All Things CR250

[Dan Davis]

I believe they are as follows:

Primary Reduction: 3:1 or 63/21

1st gear: 1.8:1 or 27/15
2nd gear: 1.47:1 or 25/17
3rd gear: 1.21:1 or 23/19
4th gear: 1:1 or 21/21
5th gear: .87:1 or 20/23
6th gear: we wish

[Ian Harrison]

Hi All

Dan is "on the money" as usual.

Our close ratio box for the CR250 ('02 onwards is):

1st 1.866:1 (1 tooth extra on countershaft)
2nd 1.470:1 (Standard)
3rd 1.210:1 (Standard)
4th 1.050:1 (1 tooth less on mainshaft)
5th 0.952:1 (2 teeth less on mainshaft

Overall spread is 49% (even with lower 1st) against 51.7% of the standard box.

We also have a 0.909:1 alternative 5th gear (1 tooth lower).

The combinations we use are:

Standard box
Standard box with low first
Standard box with 1 tooth lower 5th
Standard box with low first and 1 tooth lower 5th
Full close box

Our 6-speed box is undergoing a little re-engineering and I will post details when available.

Regards

Ian
_________________
Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012

[Chuck Bunnell]

Thanks guys. Saves me from counting teeth over and over.

[Andy Kiker]

WOW Ian, You must have some tight turns over there to need a lower 1st.
That or it must be good for doing burnouts or standing starts.

Never mind. I get it, with the lower 5th you may need a lower 1st. It takes me a little while to catch on.

So you have 5 different gear sets that you can use depending on the track you are going to. Each gear set will have its advantage at different tracks depending on track layout and turn speed. All you need is 5 motors set up with each gear set. or if you know what gear set works best at a certain track you just split the cases and put it in for that meeting. If you guess wrong just split the cases at the track and change it. Boy that sound just Great
_________________
Andy Kiker #24

Anderson Karts
WiWa GasGas
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[Ian Harrison]

Hi Andy

Pretty fair assesment So I increase your order to 5 motors then

Now I'm not driving anymore, I need something to do at race meetings

Of course with our cassette gearbox (sideloader), it's a breeze, 15 minutes for ratio changes - - - - - - - - - - - - - - - - - - -joke ).

Regards

Ian
_________________
Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012

[Roger Miller]

Is the '02 and up stock ratios the same as those Dan posted for the '01? Or is there a difference?

[Ian Harrison]

Hi Roger

Standard ratios are the same for the '02 onwards.

The differences from the '01 are stronger (wider) 5th gear and 13 spline shafts rather than the 6-spline shafts of the '01

We have a prototype kit in development to allow the (wider)'02 cluster to be fitted to an '01 without any machining.

Regards

Ian
_________________
Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012

[Andy Kiker]

Let me think about this. 5 CRs or one GasGas. Boy that is a hard decision.
_________________
Andy Kiker #24

Anderson Karts
WiWa GasGas
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[Dan Davis]

Poor Ian...
I'd be good with one Honda 05 CR250 with one 6 speed installed......Unless I can get a Gas Gas package for under 5 g's and be able to completely rebuild it myself using OEM parts that I can purchase without the ridiculous exchange rate and modify if necessary. I kinda thought that was what ICE was originally intended to be. I'm not moaning about it but just pointing out how close to FE the newer kid on the block really is.....awesome is the only word that comes to mind.

Otherwise, discarded GP TZ's in FE sure sounds attractive for similar cash outlay. I sure liked the feel of that package testing at MSR. Soooooo smooth.

[michael beamer]

I think that has been the view of the rest of the world as well. They treat the amazing $13000.00 gasgas as an Fe . But a few genius's in the US think otherwise.Lets see , two of Ian's cr250's with a few thousand left over, versus one gasgas. Not much to consider for most people.Maybe we should start a USHSK seies. Are you listening Bernie?

Beamer

[Erik Frank]

Gents,

Lets not turn this thread into another CR-250 vs. GasGas bitching contest. I wanted this topic to be a repository for CR-250 info.



-erik
_________________
Member of the Fisher-Price Racing Team

[Dan Davis]

Thx Erik, I didn't mean to help turn on the ICE blender. I'm really perfectly content competing in USSK's experimental "SS" classification. I do not think the Gas Gas should be in FE. I think it belongs right where it is. So what if a fast driver beats many of the FE karts. A fast driver in a Honda will beat some of the Gas Gas powered karts out there too. The rules including it in the US ICE class existed long before this debate started. MSR showed a good turnout for "SS" proponents so things seem just fine with racing OEM based Honda's in USSK. With that said, I'm sorry I'll not be able to attend Eagles Canyon but I'll be shooting for Mid Ohio with some new setups to work with. So bring your Honda's out & support US superkart racing where you can....at the moment it is the only way to race with a good number of superkarts in North America with exception to the USKGP events.

Oh yea....a litte contradiction in my last post......the OEM 5 spd will due for the $$ & class sake....sorry Ian. I'm sure that you will come up with a contender for the all out CR250 cased GP package. It'll be interesting to see how it all unfolds for sure.

Back to work...

[Andy Kiker]

Sorry Erik, I did not intend to do that either. The point I was trying to make was that to have all available gear ratios could be expensive.
As Dan said they are not oem based and would not be legal in a oem class.
_________________
Andy Kiker #24

Anderson Karts
WiWa GasGas
Powrpad

[Ian Harrison]

Hi Guys

I'm with Erik on this one too.

I thought Andy was just pulling my leg (as usual!!), but of course he has a perfectly valid point.

I always pull the motors down between meets, so what we actually do is change ratios then. As we know all our tracks well, selection is easy.

Our gearbox regulations are free as long as you use the same number of ratios (i.e. five), so it's all perfectly legal (for us).

With the 6 speed box we wouldn't need to change ratios, but this is not allowed for us.

Regards

Ian
_________________
Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012

[Ian Harrison]

Hi Guys

Just to round off on Andy's comment/question.

The one tooth lower top is £127.50

The close box (which includes the low first) is - £375.00

So that's £502.50 for the full set to give our 5 options . Just damn that exchage rate for you guys .

Apologies for getting commercial, but the question was raised.

The 6-speeder is nearly ready and I'll post details when it is fully tested. As Dan says this is no good for the your SS (or ICE?) class and will probably see light-of-day in the US at VIR and hopefully Laguna .

I have one US driver chomping at the bit and heading the queue (in Pole Position you might say ). Let's hope we can put the deal together and put on a good show for you all with the "Super CR250" whatever stage it is at by then

If it comes off. both our karts twin and single may be for sale after VIR.

Best Regards

Ian
_________________
Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012