Period 5 tyre recommendations

[balanse]

After "drinks in the shed" recently it seems I have been given access to a 197(something) Rickman Ronda CB750, to have a bit of a punt around on for the rest of the Vic Interclub series this year.

It should be a hoot but the machine hasn't been started in a few years and with Phillip Island on in a few weeks I have a sh1tload of work to do to get the thing ready.

A question that I have no idea on (one of many actually) is 18inch rubber.

Does anybody have the goods on what's popular for period 5 racing in 18 inch tyres. (18 x 4.10 front and 18 x 4.85 - almost 5 inches wide!!! - rear)

[aardvark]

I'm off to have some new tyres fitted to my RD tomorrow. I was running with the Bridgestone BT45's (I think they are 45's), but the tyre of choice at the moment seems to be the new Dunlop's that a lot of the blokes are running.

I'm not sure what the model designation is, but can find out for you.

[balanse]

Thanks Jase I'd be interested to know about the Dunlops.

Started pulling the thing down to clear some of the problems up and man theres a sh1tload of stuff that goes wrong with a bike just by leaving it sit around.

Biggest problem at the moment seems to be rubber bits gone hard and brittle (like the inlet manifold rubbers).

[MadKaw]

I think Avon are one of the few who make tyres in those sizes..
I'm sure Gos will have the hot tip..

[Strika]

Greg, I can't dunno what the guys are running now?? Most I think have slicks! But the hot set up used to be Metzler comp K's! Check to see what Metzler now do in the required sizes, they used to be the ducks way back, so I'm sure they would have a modern equivelent. I hope to see you out at the Island on the 2nd mate. Just depends how I go with work and I've got to be best man and MC at a wedding on the saturday, so it will be a day trip for me at best if I make it.

[Phil]

Greg, I can't dunno what the guys are running now?? Most I think have slicks! But the hot set up used to be Metzler comp K's! Check to see what Metzler now do in the required sizes, they used to be the ducks way back, so I'm sure they would have a modern equivelent. I hope to see you out at the Island on the 2nd mate. Just depends how I go with work and I've got to be best man and MC at a wedding on the saturday, so it will be a day trip for me at best if I make it.

yep, if you want to be on the pace in period 5 you need slicks. period 4 use treaded tyres.

all the period 5 bikies in the island wsbk supports had 17in rims and slicks, 4.5 i think is as thick as the rear can be but dont quote me on that. kenny the woose is the FE guru

[Gosling1]

Check that rear wheel width Balanse, as Phil says, the maximum width rear in P5 is 4.5" - most punters use 17* wheels as well........if this is not an option on the Rickman (and probably won't be), then you need to go looking for Avon's, I think AM23 ?? is the tyre of choice for all the P4 junkies who are restricted to 18" treaded tyres only.

When I raced on skinny wheels, the rear was only a 3.5" Akront, I could squeeze a 140/70 x 18 Dunlop GPR70 on it no worries - even though the GPR's are 250/400 class rubber, if you are only doing club rounds with a maximum of 5 laps per leg (or thereabouts), then the GPR's will be fine. They only start *walking around* at the end of 10-lap feature races !!

You may even be able to fit a Metzeler Laser M33 to the front in 18", these are a really good tyre (if you can't access slicks), just run it at 30psi for best grip.

Good luck mate .

[aardvark]

Just reading the 2007 rule book.

Period 5.

Unless otherwise contained in the machine's original specification,
a) For 125cc to 500cc machines, the wheel rim must have:
i) a minimum diameter of 18" and
ii) a maximum width of 2.5" front and 4" rear.

b) For unlimited class the wheel rim must have:
i) minimum diameters of 16" front and 17" rear and
ii) maximum width of 3.5" front anf 4.5' rear

Prohibited uses:
For all periods, except period 5:
1) slick or grooved slick tyres

Permitted uses:
Period 5.
1) The folling machines or their major components:
a) Kawasaki 900Z1
b) Yamaha TZ
c) Yamaha RD and LC

2) Spoked and mag wheels

3) Slick racing tyres


Not sure why, but all of the blokes over this way run treaded tyres. If I could find my 06 rule book, I could see if the rules have changed since last year.

