Bolt length for 3mm spacers… 🧐

[Tom-E86]

Hi all. Quick question.

Thinking about putting my 3mm spacers on my rear wheels just to space them out ever so slightly. I’m currently using 35mm bolts all round on my Velare 20’s, but wondering if I need longer bolts than that if I’m adding 3mm of spacer?

Not sure of the standard bolt length you’d normally use for alloys, I know there should be about 7 turns but if anyone’s had any similar experience I’d appreciate your input.

Thanks!

 

[VWDAZ71]

Probably better be on the safe side and get 3mm longer wheel bolts.

 

[DXX]

The OEM wheel bolts are more than long enough, you require a minimum of a full thread diameter engaged in the steel hub - 14mm.
3mm spacers, I have to ask, what’s the point unless you have a tyre rubbing?

 

[Tom-E86]

The OEM wheel bolts are more than long enough, you require a minimum of a full thread diameter engaged in the steel hub - 14mm.
3mm spacers, I have to ask, what’s the point unless you have a tyre rubbing?

Thanks - I’ll offer them up over the weekend, and check the amount of thread. But good to know.

Well there’s not much point really, just being fussy . They’re 10J ET38’s and I just want to see if I can get them completely flush without sticking out too much. I had them lying around anyway. If not, they’ll be up for sale soon .

Thanks for the advice

 

[DXX]

Thanks - I’ll offer them up over the weekend, and check the amount of thread. But good to know.

Well there’s not much point really, just being fussy . They’re 10J ET38’s and I just want to see if I can get them completely flush without sticking out too much. I had them lying around anyway. If not, they’ll be up for sale soon .

Thanks for the advice

You have redefined FUSSY.

 

[Tom-E86]

Ok, well I’m sure it’s not the most ridiculous question ever asked on here…

 

[WinFreak]

I had 3mm front and 10mm rear spacers on my s2000 and it made it sit perfectly

Still have the 3mm ones sat in my garage and have wondered about sticking them on the van too

 

[moomin-j]

Hi all. Quick question.

Thinking about putting my 3mm spacers on my rear wheels just to space them out ever so slightly. I’m currently using 35mm bolts all round on my Velare 20’s, but wondering if I need longer bolts than that if I’m adding 3mm of spacer?

Not sure of the standard bolt length you’d normally use for alloys, I know there should be about 7 turns but if anyone’s had any similar experience I’d appreciate your input.

Thanks!

The OEM wheel bolts are more than long enough, you require a minimum of a full thread diameter engaged in the steel hub - 14mm.
3mm spacers, I have to ask, what’s the point unless you have a tyre rubbing?

In my previous life as a hydraulic pipefitting apprentice working on flanged joints / manifold blocks into a blind tapped hole, it was always suggested that a minimum length was 1.5 x bolt diameter.
Therefore, a M14 bolt would need 21mm of engagement to ensure compliance to "good engineering standards"
Just my 2 penneth worth...

 

[Tom-E86]

In my previous life as a hydraulic pipefitting apprentice working on flanged joints / manifold blocks into a blind tapped hole, it was always suggested that a minimum length was 1.5 x bolt diameter.
Therefore, a M14 bolt would need 21mm of engagement to ensure compliance to "good engineering standards"
Just my 2 penneth worth...

Thanks for the input - going to offer them up and see what’s what.

 

[DaveD]

In my previous life as a hydraulic pipefitting apprentice working on flanged joints / manifold blocks into a blind tapped hole, it was always suggested that a minimum length was 1.5 x bolt diameter.
Therefore, a M14 bolt would need 21mm of engagement to ensure compliance to "good engineering standards"
Just my 2 penneth worth...

Probably a good point but if the thread on the hub face is only 14mm deep (I'm making that up, it might be more!) there's no benefit in a bolt that simply protrudes beyond that.

 

[DXX]

Probably a good point but if the thread on the hub face is only 14mm deep (I'm making that up, it might be more!) there's no benefit in a bolt that simply protrudes beyond that.

There’s more than 14mm of female thread. H&R state 11 threads engaged = 21mm, that’s the 1.5 x thread diameter that was mentioned earlier.
What I mentioned earlier was the OD as a MINIMUM, any length over the OD does not add strength but it does spread the torque load over a bigger area and allow for thread degradation.