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retread
05-08-2008, 10:36 PM
Has anybody got information on pulleys to change the final drive ratio? My #3266 turns almost 6 grand @ 70 mph, seems like I'd get better mileage with a lower numerical gearset. I'm willing to sacrifice some acceleration for better mpg.

bjt
05-09-2008, 05:32 AM
I'm with you on this. If someone comes up with this type of mod, I would seriously consider it.

bjt
05-09-2008, 05:44 AM
Another idea... I'm not a transmission expert or gearhead or anything like that so I'm not even sure if this is really possible or would cause other problems that would make it very undesirable. :dontknow:

The idea - make the 5th gear the size / ratio of what a 6th gear would be. Then make each gear between 1st and 5th a little taller to make up the difference between the old 5th and the new 5th gear. Almost half of my daily commute is at speeds of 45MPH or more where I would use a 6th gear ratio.

Lamonster
05-09-2008, 03:19 PM
I have an idea in my head on how to do a smaller pulley with the stock drive belt. Just need to find the time to make it happen. ::)

joelin
05-09-2008, 06:57 PM
Today I try my new hindle on my bike .I got 5000 rpm at 70 mph it run much smoother and faster . I think maybe
you should try this pipe .

joelin
05-09-2008, 07:54 PM
Think about it ,if you are going upper hill will you get the same rpm with same speed on the road . I don't think so.You need more rpm to reach the same speed . so when you get more HP from the pipe . you will need less rpm to reach the speed . I know the gear will make more different but it will cost a lot more.

Danimal
05-10-2008, 11:51 AM
Yeah - at best the Hindle will just let you get to that RPM quicker.......


I don't really mind the higher revs... this engine seems to like things at 6,000 or more. Anything much under 4,500 and it seems to dog out on you... if you are in 4th or 5th for sure.

I've had her up to 115 while still in 4th gear... 5th took me to 122... and there was still more where that came from... but I had to slow down.

joelin
05-10-2008, 11:32 PM
no offense, but you are wrong in this case. i'm a degreed automotive engineer (fwiw) and have been designing and building performance products for cars and bikes for too many years. if we assume that there is no clutch slippage, then the same rpm will always yield the same mph in the same gear. it doesn't matter if you are making 100 hp or 1000 hp, going uphill or downhill, this relationship does not change.

in your example above, you will need to twist the throttle further (need more horsepower) to maintain the same speed on a hill vs. a flat road but the rpm vs. speed does not vary.

I think I am wrong about rpm vs speed . It will be lower the gear to make higher rpm to make the same speed for uphill . thank you for your correct .

Putt-Putt
05-12-2008, 01:07 PM
Ya I would like some taller gearing too. Like retread said I would give up a little performance for better gas mileage.

trikester
05-12-2008, 03:11 PM
Funny, different strokes for different folks. I would like lower gearing so I could start out slower without having to slip the clutch so much. The top end is more than I need.

Frank

Ryno
06-01-2008, 10:14 AM
Has anyone considered removing the rear fender and replacing the stock tire with a taller one? Just curious..

Ryno
06-01-2008, 04:29 PM
hmmm... wonder if 2-3 in. taller rear tire would honestly help.. I know it would reduce RPMs at higher speeds. (better MPG) also getting a Michelin, or Kumho, that can be run at higher pressures ( with quality sidewalls for cushioning) could lower the Coefficient of friction with the road, (less resistance, better MPG)

Both of these options are very easy on the budget, and are tried and true eh.. my .02 worth.

SpyderMark
06-02-2008, 12:48 PM
hmmm... wonder if 2-3 in. taller rear tire would honestly help.. I know it would reduce RPMs at higher speeds. (better MPG) also getting a Michelin, or Kumho, that can be run at higher pressures ( with quality sidewalls for cushioning) could lower the Coefficient of friction with the road, (less resistance, better MPG)

I would be careful about changing tire sizes. The Vehicle Stability System uses sensors to measure speed based, in part, on the number of tire revolutions. If you change the tire size significantly you might render your VSS inoperative -- or even force the computer into "limp" mode.

Regards,

Mark

Dwight
06-03-2008, 11:40 AM
Something to think about - does it measure actual wheel revolutions ie; with a sensor located on the wheel, or does it measure the revolutions with a sensor in the transmission? It isn't going to cost too much to see if this will work if you can find a regular car tire that will fit. I went to a size larger tire on the rear of a conventional trike (Goldwing/Hannigan) with about a 3mph increase at normal cruise rpm.

