Getting off the line

Hi

Just read Kens reply ie changing gear at max revs for the quickest straight line speed.

What I would like to know is what do you do to get off the line in first?

Ive tried 6000 revs & dropping the clutch, fine at the sprints but not good at the track as I dont like my legs hanging out that far.
If I use less revs & feed it in I get a cleaner straighter start. However my mate lets the clutch out above stalling revs & then wacks the throttle open? And he is quick.

I try not to be ruthless as I cant afford the repairs but I find feel goes out the window when you have 34 bikes on the grid reving there nuts off.

Chris

By the way, at the traffic light sprints I find a slipping clutch & smooth throttle opening works best.

1. Take your time and build the most EFFECTIVE clutch you can with the money you have available.

2. Practice launching using different techniques at a local drag strip that times the 60 and 100 foot marks. Settle on the best 2 results and keep practicing to narrow it down to the best consistent technique.

3. Practice launching

4. Practice launching

5. Rebuild clutch

6. Practice launching

...

(if you have a fantastic launch, and an incorrectly geared bike for the track, it was all in vain. Also, if you can't hold speed through a corner. Also, if you failed to properly prepare your bike and it fails due to a simple problem. Also a hundred other reasons people lose races)

"The holeshot doesn't win the race"
...although it feels pretty great...

Chris said:

... I dont like my legs hanging out that far.

Click to expand...

Who says you can't tuck them in as soon as you leave the line?

In fact, the quicker you get your feet on the pegs, the safer you will be if there is a mash-up in front of you, or if the bike pops out of gear...

grandpaul said:

Chris said:

... I dont like my legs hanging out that far.

Click to expand...

Who says you can't tuck them in as soon as you leave the line?

Click to expand...

Agreed - I've done a hell of a lot of sprinting and drag racing in my time, and rarely have my foot off the peg for more than a few yards once I've left the line.

Chris said:

Hi
Just read Kens reply ie changing gear at max revs for the quickest straight line speed.
What I would like to know is what do you do to get off the line in first?
Ive tried 6000 revs & dropping the clutch, fine at the sprints but not good at the track as I dont like my legs hanging out that far.
If I use less revs & feed it in I get a cleaner straighter start. However my mate lets the clutch out above stalling revs & then wacks the throttle open? And he is quick.
I try not to be ruthless as I cant afford the repairs but I find feel goes out the window when you have 34 bikes on the grid reving there nuts off.

Click to expand...

Chris, it gets exciting when you have 34 bikes on the grid, doesn't it? That's a quality problem! That's when I watch the tacho most. After the race settles in I can shift by ear and feel.

Regarding the starts: For me, I wait until a few seconds before the flag is going to drop, rev the bike to redline and hold it, then release the clutch slowly (relatively) and increase the throttle simultaneously, keeping the bike in the max torque. It's a balance of left and right hand coordination. Never been one for blipping the throttle, nor dumping the clutch.

[video]https://youtu.be/Xfbl_5QeZ2c[/video]

P.S. - A great ding-dong with the Junkyard Dawg on his XS 750 Yamaha and Spargo's RD400 in this one.

For God's sake, who won, who won :shock:

I was on the seat of my pants watching the video, urging the Norton on through each corner

I've won a couple of races at an old farts meeting with the Seeley, however I've only had one very interesting ride and the bike stopped after two corners when a fuel line came off. I had a ride at an historic race meeting at Winton about 10 years ago. In two races I couldn't get decent starts due to the very high first gear. In the last race I revved the tits off the motor and rode the clutch out very quickly. On turn two I turned under the leaders and came up level with the front runner who was riding a methanol fuelled 1000cc CB750 Honda. That is when the bike stopped, which was probably a good thing because my mate had pulled the fairing up and reduced the steering lock. So if I had got out of shape, I probably would not have been able to recover. The upshot is that now that I've got the 6 speed box, I'm sure the bike will be very difficult to beat for anyone in that class. One thing I really know well is how to use a gearbox. The torque of the 850 motor is amazing.
Back then I was using the 4 speed close ratio cluster from America. A couple of years ago I made a conscious decision about my bikes, and sold a good TZ350G to by the 6 speed TTI box. I ordered it with first gear about halfway between that of a standard commando and a manx. I haven't used it in anger yet as I have to wait until I've saved some money - however It will come.

