New class for CSBK

Sky_high said:
I think the old CBR250RR from early 90's are rated at 45hp. That would be perfect for this class!!

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I enjoy the 250 and 400 inline 4s just as much as anyone. However, they would now get stomped even by the R3s and 400s. Top end sure the 250/400s would be quick, but getting there, they would get left in the dust. 30 year old tech sadly, is infact 30 years old.
 
TK4 said:
An RZ350 never had 50hp unless you ran it on nitrous, I doubt an EX500 either. Maybe an FZR400 on a good day.
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The vast majority of RZ's were sold stock from the factory with more than 50HP
RD350TYPE You have to go back to a RD-LC to get a Canadian RD with less than 50HP.
70HP in stock cases/barrels is fairly simple. 100HP is doable
IIRC the EX500 was 57 HP stock, 70HP is simple, 75HP makes a hand grenade
 
... but then any advantage a RZ or EX has in motor, they give back in handling.
A RZ or EX is a limp noodle compared to a R3 or Ninja400

I want a crack at this class with a Yamaha TR3 or TZ350
 
bitzz said:
The vast majority of RZ's were sold stock from the factory with more than 50HP
RD350TYPE You have to go back to a RD-LC to get a Canadian RD with less than 50HP.
70HP in stock cases/barrels is fairly simple. 100HP is doable
IIRC the EX500 was 57 HP stock, 70HP is simple, 75HP makes a hand grenade
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RZ350 from the factory spec sheet - 52 crankshaft HP, 30 ft/lb torque.
What does that translate to at the rear wheel ?
I built and raced a few of them, you start tweaking and the fuse gets very short.
You'll eat top ends, spread cranks, demolish clutch baskets - the list goes on.
I'd love to see a dyno sheet showing 100hp - I don't believe it.
You're right about the handling - they'd get spanked by any to the current generation lightweights.
 
bitzz said:
... but then any advantage a RZ or EX has in motor, they give back in handling.
A RZ or EX is a limp noodle compared to a R3 or Ninja400

I want a crack at this class with a Yamaha TR3 or TZ350
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The TR3 or TZ350 would get absolutely smoked by a modern lwt.

At mosport the 400s were lapping faster then the p3 heavy Superbike builds and many of the p4 bikes.
 
To put it into perspective to everyone wanting to run vintage bikes.

Mike McNeil did a 1.36 on a CB900 built to likely an 1100

Jared Walker did a 1.34 on a ninja 400
 
Does this have anything to do with the CMA relative to the MCC?
 
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Reactions: TK4
LWTRacer said:
To put it into perspective to everyone wanting to run vintage bikes.

Mike McNeil did a 1.36 on a CB900 built to likely an 1100

Jared Walker did a 1.34 on a ninja 400
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In fairness Jared was 1.34.884 and Cameron was 1.34.924
 
LWTRacer said:
To put it into perspective to everyone wanting to run vintage bikes.

Mike McNeil did a 1.36 on a CB900 built to likely an 1100

Jared Walker did a 1.34 on a ninja 400
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... Brian Henderson did a 1:33 on a RD-LC and 1:31 on a TZ350... this TZ
ff30VOr.jpg

about 20 years ago
... the vintage lap record for "middle weight production" (production bike, 1976 or older) is 1:37
... and I own a (1973 350cc) TR3 that was clocked at 154 MPH
...Josh Hayes was a second and a bit short of the outright track record at Philip Island on a "1982 vintage" bike (there was nothing made in 1982 on that bike).

... you know... further perspective
 
bitzz said:
... Brian Henderson did a 1:33 on a RD-LC and 1:31 on a TZ350... this TZ
ff30VOr.jpg

about 20 years ago
... the vintage lap record for "middle weight production" (production bike, 1976 or older) is 1:37
... and I own a (1973 350cc) TR3 that was clocked at 154 MPH
...Josh Hayes was a second and a bit short of the outright track record at Philip Island on a "1982 vintage" bike (there was nothing made in 1982 on that bike).

... you know... further perspective
Click to expand...
That info predates my experiences so thanks for it.

I hope the Pro/AM Lite grows. Hopefully a good assortment of young people coming up to try AM (however with 2 pandemic summers under our belt at present I cant think of a long list here in Ontario) and a bunch of older, slower pros to fill up the grids. O and racepro171.
 
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bitzz said:
... Brian Henderson did a 1:33 on a RD-LC and 1:31 on a TZ350... this TZ
ff30VOr.jpg

about 20 years ago
... the vintage lap record for "middle weight production" (production bike, 1976 or older) is 1:37
... and I own a (1973 350cc) TR3 that was clocked at 154 MPH
...Josh Hayes was a second and a bit short of the outright track record at Philip Island on a "1982 vintage" bike (there was nothing made in 1982 on that bike).

... you know... further perspective
Click to expand...
The bike that holds the Vintage Production lap record at mosport is a very not production cb550 that Waller has.

I would like to see any evidence that an RDLC lapped mosport in a 1.33 because Eddy Brunets GP lap record is a 1.30 on a TZ2505KE. And Darrel Cooney did a 1.30 on a P5 GSXR600

So until you can show proof I'm calling that as crap.

Again I like my old bikes, but they are just that. Old. Their brakes and chassis even on the TZ350 are garbage compared to these days lightweights.

Also Josh Hayes lapped PI in a 1.37...which is quick. But Tom Sykes SBK lap record is a 1.29....the moto3 lap record is a 1.36

Remember the older people get that faster they thought their bikes were...
 
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A stockish RZ350 can easily reach high 50's+ horsepower at the rear wheel .

Yamaha claimed 59hp for the 31k that was sold in Canada and Europe and 63 for the later 1UA models. That's at the crank of course. The 48H that was sold in the US was so choked up with emissions control kit that they claimed 52 hp for that. Most of that kit can be removed though.

I just finished rebuilding a Canadian 1UA motor that's in a US 48H rolling chassis. It was a bit of a budget build. Its running a standard Yamaha crankshaft with +0.25 over with Vertex cast pistons on a new bore. I just did a quick cleanup on the ports to remove the casting flash.

The only big thing I had to do was to recut the head and squish band to get 0.040" clearance and 15 degrees taper so it would run on what passes for pump gas in 2021.

Its running Canadian 1UA pipes with standard VM 26's, standard airbox, standard Canadian 1UA ignition and running a rebuilt oil pump - so no premix as its much more convenient on a street bike.

I've attached a snapshot below.

Its about 58 hp at the wheel (rounding up... LOL) but it took some time on the dyno to get it there. The normal big hole around 5K was tuned out. You could probably get another 2 or so with a set of Keihin PWK28's and they would probably help with that dip at 9k. Maybe even more with a good set of pipes. Still it should be a good reliable street build with more than enough power for some hooligan fun :)

I do have a good port for the 1UA that will produce ~72 hp using the standard crank but needs a good set of pipes, PWK33's and an ignition, so there is definitely work to get it there. I'll dig out the dyno for that one.

RZ350-1UA-CDN Pipes.jpg

I agree with the frame. I have ridden a stock frame RZ and FZR400 back to back on the track and there is no comparison.

The RZ can be made to handle much better though. CMR braced my race bike may years ago and I'm running a set of conventional RWU cartridge forks on the front. It did make a huge difference.

Neither are going to be a 400 ninja or R3 though, at least in terms of handling.
 
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