Buck,
Thanks for your very gentle correction. I had to refer to the only picture
I took of the original and "drop" spindles side by side while I was
rebuilding my front suspension. And you are entirely correct. The mounting
bosses for the brake calipers must also relocate higher on the "drop"
spindle to maintain proper relationship. The Tiger's detachable steering
arms also mount to these bosses, so the steering arm is relocated higher in
relation to the steering rack, and the angle of the tie rods is changed.
Generally, lowering spindles that have integral steering arms retain the
stock steering arm position between the upper and lower ball joints and thus
do not alter the original steering geometry, all other things being equal
(as you well know; I'm preaching to the choir here). Obviously, it was
unwise to generalize about our Tigers, and I want to share this with the
list.
Jim Burruss
----- Original Message -----
From: "Buck Trippel" <BuckTrippel@Verizon.net>
To: "Jim & Carolyn Burruss" <cburruss@hiwaay.net>
Sent: Friday, December 18, 2009 11:44 AM
Subject: Re: [Tigers] Drop Spindles
> PRIVATE
>
> Hi Jim,
>
> On some cars, using a dropped spindle would not affect bump steer. However
> the Rootes dropped spindle "moves" the steering arm as well. (actually the
> outboard end of the drag link stays at the same height above the ground
> however its inboard end at the rack is lowered. This causes a bump steer
> change. The stock bump steer measurement is terrible so some might not
> notice the difference. (John Morton describes it as "twitchy".)
>
> Not counting computer modeling, I've done over 100 hours of bump steer
> work on the Tiger front end but I've been mainly optimizing the MG arms,
> not the shorter Tiger arms so I can't quote exact stock numbers. However I
> have used both stock and dropped so I know there is a change.
>
> Dale and I separately developed steering arms for different Tiger
> applications that resulted in bump below .010" throughout the range of
> travel as compared to stock which my fuzzy recollection has somewhere
> larger than .150". (I've seen some Tiger numbers between .375" - .500".)
>
> Buck Trippel
>
>
>
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Jim & Carolyn Burruss" <cburruss@hiwaay.net>
> To: <tigers@autox.team.net>
> Sent: Friday, December 18, 2009 8:16 AM
> Subject: Re: [Tigers] Drop Spindles
>
>
>> When I rebuilt the suspension on my '65 Tiger, which I had lowered with
>> shorter springs many years earlier, I switched to a set of the dropped
>> spindles. I acquired them from a friend who had imported three sets from
>> Australia. The dropped spindles, plus a minor modification to my lower
>> shock
>> mounts, restored some of my previously lost suspension travel. As
>> previously
>> stated, the drop spindles alone lower the car 7/8". My car is about 1.5"
>> lower than stock, has shortened CAT springs and 205/60-13 tires, and I
>> have
>> never bottomed the oil pan.
>>
>> Lowering a car by shortening the springs will affect bump steer. Using
>> the
>> drop spindles with stock height springs (and stock A-arm mounting points)
>> will
>> not alter bump steer characteristics.
>>
>> Jim Burruss
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