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Handbrake under steering wheel, IVA compliant?
Slimy38 - 26/2/24 at 06:14 PM

I want my handbrake out the way, so I've positioned it under the steering wheel. It's reachable when in the seat and can still be operated, so in terms of the parking brake IVA requirement (capable of operation with one hand on the wheel) it's all good.

It's now the 'interior fittings' requirement that I want to clarify. The first thing I check was the exemption range behind the steering wheel. Unfortunately it's about an inch lower than the steering wheel (on the horizontal plan). So I believe it's within range of the 100mm sphere, and most definitely contactable by it.

The handbrake itself (standard MX5 handbrake) is sufficiently rounded to cover the 'blunted' requirement, is that sufficient or do I need more?


ReMan - 26/2/24 at 06:38 PM

Have you got a picture?
I'm sure its position is fine in principle, its just as you say whether it creates any hazardous projections.
Might just need the mountings covering wit the hardboard type finishing sheet, if Im imagining it correctly


Slimy38 - 26/2/24 at 06:45 PM

quote:
Originally posted by ReMan
Have you got a picture?
I'm sure its position is fine in principle, its just as you say whether it creates any hazardous projections.
Might just need the mountings covering wit the hardboard type finishing sheet, if Im imagining it correctly


Aye, I was going to post a picture once I've updated my blog (easier to get the link that way). Good point about the mounting brackets, it's effectively raw metal at the moment so yes they will need covering.


adithorp - 26/2/24 at 06:49 PM

quote:
Originally posted by ReMan
Have you got a picture?
I'm sure its position is fine in principle, its just as you say whether it creates any hazardous projections.
Might just need the mountings covering wit the hardboard type finishing sheet, if Im imagining it correctly


I'd agree with all that. Also, I've got a vague memory of someone doing similar before.


Slimy38 - 26/2/24 at 07:02 PM







[Edited on 26/2/24 by Slimy38]


Mr Whippy - 26/2/24 at 07:38 PM

quote:
Originally posted by Mr Whippy
yeah I'm quite familiar with this kind of thing as the prefect has it's handbrake next to the wheel on the dash, I think it is common on old American cars too. On your photo there is a slightly concerning sharp looking edge, looks great for removing knee caps in a crash. In the Westfield build manual, it warns to cover all exposed bolt heads with plastic caps on the top of the foot well, so I expect it to be an area inspectors will be looking for potential injury. Although it's behind the wheel, I think that more refers to stuff sticking out your dash than underneath, for example if you had big bolts sticking down holding the column on I'd expect a fail from that too.

Description
Description


On my prefect (probably on heaps of other old cars) the lever that does the mechanical advantage is located else where, in the Prefects case under the floor (tall car) and there is just a flexi cable that attaches to a ratchet lever. It might give you some idea's... One other alternative might be to get the rear callipers off a modern car like my sisters Golf that has an electric handbrake or a kit for fitting one for disabled drivers, such as Carobrake electric parking brake or Hollin Applications Ltd one, etc.

Description
Description


Above is the Prefects nonsense pile of links that makes up its brakes. But circled is the lever giving you the mechanical advantage.





[Edited on 26/2/24 by Mr Whippy]


scudderfish - 26/2/24 at 07:55 PM

I thought that was how it was done on the Dax Rush


jacko - 26/2/24 at 08:10 PM

Bigger steering wheel or lower the steering wheel by 1ins with a block under the bracket


Slimy38 - 26/2/24 at 08:59 PM

quote:
Originally posted by Mr Whippy
yeah I'm quite familiar with this kind of thing as the prefect has it's handbrake next to the wheel on the dash, I think it is common on old American cars too. On your photo there is a slightly concerning sharp looking edge, looks great for removing knee caps in a crash. In the Westfield build manual, it warns to cover all exposed bolt heads with plastic caps on the top of the foot well, so I expect it to be an area inspectors will be looking for potential injury. Although it's behind the wheel, I think that more refers to stuff sticking out your dash than underneath, for example if you had big bolts sticking down holding the column on I'd expect a fail from that too.


I will have to take care of both brackets, they're only a couple of minutes post-weld here so they'll be trimmed and shaped to be a lot more 'kneecap friendly'. You have a good point though, I do need to see what is exposed downwards rather than what is just viewed/impacted from the front.


Mr Whippy - 26/2/24 at 08:59 PM

Growing to like it tbh, but yes round off the corner of that big plate as that's dangerous. I wonder if it will be interesting extracting your legs from under the steering wheel with the brake on and the seats in place?

