Tires

[Barry]

Any teams that used tires other than Hoosier or Goodyear, can you please contact me. Thanks

Barry Lenart
blenart@visteon.com

[Barry]

Any teams that used tires other than Hoosier or Goodyear, can you please contact me. Thanks

Barry Lenart
blenart@visteon.com

[Disco]

RMIT is going to use Dunlop 10 inche. If your after someone who uses 13 inche dunlop, have a talk to Scott Wordley from Monash.

[Sam]

We looked into the ten inch option and found it way too expensive, wheels from the states were way out of our budget. we're sticking with 13's. I guess you guys need 10's with a thumper for weight issues, Out of interest - where are you blokes getting wheels and tyres from??

Allthough it was a neat little car there was no way the tokyo denki car could fit the 95% percentile driver. It will be interesting to see just how compact your beast turns out!

Sam Graham
Engine Group Leader 2003
UQ Racing

[Eddie Martin]

About the Tokyo car not fitting a 95% percentile driver. At the US comp Justin, who is 6'3", got to sit in the car and his head was well under the 50mm clearance, which was a surprise to everyone. His feet did go past the pedals though. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Eddie Martin
UOW Racing
www.uow.edu.au/eng/racing (http://www.uow.edu.au/eng/racing)

[Scott Wordley]

As disco said we use 6.5" and 8.5" dunlop 13s in an ungrooved wet compound. We've also tested the Avon Hillclimbers and Goodyears but found the dunlops were much better.

Regards,

Scott Wordley & Roan Lyddy Meaney
Monash FSAE Wingmen
http://www-personal.monash.edu.au/~fsae

[Disco]

where are you blokes getting wheels and tyres from??

Allthough it was a neat little car there was no way the tokyo denki car could fit the 95% percentile driver. It will be interesting to see just how compact your beast turns out!

We're getting our tyres through Russell Stuckey (the Victorian Dunlop Motorsport distributor), I believe that's where the monash get their 13"from. I don't think we should have any trouble fitting in the 95th percentile driver. our cheif engineer, Geoff Pearson, is 6 foot 5 and we've been designing around him. If he wasn't such a good driver, we'd tell him to get stuffed! http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Daves]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>We looked into the ten inch option and found it way too expensive<HR></BLOCKQUOTE>

Out of curiosity, why does a 10" wheel/tyre combo cost more than a 13" wheel/tyre combo?

[Disco]

I don't know how much the 13"are, but the 10"dunlops are around the $200AUS each.

[Daves]

Kodiak 10" wheels range from $88.00-$138.00 U.S., but their 13" wheels range from $277.00-$400.00. You can get 2 sets of 10" wheels for the price of 1 set of 13" wheels!

[Sam]

We couldn't find anyone that made custom 10" rims in Australia. Would have had to get them from the states! $$$ for us. not for you. and we can fit OEM calipers in 13"s

We are getting 2 sets of 13"s done by different crowds here in aust can't remember who (engine man) I believe we are planning on making one set of centers ourselves.

I am 6 foot 6, not exactly 95% percentile. our 2002 car did not fit me under the rules. I could test it though http://fsae.com/groupee_common/emoticons/icon_smile.gif

Sam Graham
Engine Group Leader 2003
UQ Racing

[Disco]

Sam,
We had to order our rims through a company called JMC racing in Belmont, NSW. He had to order them from the states. He done us a reasonable deal (8 rims for $1000). There 10x6" douglas rims, I believe that RIT uses the same rims.

[Scott Wordley]

Disco,

We have a whole bunch of brand new Dunlop 10s left over from our 1st year car. Would you guys be interested in buying them?

Regards,

Scott Wordley & Roan Lyddy Meaney
Monash FSAE Wingmen
http://www-personal.monash.edu.au/~fsae

[Disco]

What sizes (as in width) are they? If there the right sizes, for sure we'de be interested.

[Daves]

Tires are no good after 5 years, so how bad is the hardening affect after 1 year on race tires?

[Travis Garrison]

$88 a corner for 10" wheels seems a bit steep...

We have traditionally purchased 10" Douglas wheels for ~ $25 per wheel and added stiffeners. Total wheel weight came to 3.7 lbs for our latest car...and probably could be a little lighter still if we really worked at it...

Travis Garrison
WWU

[All Wheeler]

http://fsae.com/groupee_common/emoticons/icon_smile.gif Anyone game to give away the static coefficient of friction of their tyres?
Ball park estimates are good!

[clausen]

How have people decided which tyre widths to use?

I guess the rear size is a matter of compromising the larger tyre having more rubber on the road to a narrower tyre warming up quicker?

Any thoughts?

Regards

Paul Clausen
Uni of Adelaide

[MercerFSAE C. Burch]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Anyone game to give away the static coefficient of friction of their tyres?
Ball park estimates are good!<HR></BLOCKQUOTE>

Goodyear is game... go to their Formula SAE tire site. http://www.racegoodyear.com/sae.html It should have all the information you need for their 10in and 13in. FSAE-spec tires.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> How have people decided which tyre widths to use?

I guess the rear size is a matter of compromising the larger tyre having more rubber on the road to a narrower tyre warming up quicker?<HR></BLOCKQUOTE>

Check your Milliken book. In there it says something about a longer narrower contact patch having better breakaway characteristics than a short and wide patch. This helps a great deal in letting the driver feel when the tires are at the limit.

I haven't had the luxury of testing these tires but there must be some reason the top teams all use 13x6.5 tires instead of 10x7 or 13x8. It could also be due to heating the tires too, I guess!?

-Christopher

Mercer University - Drive!
Coming to an auto-X course near you, 2004!

