Looking to give this a go. New guy advice thread.

[bacon]

Hello all,

Sorry if my forum etiquette is not quite up to scratch. I've never really used one before. I've been looking to give bucket racing a go for a couple years now. Rather then going out and buying a nice running set up (like a sensible person), I've collected a rather large pile of junk. Anyway any tips would be greatly appreciated or maybe someone to tell me how it all works track side. I'm based in Auckland and have gone down to watch the mt wellington buckets before but didn't get much talk in. I have the following:

*Full riding gear(leathers, boots etc)
*yamaha rx125 + 2 spare motors
*Rgv150 rolling frame x2
*honda cb125 x1
*nexa 150 17 inch wheel set and tires
*unknown origin 17 inch wheel set and tires

I'd love to put the rx125 engine into the rgv frame with the nexa 17 inch wheels, tires and disk brakes, but these things take time and engineering experience i just don't have. But I'm sure I could knock a bucket of crap up in the meantime to give it a go. Sorry for the TL;DR. Oh and I'm Chris

[FastFred]

Hi Chris, Good collection of bits and bobs. I see your "Location" is New Zealand, whats the nearest City/Town to you? there are bound to be local boys that will make you feel welcome on race day.

[bacon]

Hi Fred,

I'm based in Auckland and have been down to the mt wellington track to watch a couple times. I gotta say, Their stuff seems a lot more high tech then my junk :P. You wouldn't happen to know anybody who has done a rx125/rgv150 transplant before would you?

Cheers,
Chris

[F5 Dave]

Good stuff, not many RXs about but they can go ok. 150 is a roomy frame so should be easy enough. Then have to work on track protection nylon & of course a pipe.

[bacon]

are skateboard wheels and wine corks still acceptable track protection?

Cheers,
Chris

[F5 Dave]

yes & no. Wine corks pop out. Chris at RMS can crack you up some bar ends pretty easy, or anyone with a lathe & some +20mm plastic rod.

[bacon]

Cheers Dave, will keep that in mind.

[Akzle]

. Oh and I'm Chris

hi chris. i'm the resident that guy.

got tools? start bolting shit together. that bad attitude isn't going to help you win races and be a fucking h3ro and get heaps of pussy and international fame and become a well respected member of the KBmunity.

[F5 Dave]

At least he comes with a warning now. Ignore him & he might go away.

[koba]

I'd love to put the rx125 engine into the rgv frame with the nexa 17 inch wheels, tires and disk brakes, but these things take time and engineering experience i just don't have. But I'm sure I could knock a bucket of crap up in the meantime to give it a go. Sorry for the TL;DR. Oh and I'm Chris

Some tips that may be helpful:

Engine position is dictated by sprocket alignment, chain length and gearbox oiling.

You want to put those 17's in which will need to be mounted so the centre of the rim is correctly aligned along the centreline of the bike at both ends.
String lines can be useful here.

There is sometimes so scope for moving the sprocket left or right a bit relative to the wheel but this is limited.
There may also be some scope to move the engine spocket slightly one way or the other but again this is getting difficult and only worth pursuing in a pinch.

Work out where the wheels are going to be and the engine's left/right position is then pretty much set. You now need to work out how far forward the engine can go, the answer is generally as far as possible.
Some other things will get in the way of this, such as chain length, clearance with the front wheel and the interaction of the chain and swingarm.

The position is now a trade off between the following:

Weight distribution - Forwards = Good
Chain run - Sprocket close to swingarm is good and the aim is to have it slightly above the pivot point and so it does rub (too much) at any angle the swingarm is going to be in.
Front wheel clearance - Make sure nothing is going to rub or hit, remember the suspension may be bottomed out under brakes...


You will have some scope to tilt the engine backwards or forwards to try and balance the criteria above but don't go too far as the gearbox oiling may go to shit.

[koba]

The RX125 should be a really good engine if developed well but for now just get it running, refresh the bigend if it has sat around unused for years put some sort of pipe on it athen concentrate on getting the chassis semi-sorted before going much further.

