Seat Belt Harness

[kayentaut]

I need to replace my Caterham branded harnesses because they are well past the expiration date. I was watching a Sparco video in which the sales rep mentioned there “… was recent data to show that 2” lap belts are safer than 3” …”

 

Can anyone comment on this? Sparco still recommended the 3” shoulder belts.

 

Thanks in adance,

Jim

[yellowss7]

I believe the 2 inch lap belts allow for a better fit, i.e tighter fit. I have the schroth ones on my Orange car with the two inch belts on the lap, and the modified two inch for the hans on the sholder harness. I have the Three inch Willians ones in the Yellow car and the fit is definitely better in the orange car. Tom

[kayentaut]

thanks for the very quick response!

[Shoe String Racing]

"I believe the 2 inch lap belts allow for a better fit, i.e tighter fit....."

agreed; to be specific, tighter fit means that the 2" belt fits into the pelvic cradle better than the 3".

[coffee break]

I have read in a manufactures information on belts that 2" belts are recommended up to a very high rate of speed. You would need 3" when you approach the sound barrier. :auto:

[DeanG]

My understanding of 2" vs 3" is the amount of give (deceleration) they have during a crash. Depending on the G loading more give may or may not be beneficial. More give = more stretch for a give impact/loading = longer deceleration which is good. Contacting something hard due to more stretch or having additional contortion of your body is bad.

[BruceBe]

It's all of the above. The 3" belts give you more surface area, distributing the load across more of your body. In a 30G impact, which can be generated at almost any reasonable speed, the more surface area the better. 3" belts can be made uncomfortably tight in any car - the issue arises with head/neck restraint devices. HANS devices, in particular, do much better with a 2" shoulder harness. We install hybrid 2"->3" harnesses, to get the best of both worlds. The upper 2" section of the shoulder harness rides very securely on the HANS, and then widens to 3" before meeting the buckle. Sub-belts are 2", and the lap-belts are 3".

 

-Bruce