[leclercjs]

Hi,

Any of you had problems with your goodyear tyres this year?? We had a lot of problems with them. They were delaminating and even after changing one at the competiton, 2 others were starting to do the same back home. We have take pictures but the rep at the FSAE Goodyear truck back in Detroit told us ''it is simply esthetic''. YEah right!!! I know that McGill is having the same problem and me and the director of McGill are planning to send a pretty nice letter to Goodyear with a lot of explanations and pictures of those badly constructed tyres.

Anyway, I would like to know if other teams than us and McGill had the same problemes with their Goodyear tyres this year at competiton or post-competition

Jean Sébastien Leclerc
Dir. Formule SAE Poly 2004
http://www.fsae.polymtl.ca

[leclercjs]

oops, sorry for the french word, problemes means problems.

Jean Sébastien Leclerc
Dir. Formule SAE Poly 2004
http://www.fsae.polymtl.ca

[Denny Trimble]

After we learned our "directional mounting" lesson (delamination across the width of the tire), the Goodyears still develop circumferencial separation grooves (see picturehttp://fsae.com/groupee_common/emoticons/icon_smile.gif

http://students.washington.edu/dennyt/goodyear.jpg

University of Washington Formula SAE ('98, '99, '03)

[dancin stu]

just started looking more into tyres now for next year, looking like 13s for us, after 2 years of running 10s, and 2 years of struggling throught the brake testhttp://fsae.com/groupee_common/emoticons/icon_wink.gif

thing that gets me though is the tyre companies reluctane ot give data. every time i phone up i get "thats too secret to release, the other companies might read it" but the way i see it is that other companies will have the means of testing tyres and hence generating a set of data - probably a lot more comprehensive than the small amounts that do get released - and comparing the tyre to their own.
when telling this to distributors you normally get a 'yeah but........ er .....er!'

i think someone said they managed to get dunlop to supply data, is this true.

could be tempted running 10s, the dunlops on this years car were very soft and seemd to get up to temp quite fats, but without some sort of data i fell it is a bit of a waste of time deciding upon geometries etc when you dont know what the tyre wants!!!

[woollymoof]

Claude Rouelle, at his seminar in Melbourne just recently, said that its a two way street. If you do testing and supply the tyre company with the results, results that they would be interested in, then they are more likely to respond with the data you are after.

Cheers,

Kirk Veitch
Swinburne University of Technology

[RacingManiac]

About those Goodyears, yeah we have the same problem with them, we ran through 3 sets I think in testing and all of them at the end are worn to the core, and on the way there layers and layers are peeling off.....When we did our tire testing down in Ohio we found out about that problem, apparently that's how they were constructed and how they are designed to wear...sure wasn't very nice when one of them worn right through....

Andrew Wong
1st year monkey @ UofT Racing

[All Wheeler]

From what I have found, most racing compounds can give a maximum coefficient of friction of 1.2, and manufacturers are reluctant to tell you (with any degree of certainty) that you can get over a value of 1. Can anyone verify this? One team told me that they were getting a coefficient of friction of 1.7!!!

[MercerFSAE C. Burch]

Really soft racing compounds like what we use must have a coefficient of friction greater than 1.5, when loaded with no more than 200 lbs. Check my previous post for a link to the goodyear fsae tire site. They have graphs on there of tire force versus slip angle for various loads.

From one of the graphs: At a slip angle of 8 degrees with a -1 degree camber and a vertical load of 250lb, the Goodyear D1385 20x6.5 tire can produce a horizontal force of about 700lb. This would be equal to 2.8g for that tire. Unfortunately, with the wheelbases, Cg heights, and the lack of downforce that most FSAE teams run, the car would flip before it managed to corner that much! Also, due to weight transfer, the loaded tires would have around 300 or so lbs on them, moving the curve to about 750 lbs of horizontal force, for a little over 2g, again assuming perfect conditions. Add in "non-perfectness", and 1.7g seems very reasonable for an FSAE car to pull.

(All data on this page is the subject of sketchy mathematics at best and is the sole scribblings of myself, use at your own risk)

-Chris
Mercer University - Drive! Motorsports
Coming to an autocross course near you, May 2004!

[inamo]

Keep an eye on your Douglas 10" wheels we've used them for the past few years but this year had two fail on us..... They are cheaper but it's another one of those trade-offs!

[Jarrod]

try speedway formula 500 wheels if you want 10's, spun aluminium three piece, so you can make your own centers.

[Big Bird]

The Formula 500 wheels are nice and light, but something to remember is that they don't run brakes inside their wheels so most of the wheels available in Oz have a really small internal diameter, (something like 8 inches). I got onto Weld Wheels in the US, they have a large diameter bell half available in 3 and 4 inch wide sizes, so you may need to import these for your inside fronts and use the locally available stuff for the rest.

Hope this is helpful for Oz teams looking at 10 inch wheels. We ended up using the Douglas option just for convenience - hoping inamo's mail above doesn't hold too much truth!

Geoff Pearson
RMIT FSAE 2003

Design it. Build it. Break it.

[MikeWaggoner at UW]

Quote:
"Keep an eye on your Douglas 10" wheels we've used them for the past few years but this year had two fail on us..... They are cheaper but it's another one of those trade-offs!"

That's because they're thin aluminum. All you need to do is make large hubs and reinforcers. Without reinforcers they'll deflect a ton.

http://dot.etec.wwu.edu/fsae/v35/Pictures/Wheels/DSC01617.JPG

UW FSAE
The views of Mike Waggoner are not necessarily the views of the UW FSAE team.