1968 Fastback

jms · Mar 17, 2022

Hi all,
I have a very early 1968 Fastback. When Ii got it it had 12.8" center to center 1706-1282 Koni shocks with 204 springs (235mm). Several things happened. First the early Fastback type center stand no longer reached the ground and secondly the spring on the left side comes in contact with the chain guard. not good. Because the early center stand is so different from the later style, I came to the conclusion that the original Fastback had shorter shocks than the later models which used 12.9 center to center length. Interestingly Andover Norton says that the early shocks are the same as the older models and that the only difference is the shrouds on the Fastback. So at the end of the day I am looking for a shock that allows the original center stand to be used and one where the springs don't interfere with the chain guard. Does anyone have any information on this. Thanks for your help.

ILLF8ED · Mar 17, 2022

jms said:
Hi all,
I have a very early 1968 Fastback. When Ii got it it had 12.8" center to center 1706-1282 Koni shocks with 204 springs (235mm). Several things happened. First the early Fastback type center stand no longer reached the ground and secondly the spring on the left side comes in contact with the chain guard. not good. Because the early center stand is so different from the later style, I came to the conclusion that the original Fastback had shorter shocks than the later models which used 12.9 center to center length. Interestingly Andover Norton says that the early shocks are the same as the older models and that the only difference is the shrouds on the Fastback. So at the end of the day I am looking for a shock that allows the original center stand to be used and one where the springs don't interfere with the chain guard. Does anyone have any information on this. Thanks for your help

Is it possible the center stand stops are worn allowing it to stop too far past the centerline.

jms · Mar 17, 2022

Interesting thought. The bike, based on it’s serial number was the 76th off the production line. It had barely ever been used and everything looked relatively new and unused. In fact it still had the “Widowmaker frame” which had never been corrected. For these reasons it had never seen much use. Worth a double check though. Thanks

Ron L · Mar 17, 2022

I have 12.9" shocks on my '68 with no centerstand issues. It does have a replacement frame as its 'widowmaker' frame had cracks welded on both downtubes and the main spine. I would not go around the block on a '68 frame.

Could the lower frame rails be bent slightly?

Matt Spencer · Mar 17, 2022

Caveman Doulton at Rangitwotoes Colledge had one of the first Commando's . SILVER FRAME ( 1st or 2nd ? Show Bike . Ex Auckland Motor show )

38.000 miles and no issues . Frame hysteria likely related to use abuse & iso adjustment / misadjustment . To A Degree . One Could ALWAYS weld in the lower brace ?
PII frame is a;lso single top tube . Not a lot of whineing there .

P11 & CRS frames !!!!!!!!!!

One could aways fit a tyre valve & blow it up ! . ( Presurise & Pressure switch with lamp . )

THOUGH dont take my advice as gospel . seems a shame to de-originalise it . Depends n the use i guess .

Wonder what goes on with the top Iso mount , up there . ?

The LAST original frame series one Commando , or were they Commando's ? .

Working at AMC - Testing Commando Frame

This is the Testing Commando Frame page of the Working at Associated Motor Cycles Ltd website

www.workingatamc.london

Sounds like it'll be orwright as long as you dont let an American ride it ! ( Wonder how much RAIN came into it / Traction ) .

The starting point of the investigation was to carry out extreme condition testing of the current Commando frame to try to replicate the frame breakages as found in America and, to this end, the Ministry of Defence (MOD) tank testing facility at Chobham, Surrey was utilised.

Four of AMC's team of test riders, Alan Jones, Bill Brooker, Neil Collett and Nick Hyde were co-opted to ride the bikes over a punishing range of surfaces in an effort to identify any frame weaknesses.

Over a period of six weeks, the team of testers would ride their respective bikes from Plumstead to the MOD site, usually taking less than 30 minutes. This was in the days before the M25, or any other motorways, which shows how incredible the riders were as well as how fast and great handling a bike the Commando was!

gortnipper · Mar 17, 2022

Sounds like the shocks are not the correct model. 7610-1654 is the right model. SP17 variant has a cover.

Koni=Ikon

7610-1654 - Ikonsuspension

7610-1654 - 7610-1654 IKON Rear Shock Absorber and Spring assemblies. One Pair. Max Length 12.99" Min 10.79" Center of Eye to Eye. These shocks fit: Kawasaki VN1500 Vulcan Drifter, incl. Fi and Interstate 99-04 4 position Externally Adjustable Rebound with just a finger touch 3...

www.ikonsuspension.com