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Old 04-26-2012, 05:44 PM   #16
pommie john
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Originally Posted by FreeTheBeast View Post
Yes, your points are valid. Here are my counterpoints... The battery is a Shorai. It is lithium iron - very light at about 5 pounds. ...
It is very heavy gauge and has gold plated (really!) terminal ends.
.....
Nice light battery.

Gold plated cable ends? Extra weight
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Old 04-26-2012, 06:05 PM   #17
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I have made the same comment about the battery on a number of cafe build threads. It is just all wrong to me in theory and practice. 5lbs? That's damn near a gallon of gas that never goes away. IMO THE secret to tuning success is the same as improving riding skills: all the little stuff adds up! Underneath the tranny/engine? We have all been through this before via Honda GP bikes. Weight can be too low as well as too high on two wheelers. You want to try to center weight around the bike's pitch axis which I suspect is somewhere about where the starter is (that's with the bike AND rider!). I would put the battery above the tranny or maybe even Ducati style and mount it on the side above the left cylinder. Easy to get to which is always a plus with constant loss systems. The weight is closer to the pitch axis and further forward which I think the bikes in general could use, not to the rear! Also on the left to compensate for the engine favoring the right as well as the weight of the drive shaft and final drive.

I think you done good putting a 18" wheel on front. I run Avon race rubber too and I suspect that my setup favors the AM18 90/90 over the AM22 110/80. It's a shame because the AM22 cups a lot less and wears better but I think just the bit bigger tire gets me some chatter that I don't get with the 90/90. Just something to maybe try. You'll be going through the tires quick enough to try the difference soon I hope!

I forgot to ask: do people run constant loss AND starters? It sounds like trouble to me but I have no experience with that combo.

supershaft screwed with this post 04-26-2012 at 06:11 PM
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Old 04-26-2012, 06:42 PM   #18
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Originally Posted by supershaft View Post

I forgot to ask: do people run constant loss AND starters? It sounds like trouble to me but I have no experience with that combo.
Yes I do. I have a Yuasa 12 amp hour battery and it lasts all weekend, but I usually put it on charge on the Saturday night just to be sure.

I did have a couple of occasions where the battery started to fail, but when it won't turn the starter it still has enough charge to run a race if you can push start it. So it gives you a warning when it's time to put it on charge
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Old 04-26-2012, 07:01 PM   #19
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Great! Sometimes I think a starter would be worth the weight! There's nothing like showing up to the starting grid late and huffing puffing dog ass tired because you couldn't get your bike started. It's NOT the path to good starts!
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Old 04-26-2012, 07:05 PM   #20
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Great! Sometimes I think a starter would be worth the weight! There's nothing like showing up to the starting grid late and huffing puffing dog ass tired because you couldn't get your bike started. It's NOT the path to good starts!
You know that feeling on the dummy grid when there's been a crash in the previous race and they keep you waiting, and you're not sure whether to stop the motor to avoid it overheating, but you're worried it will be hard to push start if you do, and you know as soon as you stop the motor, they'll wave you out onto the track?
You know that feeling?
That's what starter motors are for
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Old 04-27-2012, 03:31 AM   #21
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Thumb Good info

This will be my first year at vintage racing...and this is my first build of a vintage racing bike. I like to hear people's opinions and thoughts. I have yet to achieve any level of experience. This year is only about getting a bike out on the track. Adjustments and tweaks will come. If I feel like I want to be more competitive, enhancements will be inevitable.

This will also be my vintage racer for Pike's Peak in 5 years or so. I have to wait until I'm old enough to enter the class. The vintage class also requires the rider to be over 50 years of age.
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Old 04-27-2012, 05:50 AM   #22
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Marcus!

Looks great Andrew. Nice virgin covers : ) What are you running for gearing at NHMS? The lower the better@ NHMS, either 3:56 or the next lower ratio is about perfect for good drive without fully revving out past the checkers on the front straight.
Running without a Tach sucks when you're sitting on the grid surrounded by bikes so freekin loud that you cant ever hear your own bike revving. Tough to get a good start not knowing where your revs are. I can get away without using one on my R50, well, because its a 500 with no power so revving it to the moon is not going to loop me. My 750 on the other hand can wheelie off the line excessively if I dump the clutch above 5-6k. I would imagine the heavy flywheel and Bings may "smooth" your starts.
Hope to make it to the Vintage Celebration (spectating only this event), and hopefully will be back on the grid after some long overdue mods to my 750. REALLY cool to have you and Mike showing up as the past few years the big bikes have been dwindling in numbers. Perhaps this is the start of a resurgence : )

Marcus doesnt need any stinkin safety gear!
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Old 04-27-2012, 05:54 AM   #23
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Correction

3:56 or next HIGHER gearing, 3:41 I think
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Old 04-27-2012, 08:59 AM   #24
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Originally Posted by FreeTheBeast View Post
.

