The Lotus Cars Community banner

1 - 20 of 23 Posts

·
Registered
Joined
·
595 Posts
Discussion Starter #1
What: I have replaced my Lotus-specific, needs-adaptor wheel lug bolts with a more common item that has a standard 17mm hex head.

Why: The stock lug bolts on our Evoras are of a special pattern. When I first looked at them, I thought they were a 14mm triple square-- unusual, but not unheard of. Looking more closely, though, I saw that they had 10 points (triple square, as the name implies, has 12). The pattern's not right for a Torx either. A little web research shows they are a proprietary design from an Italian firm, Bimecc.

That's great, as long as your adaptor doesn't go missing. Of course, you could always order another from your dealer when that happens, or keep a spare adaptor on hand just in case. They're not expensive. But poking around the Elise forum-- they have the same pattern head, although the bolts are slightly shorter than those on an Evora-- reveals that it is possible for the adaptor to snap off if too much force is applied, leaving a piece inconveniently stuck in the bolt head. That could ruin your whole morning.

Switching to bolts with a conventional hex head does away with the adaptor entirely, and makes replacing a single bolt (if you damage or lose one) cheap and easy. And that's because there's a more or less off-the-shelf replacement that works perfectly.

The only drawback to conventional hex-head bolts is that your wheels would now be much easier to steal. Well, life is full of compromises.

How: Easy! Our bolts have the following specifications:

M12x1.5
28mm length
60deg cone seat

By wonderful coincidence, all recent 3- and 5-series BMWs use a nearly identical bolt, with a perfectly ordinary 17mm hex head on them. The only difference is that the BMW item is 25mm long in stock form. But there again we are lucky: since BMWs are Europe's most boring cars (after Mercedes, natch), their owners like to dress them up with fancy wheels. This means that nonstandard lengths are easy to come by.

Generally the extended lengths are specified as spacer width. In other words, a "15mm spacer width" BMW bolt will be 25 + 15 = 40mm long. So look for a 3mm spacer width bolt, and you'll have exactly the 28mm length you need for your Evora.

Installation could not be simpler. Working on one bolt at a time, simply loosen and remove the stock item using your adaptor tool, and then install and torque the new BMW bolt. Then move on to the next bolt. You don't even need to jack the car up-- just remember to fully torque each bolt before moving on to the next (duh).

Conclusion: Easier than tying your shoes. There may be no burning reason to do this mod today, but the day that adaptor tool goes missing, you'll wish you had.

Since any prices or links I put here would eventually go out of date, I'll just recommend doing a web search.
 

·
Premium Member
Joined
·
3,426 Posts
I actually really like the way the 10 point star looks - it is a little bonus when looking close at the wheels.

Though yes I have already experienced all the fun of not having the adapter. I am sticking with the patterned bolt simply for the looks. :)
 

·
Registered
Joined
·
153 Posts
Thanks for the info. There's one more important 'why'. For aftermarket wheels, you might have a different thickness on the center face or seating height for the bolt. You also might want to run spacers. In all of these cases you want different length bolts to enure the right number of threads engage.

donour
 

·
Registered
Joined
·
595 Posts
Discussion Starter #5 (Edited)
I did a quick Google search and found several places offering spacers that would work with the Evora's bolt circle and hub boss diameter. In the absolute worst case, you could buy a set for a Hyundai and have the centers turned ~1mm wider.

Here's a link to a previous thread on the particulars of Evora wheels.

(I think someone's just mad because he recently bought a set of Lotus lug bolts on the forum here for twice the cost of hex-head equivalents.)
 

·
Registered
Joined
·
1,248 Posts
West, I noticed the specs you linked (in the other thread) show the 26mm as the length, but you and a few others have said it's 28mm. Is one for the stock wheel and the other for the forged? Or does it really matter (i.e. only 2mm, either will work)?
 

