Slipper Clutch Q.. bump starts? partial loss sytem??

Started by SV88, March 23, 2008, 09:52:59 AM

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SV88

My SS motor will have a slipper clutch installed.  Does the presence of a slipper clutch eliminate the possibility of bump starting? Trying to run a pretty small battery and may go towards a total loss system for weight savings....

When the bike is dynoed, I'm going to hook up an amp meter to figure out the electrical load which will help me use a smaller battery.  Thinking about using an external battery for starting purposes - another option is to do away with the starter also.

steve.
Fastsv650/SVR6/Steve sv23
09R6rdrace,13KTM250xc enduro,03SV1000N, 99-02 sv650 project
ret. CCS MW/FL/SE 88  Moto A SSP 881

tzracer

Would really depend upon how much slip the clutch has.

I would not bother going total loss or to a battery so small it cannot start the bike. Or remove the starter. It will just be a PITA. Fuel injected bikes may also be more difficult to push start, and may be impossible to push start with a low battery. With no starter you would need to invest in rollers.

I ran a Ninja 250 battery on an 03 SV650 with no problems. Mine weighed 350lbs with a 1/2 tank of fuel. Didn't require anything really radical.
Brian McLaughlin
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George_Linhart

I've got to agree with Brian.  No starter is just asking for problems - what happens if you stall it while entering the track or even worse, when you get to the grid?  Another thought - what do you do in red flag situations where you get sent back to hot pit while they clean up the track?  You don't need a very big battery for track use - since you don't have lights and have minimized the draw you don't need nearly the size of a battery as you would on the street.  I've got a really small battery on mine, I do have pigtails set up on it so I could easily rig up an external battery for starting up for the first time on cold mornings - otherwise once it is warm even on a high compression motor you shouldn't have any problems.

I think the gain from a total loss would be offset by needing to run a bigger battery on a fuel injected bike if you ever wanted to do GT races.

George

kl3640

When I was first building my first track bike I had this same thought, but then I came to agree with the above posts that the savings aren't worth the trouble.  If there's a red flag, or you're sitting on the grid for a long time, or you fall down but are able to get up again, then you'll be stuck without your starter.  It could cost you valuable points in a race.

And as George pointed out, for longer races you will need a larger battery anyway.  I believe that even AMA bikes have small batteries and starting systems.

If you want you can get a smaller stator and smaller battery, which might save you a pound or two, but will cost you plenty of dough.  Personally, I would just get a smaller battery and spend your money and energies in reducing sprung mass elsewhere instead of no battery (like an AL subframe) and reducing rotating mass elsewhere other than the stator (lots of options to give you the same aggregate gain, although perhaps not so directly on the engine).

There are weight savings to be had from what you're suggesting, but I think that there are cheaper and easier ways to achieve the same/similar results without compromising your ability to start the bike independently, which is very important and convenient.  Even if you do all of those other things to save weight, and then are considering the charging system, ask yourself if you're to level where you're good enough to notice the difference.  As I mentioned, I saw somewhere that even AMA Superbikes maintain small starting systems, because of the value of being able to restart the bike independently in the event of a minor crash.

Ducmarc

bump starts are with the scooter wide open  .and you can't make a mistake on the starting line plus you need somebody waiting with starter cart .do what everybody says keep the starter.i do run a total loss on one of my bikes but you have to charge it after every race and it's carberated. total pain.

SV88

Thanks for the input Guys.  Scott Schaeffer had already somewhat convinced me to stay away from total loss. Hawk runs a race generator which is not cheap and requires hm to run a full stock sized battery on his SV.  He's taken rotating mass away from the crank but increased weight elsewhere.  This permits the engine to spin up a little quicker.

Part of the issue right now is that I cannot put the stock battery back in.  Hawk made me a sweet alum subframe with the tiny battery I was running on my G1.  This proved to be marginal for the g2 so back to the stock.  I'll eventually spring for an AGM or spiral bound battery with approx. the same power as the stock but lighter and more compact.  I was going to measure the bike's electrical draw next time I have it on the dyno to better select a smaller battery - does anyone know how much a g2 sv draws. 

Popular wisdom says that the fuel pump and injectors draw a lot more than the g1 but the battery are only 2 amp-hrs appart (10 vs 12 amp-hrs for the g2).
Fastsv650/SVR6/Steve sv23
09R6rdrace,13KTM250xc enduro,03SV1000N, 99-02 sv650 project
ret. CCS MW/FL/SE 88  Moto A SSP 881

APP_Racing

#6
How long would a battery last on a 2nd Gen?  Guess I was under the impression that the EFI wouldn't drain a battery from several hours?  Only because I had heard someone say they did it.

Starting was the big drain and that by putting the battery on a charger in between runs was more than sufficient?

Was I being told a big one?
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benprobst

Quote from: APP_Racing on March 24, 2008, 02:56:03 PM
How long would a battery last on a 2nd Gen?  Guess I was under the impression that the EFI wouldn't drain a battery from several hours?  Only because I had heard someone say they did it.

Starting was the big drain and that by putting the battery on a charger in between runs was more than sufficient?

Was I being told a big one?

Not being told a big one, just have to do it right.
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Ducmarc

it may depend on how much your computer draws not the firing of the injectors like you said  an accurate amp meter might tell you . running out of battery is something i always think about on the warm up cause if you make a mistake or get held up it might not restart and that's with carbs . it has never let me down though but i still think about it.tried big nicads one time about half way through the season let them run real low and they reversed polarity on me had to buy two new ign. modules from that .also computers have a minimum voltage that they operate in so you may reach that piont and not know it before it's too late. but that's life with a 315lb 900 ducati

SV88

Just bought a Scorpion AGM 8 amp -hour 115 cc amps for the SV.  Weights 7lb which is 2.5 less than stock.  $52 shipped!
Fastsv650/SVR6/Steve sv23
09R6rdrace,13KTM250xc enduro,03SV1000N, 99-02 sv650 project
ret. CCS MW/FL/SE 88  Moto A SSP 881

frskbm1

in vintage we are not allowed a kickstart so i have a total loss system. i am gonna use a odessey deep charge racing battery cause the yuisa or whatever they are are junk in no time from recharging but i would rather have a charging system just to do away with hassles between races. mike in worcester mass  lrrs/uscra#517

GSXR RACER MIKE

Do they make motorcycle size deep cycle batteries?
(since deep cycle batteries are made for endless draining and recharging like golf carts have)
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