Dwight

retread
06-03-2008, 12:23 PM
Okay, with 4 sensors, is the nanny locked into the as delivered tire O.D. for the VSS, or does it adjust itself to variances beyond normal wear?

Magic Man
06-03-2008, 07:41 PM
The VSS system is programed like any computer is. It was programmed with what the testing showed the "normal" amount of variances the engineer felt was needed for "normal" conditions. Tire wear is "normal", However, there is no "normal" set of circumstances that would have your tire diameter change to this amount, or even close outside of a major blowout or loss of air pressure. Again, these are not "normal", and indeed emergency type of events.

All VSS systems be it on a car or bike have a "moment threshold" programed into them. A "moment threshold" is that point when things are so out of balance that the "nanny" kicks in. Even if you put on a larger tire and at first "seem to get away with it" because the"nanny" is not yet kicked in. What you have done in any case is move those "moment thresholds" way outside the design limits. This could be a move ether too close together, or too far apart.

Move them too close together and the "nanny" will kick in at the slightest hint of anything. Move them too far apart, and the VSS won't kick in in time when really needed, and you could have real trouble on your hands. Ether way it's a crap shoot at best.

The BRP design team knows the RPM these units run at, and felt they could back these bikes with a factory warranty and not have a problem with the engine speeds they operate under. To risk the possibility of a VSS problem one way or the other when you really need it to save you, in my opinion is not worth the few MPG or RPMs you would save. Your safety is worth way more than that any day.

Danimal
06-03-2008, 08:02 PM
:agree:

For the small amount of possible gain.. it's just not worth it. The Rotax likes to run at higher RPMs.... so why not let it?

Now, that being said.....

The speed sensor for the rear tire is on the hub. I don't think it's going to know that you have a bigger tire installed.

Are you thinking that the VSS is going to compare your speed to the RPMs ?

There has to be an allowance there.... going uphill, downhill, etc. Heck.... you can go 70 downhill at 1500 rpm's....


On the issue of how the VSS determines what is normal... there are a few ways that could be done. There could be hard programmed values in the system... or it might take readings when you start out to determine what is 'normal'.

Maybe a combination of both.... which would compensate for tire wear.

Magic Man
06-03-2008, 08:40 PM
NO NO NO! The VSS compairs the speed of the front wheels from their sensor signals to the rear to see who is spinning who is locking up etc. The front wheels will be spinning at the "normal" 40 MPH but some how the rear will be spinning at only say 35 MPH. The computer will see this and say???

That's when the fun could begin. Now, be on the brakes and the VSS sees the rear wheel spinning so much slower than the front, and the computer thinks the rear wheel is beginning to lock up and will try to release the rear wheel brake pressure to try to get it back to the same speed as the fronts. Have the rear wheel brakes release when not needed to be released and the fronts be on full and can you say.... end swap?

But I only have an Engineering degree from RPI and am an ASE Certified Master Auto Technician as well as Class of 79 AMI Certified Motorcycle Mechanic. What could I know about how VSS systems work, they only been on cars for 10 years now?

Danimal
06-03-2008, 09:21 PM
Ok... I get you now... I was thinking from the hub out instead of the wheel in.

So he would have to make the front tires larger by the same factor to keep everything even?

I guess without being able to see the actual programming of the VSS it's hard to know exactly how it 'thinks'.

I know the VSS irks me at slow speeds.... pretty embarassing to pull out of a driveway and punch it while still at a slight turn and have it cut out on me......

It should be more forgiving at slower speeds.... IMO.....

Magic Man
06-03-2008, 09:32 PM
Now you got it! Now just think if the "moments" were even closer you would not even be able to chirp the tires without the "nanny" killing it. Or, worse yet have the the "monents" moved too far apart and have the brakes let go when you really need all 3 wheels to be stopping full force. Not good at all. All this for a few MPG or RPMs, not me.

But, you are correct in if the front wheels could be made bigger by the same amount as the rear was without hitting on the fenders than it would all work OK. But, the fenders are real close to the tires now.

Putt-Putt
06-04-2008, 08:27 AM
So thats what happened to me when I was trying to back up in a friends yard; up hill. Rear wheel spun on grass front wheels didn't move so it killed the engine. Thats not a good thing. What if you were in or at a situtation where you had a very steep incline with a drop off in front of you and you needed to back up. I could see it cutting power BUT to KILL the ENGINE. Good by over the cliff you go. Grand Canyon! In the mountains etc.. A lot of the parks have gravel roads that lead up scenic view etc. etc. NOT GOOD---NOT GOOD

Magic Man
06-04-2008, 09:38 AM
The owners manual says the the max speed in reverse is limited to 15 MPH. I have done a rearward burnout and had the engine shut right off on me too. Once you are in reverse if the rear wheel sensor sees the rear wheel spinning faster than 15 MPH it kills the motor moving or not. I think this was to stop the chance for runaway situtations in reverse and people loosing control and hitting something? The killing of the engine is a bit unsettling though I must admit.

