AHRMA MX Tech Inspection

Vintage-class shock travel guide

The following chart is used by AHRMA motocross tech inspectors as a quick method of determining maximum rear suspension travel. Inspectors may also choose to follow the procedures listed in rule 11.2(a) of the AHRMA Handbook. The chart will be updated from time to time as more information is gathered. For questions or suggestions about additions to the chart, contact one of the national motocross tech chiefs or Motocross Rules & Eligibility Committee members listed in the handbook.


Brand & Year

Model

Maximum visible
shaft length*

Comments

AJS

1969-74

250/370/410

3 inches

Standard swingarm (over axle)

2

Moved up swingarm

American Eagle

125/250/360/405

3

Stock swingarm

Bultaco

1967-73

3

Stock swingarm

Metisse

Model 11

3

Stock swingarm

1975

250 only

2

Straight up and down

Can-Am

MX-1

3

Standard swingarm

Cheney

Early

3

Nickle plated (over axle)

Late

?

Moved forward (check)

CZ

1968-73

125/250/360/400

3

Stock frame & swingarm

1974

Red frame

3

Stock frame & swingarm

1975

Falta

2

Stock frame & swingarm

Greeves

All

3

Stock frame & swingarm

Hodaka

125

3

Honda

1973-74

CR250

3

Stock setup

1974-75

CR125

3

Stock setup

125

2

With Redline swingarm (always check)

Husqvarna

1968-74

3

Without Mag swingarm (pre-'74)

1968-74

3

With Mag swingarm

1968-74

2

With Profab swingarm (straight up & down; always check)

Kawasaki

1973

F11M & F12M

3

All stock frame & swingarm

1974

KR250 & KX450

3

All stock frame & swingarm

1974-76

KX125

3

1975-76

KX250 & KX450

2

"Forward mounted" (always check)

Maico

Pre-1974

3

Stock frame

1974

2

No holes in frame mount; 1 mount on swingarm (rare)

1975

2

Holes in frame/middle lower mount (always check)

Ossa

1967-72

Stiletto

3

Over axle

1974

Phantom 125/250

3

Allow swingarm stock part

Penton/KTM

1973-74

Check

Middle lower mount (always check)

Rickman

All

3

Over axle

Sprite

All

3

Over axle

Suzuki

1971-74

TM 125/250/400

3

Stock setup

1975

TM 125/250/400

2

Straight up & down shocks

Trackmaster

All

3-5/8

Nickle plated

Yamaha

1972-74

MX250/360 & SC500

3

Stock setup

DT/RT2 MXes

3

Stock setup

YZ250/360

3

Stock setup

*Note: All measurements include one-third the thickness of the rubber bumper.

         All motorcycles must clear/pass tech inspection. Those with forward-mounted rear shocks will/should be check even closer each time.

         All motorcycles will have no more than 7 inches of front wheel movement and no more than 4 inches rear wheel travel. This is not shaft travel.

         "Travel limiters" are available for $2.00 each at every AHRMA MX event.

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