For you 125 GP Fans

[Ivan]

Here guys here some GP Monos

[xwhatsit]

Hell yes! The world has come to its senses once again -- mono is mainstream!!

Well if they can run 250 thumpers in the 125 class, does this now mean they can run 500 thumpers in the 250 class?

[Sketchy_Racer]

YOU GET OUT!!

Why have the friggen eco nazis have to come and ruin a class that cleary has great competion?? because we burn a bit of oil?? Ohh FFS how many friggen race bikes are there?? and how much of a difference is a few little race bikes really going to make. Especially compared to the fucking Yanks and thier over grown fucken SUV pieces of shit with their 10 litre engines

This worlk makes me sick

[Ivan]

I agree with Glen here,

Serious these bikes are cool, But 2 things

What is wrong with a class that is working and having better racing than moto GP????? I meanthe lead changes more? You dont see any smoke really except for initial start up, Then itclears,

The Class works fine then they are going to come in and wreck it???



2nd thing,

These bikes are 125 GP bike chassis EG Honda RS125 or TZ125, With A CRF YZF RMX KXF engine in them. These bikes are nto porpouse built GP racers, They are Hybrids using a GP Chassis, And A production engine,

Really I say Awsome they built these bikes, But give them there own class,
And I still reckon a 125 is going to blow these out the water, The only advantage they have is initial launch, and then outa corner drive no top end advantage, Wereas the standered RS is Lighter Chassis is designed for this engine, Suspension designed for this engine and frame, And is good at top end revs, I still reckon a fast rider on a125 is going to blow these out the water, I bet if you put one of these out at world 125, you wont see them be in the top 5

[HenryDorsetCase]

Ive been thinking about the issues raised about cooling, and oil control.

The guy who built the Aprilia RS250 with the Aprilia SXV550 motor put a larger oil tank in it (dry sump motor): went up by 2 or 3 litres the idea being that the larger oil volume would allow more heat to be shed into it given the change of use. You could do the same with the radiator as well I would think. more coolant volume, larger rad etc, again to try and keep the thing cool.

If this sort of config is to replace existing two strokes, and given the amount of power they want to extract, then high maintenance (it seems to me) is a fact of life. Of course the cost of that maintenance is more, what with all the extra whirly bits whirling around, but its only for one cylinder so that has a limiting effect.

Have a look here if you want to see the blog of the SXV into the RS250 and you havent seen it before......


as another point, it seems to me that this sort of conversion would be easier than converting an average street bike to go racing, once you'd assembled the bits. though until you try.....

[Ivan]

Yeah thats cool, Cept these bikes aint GP bikes


And yourgoingtoruin a class with good racing basically to make a world bucket racing championship,


Serious what do you prefer to hear?


A nice Crisp 125 screaming past, or a big ass single thumping by?


I know what I prefer

[HenryDorsetCase]

I agree with Glen here,

Serious these bikes are cool, But 2 things

What is wrong with a class that is working and having better racing than moto GP????? I meanthe lead changes more? You dont see any smoke really except for initial start up, Then itclears,

The Class works fine then they are going to come in and wreck it???



2nd thing,

These bikes are 125 GP bike chassis EG Honda RS125 or TZ125, With A CRF YZF RMX KXF engine in them. These bikes are nto porpouse built GP racers, They are Hybrids using a GP Chassis, And A production engine,

Really I say Awsome they built these bikes, But give them there own class,
And I still reckon a 125 is going to blow these out the water, The only advantage they have is initial launch, and then outa corner drive no top end advantage, Wereas the standered RS is Lighter Chassis is designed for this engine, Suspension designed for this engine and frame, And is good at top end revs, I still reckon a fast rider on a125 is going to blow these out the water, I bet if you put one of these out at world 125, you wont see them be in the top 5

I dont think thats the issue to be honest. the 450 MX conversion bikes we were originally talking about were proposed (and thats important, its only a blue sky exercise at this point) as a cheap way of entry to a race bike that is more suitable to someone going up from entry level racing. Presently those people jump straight onto a (as Roland Sands says) a 450 pound, 100+ BHP 600: given these are young people then thats preceived as too much of a jump. they talk about 125 GP racers also, and the idea is thats fine IF you weigh 52 kg and are 5'2 tall.

So to summarise, its an adjunct to, not a replacement for the 125 class, and given the writing might be on the wall for 2 strokes, a "what if" type of exercise. Bear in mind too, that there is NO US 250GP class anymore. US racing is completely dominated by street bikes/superbikes. Not saying its a good or bad thing, its just how it is.