MM

Putt-Putt
06-04-2008, 12:24 PM
My rear wheel just barely turned and it killed the engine. I tried to just feather the gas same thing. People were watching and laughing. They said the wheel just turned a little.

LittleJohn
06-04-2008, 12:33 PM
My rear wheel just barely turned and it killed the engine. I tried to just feather the gas same thing. People were watching and laughing. They said the wheel just turned a little.

My guess would have to be that the VSS is sensing the rear wheel turning in reverse, but not the front ones, so it reacts accordingly.
Just a guess

Putt-Putt
06-04-2008, 12:56 PM
Your probably right as the front didn't move.

Way2Fast
06-04-2008, 04:03 PM
I wish they would have left the computers on the desk where they belong. I can only imagine the accident situations that will be created by computers that control a vehicles handling when road salt, moisture, age, etc start to affect them. Scary !!

SpyderMark
06-04-2008, 09:06 PM
I wish they would have left the computers on the desk where they belong. I can only imagine the accident situations that will be created by computers that control a vehicles handling when road salt, moisture, age, etc start to affect them.

You mean computers like the one controlling the ABS in about 90% of today's new vehicles?

Regards,

Mark

trumphair
06-05-2008, 10:43 AM
Computers! Bah. I'll stick to my horse and buggy, thank you very much.

Just sounds like a bug/oversight in the VSS software parameters. The should make some changes and issue a software patch.

Putt-Putt
06-05-2008, 03:26 PM
Ya I think this is a case of a little too much technology and not enough just common sense in design.

Danimal
06-05-2008, 03:43 PM
What we need is Christini to come out with a Spyder kit to make it AWD like these bikes:

http://www.christini.com/index.php


That would ROCK!

SpyderMark
06-05-2008, 08:00 PM
Ya I think this is a case of a little too much technology and not enough just common sense in design.

With the majority of the Spyder's weight behind the front wheels, the Spyder is inherently unstable under acceleration in a hard turn. If the rider applies too much throttle and breaks the rear wheel loose in a turn, the resulting loss of traction at that wheel will allow centripidal force to pull the rear end toward the outside of the turn. I'm guessing BRP did the tests and determined the rapidity of such an event might preclude the average rider from responding in time to avoid a spin out.

And what of the possibility of turning too sharply while braking? Again, centripidal force is pulling toward the outside of the turn. With four wheels on the ground, the average car will likely slide before generating enough lateral acceleration to overturn. Not so with the Spyder. One less wheel makes it much easier to overturn. The VSS can apply brakes at any of the three wheels to help the rider get out of just such a bad situation. Obviously, no one would expect a rider to juggle three different brake controls at the same time in an emergency situation.

Short of a computer to "sense" a developing situation and take control of the event to prevent or mitigate it, what else could the Spyder's designers have done within the laws of physics and human response times?

Regards,

Mark

Putt-Putt
06-05-2008, 09:45 PM
I was speaking in general in addition to that. Like you can't change tail light bulbs to led's will put it in limp mode, you can't do a lot of different things electricaly because it will go to limp mode or not run. Also they could have centralized the weight distribution better. This would have made it more sure footed by putting the weight more even on all 3 wheels. I agree there is basiclyy no weight in thr rear.

retread
06-11-2008, 08:06 AM
Had an idea last night, don't know if it's feasible, would a 2 - speed hub work? Seems like a setup like the old over drive units with a kick-down on full throttle would be ideal, maybe I've got too much time on my hands.

Crazyhorse
06-16-2008, 11:22 PM
If it was me.. I would try to defeat the whole system. I only say this because I have lots (35 years of experience) riding quads and bikes and I would feel right at home on one. I Dont really care for all of the fancy electronic stability control stuff these days and that includes ABS breaks. Plus with all that stability control stuff brings down the fun factor for me anyways. But this is just my humble opinion ;D

I do know if I decide to buy a spider I will be taking all that stability control and abs breaks off of mine .. even if I have to rewire and reprogram the whole thing to do it. That way I can do anything custom that I want and wont have to be tied down to it. :bigthumbsup:

What I really would like is the T- Rex.. but that just cost way to much for me right now.. so I have been thinking this would be the 2nd best thing.