    Your example of the poor berm line and insufficient lean could have been a portrait of me, except I'm more plump.

    And the insufficient lean explains going off the high side when attempting the berm at speed. Your diagram indicates my max safe speed is about 4 mph.

    Thanx as well to Tigris99.

    Patrick

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