| Author |
 Topic  |
|
| |
Current Topic Rating:  | Join the Forum to Rate this Topic at: Classic Motorcycling Australia Forums
|
|
|
Former Member
deleted
21 Posts |
 Posted - 17 Dec 2004 : 10:00:08 PM
|
hi, i read in a few forums, about people looking for evidence of machines being raced in a period i.e. a p4 bike which was modified and raced in 1970, so you could do the same for todays racing,
but i dont really see the need for this in the MA rule book,
I have a 1971 RT2 360 yamaha and id really like to build a p4 bike from it but I havent found any info regarding one of these being raceD back then? So dose this mean if i built a bike and apply for a log book i`d be out of luck due the lack of evidence ?
by the way this bike has yamaha s "Torque Induction " i.e A reed valve I do have evidence this is fitted by the factory from new .
plus how do people get log books with r5`s which have RD forks,disc brakes and a six speed box,the rules say no major parts from an RD
|
|
|
Alan
Forum Moderator
Western Australia
353 Posts |
Posted - 17 Dec 2004 : 11:42:54 PM
|
Firstly as most of us are aware you have to read the intent of the rules as well as what is specifically written. This is where some of the confusion arises and should be tightened up. As it stands at the moment you do not have to prove that something was actually done but that may chnage. You do have to prove that all major and minor components comply with the rules as written
Secondly in relation to RD parts you are quite correct but do need to be aware that some RD parts are common to other Yamaha motorcycles which then makes them eligible. Internal parts can be modified at present which allows 6 speed gearboxes to be used as long as it doesnt change the external appearance of the machine. Yes this is another grey area.
Moving on from there you can submit an aplication detailing what you wish to do to MA, there is a form on their website but I cannot remember the title, I think it might be called an Interim Log Book Application. They will then inform you whether your proposal is acceptable. This although maybe long winded is a far better option than building an ineligible machine.
One other thing to consider is the possible introduction of "the philosophy of motorcycle sport" which if adopted in its current form could have far reaching ramifications.
I have to point out that I do not hold an official position and this is my opinion only, you should always check with MA or its Commission before going to far with any project.
Good luck with your project and I hope you are successful with it.
Alan Sidecar 21 WA |
 |
|
|
Former Member
deleted
21 Posts |
Posted - 19 Dec 2004 : 2:03:02 PM
|
thanks Alan, i have downloaded and filled an Interim Log Book Application form and sent it in.
im still interested in finding out which yamaha model had the same front brakes as a RD350 I have these parts, but if you put in they are from an "rd" on the log book application, it will be wiped like a dirty ****, i have had a look round the net but havent found anything, wondered if the first disc brake model of a xs650 yamie may be the same brake and are they before the end of 1972? |
|
|
|
Alan
Forum Moderator
Western Australia
353 Posts |
Posted - 20 Dec 2004 : 12:03:28 AM
|
I believe that the round bodied caliper with a silver disc and yamaha printed on it is the same as fitted to early XS 650 and RDs and should be legal. Would be better to get another opinion though. I had one fitted to a P4 sidecar and that was accepted. They arent a very special caliper so that could also explain why.
A good contact for you would be Marcus de Caux, I do not have any contact details unfortunately but MNSW should be able to help you.
