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Stevo
14th March 2005, 23:43
Anyone raced speedway on a dirt bike or quad bike?
The local motorbike club is looking at hiring the local speedway track for the day. We have raced the ATVs at speedway a number of times this season and it is a wicked buzz. The first time I did it with just turf tyres and tendency was to drift way wide coming out of the corners as the concrete wall loomed up much too fast.
Since then I have purchased some American Racer speedway tyres and this is a totally different ball game. Now I can fly round the track and with some sort of control which is a bonus.
On two wheelers most riders opt for a soft trials bike tyre just to try and get a little more rear end grip. The worst thing is wear on one side of the tyre.

Anyone ever had a go? Anyone want to??? :banana:

Motu
15th March 2005, 12:23
I haven't ridden a speedway bike but have done what you are talking about,if you look on my Motubike thread you will see me on the Rosebank Speedway track on my Rickman.I also used to race on the dirt track on Waiheke Island,that was a pear shaped track,so a little different,I used to ride a farm quad around there too,and had a go on a Yamaha 3 wheeler dirt track bike with Hoosiers.What sort of surface do they have,loose or hard packed clay?

The best tyres to use on a stockbike are speedway rears,they are made for it of course,come in 19in only,but you won't get much better for that purpose.Next best are competition trials tyres,the hot set up was a winter on the front and summer on the rear,it pays to cut one side of these,but you don't have to - use low pressures,your body weight in stones was the theory...9st,use 9 psi etc,adjust from there.You need a big fat tyre on the front - when you back off and lay it into the turn it will push like you've never felt in your life,you gotta ride it like that to the apex,so you need a tyre that will let you live there.You need a 19 or 18 on the front - a speedway bike runs a 23,but powerslides all the way round,it can be done on a stock bike,but it's not the fast way.

With your quad you need to get right off the seat,just your right leg on the seat,put your head under the bars and get it sideways all the way around.I've never been able to do that,but seen it done often enough.

If you need some real detail set up pointers,I'll get OWLMorris to come online - he held the No1 plate at Rosebank for about 4 years I think,he wrote the Stockbike Solo rules...pages 83 and 84 in your MNZ rule book.

Kickaha
15th March 2005, 18:07
Anyone ever had a go? Anyone want to??? :banana:


yep,let me know and we'll bring some buckets up :banana:

Stevo
16th March 2005, 19:37
yep,let me know and we'll bring some buckets up :banana:
That would be funny to see. I'd laugh my ass off. I have run up to 10psi on the outside tyre on my quad and 9 on the inside but find I get more grip straight line speed and feel from about 8.5 and 7.5 respectively. Still quite high but great feel. Still potential to go faster yet so I'll see what happens on my next outing.
I learnt to ride a three wheeler long before I ever tried four. Would be pretty eerie I imagine?

Motu
16th March 2005, 21:16
Tyre pressure relates to traction - you don't nesessarily need all the traction you can get.Low pressure increases traction,high pressure reduces it - so you can control how you come off the turn,if the presure is too low,or the track sticky (track condition will change over the day) you may hook up too early,or with a big snatch,smooth this out by raising the pressure a bit,if the track has low traction and you have trouble hooking up drop the pressure...it's an exact science that you never get right over the days riding,as you've found,1/2 lb can make a big difference.There's a lot more in it than just going around in a circle that's for sure.

pete376403
17th March 2005, 11:54
I rode at Te Marua (Wellington) for about 15 years. Started with a JAP motor in a (reputedly) Mattingly frame. Migrated this engine to a replica Jawa fram that was made for Gary Petersen. Then exchanged the JAP motors for a 2 valve Jawa. Stuck with this for a while, then got a Weslake motor (and what a piece of shit it was too) Dumped this for a 4 valve Jawa and started having fun again. Put the Jawa motor into a TQ while I was living in Dunedin for a couple of years - blew it apart big time. Salvaged the cam cover and timing cover from that motor, rest was scrap. Bought another 2 valve Jawa and finished my "racing career" with that. Not wildly successful, won a few meetings, didn't win a lot more. But was fun while it lasted. Never crashed hard enough to break any bones but I sure tried!

