Bucket options?

[k14]

CB125Twin. Probbaly not, 17 inch was pretty rare in them days. Might be something around that fits, prowl around with a caliper vernier. Is it wire spokes? If so just take the wheel to Tom Morris and get him to lace in a 17 inch rim (or do it yourself, it's not hard.)

Ahem, come for a look in my garage and you'll be pleasantly surprised. As long as you can get access to a lathe to make up a few spacers it shouldn't take longer than an afternoon to fit them up.

As for the class being expensive etc. I paid $350 for my bucket 4 years ago, I had spent less than $200 for three years of racing prior to this year. I rebuilt the top end for BOB and that cost me about $300. Since then I came 5th at BOB and even won a race against FXR's and CBR's at levels full track. So its totally up to the rider. Apart from 17" wheels and the overbore my CB is totally standard. You can certainly go out there and get something for $500 that is capable of running top 10% of the class but you will always have guys that spend more money than everyone else. That's motorsport. Nothing wrong with it, each to their own.

[k14]

I had a look at this. all the 250/4s are 4V heads and high performance with nice gearboxes. The Yams at least have very light crankcases and is the reason I didn't bother removing the unused bit on my engine. Plus it'll be a good place to mount a turbo and the oil will drain directly back into the case. I'd guess the 1/2 a FZR250 weighs less than a CB125T, and it has plain bearings on the crank, is water cooled, 4V straight intake heads, modern rods/pistons(OK 20 yrs old now) and just lovely bits of kit and a 17-18,000rpm redline.

My engine is roughly 40kg. What is your one? The alloy of the FZR would be a big weight advantage, the CB engine is a boat anchor. My CB weighs in at just over 100kg, I'm pretty sure the FZR 125 would be more than that though.

[Squiggles]

Do the AG100 motors go alright?

[Ixion]

What's the deal with scrutineering on such things? Do they need to be certified in any way. F'instance if I want to cut a bit or two out of a frame and weld a new bit or two in?

[Ixion]

Ahem, come for a look in my garage and you'll be pleasantly surprised. As long as you can get access to a lathe to make up a few spacers it shouldn't take longer than an afternoon to fit them up.

As for the class being expensive etc. I paid $350 for my bucket 4 years ago, I had spent less than $200 for three years of racing prior to this year. I rebuilt the top end for BOB and that cost me about $300. Since then I came 5th at BOB and even won a race against FXR's and CBR's at levels full track. So its totally up to the rider. Apart from 17" wheels and the overbore my CB is totally standard. You can certainly go out there and get something for $500 that is capable of running top 10% of the class but you will always have guys that spend more money than everyone else. That's motorsport. Nothing wrong with it, each to their own.

Spacers I can make (I have a lathe). It'd be the disk brake callipers that would exercise me. Another advantage of TLS I guess, all you needed was a check strap. But if the new wheel has a large disk diameter (as one would like it to), then how to mount the (new) calliper to the old fork legs.Given that's one hell of a stressed mounting.

[wbks]

So I got the cb125 single from buckets4me for nice and cheap. Now I just need to get a battery today from repco put some gas in it, a new plug and see if the points need much doing and I might just replace them anyway if they're off. Saves screwing around with worn ones, unless I can't find replacement ones to fit. Cheers for the spare parts, b4me. I'll make a new topic when I get it running and take it to mt.wellington for a day.

[k14]

What's the deal with scrutineering on such things? Do they need to be certified in any way. F'instance if I want to cut a bit or two out of a frame and weld a new bit or two in?

Nothing needed at all. Although the people doing scrutineering are usually pretty well informed and experienced and will spot a bodge job a mile away.

Spacers I can make (I have a lathe). It'd be the disk brake callipers that would exercise me. Another advantage of TLS I guess, all you needed was a check strap. But if the new wheel has a large disk diameter (as one would like it to), then how to mount the (new) calliper to the old fork legs.Given that's one hell of a stressed mounting.