[HenryDorsetCase]

Yeah thats cool, Cept these bikes aint GP bikes


And yourgoingtoruin a class with good racing basically to make a world bucket racing championship,


Serious what do you prefer to hear?


A nice Crisp 125 screaming past, or a big ass single thumping by?


I know what I prefer

big ass single any day.

but I'm not going to do anything... and as I say above, this is a proposal only. and US based at that.

[Ivan]

Yip I agree there,


Well these aint cheap tho.


To buy a chassis is afew grand for a good roller then 3-4 grand for engine, then at least 3 grand for mounting it and making it fit, your looking at well over 10 grand before your completed when you could buy a 125all ready made same horsepower and less moving parts in side

[HenryDorsetCase]

the 45o MX based proposal is the MX bike frame subframe swingarm engine. Graft on forks, new shock rearsets and Motard wheels and a race fairing, go racing. Again, the US situation is quite different to here, but given the parameters above and using mostly new parts then it would be at least price competitve with other forms of racing.

If you havent read it, read the interview with Gavin Trippe which I linked above, he does address most of the points you're raising (which I acknowledge are valid ones, but most can, I think, be answered)


Their proposal is to make it affordable by requiring that the original frame be used. they refer to the junior dirt track class which is also based on these bikes. the rule makers left the frames "open" so now to be competitive they have to use a $12000 Ron Wood or C & J frame, which defeats the purpose of the class.... hence the requirement to use the original frame.

[Sketchy_Racer]

A few points here.

Yes there is still a 250GP class in US. It runs with the USGPRU series and usually have about 20-30 bikes at each meeting. Yes not a lot but there is still a class.

oh, and another myth. I believe that largly why people are moving away from the 2T GP classes is because they have the assumption that they cost millions to maintain and keep compeditive.

YOU ARE WRONG

I am a 17yo apprentice on lousy apprentice wages and i still earn enough to just scrape by paying with my racing (so long as nothing goes wrong!)
And thats with a bike that is compeditive in the nationals. I'd like to see you find any other class (F3 - pro twins etc..) that you could be compeditive in on a wage like mine!!

The reason people are liking these new thumpers is because they can be lazy racers. and tuners. Once the motor is setup it runs pretty much as well as it did on the dyno anywhere else. So what if you have to change a few jets.. stop being so damn lazy and learn a few skills!!

Then there's the riding. People also like them because they can screw things up and get away with it. Stuff a gear change? use the torque of a 4T to fix it.. good rider?? i think not. Lazy!
Screw a gear change on a GP 2T?? your gonna get punished! Don't screw up.

Its fustrating, because 99% of the people that like the idea of changing to 4T haven't even ridden a 2T GP bike! SO most ideas and theorys about them are just peoples imaginations!

I hate inaccurate assumptions on stuff. Be informed, then make a decision!

Rant over
-Glen

[Tim 39]

A few points here.

Yes there is still a 250GP class in US. It runs with the USGPRU series and usually have about 20-30 bikes at each meeting. Yes not a lot but there is still a class.

oh, and another myth. I believe that largly why people are moving away from the 2T GP classes is because they have the assumption that they cost millions to maintain and keep compeditive.

YOU ARE WRONG

I am a 17yo apprentice on lousy apprentice wages and i still earn enough to just scrape by paying with my racing (so long as nothing goes wrong!)
And thats with a bike that is compeditive in the nationals. I'd like to see you find any other class (F3 - pro twins etc..) that you could be compeditive in on a wage like mine!!

The reason people are liking these new thumpers is because they can be lazy racers. and tuners. Once the motor is setup it runs pretty much as well as it did on the dyno anywhere else. So what if you have to change a few jets.. stop being so damn lazy and learn a few skills!!

Then there's the riding. People also like them because they can screw things up and get away with it. Stuff a gear change? use the torque of a 4T to fix it.. good rider?? i think not. Lazy!
Screw a gear change on a GP 2T?? your gonna get punished! Don't screw up.

Its fustrating, because 99% of the people that like the idea of changing to 4T haven't even ridden a 2T GP bike! SO most ideas and theorys about them are just peoples imaginations!

I hate inaccurate assumptions on stuff. Be informed, then make a decision!

Rant over
-Glen

I agree with all of that too, maintenance on a tuned 2 stroke is higher than a tuned 4 stroke, but is far cheaper. on a Tuned 4 stroke (SV's dont count as they are mini tractor motors) maintenance is still required regularly and is very expensive and much more difficult.
125gp bikes are very easy to work on.