With the Seeley, the foot-pegs are an extension of the swing-arm spindle. Because I am old my tendons don't stretch so easily and for a while when I first start riding on any day, it is quite painful getting my feet up onto the pegs. When It comes to the start of a race, my feet are up onto the pegs almost immediately and I don't feel the pain. My approach is to attack the first and second corners at the speed I would normally be doing after three laps. First corner is usually at full blast. Usually I have done a warm-up lap, so I forget about cold tyres. In any case the bike is set up to self-steer a lot , so it stays a bit more upright than many others. You will find that most of the less experienced guys will always back off a bit for the first two corners, so if you are doing this be careful you don't hit anyone. You need to turn under them, NOT over.

click said:

For God's sake, who won, who won :shock:
I was on the seat of my pants watching the video, urging the Norton on through each corner

Click to expand...

Ha ha. Yes, my adrenaline rose watching it too. Haven't looked at it in a while. Makes me anxious for 2016 to start - we have a top-secret missile in the works. 8)

On the last lap Ellis and I were side-by-side down the 2nd straight (downhill straight) making a big hole in the air, and Spargo squeaked by on his RD400 (neon yellow helmet), and stayed in front to the flag, taking the win. Damn 2-strokes! I was behind up to the final turns but missed a shift coming out of Canada Corner, and Ellis pipped me. I must've stretched my throttle cables after he got by trying to get him back. He was so strong on the brakes, but every time he'd go in so deep I could make it back up on the exit.

I generally run a single disk for less rotational mass, but after that race I started running a twin disk at this track (Road America) and Daytona.

Hi all

Thanks for your views. Its an area of my racing that I know I can do better at but rarely do Like that corner you know you can do faster but only do so when you are with faster company??? We tried timed qualifying for grid positions but have gone back to know ability for the first race of the weekend & then race results from then on. I am pleased as we lost 2/3rds of the first day to qualifying not to mention red flags & ambulances.
The Seeley is a small bike & I am 6ft2" the pegs have been moved back from the swinging arm, which is much better, however I may need to raise the seat as I get older The start really has a huge effect on your race. Most of our races are 6 lap affairs & some circuits have a bottle neck effect early on in the lap & you end up queing to get through. The lads at the front can be miles in front before you get into the traffic. Looking forward to doing a few meetings next season & hopefully a sprint or two as its the only place you can practise your starts. I want to try my mates clutch home & drive it off the line & compare it to feeding in the clutch while holding 6000 & feeding in the throttle. Some of the sprints run times for 1/8 of a mile & reaction times.

Brilliant video Kenny. One day Barbers would be my dream.
ps My lad got me a camera so I will be able to do my own videos soon.

all the best Chris

I usually get decent starts and as far as I'm concerned the worst thing you can do is keep blipping the throttle and let the revs rise and fall. You're just hoping that the revs will be up when the flag drops, but there's just as much chance that they'll be dropping.

When I was racing my Commando, I would keep the revs at 5000 which is roughly where peak torque is, and as soon as the flag drops, give it full throttle and dump the clutch pretty quickly. I wouldn't drop the clutch instantly but just quick enough to get going without the front wheel leaving the ground ( too much).

Study the starter.... I once went to a race overseas and noticed that the starter bent his knee just before he dropped the flag. I dropped the clutch when he bent his knee

Chris said:

Barbers would be my dream.

Click to expand...

If I could only race at one track ever again, it would be Barber's.

I got the holeshot there every race so far (5 times)...


That's me, rookie orange t-shirt #142

I also got the holeshot in all but ONE of 30-some races after the first 3 starts in my rookie year, I had to learn the clutch. My little 650 Bonnie is BONE STOCK apart from the electronic ignition, and I use only inexpensive EMGO cork friction plates, but I take my time setting it up just right and I don't slip it a lot. I also don't thrash the engine to red line, I just get it up in the fat part of the rev range, about 5,000RPM and do a quick release on the clutch (not a hammer drop). Works every time.