Alan sidecar 21 |
|
|
|
matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 20 Dec 2004 : 10:22:00 PM
|
not wrong Alan,plenty of yamahas in P4 running that caliper/disc setup,all early road yamahas had the same steel caliper,650's disc is bigger diameter than 350's,(650 forks have caliper mounts higher because of that difference),not sure what model makes it period 4 legal,but they're out there!, |
|
|
|
Former Member
deleted
21 Posts |
Posted - 20 Dec 2004 : 11:16:56 PM
|
| i have been searching the net , found some info , yamaha made a bike in 1970 to 1972 , the bike was called an RX350 the later models were called rx350-pro ,i have a picture of this bike it has an engine that looks like an RD and a tank which looks like a ds7. they had reed valves (RD) and a disc brake and these bike were actually basically an rd , so even though rd parts are band in the rules , if you had an rd but said in a log book aplication the bike was an rx350-pro the MA couldnt refuse on the grounds its an RD. |
|
|
|
john
Forum Moderator
Victoria
3130 Posts |
Posted - 21 Dec 2004 : 08:20:47 AM
|
| Just work to the rules and nobody will be upset. If RD parts are banned and you have an engine that has the technical designs components of a Rd and looks like an RD, surely you cant expect it to be permitted simply because it is a variation of an RD. |
John Daley Sidecar #68
' there are those who do, those who dont do and those who undo. We must lampoon the latter." |
|
|
|
Former Member
deleted
21 Posts |
Posted - 21 Dec 2004 : 8:12:11 PM
|
thanks John , but unfortunately your take on this rule doesn't sound fair or really make sense , if the bike`s a rx350-pro it would have been manufactured two years before the rd was sold , so your saying a rx350 is to close to being a rd to use .
but there are bikes competing in p4 with rd front disc brakes and forks, the owners have obviously said they are from a different bike on a log book application , but ive found the calliper on the 1972 tx750 twin is the same but the forks are different. so going by your reply forks that look like rd forks no mater what bike they are from should never be used, as you appear to say anything that looks like an rd is basically not legal . if this is the case why aren't people disqualified with rd forks , then if we say 'oh they look like rd forks but we`ll just say they are from another bike and that's ok ' then I don't understand why you cant use a rx350 engine . don't get me wrong im not worried about getting a unfair advantage , just interested
|
|
|
|
Former Member
deleted
72 Posts |
Posted - 21 Dec 2004 : 10:40:35 PM
|
Andrew, your talking about 2 distincly different bikes at the moment. the 360RTI was released in 1970 and is a scramble type bike, it was updated slightly in 1971 and became the RT360. its a single cylinder engine and i dont think the 1970 model had a reed block although the 1971 model may have.
now the 1970 RX350 is a twin cylinder bike but i think you'll find it did not have reed blocks, unlike the 1973 RD350 which did. the engine cases, barrels and heads are similar but there is a difference in the castings and the number of fins.
none of these bikes came fitted with disc brakes, i think the first road yamaha with a front disc was the 1971 XS650E and the road version of the TZ700/750 which was a GL750-4.
the rules state for P4 that reed blocks may be used if originally fitted but it also says all TZ and RD major components are prohibited.
sure, there is nothing wrong with fitting a disc to a RT360 and racing that, as everyone else is trying to use the loop holes in the rules to their own gain.
John is just trying to save you from any heartache you may encounter, no one said these rules were fair, just ask anyone with a Z900.
good luck |
There are those who do, those who used to do and those who never did..
why is this 3rd group always trying to convince everyone they know best? |
|
|
|
Former Member
deleted
21 Posts |
Posted - 21 Dec 2004 : 11:37:16 PM
|
thanks again , i understand what we`er saying im just trying to find out what makes a rd front brake good for p4.
You are wrong about RX350-PRO`S the fact is the rx 350 came out in 1970 and had reed valves , in 1972 the front brake was changed to disc, they also had a 250 version this bike was called a dx250, 1972 it was called a dx250-pro .
I also know what a rt2 is as i have one , they started in 1968 , but only got reed valves in 1972 thats when they changed from rt1 to rt2 , funny thing is dt360 came out at the same time , im not sure the difference if any, may be called a different name for different markets, its just a thing i was interested in , the rx350 was made before 1972, had reed valves , disc brakes , now i have checked with the ma rule book , john dosnt seem to be correct the rule book dosnt say anything that looks like a rd or a derivative of an rd is prohibited , just rd are prohidited , anyway they didnt need to put that into p4 , they werent made till 1973 which is outside the dates , BUT RX350 PRO`S AND DX250-PRO`S ARE IN THE CORRECT DATE, Funny thing it also says in the rule book you can use parts manufactured out side the date if there is no difference in appearance well that means that if someone really wanted to race a rd engine they only need to say its a rx350 , as the engine looks the same , i know as i have a picture of the brochure for a 1971 rx350 |
|
|
|
Former Member
deleted
1 Posts |
Posted - 22 Dec 2004 : 1:19:42 PM
|
Andrew,
Yamaha DT1,DT1F,DT2 nad their MX derivatives are alll ok for P4 lightweight
Yamaha RT1 and RT2 are also eligable for P4 Junior (standard capacity - 351cc - falls within the 5% tolerance limit for Historic racing.
