Spare Tire securement

[RobbartK]

Hello Lotus World,
Woodstock, my 70 S2, sat ideal for many years. In fact, (over time) since the spare tire was not secured it has ruined the radiator. The cooling system has been sorted. I am on to prevention of a recurrence. I see that the space for the spare has a "nut" incorporated into the fiberglass. Does anyone know the nut specs? The plan is to replace the securement device or find a work around. Let me know your thoughts... then get out there and drive. Thanks, Woodstock and Robbart

[BDA]

I can't really help you with the threads for the tire hold-down. I would guess it is 5/16-18. I can't tell what mine are because I think I drilled it out. I also have a TC which might possibly (probably not likely) be different in the first place...

BUT in case it might give you ideas, this is how I did my spare tire: I have a tire repair kit and an battery operated air compressor. I also have a can of Slime. Those are my spare tires. I believe I've heard that there is no spare with the Elise and that their spare is a can of Slime (or similar) so it's not that strange an option - and it's a lot lighter than a spare! 

[Lotuswins]

Robbart,

The thread on my TCS is 3/8 coarse thread.  I would really like an alternate to the eye bolt though, since the alloy wheel needs to be face down it needs to be removed to be filled with air.   Currently mine is strapped in with a ratcheting belt to hold the tool bag and the tire. 

I've had the can/compressor thing too, but when driving my healey I picked up a nail which sliced the tire and tube...no amount of sealant would seal it back up but fortunately I had a full spare.  Getting stuck out in the sticks is really a bad thing if you can't get cell reception. 

Jerry Rude
4005R

[bjthomp]

The nut in the fiberglass is called a bobbin. The threads of the bobbin are the same as the threads on the wheel studs (3/8 fine I think). Originally, Lotus used a stud mounted in the bobbin and held the spare in place using a lug nut. The stud passed through one of the mounting holes in the wheel. The wheel/tire assembly lays with the inside of the wheel facing up.

[Bryan Boyle]

The nut in the fiberglass is called a bobbin. The threads of the bobbin are the same as the threads on the wheel studs (3/8 fine I think). Originally, Lotus used a stud mounted in the bobbin and held the spare in place using a lug nut. The stud passed through one of the mounting holes in the wheel. The wheel/tire assembly lays with the inside of the wheel facing up.

I just jerry-rigged a method to hold the tire down...and the bolt threads are 3/8x16 if the bobbin hasn't been rethreaded.

At least that is what my thread gauge says, and I picked up that size steel bolt from the local hardware store that works just fine not an hour ago.

[Kendo]

My TCS came with no spare, so I haven't dealt with this yet.

Any idea why the spare is stored inside up? The only things I can think of are 1) that in that orientation, the bolt to secure it is shorter, so under spirited driving, there would be less of a chance of the wheel sliding around from any looseness in the fastening. And 2) inside up keeps the fastenings from scratching the outside of the wheel.

Other thoughts? Could the wheel be stored outside up with a longer bolt?

[BDA]

I agree with your supposition #1. In addition, storing the wheel outside down shortens the bolt required to hold the wheel down so there is less potential torque at the bobbin. Since it is made of aluminum, it would be easy to wallow it out. Also, having the wheel inside up (to change things up a little  ) makes a convenient place to store the tool set and the jack if I remember correctly. I wouldn't think that they were overly concerned about the appearance of the inside of the wheel because of the toolkit and jack storage. Because the wheel does not lay flat and sits partially over the M/C area, the outside is protected from abrasion from the fiberglass floor.

As I remember the original method of holding the wheel down was a bolt through a large washer in the center hole of the wheel. If memory serves, and it may not, the washer was big enough to fit partially in the center hole because of a taper in the hole. In any case, I don't believe it went through a lug hole.

So to bolster and refresh my memory, I checked the TC owners' manual and it shows a completely different method to hold the wheel down. The picture shows a strap and a wedged shaped stop being used and the toolkit and jack under the wheel (see TC Spare). That does not comport with my memory at all. The picture shows a steel wheel so I thought that may have been reused from the S2 owners' manual but from the picture from the S2 manual (see s2 spare), it shows a situation more like I described from my memory on my TCS. Now I can't say that the method shown in the TC Spare picture was never used but it was definitely not used on my car.

[SilverBeast]

My alloy spare is stored outside up with a longer bolt that goes through one of the wheel fixing holes into the bobbin. I believe my left front has been repaired as the fibreglass is much thicker in the front compartment floor in at that side. From memory it looks like a bolg had the head cut off and an extension piece welded to it with a wider section to "catch" the wheel and a short T piece so it can be fastened in by hand.

[BDA]

I am in now way disparaging or countering anybody's comments, past or future. My decidedly imperfect memory is from when my car was new.

[Bainford]

More TCS info here, for what it’s worth. I believe my fixing arrangement is original. The bolt is 3/8-16 x 4” long. The washer is 2” dia, 1/8” thick. However, my spare tire strategy is similar to BDA’s; can of slime and a tire pump (mine being a small, manual bicycle pump).

Since I’m posting on the subject, I’m showing off a photo of my never-been-mounted original spare. 

[RobbartK]

The people in this community are GREAT. Thanks for your replies. The bobbin in Woodstock (70 S2) has 3/8x16 threads. I found a neat set up in a local hardware store. It is an anchor point (two per pack) that many pick-up truck owners have attached to the bed of their truck. It allows them to attach tie downs to secure a load. The attachment is the actual part that I used. It has 7 pieces that you can use per your application. I chose this one (of several options offered) because the top (loop) moves separately from the expandable fastener at the other end. I also chose it because, if I turn the rim over and have it valve stem up, I just need to find some generic threaded rod and STILL be able to use the parts to secure the rim.
SmartStraps.com
Winston Products, LLC
30339 Diamond Parkway
Cleveland, OH 44139

I hope this helps you.