One for those with PCD adapters or bolt on spacers...

[S3 Paul]

Im in need of some hub PCD adapters.
After looking around i know i dont want steel ones as the will add even more unsprung weight,
So... seems that leaves me with H&R or FK ?
The price is about £90 diffrence but im unsure about the FK items,
Basicaly they are tapped directly into the alloy of the adapter where as the H&R ones are pre helicoiled...
Has anybody had either???

 

[patTTpoa]

No problems with FK's in the past, if you do get FK's just be careful when doing up the wheel nuts as a few people on the mkiv forum have cross threaded in the past.
But like I said I've had no probs dude!

Pat

 

[<tuffty/>]

I have seen FK's and not entirely convinced about screwing a short bolt into a bit of alloy... personally I would go for the H&R's... in engineering terms they look the better bet...

<tuffty/>

 

[damo.h]

^^as above fk on mine with no issues, think fk do do pcd/spacers with steel inserts but cost a little more think it's type b or c something like that, could be wrong. Venom Motorsport near me usually have offers on pairs and could answer any questions

 

[StaceyS3]

I've got h&R spacers where as used to have heavy steel ones and im very impressed with them as i didn't like the idea of that amount load being held on by alloy thread, the h&r ones haven't got an actual helicoil but the best way to describe it is a steel splined insert that is pressed in from the back and has a shoulder on it to prevent it being pulled through

 

[Westy]

I'm running FK PCD adapters same as Damo. They've been on for around 8 months now and I've done a track day with them with no sign of stress or wear. They are TUV approved and top quality.

 

[S3 Paul]

I Recently had to repair a set of wide spacers for one of the lads round my way as they where simply threaded into the aluminium. I fitted helicoils to all the bolt holes and he was happy.
Is there any difrence in the Aluminium used? Thats my main worry,

 

[Speedy Steve]

I have H&R spacers and there great!

 

[DJ_Troopa]

I've got H&R Trak+ hubcentric spacers on the rear. They're 30mm each side, surprisingly light for what they are, defo recommended!

 

[LD3]

I run FK's PCD adaptors 30mm & 25mm and happy with them for what its worth

 

[stevewushu]

Just bought 10mm FK spacers with bolts for the rear, 5mm for the fronts. Looks good and no probs.
Big thank you to Damian at DPM performance for supplying these.
If you want to purchase spacers check out his online shop DPM performance.

 

[Kave]

Mate the germans TUV seal of approval is not granted without stringent analysis. FK are cheapest, as they are a single solid lump of ally. Save your £100 and go for the FK's, no problems here for 10k miles. No decision as far as im concerned.

 

[Marcos]

worth a read - NEVER again will i buy FK products !!!! now with pictures - uk-mkivs

For those who are interested in the calculations as to why FK adapters fail:

Required length of thread engagement (LTE) is defined as a function of tensile strength of the bolt material (TSB), tensile strength of the nut material (TSN) and major diameter of the thread (TMD) like this:
LTE=(TSB/TSN)*0.8*TMD

This assumes the bolt is stronger than the nut, if the opposite is true, invert the TSB/TSN term.
Let's plug in some typical numbers for M12x1.5 threads in 6061 aluminium adapters with SAE 8740 bolts:
TSB=695MPa
TSN=115MPa
Thus, LTE=(695/115)*0.8*12=58mm

Now, if we make the adapters from EN 10025-2 S275JR mild steel:
TSB=695MPa
TSN=380MPa
Thus, LTE=(695/380)*0.8*12=17.6mm

 

[aragorn]

The standard wheel hub isnt much more than 10mm thick.

The hub is only 6-7 threads wide, and the bolts are M14x1.5. Clearly the numbers above need tweaked if the Manufacturer is happy with a 10mm thread engagement, but i do agree that tapping straight into alloy is NOT strong enough unless the threads are much longer.

 

[Westy]

The standard wheel hub isnt much more than 10mm thick.

The hub is only 6-7 threads wide, and the bolts are M14x1.5. Clearly the numbers above need tweaked if the Manufacturer is happy with a 10mm thread engagement, but i do agree that tapping straight into alloy is NOT strong enough unless the threads are much longer.

So far so good with my FKs (25/30mm) and i've been on track with them too. No signs of wear at all. I use the standard wheel bolts to attach the wheel to the alloy adapter but I see the weakest part being the puny bolts they give you to fix the PCD adapter to the standard hub.