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Discussion Starter #1
Hey whats going on guys?

Looking for a little direction for setting the bike up for some straightline stuff and general riding.

I am very new to the powersports stuff so forgive any ignorance

The bike is a Gen 1

-1 front
Full Arata System
Tuning and stacks coming soon

Also building a custom direct port nitrous setup to spray it until it makes 200hp.

What factors decide on what you need as far as stretching and lowering? Im looking at trying to figure out what I need to know to decide what level of lowering and stretch I need.

Does over all suspension setup Change it? Rider weight? Tire?

Or is it simple a question of how much power you make?

Trying to make an educated decision but I don't know where to start.

Thanks for any help guys!:eek:ccasion1
 

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I'm not lowered and I'm making 242hp on spray....but I only spray 4th -6th gear.... Otherwise the bike wants to come str8 up.....as far as lowering that's up to your personal preference ...the lower you go the less agile your bike will be...
 

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Discussion Starter #3
I'm not lowered and I'm making 242hp on spray....but I only spray 4th -6th gear.... Otherwise the bike wants to come str8 up.....as far as lowering that's up to your personal preference ...the lower you go the less agile your bike will be...
I have thought about really getting after it with some spray. I just dont know enough of what the gen 1 drive line will handle.

Are you stretched at all?

Im just curious what balance of lowering and stretching will get it stay hooked up and not facing the sun.
 

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I have thought about really getting after it with some spray. I just dont know enough of what the gen 1 drive line will handle.

Are you stretched at all?

Im just curious what balance of lowering and stretching will get it stay hooked up and not facing the sun.
When I had my 05 10R i used a #34 jet dry shot spraying before the air filter
and it made 201 hp at the rear wheel. I still have a few custom maps from those days.
 

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Are you building this for just drag racing or just the street as well? 1/4 mi or 1/8 mi?
 

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Supercharged Mod
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I did a lower/stretch on my gen 1 to make it a better drag bike, but I still wanted to keep it streetable with acceptable steering and suspension characteristics. No nitrous, and no plans to.

Started with some math: wanted to be near the top of 5th gear at the end of a quarter mile, and with some estimates of what the trap speed ought to be, that led to the gearing selection. I prefer to do all the ratio changing with the rear sprocket. I ended up at 17/45 (stock is 17/39) and "actual field experience" has been that this seems about right. Keep in mind that not only is this no nitrous, but also no power adders at all. If you have major power adders then use a different estimate of trap speed, and you can always go through at the top of 6th rather than 5th, crunch the numbers.

Now some estimating: 17/45 ought to accelerate about 15% harder than 17/39 (45 divided by 39).

To compensate, we need to make the bike 15% less "wheelie-prone" and a bit more for good measure. If the center of gravity height stays the same height then the distance (in the fore/aft direction) between the center of gravity and the tire contact patch needs to be 15% more (plus a bit more, just to make sure). The C of G of the combined rider and bike is a little rearward of halfway between the front and rear wheels (i.e. about 26ish inches ahead of the stock rear wheel contact patch). Add 15% to get it to where we want it to be and it sounds like a 4 inch stretch. My target was 5 1/2 inches and this is without any lowering.

If you have major power adders that result in the engine making more torque than stock then it needs to be factored in just like the above.

If you want decent steering characteristics for normal road riding then lowering needs to be minimized and you need to keep suspension travel (including the sag measurement) in a normal range. In particular, with the front suspension at full compression, the front fender must not collide with the upper fairing or radiator. If you want to maintain full suspension travel then this sets a boundary on the amount you can lower the bike, and it isn't very much! 10 millimeters or thereabouts. That's what I did.

Now it gets tricky; you need to set nominal rear ride height such that it keeps the rake and trail in the same range as stock. The down-angle of the swingarm will raise the rear if you just extend the swingarm, so you need lowering links - in combination with ride-height shims.

I used swingarm extensions, fixed-length lowering links (I seem to recall that they give about 2" lowering if installed without doing anything else), 190/55 rear tire, and some washers under the upper shock mount to fine tune the rear ride height. Initially I used three 1/8" thick washers but I'm now at two 1/8" and one 1/16" washers - I fine tuned this based on how the steering felt.