...and I was up against hot-rodded 750 Bonnies, Tridents, OHC Honda 4s, etc. in my class, typically with a full row of them starting in front of me. I even caught and sometimes passed the bikes in the other class(es) that would launch ahead of us.

To me, it's about machine setup and consistency. I think my first three races were dumping the clutch, slipping it, and dumping it; THEN I tried a quick release and got to turn 1 first (photo above). After that, I did the exact same thing EVERY TIME, and almost ALWAYS got the holeshot (more than 90% of the time)

pommie john said:

When I was racing my Commando, I would keep the revs at 5000 which is roughly where peak torque is, and as soon as the flag drops, give it full throttle and dump the clutch pretty quickly. I wouldn't drop the clutch instantly but just quick enough to get going without the front wheel leaving the ground ( too much).

Click to expand...

"Great minds think alike"

Once in a while, I would float the front tire for a good few feet. That's when I learned to get me feet on the pegs ASAP and get tucked in.

I suggest that if the weight distribution is correct on a Commando, it should spin the rear wheel before lifting the front.

Races are often won or lost in the first two corners. What you lose off the start can be quite considerable when you try to make it up later. At the start, it all happens at relatively low speed. What always worried me with the Norton box, is the likelihood of bending the mainshaft and destroying the internals when doing the big rev and clutch ride-out. It is a major disadvantage. With ANY race bike, the first thing you need when building it is a decent gearbox. If you convert a road bike into a racer there are two things - the gearbox and the steering geometry. Most road bikes have fairly neutral steering - that's OK if you don't want to go really fast through corners. With a Commando engined bike, that is where you need to go fast.

grandpaul said:

Chris said:

Barbers would be my dream.

Click to expand...

If I could only race at one track ever again, it would be Barber's.

I got the holeshot there every race so far (5 times)...

That's me, rookie orange t-shirt #142

I also got the holeshot in all but ONE of 30-some races after the first 3 starts in my rookie year, I had to learn the clutch. My little 650 Bonnie is BONE STOCK apart from the electronic ignition, and I use only inexpensive EMGO cork friction plates, but I take my time setting it up just right and I don't slip it a lot. I also don't thrash the engine to red line, I just get it up in the fat part of the rev range, about 5,000RPM and do a quick release on the clutch (not a hammer drop). Works every time.

...and I was up against hot-rodded 750 Bonnies, Tridents, OHC Honda 4s, etc. in my class, typically with a full row of them starting in front of me. I even caught and sometimes passed the bikes in the other class(es) that would launch ahead of us.

To me, it's about machine setup and consistency. I think my first three races were dumping the clutch, slipping it, and dumping it; THEN I tried a quick release and got to turn 1 first (photo above). After that, I did the exact same thing EVERY TIME, and almost ALWAYS got the holeshot (more than 90% of the time)

Click to expand...

In our Period 4 the CB750 Hondas are 1000cc and methanol fuelled. Your near-standard Bonneville should crap on a near standard CB750. If the 750 Hondas are CR 750s, that is a different story. However they are not easy to ride well. A hot Trident might be hard to beat on a big circuit.

This is one of Rex Wolfenden's Period 4 bikes, it is over 1000cc capacity running on methanol. His brother runs Honda in Australia, so who knows what is inside it ?

acotrel said:

This is one of Rex Wolfenden's Period 4 bikes, it is over 1000cc capacity running on methanol. His brother runs Honda in Australia, so who knows what is inside it ?

Click to expand...

And a nice Dresda chassis too... No wonder he's hard to beat...!

acotrel said:

I suggest that if the weight distribution is correct on a Commando, it should spin the rear wheel before lifting the front.

Click to expand...

That was the case when I raced in the UK, in cold conditions, before tyre warmers were common. It was quite easy to light up the rear tyre. In sub-tropical Australia with warm, modern tyres, nah! The rear's going to stick to the track and wheelie before spinning up.

I think the reason my bike did not wheelie is because first gear was always too high. It might be different with the TTI box, first gear should be a lot lower. Doesn't matter - with other bikes, when the front came up, I started climbing.