·
Registered
Joined
·
153 Posts
good luck finding spacers for this car.. been there done that.
There are lots of places that will make them for you at reasonable cost. If you want to do business locally, any good machine shop should be able to do it as well but will be more expensive as a one-off.

donour
 

·
Registered
Joined
·
595 Posts
Discussion Starter #8
West, I noticed the specs you linked (in the other thread) show the 26mm as the length, but you and a few others have said it's 28mm. Is one for the stock wheel and the other for the forged? Or does it really matter (i.e. only 2mm, either will work)?
Good eye. The Evora bolts are definitely 28mm; your guess is as good as mine why the shop manual says 26mm. Production change? Typo?

26mm bolts would likely hold up just fine, but offer no advantages over 28mm... so why tempt fate? ;)
 

·
Premium Member
Joined
·
6,246 Posts
Same tool as on our Elises. I have those tools all over the place. If its a track rat, I install lugs and nuts. Euro bolts are a PIA!
 

·
Registered
Joined
·
5,709 Posts
Yeah I found this out recently also and pulled out of a purchase offer on here for a set of lugs and key. 28mm needed for the Evora's deeper hub setting.
 

·
Registered
Joined
·
2,612 Posts
Not sure if the inner hub diameter is the same size as the elise/exige...I am going to say it is, just because it would make sense.

And if that is the case, then you can actually purchase spacers for a Daewoo and the inner hub centric diameter is identical to that of our cars. So save yourself a little money from having to have it machined, and get the perfect fit right away. I wish I could remember the diameter off the top of my head, but I was looking at it almost 5 months ago.

Hope that helps.
 

·
Registered
Joined
·
5,709 Posts
Not sure if the inner hub diameter is the same size as the elise/exige...I am going to say it is, just because it would make sense.

And if that is the case, then you can actually purchase spacers for a Daewoo and the inner hub centric diameter is identical to that of our cars. So save yourself a little money from having to have it machined, and get the perfect fit right away. I wish I could remember the diameter off the top of my head, but I was looking at it almost 5 months ago.

Hope that helps.
Nope, they are very different. Evora=68mm, Elise S2=56.6mm, Exige =57.1mm
 

·
Registered
Joined
·
560 Posts
Sort of on topic, looking for help:

One of my stock wheel bolts has disappeared (fell out). Do I need to replace all the bolts and key, or just the missing bolt?

Much appreciated.
 

·
Premium Member
Joined
·
6,246 Posts
Just the bolt unless they were all loose which means they're trashed.

Again, the only logical switch to make is back to lugs and nuts! Or be like a bunch of of loco Lotus guys and have star adapters all over the place.
 

·
Registered
Joined
·
560 Posts
Just the bolt unless they were all loose which means they're trashed.

Again, the only logical switch to make is back to lugs and nuts! Or be like a bunch of of loco Lotus guys and have star adapters all over the place.
Thanks!
 

·
Registered
Joined
·
560 Posts
Just the bolt unless they were all loose which means they're trashed.

Again, the only logical switch to make is back to lugs and nuts! Or be like a bunch of of loco Lotus guys and have star adapters all over the place.
What size lug nut is required? I need one for driving this weekend.
 

·
Registered
Joined
·
560 Posts
For future search results:


BMW E36 M Wheel Bolt


size

12 x 1.5 bolts

manufacturer

BMW


grade


10.9


part number

36-13-1-095-390 "213E Wheel Bolt"



My only issue with this is that I realized I was scratching the inside of the wheel with the lug wrench after a few turns...the lotus lug key extends the wrench length...not a big deal...
 

·
Registered
Joined
·
110 Posts
My only issue with this is that I realized I was scratching the inside of the wheel with the lug wrench after a few turns...the lotus lug key extends the wrench length...not a big deal...
You need some thin-walled sockets made with an exterior coating to protect the wheels properly. Your wheels still need to be relatively clean too.
http://www.torquestick.com/cart/home.php?cat=16
 

·
Registered
Joined
·
595 Posts
Discussion Starter #20
Just a quick correction to the first paragraph in my original post: another lister who has a lot of experience replacing lost lug bolts points out that the 10-point sockets are not proprietary. It seems like the dealer is still the cheapest source, but do some googling.

I've been running the 17mm hex bolts now for several years and they continue to be a cheap and robust way to never have to think about something as boring as lug bolts.
 
1 - 20 of 23 Posts
Top