Discs aren't usually a problem. There is two ways to do it, I got a NSR front wheel and disc and machined about 2mm off the perimeter of the disc. Then I ground out the remaining 1-2 mm from the caliper.

Alternately you can get a big hunk of alu and make an adapter that bolts onto the fork leg and spaces the caliper to the correct position that way. If you have a mill you can make a really nice job of something like that but it can be done by hand and drill press if need be.

[Sully60]

So I got the cb125 single from buckets4me for nice and cheap

Good shit man! Those things can be made to haul arse, you'll be whipping FXR's in no time!

Spacers I can make (I have a lathe). It'd be the disk brake callipers that would exercise me. Another advantage of TLS I guess, all you needed was a check strap. But if the new wheel has a large disk diameter (as one would like it to), then how to mount the (new) calliper to the old fork legs.Given that's one hell of a stressed mounting.

You've come a wee way since the "brakes are an over rated luxury" phase.
Check this out. Two bits of 10mm aluminium plate cut out by hand, shim steel to get the lateral alignment, mating holes drilled, done. Had an engineers report done due to the hand made nature of this adaptation and according his calculations each bolt has a safety factor of two for the application.
Best part is this setup fitted and worked reliably on all four Japanese brand MX bikes.
You don't need brakes like this on a bucket but you do need to slow down accurately and consistantly

What's the deal with scrutineering on such things? Do they need to be certified in any way. F'instance if I want to cut a bit or two out of a frame and weld a new bit or two in?

You'd be lucky to pass if you haven't done that

As long as the engineering is up to scratch you'll be fine. Like K14 says anything obviously sub standard will attract attention and you may be told to fix it before you can race.

[Pumba]

So I got the cb125 single from buckets4me for nice and cheap. Now I just need to get a battery today from repco put some gas in it, a new plug and see if the points need much doing and I might just replace them anyway if they're off. Saves screwing around with worn ones, unless I can't find replacement ones to fit. Cheers for the spare parts, b4me. I'll make a new topic when I get it running and take it to mt.wellington for a day.

Nice work mate, for what its worth if the points are rooted rather than replacing them you would be better off to convert it to a CDI ignition, did that with the RX and it changed the bike.

[Sully60]

Nice work mate, for what its worth if the points are rooted rather than replacing them you would be better off to convert it to a CDI ignition, did that with the RX and it changed the bike.

Wot he said^^^^^.

Points are a fricken nightmare, eh Ixion?

[Ixion]

Absolutely nothing wrong with points. A lot more relaible than those bloody electronic things. Electroinics is just a pain in the tit, except for fuel injection which is good becaus eit enable one to dispense with the Abomination unto the Lord which Is the Carburettor.

But, to the point (geddit ? geddit ? every one a gem ) : is an AG100 a perverted AX100 or a bastardised A100 ?

[Sully60]

Absolutely nothing wrong with points. A lot more relaible than those bloody electronic things.

Which is why my twin gained nearly 3hp and can now run all day with a 7a/h battery and total loss ignition and it doesn't need chokes to get started. All after converting from points to a basic electronic system.

But, to the point (geddit ? geddit ? every one a gem ) : is an AG100 a perverted AX100 or a bastardised A100 ?

Careful there, you've actually got two different brands of machine mixed up there and no, none of the models you mention are the same mechanically in any way.
The AG is a Yamaha and is not a perverted anything, it was built exactley the way it was right from the start for worrying farm animals

[koba]

Which is why my twin gained nearly 3hp and can now run all day with a 7a/h battery and total loss ignition and it doesn't need chokes to get started. All after converting from points to a basic electronic system.

[wbks]

Does it take much to put a CDI into it? I'd like to improve it and all but I just want to get it running to begin with. And btw will a simple small 12v motorcycle battery work fine to run the total loss system? Just clip it in and go?

[Pumba]

Fitting the CDI for me was not to bad, but then the donner CDI was off a AG100 which has a pretty much identical bottom end casing to the RX125, so gust had to slot some holes and bolt it up.

Got my mechanic mate to make sure all timing and firing was correct, so that was real easy for me