Chapman strut

Mike wrote:

"I've always envisioned it as a modified front drive
strut with a bottom A arm and Nissan/Datsun type drive
shafts. One of the Nissan diffs had drive flanges on
the side which may fit your idea."

I agree that this is the way to go. Even Colin
abandoned the Chapman strut and adopted a lower arm
after 1959. The Lotus 17 was the last design to use
the Chapman strut. Other models to use it were the 12,
14 (Elite) and 16. The strut proved too tall for use
on the lower rear engined cars and a harsh lesson had
been learned with the cut down front stuts used on the
17.

In 1960-61 he used a fixed halfshaft and the lower arm
in combination with trailing links to implement full
IRS. The lower arm required an extremely outer pivot
allowing only 50-75mm road clearance.

For 1962 Rotoflex joints were added to the halfshafts
for handling track changes and an arm to locate the
top of the upright. The Rotoflexs were were also used
on the Elan's halfshafts. The Elan successfully used a
McPherson (actually invented by Cottin and Desgouttes
in 1926) rear suspension very similar to many of the
current FWD designs. This represented the use of
Chapman type strut together with the lower arm and a
movable halfshaft.

=====

Geo. Cushing, Delanson, NY, US

http://www.georgecushing.net

G'Day George,
That's good info mate, thank you. I have only had a half hearted dabble with the idea, but I envisaged a cut down FWD strut with a lower A arm incorporating a coil over or with the coil over shock built in. The technology is certainly available given what is seen under the rear of the rally cars.
Regards, Mike.
----- Original Message -----
From: George Cushing
To: Locost_Oz (AT) yahoogroups (DOT) com
Sent: Friday, August 08, 2003 12:40 AM
Subject: [Locost_Oz] Chapman strut


Mike wrote:

"I've always envisioned it as a modified front drive
strut with a bottom A arm and Nissan/Datsun type drive
shafts. One of the Nissan diffs had drive flanges on
the side which may fit your idea."

I agree that this is the way to go. Even Colin
abandoned the Chapman strut and adopted a lower arm
after 1959. The Lotus 17 was the last design to use
the Chapman strut. Other models to use it were the 12,
14 (Elite) and 16. The strut proved too tall for use
on the lower rear engined cars and a harsh lesson had
been learned with the cut down front stuts used on the
17.

In 1960-61 he used a fixed halfshaft and the lower arm
in combination with trailing links to implement full
IRS. The lower arm required an extremely outer pivot
allowing only 50-75mm road clearance.

For 1962 Rotoflex joints were added to the halfshafts
for handling track changes and an arm to locate the
top of the upright. The Rotoflexs were were also used
on the Elan's halfshafts. The Elan successfully used a
McPherson (actually invented by Cottin and Desgouttes
in 1926) rear suspension very similar to many of the
current FWD designs. This represented the use of
Chapman type strut together with the lower arm and a
movable halfshaft.

=====

Geo. Cushing, Delanson, NY, US



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