My P4 race bike (Suzuki t-250 frame with either of the above motors is log booked.)
I have the manuals and production dates at home if you need them.
Both motors are easy to work on , near bullet proof and are great short-track motors (don't have the top end of a worked R5, DS-7 or TD / TR) as they have bucket loads of low down grunt. The only issue is gearboxes - get the close ratio mx box and make sure the dogs on the gears are undercut - otherwise you will destroy the shifter forks and drum when you start to get some power out of the motor.
Contact me by e-mail if you want more info.
BTW my bike is currently also for sale (I am moving to Karratha).
Cheers
Mark |
|
|
|
Former Member
deleted
72 Posts |
Posted - 22 Dec 2004 : 10:53:27 PM
|
the difference between the DX/RX series and the RD series is a different shape clutch/engine side case, different number of fins on the barrels, and the while the RD has a square rubber inlet manifold attached to the barrel the DX has a round one. there are other minor differences like 5 speed g/box on the DX and different clutch cable entry into the side cover, the main one is the reed block, or lack off. but if you can prove your DX250/RX350 originally had a reed block then all you need to do is find one and race it.
anyway take all the information you can gather up on board and build your bike the way you want it. just remember if some competitor or eledgability scruneteer get wind your useing RD parts, it all could come to an abrupt end as RD parts are specifictly excluded from the class. this rule may have been added to stop people fitting the later RD engine into the earlier DX/RX bike
once again, the comments here are only trying to help you out. for there never seems to be anyone from MA with authority who is willing to comment or make some sort of judgment on eledgibility issues on this site.
perhaps its time an official MA site was set up for these type of questions where definitive answers can be given before a competitor begins to build his project. |
There are those who do, those who used to do and those who never did..
why is this 3rd group always trying to convince everyone they know best? |
|
|
|
matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 23 Dec 2004 : 12:24:20 AM
|
| when did TX500's come out,they have the same disc f/end as RD'S,does anyone know?, |
|
|
|
popeye
Level 2 Member
Western Australia
187 Posts |
Posted - 23 Dec 2004 : 08:42:32 AM
|
TX500 was released in 1973 model year.
DX/RX model 2 strokes were japanese domestic models, probably rolling test beds for the RD spec models released to the world in 1973. All the literature I can find is japanese but it sounds like they have the goodies, especially the 72 with the front disc. |
Life may not be the party we hoped for, but while we're here we may as well dance |
|
|
|
Former Member
deleted
21 Posts |
Posted - 23 Dec 2004 : 12:27:01 PM
|
HHH. The bike your discribing is in fact called an R5 not a rx350-pro as rx350-pro has reed vales.
for a very quick read this web page .
You must be logged in to see this link. |
|
|
|
Former Member
deleted
72 Posts |
Posted - 23 Dec 2004 : 8:26:22 PM
|
sorry Andrew but i'm refering to the RX/DX series and not an R5. probably the best thing for you to do is park a RX next to an RD and compair the differences. as i said, if you can prove your RX has a reed block then you should have no problem useing reed blocks in P4 as that is all the rules require.
there is nothing more i can add to this topic except once again say good luck in your RX/DX project or your RT360, which ever you decide on.
but hey, if you have trouble finding your RX then why not race the RZ 201? |
There are those who do, those who used to do and those who never did..
why is this 3rd group always trying to convince everyone they know best? |
|
|
|
Former Member
deleted
21 Posts |
Posted - 23 Dec 2004 : 9:10:36 PM
|
| cool hhh , was just a little confused when you said a rx350-pro didnt have reed valve as they did, and there is a lot of eviedance to prove this |
|
|
|
popeye
Level 2 Member
Western Australia
187 Posts |
Posted - 23 Dec 2004 : 10:32:23 PM
|
You must be logged in to see this link.
