OzVMX Forum

Marque Remarks => Spaniards (Bultaco, Ossa, Montesa etc) => Topic started by: matcho mick on July 19, 2009, 01:30:18 am

Title: ossa frame shrinkage!!!!
Post by: matcho mick on July 19, 2009, 01:30:18 am
i've given up,nearly 2hrs & the motors not quite all the way in ,1/2 hole out on the 2 rears,i know where theres a14lb sledgy (FBH ;D) ,but i can't wake the horses to get it,geezas talk about a tight fit!,it's a trials "open" frame so theres nothing to lever off,grrrr, >:( >:(
Title: Re: ossa frame shrinkage!!!!
Post by: DR on July 19, 2009, 10:14:44 am
maybe if you put the engine in the freezer an' leave the frame out in the sun it will expand a little and the motor will slip in ;D
Title: Re: ossa frame shrinkage!!!!
Post by: David Lahey on July 19, 2009, 07:12:21 pm
Youre pretty keen doing that sort of thing in the middle of the night - does that mean you were trying to get it ready to go for a ride today?
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 19, 2009, 07:58:45 pm
it's in ,just need bigger hammer,(4lb not the 14lb  ::)),think it & me was too cold that hour of morning, ;),not trialsing this one feetup,flat track experiment,i've put a SDR s/arm in to get the wheel base longer ,hopefully it will work with the steeper steering for track,sorta raided my trials ossa's front forks for the smaller hub locating tab setup,binned the larger brake hub setup,not game to try the small hub rear setup,axle size is 12mm,(or 10  :o),hopefully ready for Nepean 2 dayer next month ::)
Title: Re: ossa frame shrinkage!!!!
Post by: JC on July 20, 2009, 10:54:01 am
Mick, that's a project I've considered too. What engine are you using tho? MAR/Explorer have useless gear ratios for anything else - close on 1st 3, huge gap to 4 &5.  SDR & Pioneer have large gap 4-5 also.
Title: Re: ossa frame shrinkage!!!!
Post by: firko on July 20, 2009, 11:14:14 am
I can remember a Yamaha TY250 fitted with a longer swingarm and a YZ engine racing at a Nepean irt track back in the early 80s. Could it have been Brett Chipperfield or Wayne Boatright? Seemed to handle pretty good frm my position behind it on the track ;D.
Title: Re: ossa frame shrinkage!!!!
Post by: David Lahey on July 20, 2009, 11:29:26 am
Sounds like it will be a great machine and good move keeping the big rear hub. Those rear trials axles are like spaghetti.
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 20, 2009, 11:45:20 am
SDR with Phantom head n barrell,gear ratios??,what gear ratios  ;D
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 20, 2009, 11:49:26 am
geezas,ordered from Ossa World last friday (1.30am  ::)),which i guess was the day before over there!  :D,just turned up at my door  8), :P
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 24, 2009, 12:32:30 am
hey Jim,the beast now has spark 8)
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 24, 2009, 11:25:02 pm
grrrr ,poxy Bandito pipe fouls the chain run  ::),will havta go to smaller sprockets for clearance,(or shorter shocks),delorto might be back on the agenda,just need pantah mainjet /floatbowl retainer,apparently it's 10mm shorter,should just clear crankcase then 8), :P
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 26, 2009, 01:49:07 am
braking news ::).both f/r brakes functioning,sorted smaller sprockets,at least 1/2 doz different s/cvr options,(decisions decisions),geezas only 7 more sleeps :P
Title: Re: ossa frame shrinkage!!!!
Post by: jimg1au on July 26, 2009, 08:04:28 am
mick
what gearing are you going to run.
i have 17/52 on the cz400
cheers
jim
Title: Re: ossa frame shrinkage!!!!
Post by: jimg1au on July 27, 2009, 05:03:35 pm
mick
how is the bike comming along.in off to menai tuesday to do some plug chops on the cz.there is a long flat road near mini bike club all fenced off but you can get a bike to it.it starts real easy and idles well clean revs now to see if it goes.hope so looking forward for a race again with that 350 honda of yours and how i have a 250 as well
cheers
jim
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 28, 2009, 12:40:34 am
g'day Jim,slowly comming along!,fiddly stuff ;),wow 17/52,ossa was running 13/51,now will try 13/44,bit of a jump,rathered 46/47 rear,but if i can get a 12 c/s for backup alls good,good luck with testing mate,i'll prolly do that sat ::),cheers
Title: Re: ossa frame shrinkage!!!!
Post by: JC on July 28, 2009, 11:03:38 am
Mick,

If you gear it too tall, I doubt you'll pull the gap between 4th & 5th. It's a considerable jump.
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on July 29, 2009, 01:07:26 am
yeah,i hear ya JC,gunna take a punt onit :-\,(can always leave it in 4th  :D)all control cables done,s/cvrs,kill switch to go,then make engine noises,(TTS @25-1  ;D ;D),errr later today (obviously ::)), :P
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on August 05, 2009, 11:38:20 pm
bloody compootas,been offline awhile >:(,well the experiment worked!,bit twitchy but i sorta got use to it,gearing was ok afterall,jetting was ballpark ok,needs richening midrange,pings a tad,so full throttle cures that  ;),finished it late friday nite,ran the XL into the workshop,pushed the door open with the frontwheel,door then knocked the ossa over onto a floor stand which punched a neat slotted hole through the tank pharrrrkkkk,(the primer grey bit on tank in Firko's shot),going to soften the rear,shock swap & try again this weekends St George club round,might dial the jetting a bit closer too,cheers all :P
Title: Re: ossa frame shrinkage!!!!
Post by: JC on August 07, 2009, 07:53:57 am
"Firko's shot" ???  Did I miss something? Where can I see "firko's shot"?
Title: Re: ossa frame shrinkage!!!!
Post by: matcho mick on August 07, 2009, 11:21:39 pm
JC,in Vintage Track, page 3 of nepean pre 75 thread ,has some good piccies thanks to Firko,cheers :P