The RGV150 isn't a great one but is steel so modifications are easy and it's a reasonable starter platform.

[koba]

Hmm, just read that again...

I may have wasted a bit of typing time, no worries; I'm getting quite quick these days!


You have a full RX125 with 2 spare motors?

Just get that going and bucket worthy.
17's and good slicks.

Race,
Race,
Race,

Then you will start to get a picture of where to go.

[bacon]

Cheers koba will do. To get those 17s into the rgv150 frame i need to widen the rear swing arm and accommodate for a larger axle. If anybody knows an engineer who could do it for a cheap flat rate I'd really appreciate it.

[TZ350]

RX125

278098

At Mt Wellington there used to be a very good RX125 in its original frame with 17" alloy wheels from I think a TZR or FZR250.

And the RD tuning info by Dale Alexander (Google him) could possibly be a good place to start with tuning the RX as its very similar to an RD250.

278099

Team ESE started by using RG250 pipes. Then later we modified them.

278100

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=2006757#post2006757

The link goes to another thread where there is a bit of info on modifying the RG250 chamber.

[Bert]

Cheers koba will do. To get those 17s into the rgv150 frame i need to widen the rear swing arm and accommodate for a larger axle. If anybody knows an engineer who could do it for a cheap flat rate I'd really appreciate it.

rather than widening the swingarm how much scope is there to reducing the size of the rear hub (quite a common thing done with FXRs using impluse or gsxr wheels etc) and in terms of axle, replace with different bearings to reduce size.

[avgas]

Proper bucket :shit:

:wings:

[Henk]

Or if the difference in axle sizes is enough, make the wheel spacers captive in the bearings and make the slots in the swingarm smaller to take the axle, don't try to do it all with spacers, Pumba tried that and watching him change wheels is enough to make a grown man cry.

[Pumba]

Henk is right. Dont try it.

Just a thought. What size are are those Nexa rims? They should have stamped on them somewhere "3.0x17" or "1.25x17" or some other similar set of numbers. No point going to the effort of trying to get them on the RGV if the are not wide enough to run slicks

[F5 Dave]

278099

Team ESE started by using RG250 pipes. Then later we modified them. .
Should have kept the rest of the RG250 chassis Rob, they handle well & are light & strong enough for the power. Just ally is harder to work with.

Koba has some good points, I will add sprocket position is best with chain juust rubbing on top of sw slider with smallest sprocket you will use (probably a 12 for kart tracks, or 2 less than std). When you sit on the bike the sw will compress so the chain just misses.

I find a 6' length of 25mm square tube from Mitre 10 for about $30 makes all the straight edge stuff much easier.

[bacon]

Cheers for the help guys, i sure do appreciate it. For my first knocking together of parts I'm going to try use the rgv150 chamber on the rx125. I have a feeling its not going to work great but surely anything is better then the stock pipe. Im not sure if i can decrease the size of the hub on the rear 17 also the tire rubs the swingarm. I think for now ill use the front end off the nexa and its 17ich wheel and tire(crappy Chinese but brand new) and the stock rgv thin 18inch wheel and tire on the back. Im not sure how a fat 17 on the front and thin 18 on the back is going to effect handling though . Also I'm just about to head on a camping trip so sorry if my next reply is a little delayed.

Cheers for the information and advice,
Chris

[TZ350]

For my first knocking together of parts ... I have a feeling its not going to work great ...

Chris it just does not matter whether it works great or not because you will learn so much from it and the first step will lead to the next until greatness is acheved or at the very least you will have a hell of a lot of fun in the company of great people and in my book that is the greatest thing of all.

[koba]

Just to throw another idea into the mix you could use another swingarm altogether.
The RGV's one looks somewhat inadequate.

I'd personally just get an RX going with crash protection to start with.

You are right about the pipe, it won't be great but will likely be better than standard.