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-   -   450 Super Single Project (http://www.motorcycle.com/forum/motorcycle-general-discussion/6662-450-super-single-project.html)

Gluge 10-31-2007 06:43 PM

Quote:

Originally Posted by acecycleins (Post 172411)
Wouldn't it be easy to require dyno runs of the top 5 positions and anyone out of spec would be disqualified? Hp limits seem to be the key in this. Run only 450cc 4-strokes and use something like AMA superstock rules for mods. Then suspension is the factor- not who's spending the most on the motors.

No they do that with some of the classes at WSMC - like 2-stroke production. Problem is it's SO easy to lower your hpr... a little hidden switch that changes your ignition timing, take a little peice of tape off that was covering an extra carb vent.. etc.

Problem also is then you have to dyno almost every day if your trying to run as close to the hpr limit as possible and doing jetting changes you'll want to be sure and not go over so you'll need to dyno often.

It kinda works for a really relaxed club but it wouldn't work on a very large competitive scale.

The_AirHawk 10-31-2007 08:06 PM

Quote:

Originally Posted by Gluge (Post 172532)
Really there are only three options when buying a 125 GP bike - Aprilia RSW125, Honda RS125 and Yamaha TZ125.

So basically I feel 125 racing is going to be cheaper than this 4-stroke dirt bike engine racing. More fun (slightly better power to weight) and the bikes new and used are all readily available with people already racing them.

So, I can just go-down to my 'PrillaHondaYamaha dealer and pick one of these out from amongst the rows and rows of them lining the walls of each showroom?

Sorry, but besides seeing one on a track, or on a trailer going to or from a track - I've hardly seen one of these bikes.

I won't argue with you about the cost of racing a 125 - hell, I've thought about it over and over myself, if I were even two-hours closer to Hallet I'd probably already have bought a used one out of the classifieds in RRW. As to the "more fun" thing - that's subjective. :D

But, there are like a freakin' Bazillion 450 4-stroke dirtbikes all over. Everywhere. They're a bread-and-butter bike. I think THAT is one of the reasons this guy has come-up with the idea for a spec-racing class. Just take the bike you already own - slap a set of wheels & tires, road-going fork tubes in the triples (most of 'em already have USD front ends), and dzus-on a cheap fibreglass roadrace fairing - then go racing a bike you're familiar with, that you have a pile of spares for, that you could probably even convert-back and go back to dirt-racing the NEXT weekend.............

seruzawa 10-31-2007 08:22 PM

Sounds good....
 
... except for the fact that if you put 450MX motors in road racing applications that 30 hour engine life is gonna drop to what? 15? 10? Can you come up with $3K for a rebuild every 2-3 race weekends?

Gotta allow the 250MX engines to compete with the 450s like they do in off road. Then you might afford it.

BrowningBAR 10-31-2007 08:36 PM

This rebuild stuff sound very retarded. Let's get a Boeing engineer on this to straighten it out. I'm sure Gabe will lend us one.

pplassm 11-01-2007 06:30 AM

Quote:

Originally Posted by seruzawa (Post 172546)
... except for the fact that if you put 450MX motors in road racing applications that 30 hour engine life is gonna drop to what? 15? 10? Can you come up with $3K for a rebuild every 2-3 race weekends?

Gotta allow the 250MX engines to compete with the 450s like they do in off road. Then you might afford it.


Althoug I have made a lot of the maintenance requirements of 4 stoke MX bikes in the past, I think they will do just fine in this application.

The big realization that people will have to get is, that these are racing machines, not low stessed street bikes.

250 2strokes would be nice to see in there, but they will need help to keep up. 360cc overbore, anyone?

Kevin_Duke 11-01-2007 10:10 AM

Quote:

Originally Posted by Gluge (Post 172533)
No they do that with some of the classes at WSMC - like 2-stroke production. Problem is it's SO easy to lower your hpr... a little hidden switch that changes your ignition timing, take a little peice of tape off that was covering an extra carb vent.. etc.

