History Todays Find == RAJO Offset Model T Spindle

FOURTY years after finding a set of RAJO Offset spindles I found another today! Rare? Maybe, finding the mate for the passenger side will be my Hershey quest this year, unless a HAMB member has one they will part with. Bob

 

Interesting item Bob. What is the purpose of the offset ? JW

 

I've never heard of those, but I am curious to know what advantage they gave. Does the hub get offset towards the front or rear? I can see that offsetting towards the rear would effectively increase the caster effect without altering the actual angle of the axle, but I can't work out if that would be an advantage or not.

Mart.

 

the only thing i can see that doing is inducing a death wobble?? but i guess there was a reason for it. please teach us

 

I'll post the original add for them tonight. They were advertized as "Self Steering" safety improovements. If they really did work there would be more of them at swapmeets IMO. Someone on the HAMB must have driven a T with them and should report the event. Just a few days ago i ran across an old post on the HAMB about a guy making offset spindles for an early 1950's Chevy. I posted the RAJO ad in my reply. I spent more time looking for it last night than I should have. I'll take photos tonight. Bob

 

Bob,

I have an extra set of Chevrolet spindles if you''re interested- no offset, but they'll drop your nosse in the weeds an extra whopping 1/2" from '26-27 spindles

 

Thanks Mac! I've got a set on a dropped T axle now. Back burner Speedster project. Bob

 

1963, a family friend was moving and had a garage full of T stuff to unload.
I was 11 years old and was able to talk my dad ( a T guy himself ) into lending me the money to buy the whole mess to build a speedster. In that pile were 2 pair of RAJO spindles & a BB Rajo head !
I did build the speedster and owned it for over 20 years.

 

Thanks Bill! That is the ad I posted a few years ago. Bob

 

Such old metal best to have them checked for cracks before using them!

 

Will add it to the pile, '39 roundbacks and '32 split wishbones. Bob

 

The Rajo spindles are offset to the rear 5/8". This has the same net effect as increasing caster - although the caster itself doesn't change; the trail changes, leading to increased high speed stability and self-centering.

In other words, the contact patch of the tire is moved further behind the spindle's pivot point...when the wheels are turned, the longer-trailing contact patch increases resistance to the turn - the wheels want to remain/return to center.

I'd be interested to know what affect this increase in trail has on understeer/oversteer in a racing environment.

 

Ok, guess i need the drivers side now that I know the stub axle is moved back. I wonder if these saw use on Model T Snow Mobiles that were converted to skis up front? Bob

 

I'm more inclined to believe they were designed for racing...in the 20's I would imagine the market for racing equipment would have easily been ten times larger than snowmobiles.

It is interesting to note that there are a couple late model sports cars that use the same principle; low caster angle with offset spindle to increase trail; but probably for different reasons. On the Model T, a caster change (and the resultant change in trail) would require bending the axle or manipulating the spring perches...it's much easier to gain the same result with an offset spindle.

 

Small world!

 

I like how the ad has a picture of a furniture caster.

Mart.

 

I've always thought that was an overhead view of things? P.S I've always liked your website. Bob

 

Never noticed the furniture caster until just now...a perfect example of mechanical trail! The caster as pictured has zero degrees of caster, but is offset from the centerline. Since the contact patch of the 'tire' is behind the pivot axis, you have the same net effect as positive caster.