It took some fiddling with ride-height washers and spring preload to get it worked out but I'm happy with the end result. Steering feel during normal riding is almost normal; it's a wee bit slower/heavier than standard but it's not a bother. Cornering clearance is still good (because it's only lowered by about 10mm ...), suspension compliance seems same as stock (because full compression and rebound travel is available), it doesn't bottom on bumps any more so than it did when stock, and there is still at least *some* swingarm down-angle to give at least *some* anti-squat geometry. And the front fender won't collide with anything, and the suspension will hit mechanical limit before the oil drain plug smacks the ground ... it probably has enough ground clearance to drive off a normal kerb, although I'm not about to try it (again, it's only lowered 10 mm).

It is never going to have as much grip exiting corners as a stock-wheelbase bike. But for a street ridden bike ... it's fine and is actually a silly fun street bike, because the shorter gearing lets the engine get into the power band at sane road speeds ... and because it doesn't steer like a school bus.

A bike with more extreme power adders will need more stretch and/or more lowering ... and more rear tire grip to avoid spinning the tire on takeoff.
 

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Discussion Starter #8
Are you building this for just drag racing or just the street as well? 1/4 mi or 1/8 mi?
Both. No track days (road racing) for me, but I just don't want to kill the overall feel of the bike to be ruined.

No set length on the track. I will probably re-gear for some of the longer events.
 

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Discussion Starter #9
I did a lower/stretch on my gen 1 to make it a better drag bike, but I still wanted to keep it streetable with acceptable steering and suspension characteristics. No nitrous, and no plans to.

Started with some math: wanted to be near the top of 5th gear at the end of a quarter mile, and with some estimates of what the trap speed ought to be, that led to the gearing selection. I prefer to do all the ratio changing with the rear sprocket. I ended up at 17/45 (stock is 17/39) and "actual field experience" has been that this seems about right. Keep in mind that not only is this no nitrous, but also no power adders at all. If you have major power adders then use a different estimate of trap speed, and you can always go through at the top of 6th rather than 5th, crunch the numbers.

Now some estimating: 17/45 ought to accelerate about 15% harder than 17/39 (45 divided by 39).

To compensate, we need to make the bike 15% less "wheelie-prone" and a bit more for good measure. If the center of gravity height stays the same height then the distance (in the fore/aft direction) between the center of gravity and the tire contact patch needs to be 15% more (plus a bit more, just to make sure). The C of G of the combined rider and bike is a little rearward of halfway between the front and rear wheels (i.e. about 26ish inches ahead of the stock rear wheel contact patch). Add 15% to get it to where we want it to be and it sounds like a 4 inch stretch. My target was 5 1/2 inches and this is without any lowering.

If you have major power adders that result in the engine making more torque than stock then it needs to be factored in just like the above.

If you want decent steering characteristics for normal road riding then lowering needs to be minimized and you need to keep suspension travel (including the sag measurement) in a normal range. In particular, with the front suspension at full compression, the front fender must not collide with the upper fairing or radiator. If you want to maintain full suspension travel then this sets a boundary on the amount you can lower the bike, and it isn't very much! 10 millimeters or thereabouts. That's what I did.

Now it gets tricky; you need to set nominal rear ride height such that it keeps the rake and trail in the same range as stock. The down-angle of the swingarm will raise the rear if you just extend the swingarm, so you need lowering links - in combination with ride-height shims.

I used swingarm extensions, fixed-length lowering links (I seem to recall that they give about 2" lowering if installed without doing anything else), 190/55 rear tire, and some washers under the upper shock mount to fine tune the rear ride height. Initially I used three 1/8" thick washers but I'm now at two 1/8" and one 1/16" washers - I fine tuned this based on how the steering felt.

It took some fiddling with ride-height washers and spring preload to get it worked out but I'm happy with the end result. Steering feel during normal riding is almost normal; it's a wee bit slower/heavier than standard but it's not a bother. Cornering clearance is still good (because it's only lowered by about 10mm ...), suspension compliance seems same as stock (because full compression and rebound travel is available), it doesn't bottom on bumps any more so than it did when stock, and there is still at least *some* swingarm down-angle to give at least *some* anti-squat geometry. And the front fender won't collide with anything, and the suspension will hit mechanical limit before the oil drain plug smacks the ground ... it probably has enough ground clearance to drive off a normal kerb, although I'm not about to try it (again, it's only lowered 10 mm).

It is never going to have as much grip exiting corners as a stock-wheelbase bike. But for a street ridden bike ... it's fine and is actually a silly fun street bike, because the shorter gearing lets the engine get into the power band at sane road speeds ... and because it doesn't steer like a school bus.