[Tim 39]

did I mention half of what makes 125GP so great is the bikes amazing handling. With a big dirty 4 stroke in there they just wouldnt be the same. To be any good at all they'd need to redesign a motor to use and the frame to put it in, rather than just chucking a motox motor into a 125gp bike.

I haven't yet seen someone ride a 125GP bike for the first time without coming in with a huge smile saying "those things are awesome!"
I think putting a 4 stroke in the 250 bikes wouldnt be so bad as they are a lot bigger and heavier anyway, so the difference wouldnt be as noticable

[Sully60]

A few points here.



YOU ARE WRONG

I am a 17yo apprentice on lousy apprentice wages and i still earn enough to just scrape by paying with my racing (so long as nothing goes wrong!)
And thats with a bike that is compeditive in the nationals. I'd like to see you find any other class (F3 - pro twins etc..) that you could be compeditive in on a wage like mine!!

The reason people are liking these new thumpers is because they can be lazy racers. and tuners. Once the motor is setup it runs pretty much as well as it did on the dyno anywhere else. So what if you have to change a few jets.. stop being so damn lazy and learn a few skills!!

Then there's the riding. People also like them because they can screw things up and get away with it. Stuff a gear change? use the torque of a 4T to fix it.. good rider?? i think not. Lazy!
Screw a gear change on a GP 2T?? your gonna get punished! Don't screw up.

Its fustrating, because 99% of the people that like the idea of changing to 4T haven't even ridden a 2T GP bike! SO most ideas and theorys about them are just peoples imaginations!

I hate inaccurate assumptions on stuff. Be informed, then make a decision!

Rant over
-Glen

Some good stuff here Glen
But thats from your perspective. When I was your age all these things applied, now I have responsilbilities such as rent/mortage, wife, child, etc etc I have found the most valuable resource to be time.
I have an amazingly understanding partner who lets me spend an inordinate amount of time fiddling with my stable of highly prepared race machinery But something somewhere eventually has to give.

I know his name has shown up in this thread more than once but take a look at Jason Easton, surely you don't regard him as lazy?
To race any motorcycle competitively you constantly update/develop/retune so there are skills to be learned regardless of what type of machine you race.
Lazy riding??? Sorry I don't buy this, it takes little effort to change down two,three, four gears going into a corner to keep the revs in the right range.(especially with no back torque) If you come out of a corner in two higher gear on a 125 (and you have a brain) you'll only do it once.
You've probably made an assumption on what its like to ride a big single.
The crank from one of these engines (450cc) would almost weigh the same as an entire 125 gp motor (not the gearbox also) and they spin at close to the same rpm as a 125 so you may be lazier with your left foot but man your gunna have to put the big effort into stopping the thing and turning it compared to a 125.

Assumption is the mother of all fuckups!

ReRant over!

[Ivan]

Good points from both opinions,

Now heres my thoughts,


Yes a 125 rider requires alot of skill to get the gear change crucial, as other wise he just runs outa power, were as a four stroke rider can say slap down 1 gear this is from my experience riding four stroke singles btw

(DR350 DRZ400 with Yoshi kit And a GB500 bored to 600) plus others


You can easily leave a gear, to high and pull good torque from it, were as you cant on a 2 stroke with out clutch,

Cornering on a 125 tip in carry heapsa corner speed apply lots of gas drive out screaming the engine,

Single Button off and try tip in actually is alot more difficult, Once youve got it turning its fine, of road you normally help turn with the back stepped out as it impresses the chicks but its harder to tip in


Tuning on day


The 125 rider needs to ahve his jettign etc tunedperfectly to barametric pressuresetc were as the 4 stroke guy can through his bike on Dyno slap on some parts jet the carb to suit, Keep going,


Temperature drops,

The four stroke works pretty much the same in this condition,

Were as the 125 jettign goes up the crapper


So really in the long run the 125 requires more but also makes it better racing,

I mean serious on race day tommorow ill set my temp gauge up get the right air pressure alter my jet to suit go out ride it thats it,


A 4T requires Pistons cam chains head gaskets valves oil etc

A 2T requires a piston maybe a Oring in the head if its getting old, some 2T oil in the fuel and Gear box oil changed every few rounds


I mean serious


Do a piston change takes on average an hour yip I know you can do it fast but just checking barrel coating etc,


Thatsit really

500 K's on a piston almost a season
2000 K's on a crank you work the maths out


I mean they not that hard im not insulting him but Sketchy hadnt had a bottom end apart before on a bike he did his RS real fast and got good performance out his engine

I mean its pretty simple


GO THE FUCKEN 2 STROKE FUCKERS