157 replies to this topic

[Spitfire Engineering]

The 'which toe link kit' is a question I'd like answered.  I really like the Nitron one with the different theads on the joints.  I believe that rather than one RH and one LH thread they have two the same but with different pitches so the adjustment is finer.  It's a little academic thoughas I don't believe Nitron make them anymore.  The spitfire ones look the best available kit to me although I do have a few issues in that my subframe doesn't have the locating slot parts

 

If it is the adjuster option that you liked on the Nitron we have offered an option on this for about 7 years! it's a shorter bar with a seperate adjuster.

Not popular though.

 

Locating slot parts??

If you are refering to the vertical slot in the bracket? that is only used for the brace. Once the brace position is finalised the hole in the brace is used as a guide to  drill through to the 

subframe. The slot indicates the upper and lower limits of where the hole can be placed.

 

Otherwise the slot is not uses, just the four bolts as with all the other models.

 

There are three brace options now by the way, positioning is based on exhaust position.

We have a fiiting spec sheet which shows you how to determine which if any braces can be fiited to the VX.

 

[FLD]

The 'which toe link kit' is a question I'd like answered.  I really like the Nitron one with the different theads on the joints.  I believe that rather than one RH and one LH thread they have two the same but with different pitches so the adjustment is finer.  It's a little academic thoughas I don't believe Nitron make them anymore.  The spitfire ones look the best available kit to me although I do have a few issues in that my subframe doesn't have the locating slot parts

 
If it is the adjuster option that you liked on the Nitron we have offered an option on this for about 7 years! it's a shorter bar with a seperate adjuster.
Not popular though.
 
Locating slot parts??
If you are refering to the vertical slot in the bracket? that is only used for the brace. Once the brace position is finalised the hole in the brace is used as a guide to  drill through to the 
subframe. The slot indicates the upper and lower limits of where the hole can be placed.
 
Otherwise the slot is not uses, just the four bolts as with all the other models.
 
There are three brace options now by the way, positioning is based on exhaust position.
We have a fiiting spec sheet which shows you how to determine which if any braces can be fiited to the VX.
 

 
Sounds like you have it all covered! 
 
The locating lugs I refer to are usually part of the subframe.  These are like half washers brazed on before galvanising that are used to stop the toe link ball joint rotating when you torque it up. 
 
The ones you can see on this 'tired' subframe.


Here's mine! Yikes.


My plan would be just to turn some HE15 to make replacement parts that don't have the slot fitting but thought I'd mention it first.

Edited by FLD, 26 April 2015 - 10:47 AM.

[pete-r]

We sent you a message on here Pete, thanks.  

Email sent, cheers.

[Captain Vimes]

You need to have it milled from carbon carbon panels from the leading edges on the space shuttle. Using only 26 year old virgins as the engineers.

Sounds like what I need, I'm just struggling to find any engineers that are suitably qualified.

[Zoobeef]

At least you're not in the north, you'd struggle to find any virgins at half that age.

[Spitfire Engineering]

 

 

The 'which toe link kit' is a question I'd like answered.  I really like the Nitron one with the different theads on the joints.  I believe that rather than one RH and one LH thread they have two the same but with different pitches so the adjustment is finer.  It's a little academic thoughas I don't believe Nitron make them anymore.  The spitfire ones look the best available kit to me although I do have a few issues in that my subframe doesn't have the locating slot parts

 
If it is the adjuster option that you liked on the Nitron we have offered an option on this for about 7 years! it's a shorter bar with a seperate adjuster.
Not popular though.
 
Locating slot parts??
If you are refering to the vertical slot in the bracket? that is only used for the brace. Once the brace position is finalised the hole in the brace is used as a guide to  drill through to the 
subframe. The slot indicates the upper and lower limits of where the hole can be placed.
 
Otherwise the slot is not uses, just the four bolts as with all the other models.
 
There are three brace options now by the way, positioning is based on exhaust position.
We have a fiiting spec sheet which shows you how to determine which if any braces can be fiited to the VX.
 