A bike with more extreme power adders will need more stretch and/or more lowering ... and more rear tire grip to avoid spinning the tire on takeoff.
Great Post. Thanks much for such a response. I will definitely keep this in mind as I weigh out the options. It sounds like we both had similar ideas about how we wanted the bike to perform.
 

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I have thought about really getting after it with some spray. I just dont know enough of what the gen 1 drive line will handle.

Are you stretched at all?

Im just curious what balance of lowering and stretching will get it stay hooked up and not facing the sun.
I lowered it with 3 hole links in the lowest setting, then lowered the front end about 1-1/2 and used a strap to pull it down til it almost hits the top of the fender. And the bike was at around 65" wb
 

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Gen2 Ripper
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For street and drag setup, I lowerd my Gen2(should hold true gen1-3) I lowered rear 1.5" and front 1.5". I am at 62.5" wheel base(measurement from center of both axles) and this works best for my weight 190 suited on street. I spray a 30 dry shot and can spray 1st though it does lift a bit. When I was lowered 2"(actually 2.5" sitting on it) it scraped exhaust header and belly fairing alot. If you put a sidewinder exhaust and a shallow oil pan on it, you can slam it down 3" or more but no more street riding.
 

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Seat Time

Don't beat me up for saying this, its just my opinion. If your new to drag racing (on a bike), I would hold off on the nitrous. I bumped my head with this trying to go faster before I got my skill up. I ended up with busted oil pans and broken front fenders. Now 8 months later by bike is a tenth faster than my best nitrous pass, all with seat time and big sprockets lol.

My bike is 63in and lowered 3in front and rear, it does ok on the street. But gotta pay attention to the road cause it will scrape if you not careful, speed bumps are out of the question

With your mods I think you could get away with out being too long, like less than 64in. At least lower 2in and go with the adj rear links (threaded type), if you go longer or lower later ya wouldn't have to replace em. Get a front strap too! Good Luck
 

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Discussion Starter #13
For street and drag setup, I lowerd my Gen2(should hold true gen1-3) I lowered rear 1.5" and front 1.5". I am at 62.5" wheel base(measurement from center of both axles) and this works best for my weight 190 suited on street. I spray a 30 dry shot and can spray 1st though it does lift a bit. When I was lowered 2"(actually 2.5" sitting on it) it scraped exhaust header and belly fairing alot. If you put a sidewinder exhaust and a shallow oil pan on it, you can slam it down 3" or more but no more street riding.
Thanks for the information. Ya I do not want a track only bike in anyway.

Don't beat me up for saying this, its just my opinion. If your new to drag racing (on a bike), I would hold off on the nitrous. I bumped my head with this trying to go faster before I got my skill up. I ended up with busted oil pans and broken front fenders. Now 8 months later by bike is a tenth faster than my best nitrous pass, all with seat time and big sprockets lol.

My bike is 63in and lowered 3in front and rear, it does ok on the street. But gotta pay attention to the road cause it will scrape if you not careful, speed bumps are out of the question

With your mods I think you could get away with out being too long, like less than 64in. At least lower 2in and go with the adj rear links (threaded type), if you go longer or lower later ya wouldn't have to replace em. Get a front strap too! Good Luck
Trust me, I have plenty of respect for this bike. The nitrous will not be used in the immediate future, at least not by me. I am flat out a squid. :crackup:
I am just trying to build a nice bike and still be safe.

Thanks for the feedback on how yours performed. I will for sure be going adjustable on the lowering.

Does the shock setup change how much stretching or lowering should be done? In a sense, is there a certain balance that with the right parts will hook up and give better handling than another setup?
 

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I'm light only 145 and maybe 160 suited, and I've been playing with the stock shock. My 60', 330', and et have been showing improvement, I went 1.48 sixty foot last time out and I dont even have a full system! Larger guys go with the stock busa shock, better tune ability I think I'm tempted to try one. The longer you go the more leverage is on the shock thus making it softer.
 

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Supercharged Mod
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Does the shock setup change how much stretching or lowering should be done? In a sense, is there a certain balance that with the right parts will hook up and give better handling than another setup?
YES; if you want correct steering response then you have to maintain the correct steering geometry. If you want to maintain acceptable cornering, particularly on bumpy pavement (like we have around here) then you have to maintain proper cornering clearance and you have to maintain acceptable suspension travel, both in bump and rebound, above and below nominal ride height.

