Hoosier 10 inch tyre CAD

[sunsworth]

Hello All,

My name is Sam Unsworth and I am the Suspension leader at Oxford Brookes Racing for the coming FS year.

I was wondering if anyone has an accurate CAD file of either the Hoosier 6.0/18.0-10 LC0 tyre or the Hoosier 18.0 x 6.0-10 R25B tyre, preferably in a Solidworks or Catia format (although a STEP or IGES file would still be useful). Unfortunately we haven't been able to purchase a tyre to measure first hand (and due to the purchasing system at Brookes the order would take some time to go through) so we would like to get a CAD model as soon as possible to get the design of a 10inch package underway.

Any help would be greatly appreciated.

Thanks in advance

Sam Unsworth

[tromoly]

You could take the tire dimensions from Hoosier's website (http://www.hoosiertire.com/rrtire.htm) and make your own tire, it's worked for my old school for a while.

[sunsworth]

I have considered that but it would be nice to have model which is representative. If not I can always make a start with those dimensions and then once we acquire a tyre adjust the model to suit, was just wondering if anyone on here had an accurate model to hand which they could put up.

I'm pretty sure it would be useful for a number of teams making the switch to 10inch to just have a generic model available from here (which is one of the reasons I started a new thread).

Thanks

[mech5496]

We do have a rough CAD that started from the Hoosier web site dimensions, and updated with actual dimensions once we got the tires back in 2009. It is really rough (only main dimensions correct, no proper sidewall radiuses etc.) but it is OK to check clearance etc., I'll see if I can get our suspension guy to share it.

[JulianH]

I have considered that but it would be nice to have model which is representative. If not I can always make a start with those dimensions and then once we acquire a tyre adjust the model to suit, was just wondering if anyone on here had an accurate model to hand which they could put up.

I'm pretty sure it would be useful for a number of teams making the switch to 10inch to just have a generic model available from here (which is one of the reasons I started a new thread).

Thanks

Why don't you arrange a little trip to Hatfield, visit the University of Hertfordshire, have a beer and borrow a tire for your measurements?

[Swiftus]

I want to point out that old adage that 'everything is rubber', especially tires which actually are rubber. Using the measurements from Hoosier themselves and then designing in some safety margins for the movement of the tire as it flexes is probably going to leave you with so much margin that the actual precise dimensions are not necessary. If you think about it, when the tire is fully inflated it has one shape with certain dimensions, and when it is flat it has another shape with other dimensions.

[sunsworth]

Why don't you arrange a little trip to Hatfield, visit the University of Hertfordshire, have a beer and borrow a tire for your measurements?

Mainly because there is no one in at the moment (that I know of) as I spoke to one of the alumni the other day to discuss engine parts. Could try to arrange that to be honest, but it would have to wait until they started back at uni.

[sunsworth]

I want to point out that old adage that 'everything is rubber', especially tires which actually are rubber. Using the measurements from Hoosier themselves and then designing in some safety margins for the movement of the tire as it flexes is probably going to leave you with so much margin that the actual precise dimensions are not necessary. If you think about it, when the tire is fully inflated it has one shape with certain dimensions, and when it is flat it has another shape with other dimensions.

Swiftus, you are of course right. I completely agree that the dimensions would change pretty dramatically depending on pressures (this is probably one of the reasons why Hoosier don't supply a model). The main reason for an accurate tyre model is to be able to model the widths accurately so that we know how much margin we have with our wing package

[sunsworth]

We do have a rough CAD that started from the Hoosier web site dimensions, and updated with actual dimensions once we got the tires back in 2009. It is really rough (only main dimensions correct, no proper sidewall radiuses etc.) but it is OK to check clearance etc., I'll see if I can get our suspension guy to share it.

If you could then I would be very grateful.

[CWA]

"..is to be able to model the widths accurately so that we know how much margin we have with our wing package.."

Seems fair enough.

With this in mind then, don't forget to consider lateral deflection of the tyre during cornering. I'd say this effect is going to be about an order of magnitude greater than any affect pressure changes will have on your packaging space. To verify these effects, you can either rig up one of your old cars with a gopro and see for yourself, check out onboard online footage of some other teams, or use TTC data (hint - MX, FZ and FY).

[mech5496]

What CWA said ;)