This will also be my vintage racer for Pike's Peak in 5 years or so. I have to wait until I'm old enough to enter the class. The vintage class also requires the rider to be over 50 years of age.
I didn't know about the rider age limits at Pikes Peak. I am tempted to try this just for the experience--the winner will need also-rans like me to make the win even more satisfying. I have an R90 that should do nicely.

Have you talked to Junkyard Dog about his airhead BMW racers?

Good luck.
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Old 05-13-2012, 03:54 PM   #25
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FTB,
How was your weekend

silver hammer?
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Old 05-13-2012, 05:11 PM   #26
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Actually that shorai battery of yours should weigh well under 5 lbs. More like 2-2.5. I'd be more concerned with using it in a constant loss system as the Li-Fe batteries don't like being discharged a lot. If you drain it too much it's permanently toast and will never take a charge again. I'd try to find some kind of deep cycle battery if your running a constant loss system.
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Old 05-13-2012, 06:11 PM   #27
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Nice bke, I'm in my first season ever of classic racing.....more just out there 'doin' it" than anyting. I currently running a massive 32 amp Motobatt battery ( I pinch it from my Ducati) as I also run a starter...be it a cheap copy of the BMW one...( charge easily lasts for a 2 day meet)
Pommy John is right about sitting on the dummy grid....some times the breakdown wagon can take ages....
The Shorai batteries have become popular here for racing and its been discussed as mentioned in earlier post that they die if over discharged.
I'm running Bridgestone 45's.....seem to suit my purposes....which is mainly improving the rider skills.
We don't have rider age cut offs
Still if I can keep in front of my mates T140 I'm happy.
Have fun.
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Old 05-13-2012, 06:18 PM   #28
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Originally Posted by Voltaire View Post
Nice bke, I'm in my first season ever of classic racing.....more just out there 'doin' it" than anyting. I currently running a massive 32 amp Motobatt battery ( I pinch it from my Ducati) as I also run a starter...be it a cheap copy of the BMW one...( charge easily lasts for a 2 day meet)
Pommy John is right about sitting on the dummy grid....some times the breakdown wagon can take ages....
The Shorai batteries have become popular here for racing and its been discussed as mentioned in earlier post that they die if over discharged.
I'm running Bridgestone 45's.....seem to suit my purposes....which is mainly improving the rider skills.
We don't have rider age cut offs
Still if I can keep in front of my mates T140 I'm happy.
Have fun.



I can't tell you how many people tell me to ditch the starter motor "All that extra weight" they say.
My view is that the best way to improve my lap times is to use the throttle more and the brakes less. A few pounds of starter ain't going to make a bit of difference.
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Old 05-13-2012, 06:34 PM   #29
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Originally Posted by pommie john View Post
I can't tell you how many people tell me to ditch the starter motor "All that extra weight" they say.
My view is that the best way to improve my lap times is to use the throttle more and the brakes less. A few pounds of starter ain't going to make a bit of difference.
I was told by a BMW sidecar guy to get a small Toyota one and adapter, I suspect they are thinking I'm running an old Bosch starter....the Valeo copy at $99 US is a lot lighter.....and if it breaks I have another.....
In my case you are spot on about more throttle less braking over a few kgs.
Hey PJ what sort of tyres do you run?, we have to use treaded type and treaded race compound Avons are 3x the price of good old BT45's
( sorry OP for hijacking your thread....)
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Old 05-13-2012, 09:10 PM   #30
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Originally Posted by Voltaire View Post
I was told by a BMW sidecar guy to get a small Toyota one and adapter, I suspect they are thinking I'm running an old Bosch starter....the Valeo copy at $99 US is a lot lighter.....and if it breaks I have another.....
In my case you are spot on about more throttle less braking over a few kgs.
Hey PJ what sort of tyres do you run?, we have to use treaded type and treaded race compound Avons are 3x the price of good old BT45's
( sorry OP for hijacking your thread....)
I use the outrageously expensive Avons. I haven't found anything suitable to replace them. Some guys use a Dunlop KR 124A on the front and a KR164 on the rear, but they are the same price as Avons.

On my Norton 750 I use a Dunlop TT900 GP 90/90 and 120/80, but they are only H rated which is 130MPH max. The big BM goes faster than that.

I tried the BT45 on the front but had a crash when I lost the front braking into a hairpin and found that saving money on tyres is a false economy .... the crash cost more than the tyres would have
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