 

 
Sounds like you have it all covered! 
 
The locating lugs I refer to are usually part of the subframe.  These are like half washers brazed on before galvanising that are used to stop the toe link ball joint rotating when you torque it up. 
 
The ones you can see on this 'tired' subframe.


Here's mine! Yikes.


My plan would be just to turn some HE15 to make replacement parts that don't have the slot fitting but thought I'd mention it first.

 

 

 

OK now I see.

Well it is no issue from our perspective as the fasterer is a bolt, so no requirement for the slot anyway, and the VX slot as you mentioned was add on to the load bearing surface so no issues there either. (The toyo engined Elises had a hardened slotted washer which was integral to the strength).

 

And the fact the normal collets will not fit is not an issue either, it just means it needs a custom collet, as all kits are made to order anyway it is not a big deal.

 

Now I think about it, it is preferable! I've never liked the slotted setup as it limits the surface area available for load bearing, without the added bits you can use a large round collet instead.

 

[Spitfire Engineering]

 

 

The 'which toe link kit' is a question I'd like answered.  I really like the Nitron one with the different theads on the joints.  I believe that rather than one RH and one LH thread they have two the same but with different pitches so the adjustment is finer.  It's a little academic thoughas I don't believe Nitron make them anymore.  The spitfire ones look the best available kit to me although I do have a few issues in that my subframe doesn't have the locating slot parts

 
If it is the adjuster option that you liked on the Nitron we have offered an option on this for about 7 years! it's a shorter bar with a seperate adjuster.
Not popular though.
 
Locating slot parts??
If you are refering to the vertical slot in the bracket? that is only used for the brace. Once the brace position is finalised the hole in the brace is used as a guide to  drill through to the 
subframe. The slot indicates the upper and lower limits of where the hole can be placed.
 
Otherwise the slot is not uses, just the four bolts as with all the other models.
 
There are three brace options now by the way, positioning is based on exhaust position.
We have a fiiting spec sheet which shows you how to determine which if any braces can be fiited to the VX.
 

 

 
Sounds like you have it all covered! 
 
The locating lugs I refer to are usually part of the subframe.  These are like half washers brazed on before galvanising that are used to stop the toe link ball joint rotating when you torque it up. 
 
The ones you can see on this 'tired' subframe.


Here's mine! Yikes.


My plan would be just to turn some HE15 to make replacement parts that don't have the slot fitting but thought I'd mention it first.

 

 

Meant to add this would made in 7068 as standard, over twice the yield/UTS of HE15

 

Gaz

 

[Spitfire Engineering]

I have posted this across from the SELOC forum as it contains information regarding high spec bolts.

 

 

[color=rgb(0,0,0);font-family:Verdana, Arial, helvetica, sans-serif;font-size:12px;font-weight:normal;]Quote:[/color]Originally posted by jbt_se
I broke one outer toe link bolt last year (luckily in slowest corner of the track). The bolt broke at the thread root which is the weakest point of the bolt. One problem with the kit is that it uses standard bolts with way too much thread on the bolt and as a result of this the thread root ends up just between the upright and the spacer which is the shear point.

This is true if the upper collet design is loose in the upright for two reasons.

First, if the entire assembly can slide sideways until the bolt contacts the side of the hole in the upright, then this contact point now becomes the fulcrum, this will a impart a very high shear force on the bolt.
If the collet hits the side of the recess first then the outer side of the collet becomes the fulcrum and most of the applied forces are now taken as increased tension on the bolt. (as an added bonus you reduce the mechanical advantage at the same time, as the edge of the collet is much further away from the centre of the bolt than the edge of the bolt! 

Although the bolt will probably still fail at the same point due to excess tension (regardless if it is at the entry to the upright or completely out of it) but if this section is also on the fulcrum it is easy to see how it is overloaded easier now, being at the physical point of application of the shear forces which will include contact deformation as well.

