Chain support ( guard )

[firko]

So.....it's only the countershaft we need to cover? I'm confused.

[Noel]

No firko,
It has just turned into an other debate about the rules as written
Noel

[Tossa]

You want to confuse it any more the only mention with modern bikes is theis (well all I can find)


15.22.8 Drive chain protection
 
 
15.22.8.1 Front sprocket may be guarded so as to prevent direct access to the chain or sprockets with the fingers.

[HeavenVMX]

the wording is "swing arm      pivot"

Yes Noel swingarm pivot is mentioned in 16.15.4.5 relating to countershaft sprockets but not mentioned in regard to projection sprockets 16.15.4.4

[Tossa]

but wait theres more in Enduro and reliability they actually mention final drive sprocket:


17.18.7 Drive Chain Protection
 
 
17.18.7.1 Primary drives (the drive connecting engine to clutch) must be guarded so as to prevent direct access to the chain or sprockets with the fingers.
 
17.18.7.2 The guard must be constructed of:
a.Metal having a minimum thickness of 1.6mm, which may be mesh or expanded metal provided the openings do not exceed 10mm, or
b.Fibreglass having a minimum thickness of 3mm.
 
 
17.18.7.3 If a plastic, fibreglass or part open chain guard is used, a steel bolt of not less than 10mm diameter, placed outside the bottom rear quadrant of the clutch sprocket. This bolt, if damaged, must be replaced.
 
17.18.7.4 Projecting sprockets, which are not behind a clutch assembly or directly behind a frame member, must be guarded where the sprocket teeth are further than 30mm from a frame member or swinging arm.
 
17.18.7.5 A counter shaft sprocket which is more than 30mm from the outside of the swing arm pivot, must be covered.
 
17.18.7.6 A chain guard made of suitable material must be fitted in a way to prevent trapping between the lower drive chain run and the final drive sprocket at the rear wheel.

Three different disciplines three different rules   WTF.

My interpretation is this that nowhere in our regs does it mention the words Final Drive Sprocket (rear wheel) therefore the only one that needs covering is the primary (motor end)  Two different sprockets primary (motor) final drive (rear wheel)

[HeavenVMX]

Yep just reading that as well. So if you enter your classic into open competition there are three seperate rules on the same thing

But where does that leave us as Dirt Track seems to be the only one with a specific reference to a rear sprocket

It seemed we needed a rear sprocket guard now not so sure but why the differences.

[Noel]

Don't forget that Mom's are read in conjunction with sup reg's which could  include/delete  certain Items if aproved

 

Noel

[firko]

To cover any future scrutineering dramas I'll fit suitable covers to both countershaft and rear wheel sprocket. I've pretty much always run countershaft sprocket covers on my bikes but the brave new world where I've never tread before is in making my rear sprocket finger proof.

Below: My Maico is easy. I've had the stainless steel countershaft cover on it for thirty years and it shouldn't be very hard to mount something off my rear brake stay for the rear.
                                                                                               

[Tossa]

Yep just reading that as well. So if you enter your classic into open competition there are three seperate rules on the same thing

But where does that leave us as Dirt Track seems to be the only one with a specific reference to a rear sprocket

It seemed we needed a rear sprocket guard now not so sure but why the differences.

That's my point reading the Dirt Track regs it mentions;

20.16.8.6 A chain guard made of suitable material must be fitted in a way to prevent trapping between the lower drive chain run and the final drive sprocket at the rear wheel.

specific mentioning of the sprocket cover requirements

[bazza]

Glad I live in NZ this is all covered by the rule #1 = Load bike go to track and enjoy your self

[Ted]

So I asked a question in the first post of this topic.... Do you have to fit a chain guard to the rear sprocket of a Evo bike?

 I am lost in the five pages.

Yes or No?

[TM BILL]

Glad I live in NZ this is all covered by the rule #1 = Load bike go to track and enjoy your self

 

[Tossa]

My opinion by the way they have written itr and the fact there is no mention of final drive sprocket within Classic MX/ Dirttrack   ---- NO

[Ted]

Thanks Tossa

[KTM47]

Don't forget that Mom's are read in conjunction with sup reg's which could  include/delete  certain Items if aproved

 

Noel

OK lets get one thing straight Supp Regs can not include or delete GCRs.

As it stands now in the new MOMS  www.moms.org.au Classic MX & DT do not have to have the rear chain guard, but they do have to have the front sprocket guard.  Primary drive is something else eg Maico chain primary drive.

However the minutes from the Classic MX & DT Commission which have been approved by the MA Board do say that the exemption for Classic MX & DT is to be taken out of the old rule 12.8.8.6.  So sooner or later Classic MX & DT bikes will have to have a rear chain guard.  The modern chain guides have been accepted on the modern bikes so that will be good enough.

The fact that the current on line version of MOMS does not say this yet doesn't mean it won't sometime soon.  When they were put online they just used the 2013 MOMS and haven't updated them yet.  Proof of this is the fact that the new Women's Classic MX class isn't in the online version but we have been told they are approved.

There is a committee that is looking into getting everything up to date in the new MOMS.

Kevin