Suspension travel limit - which bikes?

[JohnnyO]

John. Who measured your suspension travel at QMP in 2012?

I think Dave did, I walked away and left them to it. .

[worms]

Gents - which bikes are affected by the suspension travel limiting rules - both pre and post 75.  I know the YZ Bs in pre 75 have to be limited - what bikes after that and which eras please?

thanks

Rossco

sorry Rossco, looks like Bill and Ben and the flower pot racing men, have got a hold of your topic, it was a really easy question.

cheers worms,

[evo550]

Wouldn't you just put the bike on a stand with both wheels in the air and measure from top of the wheel to the underside of the guard. Shock shaft length would differ depending on it's position on the swingarm.

That's not accurate, many bikes bottom before they hit the guard. You can bolt longer shocks on with the same shaft travel and increase the gap between the tyre and guard but not increase the wheel travel..

That's right, but it can also work the other way, a shock with more than 4 inches shaft travel does not always equate to more than 4 inches wheel travel. There are a lot of variables when trying to calculate WHEEL travel by measuring shock shafts... the rule calls for WHEEL travel not shock length/travel, so wouldn't it be simpler and more accurate to measure the distance between the wheel and underside of guard, this would give you the actual distance the wheel can travel.

[KTM47]

Not measuring shock travel. Measuring wheel travel.

[KTM47]

John. Who measured your suspension travel at QMP in 2012?

I think Dave did, I walked away and left them to it. .

No I did. I am a MA licenced measurer. No one will get a measurer's licence unless they have suitable trade qualifications.

[mick25]

Not measuring shock travel. Measuring wheel travel.

while we are talking about these travel limits we need to take into account swingarm flex as well

[worms]

so you guys were measuring wheel travel, wow,
at who's request?

yours, the stewards or the CoC, who's?

so being a bunch of so and so's, before a protest is made is in the best interest of the sport, really.

your not a cheat until you've competed. I dont get the mentality of it all.

[JohnnyO]

Wouldn't you just put the bike on a stand with both wheels in the air and measure from top of the wheel to the underside of the guard. Shock shaft length would differ depending on it's position on the swingarm.

That's not accurate, many bikes bottom before they hit the guard. You can bolt longer shocks on with the same shaft travel and increase the gap between the tyre and guard but not increase the wheel travel..

That's right, but it can also work the other way, a shock with more than 4 inches shaft travel does not always equate to more than 4 inches wheel travel. There are a lot of variables when trying to calculate WHEEL travel by measuring shock shafts... the rule calls for WHEEL travel not shock length/travel, so wouldn't it be simpler and more accurate to measure the distance between the wheel and underside of guard, this would give you the actual distance the wheel can travel.

No because I put longer shocks on my pre 78 RM's because I'm tall but they still only have 9" travel and 10" clearance..

[sleepy]

John. Who measured your suspension travel at QMP in 2012?

I think Dave did, I walked away and left them to it. .

No I did. I am a MA licenced measurer. No one will get a measurer's licence unless they have suitable trade qualifications.

Your telling use that MA have given a license for suspension travel measurements!

In the early days of vintage they used to get Firco(Sorry Mark) to bounce on the seat to check the travel with a tape measure of all things. On one occasion fork diameter had to be measured and someone came up with a vernier for that.

[KTM47]

Ross unfortunately it has become the norm on the forum for eligibility issues to turn into a bunfight, however this one has stayed relatively civilised. Your question is legitimate, and as Dave says put your query to MA.
With all rules, lines have to be drawn in the sand and they don't always suit everyone. The suspension travel limits have worked well I think and have helped to keep less advanced bikes in the game. I had my '74 Maico rear end limited and it was no biggie. If the limits are left open I think Geof's scenario is not that outlandish.
Kev you are a stickler for accuracy, and with that in view I am surprised you claim to have been the measurer at the 2012 Classic Nats.
Chief scrutineer was Kerry Marsh, assistant scrutineer Michael Vandenbroek, technical adviser Dave Tanner. Tanner did the measuring.
Sources are Sup regs, stewards report, C of C report, and my recollection as event co-ordinator. This is not a comment on your knowledge or expertise.

Col I accidentally deleted one of my posted. Anyway I was asked to do the measuring at QMP in 2012. Apart from the MA Steward to my knowledge I was the only other person there who has/had a measurer licence. I was only asked at the last minute. You can not get a measurer's licence unless you have suitable TRADE Qualifications. You can post your apology here.

[KTM47]

so you guys were measuring wheel travel, wow,
at who's request?

yours, the stewards or the CoC, who's?

so being a bunch of so and so's, before a protest is made is in the best interest of the sport, really.

your not a cheat until you've competed. I dont get the mentality of it all.

Maybe you should read all the posts. The suspension travel was measured after the third Moto in the impound.

[Daryl Jones]

Wouldn't be many 'eligible' pre-75 bikes if the total rear wheel travel was measured without the bump stops.

[09.0]

Two of my bikes were measured by Kev in impound and another was measured in the pits after someone complained that my Maico did not comply. I was asked to clear the air and I allowed him to do so.
I'm sorry Ross but I look at this thread with a bit of cynicism as you have been on here a long time as I have and seen this question asked and argued many times, with you being in the thick of it seeing you have one of the bikes on the list that have to be restricted.
I can't help but wonder why you would bring this up yet again.

[sleepy]

Wouldn't be many 'eligible' pre-75 bikes if the total rear wheel travel was measured without the bump stops.

If the swingarm , and shockmounts are original AND the shock length is no more than 340 mm , then there is no option to exceed the 102 mm travel . Very simple .

If the shock has 102mm of travel and all is original then the wheel will have more than 102mm of travel making it not legal. If the shock was mounted on the axle and mounted close to vertical then the wheel would match the shock but I haven't seen a bike like that yet.

My method to measure travel is to remove a spring and fit that shock only. Let the bike sit fully compressed under it's own weight. Take a measurement from the axle to a fixed piont verticaly above then lift the bike and let it hang. Take another measure and the difference is the travel.

[Nathan S]

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.