[balanse]

Thanks for the info guys. The bike has a 110/90 rear and a 100/90 front at the moment, should be right with 120 and 100 by the looks.
trying for the Bridgies or Avon - we'll see what comes up at what sorts of prices.

Feels like all I'm doing at the moment is pulling stuff apart and not making any forward progress. With the deadline Sunday week it's feeling like a long shot at the moment. Waiting for parts on order and in the meantime up to my neck in carbie cleaner, fork oil and feeler guages.

Its a good thing to work on though. Compared to the ZRX it's simplicity with a capital C. Lotsa room to get at things and bugger all hoses and wires to disconnect. No such thing as a captive nut though...gotta be ready to catch the nut and washer every time I undo something on the frame.

[Gosling1]

.....Not sure why, but all of the blokes over this way run treaded tyres. If I could find my 06 rule book, I could see if the rules have changed since last year.

I am *110%* sure that the rules re: tyres have stayed the same for a few years now. The big 17" wheels can be used on all Forgotten Era (P5) bikes over 500cc. Treaded tyres of today are pretty much as good as, if not better, than slicks, for 99% of riders. Slicks are cheaper, but you have to spend a lot of time setting up your suspension to make them work properly, and most punters don't bother.......

Balanse - just keep up the good work. Once all the bits have arrived, you will be able to knock most jobs over pretty quickly, its just a matter of gritting your teeth and keep on punchin'

It will be worth all the effort, when you are sitting in a grid with a shitload of other bikes, revving the tits off your Rickman, all waiting for the flag to drop !!!!!!

[aardvark]

I did some investigating today. It turns out that if your model bike came with 18" wheels when new, then you have to run 18's.

If it came with a choice of 17's or 18's, then you can run 17's.

The reason all the blokes are running treaded tyres on the RD's is that the RD only came out with 18" wheels and they no one makes 18" slicks!!

[balanse]

Almost there, after some 40 hours and doing front wheel bearings, front caliper services, master cylinder service, brake line clean out, valve adjustment, removing road gear, replacing handlebars (a few times), replacing spark plugs, adjusting valves, removing cleaning and replacing carbs (all pilot jets were blocked), flushing oil out and refilling with fresh, new oil filter, new air filter, new carb inlet manifolds, replacing tacho cable, replacing 3 rear wheel spokes, replacing rear wheel bearings, had a rear sprocket made up and fitting it, remove attempt recharge and replace battery, servicing rear caliper, flushing rear brake lines, fitting front and rear tires, drilling and lockwiring all lubricant exits and making number plates and brackets......it's almost ready.

Actually would have been done a couple of days ago but for the fk'around that passes for a motorcycle industry in this nation. Why don't people just say "nope can't do it" rather than holding onto your stuff for 5 days and then finding there's "a problem" (which was a part of the original description). Problem with the Rickman frame is the complete lack of parts availability and everything needs to be made....anyway

Went for the Avon AM22/AM28 tyres in the end, these things are as dear as poison - $600 odd for a pair of 18 inch tyres! Kerrriiiist!! I had expected that about $300 per pair would be tops, but am now much better informed, thanks. Apparently hand made in small batches by the Avon racing department was the story I got to explain the cost. Who knows? Mate who races a 500 Titan Spewyy gave me a couple of used ones from his garage collection so they are on.

Now I just hope it survives most of the day on Sunday, motor starts fine and sounds normal but will see how it runs. There is nothing worse than going to all the trouble to get up and get there only to have the day end early through failure.

Fingers crossed, will try to get some pics happening after I get to know the others who live in my house again.

[Gosling1]

Good luck on Sunday mate, I hope it works out OK. Sounds like you have been burning lots of midnight oil

It will be worth it in the end........

[robracer]

Good luck balanse hope it runs well & there are no probs

[aardvark]

$600 for a set of tyres?? Racing isn't that much fun!