OzVMX Forum

Clubroom => Bike Talk => Topic started by: Broadsta on August 28, 2007, 10:04:07 pm

Title: GT80
Post by: Broadsta on August 28, 2007, 10:04:07 pm
What i want 2 no is, which class canu race these things in? ive seen plenty of 80cc bikes in these posts but never at any race meetings.
Title: Re: GT80
Post by: Noel on August 29, 2007, 08:22:20 am
Hi ,
My understanding is that only juniors would be allowed to race them.
for a senior's bike it needs to have a minimum wheel diameter of 17 inches and
a minimum capacity of 100 cc.
I'm happy to be corrected by someone who knows for sure.
Noel
Title: Re: GT80
Post by: caps 999 on August 29, 2007, 07:50:09 pm
front or rear wheel cause i just got a yz100j front wheel19" rear 16" and i want to hopfully race it
Title: Re: GT80
Post by: caps 999 on August 29, 2007, 07:55:03 pm
sorry i just realised it runs a 21 and 18 setup
Title: Re: GT80
Post by: Doc on August 29, 2007, 08:04:43 pm
There was a guy at the vintage nats racing an XR75 and from memory I believe it had stock sized wheels..this bike was taken out to about 150cc I believe but it's still an XR75 regardless. It dusted off many full sized bikes and was quite rapid. I don't recall seeing anything in the rule book that states you can't ride an 80 mini.  My assumption is that the powers that be think we are too big for mini's and why would anyone disadvantage themselves by riding such hence no mention of them in the rule book. What they don't realize is I and maybe some others personally weigh and measure the same as I did at 15 and my '77 RM80 still suits me down to the ground (if only it had a 400 motor) ;)
Title: Re: GT80
Post by: Noel on August 29, 2007, 08:19:57 pm
Hi Doc,
I spoke to that guy at the Nats and he confessed to there being a
gray area as to how  diameter is measured
"with or without the tire "?
You are right I have not seen it written any where only   "heard" the parameters
Cheers
Noel
Title: Re: GT80
Post by: Doc on August 29, 2007, 08:30:47 pm
g'day Noel, yeah mate I really was impressed with that little XR. I've just been scouring the rule book for reference to such but found nothing. I also went back through the program from the event and the guys name is Les Barfoot , apparently this bike was only out to about 100cc. The pic below is the bike and rider at the said event.  ;)

(http://www.vmx.zoomshare.com/album/2007%20Australian%20Classic%20MX%20Championships%20-%20Friday%20Practice/images/a5d2a2315860b18bffb235b5aba55151_11822372370/image.jpg)
Title: Re: GT80
Post by: caps 999 on August 29, 2007, 08:53:57 pm
i had a 140cc xr75 awsome little bike it ran a alpha romeo car piston and the crank was out of a xl175  which was litend and machined to fit a far as i know back then  could have raced it this was around late 2006
Title: Re: GT80
Post by: DJRacing on August 29, 2007, 09:04:18 pm
Geez Caps how long did it take ya to find out that a Alfa piston would do the job? ;D
Title: Re: GT80
Post by: Tim754 on August 30, 2007, 04:23:03 pm
Just sussed out the rule book and cannot find this wheel size stuff(*). I say go for it but beware! you ...will ....be passed by a lot of punters so race with care and up to your machines and your limitations. :)  Tim754
(*) Somebody may have seen the reference, please post the item and sub item numbers for all if they exist.
Title: Re: GT80
Post by: caps 999 on August 30, 2007, 04:50:27 pm
i actually got the piston from a guy that had done one befor i had to machine valve pockets and get a custom sleve fabricated and drill the centre cases but man did it fly
Title: Re: GT80
Post by: Broadsta on August 30, 2007, 10:09:00 pm
Soooo what u guys r sayn is that imay b able 2 race this bike  but in what class 125s? And Tim idont think being passed will b a problem cos this thing aint no stocko, it goes like a cut snake.