So plan A is to make sure the collet is close fitting in the upright recess to stop the bolt sliding sideways and making sure the collet takes some of the shear directly

Secondly is what happens after the bolt stretches (things are already not acceptable).
In the loose collet case, the external assembly will rotate around the contact point until either the collet hits the side of the upright (this may be too late for the bolt or at least it will start the cycle which will cause it to fail later) 
Now a very important observation becomes evident IF the collet design is not going to stop assembly rotation then, ironically, you would be better with an 8.8 bolt as at least this is less likely to fail first time.

If during rotation the collet touches the upright, or is already touching the upright then the collet is the new fulcrum with a much reduced load on the bolt, bizarrely the forces may even be reversed on the bolt as the collet rotates on the new fulcrum.

So plan B is to make sure the collet is close fitting so if the bolt does yield any motion is restricted to a few microns before the collet does the work. In this case a 10.9 is a better option as the risk of bending is almost zero.

Luckily for us plan A and plan B are the same 

So, in conclusion this is not just a simple bolt failure it is more a design issue.
The choice of 8.8 or 10.9 is a function of the collet design, 10.9 may not be the best choice.

What is the best choice is a very close fitting collet made from something really hard like Ray Winstone, or 7068, this allows you use a 10.9 and get all the benefits without most of the risk.

Even better ream the upright to 12mm, and use an M12 x 8.8 

 

[pete-r]

Spoke to Gaz at Spitfire today and going for one of his kits. Thoroughly nice chap, I was trying to keep up but he knows more than I ever will!!!

[oblomov]

What torque values are we talking about on all these various toe link options?

[Spitfire Engineering]

M12 fastener and bearing conversion kits for aftermarket toe links

 

Please see the modification forum for details

 

Gaz

[Zoobeef]

Just replaced the toe links with new bits.

 

Found that to torque the bolts properly (ie on the nut side) you have to remove the caliper. Although,  after removing and refitting a couple of times and testing the torque on both sides it seems to be the same.

 

Before the day I can check the torque the proper way but on the day for random checks is doing from the head end going to be sufficient?

[stevey.d]

M12 fastener and bearing conversion kits for aftermarket toe links   Please see the modification forum for details   Gaz

If access to top and bottom of bolt is difficult for a frequent torque check, would it not be better to offer a spindle similar to nitrons s99? Once torqued the clamp load should be maintained as the loads are directed into the hub with no 'play' as with when using spacers/collets etc? I'm looking into upgrading mine as you know, I have the tapered outer hub type So I presume the spindle would be the strongest option? Thanks

[Spitfire Engineering]

 

M12 fastener and bearing conversion kits for aftermarket toe links   Please see the modification forum for details   Gaz

If access to top and bottom of bolt is difficult for a frequent torque check, would it not be better to offer a spindle similar to nitrons s99? Once torqued the clamp load should be maintained as the loads are directed into the hub with no 'play' as with when using spacers/collets etc? I'm looking into upgrading mine as you know, I have the tapered outer hub type So I presume the spindle would be the strongest option? Thanks

 

 

[Spitfire Engineering]

 

 

M12 fastener and bearing conversion kits for aftermarket toe links   Please see the modification forum for details   Gaz

If access to top and bottom of bolt is difficult for a frequent torque check, would it not be better to offer a spindle similar to nitrons s99? Once torqued the clamp load should be maintained as the loads are directed into the hub with no 'play' as with when using spacers/collets etc? I'm looking into upgrading mine as you know, I have the tapered outer hub type So I presume the spindle would be the strongest option? Thanks

 

 

 

 

It is an option that has been available for about 10 years  

But you still need to access the top as that is what holds it in place as it did with the Nitron.

 

Account still not sorted so no images  

 

As for it's strength, not really, both the M12 conversion and the solid spigot conversion are both so much stronger than the inner fastener setup that neither will option will be the weakest link (ha ha).

The inner fastener will always fail first so it is academic.

And the bolt setup is much cheaper as well.

 

 

 

 

 

[Spitfire Engineering]

Just replaced the toe links with new bits.

