Square Barrell Gearing

[Rosco400]

What Gearing is standard for motorcross and dirttrack for 250 Square barrell. noticed bike just would not get off line at Coffs Meeting on the dirt track and died on the line on first gear takeoffs but did go like the clappers when was wound out, probably should of asked this question before I went so as usual, learned the hard way, can I please be enlightened so as not to make the same mistakes again

[firko]

Rossco, I use different gearing for different tracks. For instance at Nepean I use 12/52(4.4:1) on my 250 and 350 Maicos for Nepean and 13/52 (4.7:1)on my old 440. For the old Amaroo dirt track I used 12/50 (4.2:1). For motocross I used to use 11/59 (5.4:1) at the old Amaroo track on the 250 and 350 and 12/59 (4.9:1) on the 440 . For Ravenswood in Victoria I used 12/59 on the 250 and 13/59 (4.7:1) for Coffs motocross the bike ran 12/56 (4.8:1). I don't know what the Coffs dirt track is like to ride or what gearing you were running so it's hard to advise you. It sounds like you may have too many teeth on the front sprocket. What sprockets were you running Rossco?

[Lozza]

Rossco Rossco Rossco Rule of thumb for any track any bike is top gear, peak revs at the end of the straight.Not reaching peak rpm= gear down reaching peak to early gear up. Converting to ratios makes it easier to work out too eg 15/45 ratio of 3.00 ,14/45 = 3.21 etc etc
HTH

[Freakshow]

On the dirt track as its straight you should still be feeding it clutch for at least the first 20 mtrs out from the gate,  Slip the shit out the clutch being stuck on the line on a 2 stroke means nothing if you cant pull the gear on the track.   As firko and lozza said you gear for the track then work you way back, you need to be geared to pull full noise on each lap, not worry about the one time you leave the gate,  feed the clutch and you wont give them any ground, unlike what you loose on the track if you pulling the wrong gearout there lap after lap.

[Moto]

Rosco,
         This year I was running 14 : 42 at  Coffs, and the way I was pulling away from you on the main straight you might like to try this ratio next year. I am only too willing to help.

[firko]

14/42 on a Maico? You'd barely get a 42 tooth sprocket on a Maico and a 14 only just fits on the front. Possible but doubtful. You'd never get it off the line. Cool for salt lake racing I suppose.

[Rosco400]

Rosco,
         This year I was running 14 : 42 at  Coffs, and the way I was pulling away from you on the main straight you might like to try this ratio next year. I am only too willing to help.

Very funny Tony

Firko, bike is currently set up with 13:59 and as this was my first outing on it, just trying to get a general ratio for MX and Dirttrack

[firko]

Rossco , 13/59 is 4.7:1 ratio which is motocross gearing. I bet you were running out of revs on the straight. From memory the Coffs track is pretty open and fast so I'd try a 52 or at least a 56 rear sprocket next time. It's not going to get you off the line any better though. Try bigger revs and second gear. It took me many years to sort out the gearing for various tracks for my old Maico. Like Lozza said, you want to be getting to max revs in top gear just before you hit the brakes for the turn at the end of the straight. Getting off the line is a different science again that involves clutch technique, tyre pressures, what gear you are in and the amount of revs you use. On a Maico it's never going to be perfect due to the Maico clutch shortcomings and the relatively high first gear compared to 5 and 6 speed bikes but you'll get it with practice. Back in the dark days I once spent a whole Nepean practice day practicing starts. It was a bit anal but in the end I was getting off the line with the skinny guys on their 5 speed bikes.

[Rosco400]

Thanks Firko, Guess i had been comparing the takeoffs to the AW400 and wasnt feathering the clutch enough, will just keep practising and will eventually get it but gives a starting point to have a play with
Cheers Ross