the link shows an R5.
then we have the descriptions translated from a japanese site at
You must be logged in to see this link.http://homepage3.nifty.com/mcdb/yamaha/yamaha_r.htm&prev=/search%3Fq%3D1971%2Brx350%26hl%3Den%26lr%3D%26sa%3DG
Sport 350RX (1970)
Air cooled 2st piston reed valve para twin 348cc. The 350R1 (1967) the 350R3 (1969) with as for 350 load sports which continue in 1970 year RX350 full model change. Frame of metal tubing double cradle, new design such as piston reed valve and engine of 5 port cylinders. Marketing racer TR-2 (1970) from feedback was praised. As for design the XS-1 (1970) those which are decended. In the spoke wheel of F3.00-18 and R3.50-18 combination of front and back drum brake. As for rear wheel 2 shocks. Nominal full speed 170km/h, 0 -> as for 400m 13.8sec. 750 eaters, alias of the drug star was taken from the efficiency. The power unit became the base of the load racer TR3.
--------------------------------------------------------------------------------
Sport RX350 (1971)
Air cooled 2st piston reed valve para twin 348cc. 350RX (1970) following in 71 car name in RX350 modification. Color change is received, but there is no modification in specification.
--------------------------------------------------------------------------------
Sport RX350PRO (1972)
Air cooled 2st piston-valve para twin 347cc. The model of the F disk brake specification which in the RX350 1972 years is added. With the hydraulic system which loads the opposition 1 pot piston caliper before the F fork, it equips one disk in the right side. Powerful braking effort was appraised, but in the system of that time also sweetness of effectiveness at the time of rainy weather travelling was pointed out. The color ring is modified, but basic the RX350 (1971) With being common, there is no modification even in the engine specifications. We are modified by those where the R shock is called sport type of irregular pitch, the spring which has the dense part above and underneath is used. Nominal full speed 170km/h, 0 -> as for 400m 13.8sec. 1 month the F disk brake specification car DX250PRO (1972 was announced to also the sibling car DX250 to sale of this 350PRO lately. The RX350 following in 1973 is changed to the RD350.
just to add to the confusion............. all that is needed is confirmation from Yamaha Japan of the engine/frame numbers of the bikes in question and you are in business.
|
Life may not be the party we hoped for, but while we're here we may as well dance |
Edited by - popeye on 23 Dec 2004 10:38:35 PM |
|
|
|
Former Member
deleted
21 Posts |
Posted - 24 Dec 2004 : 08:33:18 AM
|
| well done, when hhh put that a rx didnt have reed valves i thought he`d been confused with an r5 , and reading your comments and quotes this seems to be the case, i hope this helps all the frustrated people with reed valve cylinders , and would like to use them in p4 , the main thing i see about this is it would cut the cost of building a r5 racer as , its a lot easier to fing these cylinders than non-reed items |
|
|
|
popeye
Level 2 Member
Western Australia
187 Posts |
Posted - 24 Dec 2004 : 08:59:31 AM
|
I would still keep digging if I was you, it is not going to be easy to get this one over the line, it is a potential "class killer".
When you have an official Yamaha document with the specs on it, fill your boots.
I have an R5 top end for sale and also a rolling chassis, the bottom end of the engine has gone to P5 TZ land. |
Life may not be the party we hoped for, but while we're here we may as well dance |
|
|
|
Former Member
deleted
21 Posts |
Posted - 24 Dec 2004 : 09:51:46 AM
|
lol it would take a better rider than me to make a bike a class killer,
and unless a few blokes started to race rx350 it wouldnt be worth the grief youd spend more time with the engine in bits after protests than actually riding it, plus you would be have so may aruments it would be just be too stressfull.then if you beat a manx or a 7r i think there would be a rule to stop you racing it made up real quick |
|
|
|
Former Member
deleted
72 Posts |
Posted - 24 Dec 2004 : 8:42:05 PM
|
nice picture popeye, but i would believe the owner who claims its a RX rather than your claim at it being a R5.