 

Found that to torque the bolts properly (ie on the nut side) you have to remove the caliper. Although,  after removing and refitting a couple of times and testing the torque on both sides it seems to be the same.

 

Before the day I can check the torque the proper way but on the day for random checks is doing from the head end going to be sufficient?

 

In this application Mark there is little difference in result should you torque the bolt. (you can easily test this empirically by reversing the tools after the initial set, any difference, +/- 1 or 2nm can be applied in subsequent bolt sets).

Both nut and bolt have a similar bearing surface area and both (I assume) are placed on a new, correct washer, both have similar plating.

Surface friction on the shank is negligable and can be negated by lightly oiling first anyway. At M10 x 90mm torsional wind up will be minimal and not effect the bolts properties. (with an M12 it is even better).

I assume all the other corrections for lock-nut type etc have been appled to the original torque figure.

 

That should make it much easier in future  

 

[stevey.d]

 

 

M12 fastener and bearing conversion kits for aftermarket toe links   Please see the modification forum for details   Gaz

If access to top and bottom of bolt is difficult for a frequent torque check, would it not be better to offer a spindle similar to nitrons s99? Once torqued the clamp load should be maintained as the loads are directed into the hub with no 'play' as with when using spacers/collets etc? I'm looking into upgrading mine as you know, I have the tapered outer hub type So I presume the spindle would be the strongest option? Thanks  

   

  It is an option that has been available for about 10 years   But you still need to access the top as that is what holds it in place as it did with the Nitron.   Account still not sorted so no images     As for it's strength, not really, both the M12 conversion and the solid spigot conversion are both so much stronger than the inner fastener setup that neither will option will be the weakest link (ha ha). The inner fastener will always fail first so it is academic. And the bolt setup is much cheaper as well.          

So I assume its only the early m10 hub style that fail? As the tapered joint is larger? Have there been no failures of the inner joint then? Seems like unless you have a cross brace or larger inner joint you move the problem to the inner? Steve.

[Spitfire Engineering]

 

 

 

 

M12 fastener and bearing conversion kits for aftermarket toe links   Please see the modification forum for details   Gaz

If access to top and bottom of bolt is difficult for a frequent torque check, would it not be better to offer a spindle similar to nitrons s99? Once torqued the clamp load should be maintained as the loads are directed into the hub with no 'play' as with when using spacers/collets etc? I'm looking into upgrading mine as you know, I have the tapered outer hub type So I presume the spindle would be the strongest option? Thanks  

   

  It is an option that has been available for about 10 years   But you still need to access the top as that is what holds it in place as it did with the Nitron.   Account still not sorted so no images     As for it's strength, not really, both the M12 conversion and the solid spigot conversion are both so much stronger than the inner fastener setup that neither will option will be the weakest link (ha ha). The inner fastener will always fail first so it is academic. And the bolt setup is much cheaper as well.          

So I assume its only the early m10 hub style that fail? As the tapered joint is larger? Have there been no failures of the inner joint then? Seems like unless you have a cross brace or larger inner joint you move the problem to the inner? Steve.

 

 

With the standard setup Steve it can be either end as the failure usually comes on the threaded section, so all the extra strength in the heavy tapered section is not utilised.

(The ball joints also wear but unless ignored normally does not result in an early failure, i.e detachment).

 

With aftermarket options there is usually a double shear bracket fiited onto the subframe, as long as the bracket is of heavy enough construction and well fastened so the bolt motion is fully resisted (hence the heavy insert washer into the bracket) then the shear force on the bolt is spread across both the subframe and the bracket, the exact amount can be calculated by the ratio of distances from the centre of the rod end ball to each support respectively.

 

The brace is a nice option for the VX but this is more to do with resisting the lateral distortion of the subframe. Some brace options utilise the mounting for a double shear setup negating the need for a subframe mounted bracket.

 

A large inner joint is used by ourselves for several reasons but mainly for longevity, but the fastener will always be the weakest point probably by a whole order of magnitude.

 

Gaz