[attachment deleted by admin]
Title: Re: GT80
Post by: Doc on August 31, 2007, 05:39:54 am
Broadsta, if your thinking of running the 80cc in the 125 class you will be passed  ;)
As quick as a worked vintage 80cc may feel it would still be very hard pressed to keep up with a full size bike on a full sized track.
Title: Re: GT80
Post by: Tim754 on August 31, 2007, 04:59:29 pm
Assuming it is a pre75. Models (367 /374 ? ) You may race in 125, All powers, your age group races, and maybe others.   Nice Little YZ80 Sidecar piccie is yours?, Back to the your MX 80 ,  You can fit the 5 speed box out of an early C./D YZ80 straight into your MX/GT80 cases as a unit. Done it before ...twice, The MX shafts are the same items except that they only 4 gears and a blanked out spot!  Tim
Title: Re: GT80
Post by: Doc on August 31, 2007, 06:17:56 pm
 ;D now Tim, just to be argumentative, whilst perusing the the rule bible I did notice something. The gearbox 'must' retain the correct amount of ratios as per manufacture thus making a 5 speed GT only eligable in pre78  :P not that I think anyone would care unless they have a can of whip ass opened on them by a GT80  :o ;D
Title: Re: GT80
Post by: Tim754 on August 31, 2007, 07:07:13 pm
Oops !!!!  :-[agreed  ;D but gee"s who would know................. ::) ;)
Title: Re: GT80
Post by: Broadsta on August 31, 2007, 09:20:00 pm
Well worded Doc, & i'd probably hav 2 agree with u, on a big trak  with a coupla decent straights but i hav alot of faith in this bike (i've owned it 4 29 yrs)goin as far as sayin, it would  b the quickest gt80 in Aust. Tim, put a 5sp in it in 79  after realizing the dude i was racin (ds80) clicked the shift lever down instead of up on the start line, and yes the pic of the chair is of me  & Peter Honebone swinger at Sheparton 1980 state titles. The barrel n head head etc r definaetely pre 75 but the frames not as i snapped the down tube at Breakwater trak (geelong) & the old mans mate said he could fix it replacing it with a yz80 b frame.I've since replaced it with a mx80 frame.
Can i race the 125's?
Title: Re: GT80
Post by: Nathan S on August 31, 2007, 09:28:45 pm
Yes. Sounds like you'd be racing in the pre-78 125s though, due to the 5-speed - but like others have said, if you entered the pre-75 125s, I doubt that anyone would make a song and dance about it. Maybe an issue if you went to a big meeting.
There's a list of eligible bikes for each era in the rule book. There's no minibikes in there, but I assume the list didn't include them because nobody expected anyone to want to race one. No matter - bikes not on the list can be raced if you can prove it is eligible.

How do you reckon you'd go on the rougher stuff against the full sized bikes?

Ah bugger that - if you own it and you love it, you should race it. Everyone's competitive streak comes out as the gate falls, but there's more to VMX than trying to win races.

Title: Re: GT80
Post by: Doc on September 01, 2007, 10:07:58 am
Broadsta, I'll overlook your 5 speed if you overlook my leading axle front end and 17" front wheel on my RM80 ;)

(http://farm2.static.flickr.com/1218/860831371_3b260b9f62_o.jpg)

30 years ago this bike was delivered to me from Phil Thew Moto for the grand sum of $499.00 including a Stage3 Racing kidney belt and gloves..a bargain even back then! ;D never mind the JR in the foreground it's my most recent addition ::) 
Title: Re: GT80
Post by: Broadsta on September 01, 2007, 10:23:55 pm
G/day Nathan, did'nt no there was such a thing as a rough track in vmx although conondale was pretty rough on day 2 even on my evo bike. I agree its not all about winning, but if ur at the pointy end of the field i'm sure ur gonna try 4 the win. also u would'nt happen 2 have any gtmx80 parts kickstart yz80d, rear shox again yz80d would b good, seat lock, h/bars, thks mate.
Hey Doc, did,nt c a thing mate. Im pretty much a yamaha man (though ido own a bultaco) but u found my weakness ya bastard, thats 1 smik lookin rm would'nt b outa place in the lounge room
Title: Re: GT80
Post by: Doc on September 02, 2007, 07:16:29 pm
Thanks Broadsta, the little RM does look tidy but she's a ride bike like all the others. Restoring or semi-restoring bikes just to look at seems a bit of a waste and I firmly believe 'nothing' is above being ridden (thrashed)..my bikes aren't an investment I hope to retire on or anything..if it breaks it's just an oops..it's only mechanical so ya just rebuild it again..sure sounds like a lot more fun than just looking at it  ;D 
Title: Re: GT80
Post by: caps 999 on September 02, 2007, 07:54:58 pm
compleatly right doc whats the use of having a bike your only going to look at im just finishing my complete nos restoration of a 250j and if its ready ill see you all at the next viper round  ;D
Title: Re: GT80
Post by: Broadsta on September 03, 2007, 08:07:53 pm
Right back atcha Doc,tho i find it hard 2 believe that bikes ridden mate, its far 2 clean, or u'v got 2 much time on ur hands.  ;)
Title: Re: GT80
Post by: Doc on September 03, 2007, 08:42:36 pm
 :D given half a chance it would be ridden Broadsta, I'm lucky ride more than 2 or 3 times a year at best so maybe next year the little RM will get a turn ::) it goes well up and down the street but the neighbors have no appreciation for my vintage MXers. This pic was taken back in the day when I could actually ride it locally, the spot where this pic was taken is now under the Gateway Motorway at Nudgee  :'(