but to be really pedantic, the bike in the picture is actually a bit of a hybrid. the bike appears to be a 1970 DX250, the lack of any bracing under the tank gives the year away, but someone has fitted the 1972 DX250 PRO engine and the number of fins on the rear of the cylinder gives this away.
now who's to say when this picture was taken and who took the picture? thats the problems you get when you try and get a log book for your bike without dated magazines or workshop manuals.
andrew if you reed my posts carefully you'll see i wrote that i didn't THINK the RX/DX had reed blocks, i never claimed they actually didn't.
even now with the DATED information i have(information printed in the actual period, not historic review magazines) i can't find any information stateing otherwise.
|
There are those who do, those who used to do and those who never did..
why is this 3rd group always trying to convince everyone they know best? |
|
|
|
Former Member
deleted
29 Posts |
Posted - 24 Dec 2004 : 10:42:10 PM
|
JUST BEEN READING THIS THREAD WITH INTEREST. I RECON YOUR QUESTIONS WILL BE ANSWERED ONCE YOUR PRE BUILD APPLICATION IS RETURNED FROM M.A. IL GIVE YOU THE HOT TIP THOUGH. YOUL BE HARD PRESSED TO BUILD A BIKE FASTER THAN A HOT R5 OR TR3. SECONDLY, YOUL FIND THAT A HOT R5 BARREL WILL WILL PRODUCE MORE POWER WITH ITS PISTON PORTED INTAKE, THAN AN RD350 BARREL WITH ITS REED INTAKE. I HAVE PERSONALY DONE ALOT OF PORTING WORK WITH RD350s, AS HAS IAN WILLIAMS AND ANOTHER TUNER I KNEW YEARS AGO. NONE OF US COULD GAIN ANYWHERE AS MUCH POWER WITH THESE RDs, AS WE COULD WITH AN R5. THE RD400 REEDED MOTOR ON THE OTHER HAND WE MANAGED HUGE POWER FROM. WHY THE RD350 WONT HOT UP WELL IS STILL A MYSTERY TO MANY. I RACED A TD3 250 FOR MANY YEARS AND WE ALL USED THE XS650 FORKS AND DISKS AND CLAMPS FROM THE 1971/2 MODEL. THESE ARE THE BEST FORKS AND BRAKES FOR THE CLASS AND WILL STAND THE THING ON THE FRONT WHEEL IF GRAB EM TOO HARD. THE CALIPERS WERE THE SAME ALL THE WAY THROUGH FROM XS650, SR500, RD ETC , SO WRITE DOWN THAT THE WHOLE FRONT END IS XS650. WAIT TILL YOU HEAR FROM M.A, BEFORE LIFTING A SPANNER AND HAVE ALL YOUR DOCUMENTED EVIDENCE WITH YOU AT THE TRACK, THEN NO ONE CAN PROTEST YOU IF YOUVE GOT THE EVIDENCE. HAVE FUN.
WHITEY |
|
|
|
popeye
Level 2 Member
Western Australia
187 Posts |
Posted - 24 Dec 2004 : 11:08:40 PM
|
| wishing I could have kept the R5 together now, although it would have taken forever to build it on my budget. |
Life may not be the party we hoped for, but while we're here we may as well dance |
|
|
|
Former Member
deleted
21 Posts |
Posted - 25 Dec 2004 : 09:17:02 AM
|
thank you ,thats actually what i wanted to know, what to call the front forks/brakes to beable to use in p4.
actually Whitey I understand what your say regard r5 cylinders , i have read some road racers of the time swapped to r5 cylinders as they give much more power at higher revs, they say low to mid range is a little better on the rd , but maybe a boost bottle on an r5 will get it up to an rd low power,
although saying this i have seen a lot of info regarding rd reed valve mods and fitting rz valves , which are much bigger and werent available till the 80`s
heres a very interesting site which points out this and many other mods
You must be logged in to see this link. |
|
|
| |
Topic |
|
Topic Locked
