Trigos and cut down drive pins

[KevinW]

Finally in a position to fit Trigos which I have had for a while. I need to get 8-10mm machined off the back of the rear wheels to make them sit nicely in the wheel arch using the 5 pin Trigo hub adaptors. But this will create a problem for the drive pins: which will then be too long for the reduced depth holes in the wheel.

I think Kirkham did some reduced length pins, but I cant find the thread, and not sure if these are still available. I found another thread this side of the pond suggesting mounting the pins and then cutting them to the right length once mounted, using an angle grinder. Not keen on the latter approach as i think ths will render them unservicable in the event of a problem further down the line.

Any comments/suggestions?

[Roger Bolick]

Purchase a SPARE pin that matches yours. Mount this in a piece of ~1/4" aluminum similar to how yours are mounted to the hub or adapter. This is a pattern.
(pattern needs to fit in each hole on the back of your wheel so Pin is likely near edge)

Take this to the machine shop so the holes can be "deepened" at the same time as the cut, by "leveling" each wheel once.

Advise machine shop:
1. Front of wheel is visible, DO NOT Scratch.
2. Sample Pin mounted in aluminum must sit flush in each hole.
3. Do NOT touch OD of hole, i.e. use a smaller bit
4. Do NOT drill though wheel (seems obvious, but...)

Pin tip design varies wildly... but most are domed, thus a bit with a similar shape, smaller OD than the existing hole, can be used to clearance each hole.

8-10mm is ~0.35 inch, but assuming some existing clearance and a dome bit, its likely the hole just needs to be ~0.1875 deeper, and shaped to fit YOUR pin pattern.

Done properly, it seems a minor amount of material will be removed, i.e. easy.

Good luck.

[LMH]

The drive nuts on my Hurricane were Trigo and used an Allen wrench to tighten the nuts. Seems to me with my extremely poor memory, that Kirkham did make some shorter with a hex on the outside. That allowed the stud to protrude farther into the nut allowing it to be shorter. Was a long time ago though.
I think it was kind of experiment David was doing and not a regular item he produced. Might try calling him and asking.
Larry

[spdbrake]

I read on the Crendon site your car uses Jag XJ brakes/suspension.
IF your suspension is 04 and On it's M12 X 1.5 and I'd recommend using The Peg bolts from Backdraft racing in the 35.5mm length. These are smaller dia and lower profile in head height. Your wheel would need to be indexed 45deg and redrilled to the new dia.
https://www.iconicparts.com/peg-drive-bolts.html

IF your suspension is 63-03 it uses 1/2"-20 studs and Backdraft Pegs won't work.

You could also use the Backdraft hub Adapters as they are thinner than the Trigos but also will have to drilled to 5x120.7mm pattern (XJ 63-03) or 5x108mm pattern (XJ 04 and On)
(Backdrafts use BMW 5x120mm patterns)
https://www.iconicparts.com/peg-drive.html

In that case I'd contact Image Wheels in Tipton (120 miles N of you). I'm pretty sure they can come up with a work-around. Bolt on Centre Lock Adaptors - Image Wheels

[Ron Scarboro]

Any risk of pin breakage with shortening the pins?

I'd like to inset my wheels as much as possible on the rear (up to 1/2 inch) my GT40 on my 6pin hubs.

Thanks,


Ron

[spdbrake]

I don't know what model GT40 you have. If you shorten the tops of the pins you may not have anything for the Allen wrench to work with.

The pins are under Shear and tensile loads. I wouldn't cut or grind anything that gives you less thread engagement at the hubs or studs.

The ERA 427 Jag hub is shown
http://www.erareplicas.com/427man/wh...drive_hubs.pdf

If your GT40 does use Jag hubs these shorten 6 pin hubs from Vintage Wheel would tuck your wheel 1.0" per side.
https://vintagewheelsus.com/index.ph...roducts_id=521

[LMH]

Kevin, this may be the thread you were thinking of. Lots of info in it!
Pin drive bolts splitting Help Please
Larry

[CompClassics]

I am not so keen on the die grinder approach, you would be introducing a lot of heat into a previously heat treated part.

[Mark IV]

Ron,

No issues with your pins as they are effectively "bolts" as opposed to the adapter type pins that are hollow and hold the hub adapter on as well as transfer drive forces. Your wheels are driven by the splines.

BTW thanks for arranging the wheel pickup. CECC is a nice setup!

[KevinW]

Thanks for the comments.
Food for thought that I need to mull over and make some more measurements.