tlronny
18th March 2005, 06:13
About 8 local boys had a go up here at the Meeanee track a couple of weeks ago after the meeting got rained out so the track was greasy as !
Unfortunately most of us had bald tyres on or the real speedway ones so they were next to useless.
I had 18" Turf Tamers on so it wasnt too bad but just about everyone was spinning out at each end.
It was an absolute blast and I'll be in again if they ask us.
A lowering kit would help heaps but what I did was drop the preload to minimum at both ends which dropped the ride height a couple of inches.
I also flipped the front wheels to increase the width by about 2" a side.
Traction was the key point and I would say it could be quite hard finding just the right amount of slide/traction needed to get round fast !!
Horsepower wasnt a factor really as we had a huge cross section of bikes from a 4x4 Polaris 400 2 stroke to a fully kitted 500 Predator show up and it came down to setup.
Even an old 250 quadracer with a GSXR 400 motor wasnt any good !

Stevo
18th March 2005, 07:55
Lowering is pretty simply done. I took about 4 or 5 hours to do mine but I carefully measured everything so I did a job I was happy with.
I run both 2 inch spacers on the right rear wheel. Made a suspension mount strut for the rear and extended the shock mounting point at the front as you will see by hinging at the base of the A arm.

Stevo

tlronny
18th March 2005, 13:35
Did lowering both ends have a noticeable effect on the ride ?

Stevo
20th March 2005, 22:07
Did lowering both ends have a noticeable effect on the ride ?
Shit yes!
Shouldn't have the front lower than the back either if trying this at home. Causes the front to nose dive even tho I rarely use the brakes at speedway (only if someone cuts across etc) but is to do with weight transfer. I measured the bike before and after lowering. The front is approx 3 inches lower and the back 3 1/2 ish and also the back has more sag than the front. A lot of guys use straps to crank down on their suspension springs and give a lower ride height, but I thought this to be a crap idea. It gives a rough ride as the suspension cannot work which = poor traction and a rougher ride. Is all about lowering the centre of gravity in essence. :ar15:

tlronny
21st March 2005, 07:13
Your method for lowering the front is quite "interesting" - could you not of used some lowering blocks on the lower outer A arms instead or an L plate up top ?
Did you have to change any settings after this or maybe the gearing ?

:niceone:

Stevo
23rd March 2005, 22:10
Hmmmm.
Lowering - Well I could have just added a series of mounts further out on the A arms but the main reason I did what I did was that the steel I used was 30x10 and so hellish strong and I thought if I effed it up I could drill another hole reasonably close to the other and still have strength in between. Added a bit of weight admittedly but compared with most others racing speedway against me I still think I have one of the best set up bikes for it. I am considering doing what you suggest to reduce weight now that I know for sure where and how I want my bike setup.

Gearing - Standard on the Honda is a 14 tooth on the front and a ?? on the back. Set up for 20 inch rear tyres. I have a 15 tooth front sprocket which I put on as my race tyres are 18 inch rears and I found it was a bit slow with the 14 tooth. I use my 20 inch tyres for practising and stuff, and both racing and speedway tyres are 18 inch. If I was trail riding (and generally I don't) I would prob put 20 inch tyres at least for ground clearance reasons, but go to 13 tooth front sprocket as the Honda has a very tall first gear esp noticeable on firebreaks!

Does that help?

Stevo

Stevo
23rd March 2005, 22:13
Edit note. Racing at Nelson Speedway I run in fourth gear with no problems but at Blenheim I am hitting the limiter by 3/4 the way down the straight so next time might try running the 14 tooth front sprocket and running 5th gear?? Gotta find the best setup. :banana:

tlronny
24th March 2005, 06:30
Thanks for that info - sounds like you are in the same development stage as us up here !
Theres quite a bit to it when you get into it.
They run regularly at Palmy now too and I think you have to have nerfs and a lanyard switch as well

:2thumbsup

Stevo
1st April 2005, 00:06
To not have nerfs at speedway is to be slightly suicidal I woulda thought. A kill switch is always a good idea, whether trail riding or racing. Saves you walking so far to your bike when you arse off it and potentially could save your bike, eg from rolling down a hill and off the side when it may have otherwise stopped!
I think to run under MNZ regulations you are supposed to have both.

So are you racing your quad now TLRonny? :Punk:

tlronny
4th April 2005, 06:20
Only that one practice at Meeanee and the trail rides we have up here but will look at Palmy for sure - once I fit the lowering kit and find out if I have to have nerfs or not.
MX is too hard for me on a quad (nanna !)