Suspension travel limit - which bikes?

[09.0]

The rules specify wheel travel. Shock travel is just one of the factors that determines the wheel travel.

We are having this discussion again because leadership is missing.

I think we are having this discussion again mostly because some don't agree with the rules. It's not as though they are not clear enough now.
You are pushing an issue regarding accuracy and method. Method if you ask those that police it (that's what I did) is as per Kev.
Accuracy is within a percentage which would soak up those badly made tape measures that I use every day to make a pool level and measure minute gaps in tiling.

[GMC]

the good old tape measure probably has a millimetre or more of slop in the hook rivet.
[/quote]

Tape measures are supposed to have that slop at the hook
The movement of the hook is meant to be the equivalent of the thickness of metal of the hook so that you can get an accurate measurement whether measuring inside or outside of an object

[Momus]

the good old tape measure probably has a millimetre or more of slop in the hook rivet.

Tape measures are supposed to have that slop at the hook
The movement of the hook is meant to be the equivalent of the thickness of metal of the hook so that you can get an accurate measurement whether measuring inside or outside of an object
[/quote]

I know.  Rivets and holes wear and hooks bend and people err in their ability to use tools as well. 

A steel ruler has a square end that is self supporting on the axle or swingarm and guides itself so to my thinking is going to be closer to foolproof.

To demonstrate my conviction on this to myself I have a Mitutoyo stainless steel ruler 2 metres long.

[skypig]

Bill Shorten - suspension measurer 

He will redefine the word "travel", to ensure that the 0.7% of riders with their foot pegs mounted to the swingarm don't feel discriminated against.

"Shorten". Cracks me up.

[Michael Moore]

If it is of any use as a reference you can download the 2015 AHRMA rulebook here:

http://www.ahrma.org/ahrma_pdfs/Z-2015/Forms/15_Handbook_web.pdf

VMX suspension rules start on page 69 and mentions

the rear suspension is fully compressed by the examiner with the rider aboard to compress any rubber bumpers . . . Due to the use of non-standard or different types rubber bumpers, this check may be overridden by the tech inspector’s discretion. . . .Forward-mounted or laydown shock mounts will be closely scrutinized and checked for travel, with three-fourths of the rubber bumper counted as shaft travel.

PVMX suspension tech is on page 80 and appears to be pretty much the same wording other than the allowable travel.
 
Different bump stops will have different compressed lengths so it seems like you'd want to fully compress them to arrive at the true travel available.  Old Girlings etc seem to have pretty hard and incompressable bump stops compared to modern dampers which are designed to give controlled action and are not just there to prevent metal/metal contact at full bump.

I can see how the provision to count 3/4 of the bump stop as available travel could be a reasonable rule of thumb to apply, but it would have to be understood that it may not be as accurate as using the fully-compressed length.  But doesn't whatever method is chosen need to be something that can be applied at the track without a major disassembling of bikes/dampers?

HTH,
Michael

[Rossvickicampbell]

Brad - as mentioned earlier - yes there is a current rule in place re suspension limiters - I am chasing the logic behind it so I can get the full story to work out whether to place a submission to see if feasible to remove it - race our bikes (across a couple of eras) as they came from the factory.  No more no less.  Instead of being a forum "whinger" (not aimed at any in particular by the way  ) I was after some info so I can actually do something instead of just talk about it like a lot of guys on here do.  It appears there are a few people impacted by the rule across the various bikes.

Simple really - if it goes in so be it, if it doesn't then it doesn't hurt - is that Ok??   Am not bringing it up again for the sake of shite stirring but to find out what bikes are affected.

Some people have a genuine agenda on here?  I am surprised you doubted me 

[Ted]

I asked MA how to measure wheel travel a couple of years ago. I'm still waiting for a reply

[KTM47]

I asked about six months ago (just to confirm what I already knew) and got an answer.  You just have to ask the right person.

[Gippslander]

Is it correct that my standard 74.5 Maico is only eligible for EVO because it is has too much travel for pre-75 and is just not allowed into pre 78?

[Nathan S]

Is it correct that my standard 74.5 Maico is only eligible for EVO because it is has too much travel for pre-75 and is just not allowed into pre 78?

Correct. For a sport that is supposed to be representative of the past, that situation is insane.

[Nathan S]

.... You just have to ask the right person.

And that's the problem right there.
The rules should be in the book, and should be clearly stated.

We can bitch about forum stirrers all we want, but clear rules will blown every single one of them clear out of the water. Fix the rules and ALL OF THESE ISSUES DISAPPEAR.

Instead, we seem to have secret handshakes, confusion, uncertainty, and inconsistency.

And it's not going to go away until we have some leadership from those with the power.

[GD66]

I asked MA how to measure wheel travel a couple of years ago. I'm still waiting for a reply

MA GCR 16.15.10.2 says front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle.
Is that not enough info ?

[Michael Moore]

Several weeks ago I enquired of the VMX committee of AHRMA (and the silence is deafening) how to measure the travel on a leading link fork (LLF).  Teles are measured along the tubes, but that 7" of travel at an angle gives a smaller amount of vertical wheel travel. 

Do LLFs get measured 7" along the chord from full bump to full droop (somewhat like a telefork) or do you measure 7" of vertical travel as with a rear swing arm suspension?

Beats me.  I guess the tech committee doesn't know either.  Either way would be fine if I knew which one was preferred.

cheers,
Michael

[Ted]

I asked MA how to measure wheel travel a couple of years ago. I'm still waiting for a reply

MA GCR 16.15.10.2 says front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle.
Is that not enough info ?

So you can read and quote from a book. Now tell me the procedure to be used to measure wheel travel.

[JohnnyO]

Is it correct that my standard 74.5 Maico is only eligible for EVO because it is has too much travel for pre-75 and is just not allowed into pre 78?

Or you could put travel limiting spacers on the shocks and race it in pre 75 like everyone else does both here and in the USA.. It's not hard