Problem also is then you have to dyno almost every day if your trying to run as close to the hpr limit as possible and doing jetting changes you'll want to be sure and not go over so you'll need to dyno often.

It kinda works for a really relaxed club but it wouldn't work on a very large competitive scale.

The MOTO-ST national series has dyno hp limits...

Gluge 11-01-2007 01:19 PM

Quote:

Originally Posted by The_AirHawk (Post 172539)
So, I can just go-down to my 'PrillaHondaYamaha dealer and pick one of these out from amongst the rows and rows of them lining the walls of each showroom?

Yamaha Dealerships sometimes have one, Honda of Thousand Oaks sometimes has one. It's not the sort of bike most people buy so it doesn't make sense for them to keep them stocked. I mean how many people do you know who are in the market for a new entry level road race bike?

Quote:

Originally Posted by The_AirHawk (Post 172539)
Sorry, but besides seeing one on a track, or on a trailer going to or from a track - I've hardly seen one of these bikes.

Makes sense they're not street legal so I'm be surprised to see one anywhere else :)

Quote:

Originally Posted by The_AirHawk (Post 172539)
I won't argue with you about the cost of racing a 125 - hell, I've thought about it over and over myself, if I were even two-hours closer to Hallet I'd probably already have bought a used one out of the classifieds in RRW. As to the "more fun" thing - that's subjective. :D

True there aren't many new ones sold, probably less than a hundred each year (TZ125's are down to 20 a year I think) But I'm sure with higher demand there would be more.

Honda of thousand can probably order one for you. They're a HRC dealer they're $11,250 new. Used is the way to go though best place to look is USGPRU > Welcome to the United States Grand Prix Racers Union forums.

That would get you a ready to go bike capable of winning right out of the box. VS having to find a front end, fitting body work, new wheels, wheel spacers etc. And if you notice in the article they say they still need to be sorted out some. You think your average entry level road racer is ready to do all that and then spend time sorting out the handling of their bike? Chances are they probably don't have the experience needed to know how to sort of the handling of their bike.

acecycleins 11-01-2007 01:41 PM

Quote:

Originally Posted by Kevin_Duke (Post 172591)
The MOTO-ST national series has dyno hp limits...

The entire point of the exercise is to put "like" bikes on the track and test rider skill and machine durability, right? All the while, grooming up and comers and giving old guys somewhere to play on the cheap. That's what I got out of the article.

Gluge 11-01-2007 01:50 PM

Quote:

Originally Posted by pplassm (Post 172566)
Althoug I have made a lot of the maintenance requirements of 4 stoke MX bikes in the past, I think they will do just fine in this application.

The big realization that people will have to get is, that these are racing machines, not low stessed street bikes.

250 2strokes would be nice to see in there, but they will need help to keep up. 360cc overbore, anyone?

Haha 250 2-strokes would eat them up. A Honda RS250 makes around 70 hpr at the rear wheels. and weighs 250lbs (same weight they claim for these 450's) Where as the 450's make what 40 hpr at the rear wheel?

My less than $5000 RS125 makes 40 hpr at the rear wheels and only weighs 156lbs. I even race it in the 250 GP class and have a lot of fun.

SeanAlexander 11-01-2007 03:50 PM

What those arguing for 125 and 250GP bikes are forgetting to mention is: The vast majority of adult club racers cannot physically fit on 125 GP machinery and some don't even fit on 250s. However, almost everyone can fold themselves into the clip-ons and rearsets of a 450MX/GP conversion. If I was 5'8" and 165Lbs I'd race 125GP bikes in a second. So for the cost; the 450MX/GP route is looking pretty attractive.

PS Speaking of cost, the suspension is fairly expensive up-front, but once it's dialed in, it's not much more costly to maintain than clutch plates. 450 four-strokes will surely require a decent budget to keep fresh in a roadrace setting, but the #1 budget killer for a serious club racer is (and will probably always be) Tires, Travel and Entry Fees.

-Sean


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