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Larry Lem

40 Posts

Posted - 08/26/2015 :  14:38:26  Show Profile

One of the subjects brought up at the IHPVA general membership meeting held during the week of WHPSC 2014 was the flying start event rule that limits assistance to the first 15 meters of travel. Some folks envisioned constructing a catapult device that would accelerate a vehicle to high speed within that distance, didn’t see anything within the rules to prevent that and requested a clarification.

The IHPVA board of directors has discussed this issue without resolution. Use of email and lack of responsiveness have made this difficult. Discussion is planned to resume in person at the WHPSC 2015 event. (It’s not clear if the discussion is for board members only or open to the public.) This post is written to bring the public “up to speed” on the subject.

Background / Discussion

The flying start launch rule was revised in 2015 and is presently written as follows. Flying Start: A flying start is defined as a start where the vehicle may be assisted by accelerating before entering the timed portion of the course. Push assists are permitted, by no more than 3 persons per single rider vehicle with an additional 1 person per additional rider. (eg tandem). Pushers may not assist the vehicle for more than 15 meters.

Some singletrack vehicles without landing gear are able to launch with assistance for stability and minimal or no propulsive assistance.

Multitrack vehicles, singletrack vehicles with retractable landing gear are able to launch with no propulsive assistance.

Competitors have used launch carts to assist in vehicle stability. Folks have also pushed on the carts or vehicles to aid propulsion. More recently, folks have used team members on inline skates to support the vehicle. In all cases to date, the assistance in propulsion has been limited to how fast a person could run while pushing rider + vehicle within 15 meters. A rough estimate of the most speed gained during these launches is about 10 mph.

Gaining speed prior to 15 m helps the competitor achieve control stability helping to ensure successful launches. Successful launches keeps the WHPSC event moving within its limited closed-road time periods. The IHPVA rules apply to all flying start events, not just the WHPSC.

Gaining speed prior to 15 m via assistance in propulsion effectively lengthens the course distance. This is important at the WHPSC Battle Mountain course as top speeds of some vehicles is limited by course distance.

While the legality of the usage of launch carts has sometimes been questioned, it was never established that they were illegal. This was likely due to the rules not being clear in this area. No official could wave the rules at a competitor and say “That’s illegal, you can’t use that.”. Whether that was the situation or not, this needs to be clarified to prevent questions on the legality of launch methods.

Some IHPVA board members have quoted the “vehicle integrity” rule for justification as to why launch carts are illegal.

3.1.5 Integrity: No vehicle may discard any part after beginning motion.

But if this were the case, that rule could have (should have) been applied every time a competitor brought a cart to the launch area.

Further investigation into the origin of the vehicle integrity rule revealed that it was intended to prevent competitors from designing multirider vehicles where all but one rider would propel a vehicle up to high speed and then a separate vehicle would detach and be propelled by the rested rider to an even higher speed. (We know today that designing such a vehicle that could accomplish this and break 80 mph would be quite a feat!)

The IHPVA founders likely didn’t envision the use of launch carts or skaters. We are in new territory What we must consider today is whether we are okay allowing the use of launch carts, folks on skates or any means of launch assistance in flying start events.

Some board members noted it would have been better if the
launching during flying start events was identical to the launching methods during standing start events. The assistants are only allowed to provide stability to vehicles, not propulsion. Standing Start: A standing start is defined as an unassisted start from the stationary position, except that the vehicles which are unstable at low speeds may be assisted by one assistant for not more than 15 meters. The assistant may not push the vehicle.

But as we have already allowed pushing assistance, it is too difficult to change the rules to revert to disallowing pushing. As such, some board members have lobbied that what we should be trying to do is limit the amount of pushing within the first 15 meters. Whether a launch cart or an inline skater is used with assistants pushing the cart or skater, the resulting speed at release will be limited. This would match the most assistance that has been used to date.

Other board members would like to see launch carts banned but skaters allowed and are basing this on the vehicle integrity rule noting that the integrity rule is satisfactory as written, we simply need to enforce it.

Larry Lem

Don S

88 Posts

Posted - 09/01/2015 :  13:52:58  Show Profile
3.1.5 Integrity: No vehicle may discard any part after beginning motion.

Other board members would like to see launch carts banned... ...basing this on the vehicle integrity rule noting that the integrity rule is satisfactory as written, we simply need to enforce it

From a different perspective it could be construed that the integrity rule does not apply to the use of launch carts as the launch cart is no more a part of the vehicle than the inline skates are. Both are separate conveyances that are either directly or indirectly used to stabilize and/or assist the starting vehicle but neither item is at any time or in any manner mechanically attached to become a part of the vehicle.

It should also be noted the launch cart itself does not provide any energy to the starting vehicle ("effectively lengthening the course distance"). Based on on this effective lenthening of the course, allowing push assisted starts gives the assisted vehicles an advantage over unassisted vehicles. From this perspective the pushers are a form of stored energy for the rider and it could be argued that allowing push starts is in conflict with rule 3.1.2 Energy Storage which states that "No device... ...which releases energy under control of the operator, may be used... (this means absolutely no chemical, electrical, kinetic, potential, or other form of energy storage at the start.)

Revising the rules for 2016 so that no external form of forward propulsion can be provided to a starting vehicle would make it a fair competition for all competitors by eliminating the advantage of an "effectively lengthened" course and the advantage of external power accelerating the vehicle from the starting line.

"it's important to understand what makes them fast. It's more important to understand what keeps them from going faster." DS
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