The suspension travel limitation is not at the rear; the limitation is at the FRONT, as previously explained. Maintaining full compression (bump) travel without the possibility of the fender colliding with the upper fairing or the radiator sets a limit on the amount that the front can be lowered.

Lowering screws up handling a lot more than stretching within reason.

Keep in mind that I have a roadracing background, and as a result I am VERY fussy and finicky and insistent about maintaining correct, neutral steering response and I notice ride height changes of a couple of millimeters out of kilter front and rear.

See this drill bit ... The length of it is the amount that the forks can compress.



That drill bit, when held parallel with the forks, needs to fit between the top of the fender and the bottom of the upper fairing, otherwise it can collide.

This is pretty much all you can lower the forks subject to that constraint.



Note that you can take preload out of the forks (note the position of the adjusters) to get a more-than-usual (compared to a roadrace setup) amount of rider-aboard sag. Stretching the bike transfers more weight onto the front end and results in even more rider-aboard front sag. I've since fiddled with these some, to fine-tune it a bit.
 

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Discussion Starter #16
YES; if you want correct steering response then you have to maintain the correct steering geometry. If you want to maintain acceptable cornering, particularly on bumpy pavement (like we have around here) then you have to maintain proper cornering clearance and you have to maintain acceptable suspension travel, both in bump and rebound, above and below nominal ride height.

The suspension travel limitation is not at the rear; the limitation is at the FRONT, as previously explained. Maintaining full compression (bump) travel without the possibility of the fender colliding with the upper fairing or the radiator sets a limit on the amount that the front can be lowered.

Lowering screws up handling a lot more than stretching within reason.

Keep in mind that I have a roadracing background, and as a result I am VERY fussy and finicky and insistent about maintaining correct, neutral steering response and I notice ride height changes of a couple of millimeters out of kilter front and rear.

See this drill bit ... The length of it is the amount that the forks can compress.



That drill bit, when held parallel with the forks, needs to fit between the top of the fender and the bottom of the upper fairing, otherwise it can collide.

This is pretty much all you can lower the forks subject to that constraint.



Note that you can take preload out of the forks (note the position of the adjusters) to get a more-than-usual (compared to a roadrace setup) amount of rider-aboard sag. Stretching the bike transfers more weight onto the front end and results in even more rider-aboard front sag. I've since fiddled with these some, to fine-tune it a bit.
Great post again. I very much appreciate the input.

Still got more questions lol. Since I will be strapping the front down for the track, would that would mean I should lower the bike less as well? I guess does the lowering help much if you are also going to strap the bike.

Again, I'm a squid. But I am trying to learn. :)
 

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Supercharged Mod
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If you are strapping at the track then you can set the front ride height as shown above to maintain correct steering response and cornering clearance when riding elsewhere, and use the straps to compress the front end a bit more at the drag strip. Likewise at the rear, if you want to go this route, you can get adjustable lowering links and establish two positions - one for having decent road manners and the other for the drag strip.
 

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Discussion Starter #18
If you are strapping at the track then you can set the front ride height as shown above to maintain correct steering response and cornering clearance when riding elsewhere, and use the straps to compress the front end a bit more at the drag strip. Likewise at the rear, if you want to go this route, you can get adjustable lowering links and establish two positions - one for having decent road manners and the other for the drag strip.
Hell ya. That sounds like the ticket. Ill do that for sure. I am thinking around 6' on the stretch, but still not sure if an aftermarket swingarm is worth it. I am doing a little looking on that now.

I really appreciate the help sir. Let me know if I can help you out in the future.
 

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BigCat for Prez!
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Go for some extensions on ebay, i got mine for $100 and theyre still doin good. Im stretched 8in and can still bring my knee down. after i stretched it i softened my suspension up so that when i sit on the bike its squats back to the original height, its just not as flippable in real windy roads. Im 182lbs but im built so i have the advantage of throwing the bike over better than a smaller guy.
 

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Slow Poke
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I'm not lowered and I'm making 242hp on spray....but I only spray 4th -6th gear.... Otherwise the bike wants to come str8 up.....as far as lowering that's up to your personal preference ...the lower you go the less agile your bike will be...
I wanna see that!!! You must be spraying the piss out of it! I had a 38 dry shot on mine on a stock motor and made 202 hp. I didn't think the 10 motors would hold that much hp
 
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