(http://i12.photobucket.com/albums/a205/Doctor_Suzuki/019cb354.jpg?t=1188816335)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
Title: Re: GT80
Post by: YZ250H on September 04, 2007, 01:41:08 pm
I'd love to see some photos of that resto when you are finished Caps. ;)  All these photos of other guys restos keep me motivated to finish mine.  Rolling frame very very soon then not far to the end for the 250H. 8)
Title: Re: GT80
Post by: 500Fool on September 04, 2007, 04:16:02 pm
I'd love to see some photos of that resto when you are finished Caps. ;) 8)

Don't think he has his camera back yet, when he does he's going to get some piccies of the RH  ;D
Title: Re: GT80
Post by: caps 999 on September 04, 2007, 07:01:42 pm
the rh is long gone now i got the camera back last friday i know must have gone to kazacstan or something just so 500fool doesent have to type another coment heres a pic of when i got the 250 j my 80j is in the back ive started reassembly the only thing i really need is a left hand fork leg please help someone
BEFORE
(http://i187.photobucket.com/albums/x197/caps999/000_0007.jpg)
AFTER is on the way
Title: Re: GT80
Post by: YZ250H on September 04, 2007, 07:06:31 pm
She doesn't look too bad even as a "before".  Maybe quicky could take a few lessons from you on "starting points for restos "  :P :P :P  Mind you the 125H I'm working on isn't much better than Quickies TM :-[
Title: Re: GT80
Post by: Broadsta on September 04, 2007, 09:36:36 pm
Cool pic Doc, check the protective gear out ,the helmets aclassic, didu hav the good ol rossi's as well. Heres a pic of me on a yz80d wearin pretty much the same gear, cept ithink i musta bin abit cooler than u Doc ihad the open face skiddy no peak but. When  i get the gt race ready mayb u could bring the rm 2 a bmc event 4 abit of classic suzuki v yamaha battle.
 
Hey 250h ,heres apic 4 abit of inspiration.
Caps ihav some pics of 80 & 125j's  & a 250k if there of any help.

[attachment deleted by admin]
Title: Re: GT80
Post by: caps 999 on September 04, 2007, 09:47:19 pm
load em up then  ;)
Title: Re: GT80
Post by: YZ250H on September 05, 2007, 09:14:53 am
That 125 J looks sweet Braodsta 8).  Any chance you can post a bigger one so I can see some more detail ??
I had a Deltek minibike similar to that one.  Mine was blue.  Had a rope start (which you tied around the bars after you started it).  Just watch you leg on the starting pulley !!!!! :D
Title: Re: GT80
Post by: caps 999 on September 05, 2007, 11:02:53 am
tyhats a 125h with j number plate
Title: Re: GT80
Post by: YZ250H on September 05, 2007, 12:37:41 pm
I was wondering how long you'd take to pick me up on that  :P :P
Title: Re: GT80
Post by: caps 999 on September 05, 2007, 07:54:47 pm
im sorry im not really a yammy fan i just like the 1982 models for some reason  ::)
Title: Re: GT80
Post by: YZ250H on September 05, 2007, 09:00:54 pm
By the look of your collection you like the A LOT ;D ;D
Title: Re: GT80
Post by: 505 on September 23, 2009, 07:22:46 pm
I remember racing my SL70 against several GT80s back in about 1976 & 77 they all had yz80 top ends on them & were rocket fast down the straights, even with my SL70 being 82cc with motoplat ignition, roller cam 22mm carby, frogmod pipe, cr125 forks & custom swingam with the shock forward mounted for a whole 7 inches of travel, it was near impossible to keep up with the GTs. in 1978 i bought a worked xl75 off another racer & it was able to beat the GTs everynow & then. Karston Jorgenson, Glen Watson, Rodney Meekins, Chris Cavanagh all had these GT80 rocket back in the day & racing with them & the other guys on 4strokes was awesome.
back then my SL could hold its own against the average 125 play racer on an MX track but guys that raced regularly would leave an 80 for dead