Have a look at the Westfield build manual if you haven't seen it before, it's really good and free to download. I spent hours reading it.

linky

[Edited on 26/2/24 by Mr Whippy]


Slimy38 - 26/2/24 at 09:05 PM

quote:
Originally posted by scudderfish
I thought that was how it was done on the Dax Rush


Aha, I wondered whether there was a manufacturer that did it as standard, I'll see if there are any build diaries still online for the Rush. Thanks.


Slimy38 - 26/2/24 at 09:07 PM

quote:
Originally posted by Mr Whippy
Growing to like it tbh, but round off the corner of that big plate as that's dangerous. I wonder if it will be interesting extracting your legs from under the steering wheel with the brake on and the seats in place?


I've already tested that! My knees get to the wheel before they get to the brake, even when it's fully on.


adampage - 27/2/24 at 11:42 AM

Hey - you've probably seen one of these but here's a good pic of the Caterham one on pass side

https://collectingcars.imgix.net/012210/MMP-52.JPG?fit=clip&w=2000&auto=format,compress&cs=srgb&q=85

You can see the passenger's knees might be a bit further away than yours, but similar risk I suppose.

Can you pad yours a bit, rollcage padding or something like that?

Good luck!
Ad


nick205 - 27/2/24 at 11:48 AM

I can understand the logic of wanting to avoid having the handbrake lever on the top of the centre tunnel. It was located here on my MK Indy (manufacturer fitment). Easy enough to fit and setup, but it was right in the way of my left elbow when driving.

If building again I'd be aiming to locate the lever on the passenger side of the centre tunnel.

Or try and have a push-button handbrake (like many tin tops now have) with a dashboard / centre tunnel push-button.


Slimy38 - 27/2/24 at 04:32 PM

quote:
Originally posted by adampage
Hey - you've probably seen one of these but here's a good pic of the Caterham one on pass side

https://collectingcars.imgix.net/012210/MMP-52.JPG?fit=clip&w=2000&auto=format,compress&cs=srgb&q=85

You can see the passenger's knees might be a bit further away than yours, but similar risk I suppose.

Can you pad yours a bit, rollcage padding or something like that?

Good luck!
Ad


That's actually what I first considered (in terms of the handle being above the tunnel), but putting it there and giving it a go I found it very uncomfortable. It's why I went with my second choice of under the steering column.

Good shout about the rollcage padding, that would work nicely. What is an IVA compliant fixing system now, I believe they don't approve of tie wraps anymore? I'd probably glue it to be honest.


Slimy38 - 27/2/24 at 04:34 PM

quote:
Originally posted by nick205
I can understand the logic of wanting to avoid having the handbrake lever on the top of the centre tunnel. It was located here on my MK Indy (manufacturer fitment). Easy enough to fit and setup, but it was right in the way of my left elbow when driving.

If building again I'd be aiming to locate the lever on the passenger side of the centre tunnel.

Or try and have a push-button handbrake (like many tin tops now have) with a dashboard / centre tunnel push-button.


That's true, I wanted to avoid it mainly because it looks nicer (in my opinion) but yes it is where your left elbow lives. I did consider recessing it or having it on the passenger side (like it was on the MX5 donor), but again I preferred it to be out the way.


adampage - 27/2/24 at 05:23 PM

I bought a couple of BMX handlebar pads actually, rather than rollbar, they come with neat fabric 'tubes', with velcro to hold them, it looked almost factory fit and IVA liked it.
(Admittedly it was on headlight bar rather than handbrake, but still tested with the sphere, and definitely visible).


quote:
Originally posted by Slimy38
quote:
Originally posted by adampage
Hey - you've probably seen one of these but here's a good pic of the Caterham one on pass side

https://collectingcars.imgix.net/012210/MMP-52.JPG?fit=clip&w=2000&auto=format,compress&cs=srgb&q=85

You can see the passenger's knees might be a bit further away than yours, but similar risk I suppose.

Can you pad yours a bit, rollcage padding or something like that?

Good luck!
Ad


That's actually what I first considered (in terms of the handle being above the tunnel), but putting it there and giving it a go I found it very uncomfortable. It's why I went with my second choice of under the steering column.

Good shout about the rollcage padding, that would work nicely. What is an IVA compliant fixing system now, I believe they don't approve of tie wraps anymore? I'd probably glue it to be honest.


Rod Ends - 27/2/24 at 05:28 PM

Lotus 7 series 1 had under-dash handbrake.

Lotus 7 series 1 dashboard
Lotus 7 series 1 dashboard