Squeezing out more mpg from the suzuki
 

Hello, I have a 2000 sv650 that I commute on daily 20 miles each way through some of the worst traffic in America (101 and 405).

I absolutely love my bike, it's faster than a Ferrari but gets better mpg than a Prius. And I do ride my honda elite 80 around town for groceries etc.

But I want more mpgs... I'm averaging about 47ish mpg right now (not sure if my fuely is linked to this account?) which is great, because I don't even try really, but the funny thing is, when I do actually try it's never any better and sometimes even worse than average. My hypermiling works fine in my car but not so much on the bike. I'm wondering if it's possible I'm shifting too early?

Also, I was thinking about aero modding the bike with a big sell, but decided it's just too much work and trouble, plus I wouldn't be able to split lanes as well. So instead I'm thinking I'll aero mod all the components individually. Maybe even a stream lined helmet/jacket/outfit. And isn't it aero to coil something around a column like if I wrapped a wire around the rods holdin my mirrors etc. and I'm thinking I'll remove the mudguard on the back.

I already have a smaller drive sprocket to change the gearing. Any other ideas for squeezing out a couple more mpgs?

Personally I think you deserve some kind of award in recognition of the fact that you can even get that kind of MPG in those conditions. I know what kind of traffic you deal with.

Houston Texas, 1982, it regularly took 2 hours for my brother to drive less than 10 miles to work, from I 15 north into the city. Fortunately for me, I could walk to work in 10 minutes, drive to my apartment and back at lunch while the ads were on television and not miss any of the show.

His solution was to leave 2 hours earlier and get home two hours later, which cut his commute time by 75%. Might as well get paid to work longer hours instead of sitting in traffic half the time you get paid for work.

You don't need to win any contests here and with the pitiful average speeds in that kind of traffic, I doubt my GZ 250 would do much better than your 650. Lane splitting is your only salvation, but here it's a potential wreckless driving ticket.

regards
mech

The simplest, most effective aero mod is a tapered tail box behind the rider. If traffic is 20 mph bumper to bumper then an electric bike is viable.

Had you had an injected SV (from 2004 ?) I would have suggested to run it on a single cylinder with the deactivated cylinder forced at WOT to reduce pumping losses.

Even better, to Atkinson it by delaying intake cams two tooth (involved quite a lot ...).

But since it is not injected, it is much more hassle and expense ...

Using the Elite to work is not an option, is it ?

lol thanks for nominating me for a traffic mpg award. Yea traffic is ridiculous, luckily I'm able to make my own hours for the most part so I usually get there at 11am and leave around 7pm which does help with traffic.


I have a garage full of ebikes and escooters, but I rarely use them. I think 40mph is like my magical number that I need to go. The Elite will do 45mph, which is not enough for me to get on the 405 or 101. I used to commute with a 1970 honda cb100 which topped out at 70mph and definitely wasnt freeway legal, but at least I could kind of go with traffic if it happened to free up for a stretch.

I could take side roads with the Elite but that would put the commute at over an hour. In a car it's 40minutes - 1.5 hours depending on traffic. On the motorcycle its 25-45 minutes.

I'm thinking I may do a tapered tail box, anyone have any inspiration for me?

Is it a N (naked) or S (fairing) model?

47 mpg for a 20 mi ride in heavy traffic isn't bad. If it's slow-going and start and stop, any aero aids aren't going to show big improvements.

I have 2 SV650s - a 1st gen ('00 - carbed) and 2nd gen ('06 - F.I.) - both nakeds. The 2nd gen will get about 55 mpg at 75 mph on ethanol-free 87 (about 5% better than gas with ethanol). I have also geared it up 1T on the countershaft sprocket, which smoothed the cruise significantly but didn't give a significant increase in mpg. Best I've got is 62 during some moderate backroad riding.

I haven't ridden the 1st gen enough to get any numbers (I bought it as a non-running and partially disassembled project bike), but generally they don't do quite as well as the 2nd gen in mpg.

For your situation, I would concentrate on throttle-opening. Try to reduce the amount of throttle-opening as much as possible. When you have the chance, try to get into as high of gear as possible - then cruise with as small of throttle opening as possible. Less RPMs are good, but I feel that less throttle opening is more important.

Run regular (87 octane) gas, without ethanol is best - but I bet it's not available for you. A non-O-ring chain would reduce drag but give you less lifespan.

I am not sure low throttle opening is the key.
At least it is the opposite of the pull & glide concept wich tries to use the engine at its best efficiency : with throttle at 75%.

Is pull and glide at your average 40 mph in top gear doable ?

A locking, solo trunk box bolted to the passenger seat is convenient for carrying stuff even if your 40mph average won't allow any aero mods to help the fuel economy much. A solo box can be long and skinny for an aero improvement instead of the cube shape of most normal moto trunks. You could make something out of plywood with a taper or just buy a large tool box. Anything long and narrow you put behind will be an aero inprovement
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Shop Centrex Plastics, LLC Commander 25-Gallon Tote with Latching Lid at Lowes.com
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How often do you have to exceed 65mph to keep up? A Honda PCX150 is the ideal stop and go commuter. No shifting. No chain to lube. 300 pounds and ultra low cg is easy to handle in and out of parking spots that no other vehicle can use. And the best part, 100 mpgUS at 40 mph. You can buy a hardly used one right now for $2,000 and it will last forever. I have 17,000 on mine and with electric heated gear, I ride it 75 miles every day there is no ice.
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http://powersports.honda.com/2013/pcx.aspx
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The new Yamaha Smax will be a little faster on top speed and a little less fuel efficient if anyone needs a 70 mph cruise capability.
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http://www.yamahamotorsports.com/spo...20/0/home.aspx
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In his situation with unpredictable stop-and-go traffic it's going to be difficult to use the engine in it's most efficient range. That's why I suggested just keeping the throttle-opening at a minimum.

Even in wide-open riding conditions, I find pulse and glide not very effective on a cycle - especially with a SV650 which has an enormous amount of engine braking when you close the throttle. I've found it best to just keep the throttle opening as small as possible while cruising. When accelerating go for strong but brief spurts of acceleration - then the highest gear you can smoothly cruise at (without bogging) when you have reached your desired speed.

There are better options than a SV for commuting in those conditions (as sendler noted), and a CBR250R would be a good choice if you didn't want to go the scooter-ish route. I still wouldn't expect amazing numbers, even from the CBR, in those conditions.

Other minor improvements that could be made to the SV to increase MPG in those conditions would be a thinner oil (30-grade synthetic instead of 40) and a hotter-range spark plug.

Of course the closed throttle gliding is done with the clutch in.:) Unless you don't have a clutch. The freedom of which in stop and go traffic is impossible to relate until you try it. You can wear any boots and snowmobile mitts you like since you never have to shift.

Might be for some, but not something I personally like to do on a cycle.

Thanks for all the info. I do occasionally hold in the clutch when hills/traffic allow but my bike has quite a bit of clutch drag so it doesn't coast as nicely as I'd like. I also have a couple spots where I shut off the engine, but I'm usually busy squeezing my way to the front of the line. The sv650 can fit anywhere I can fit :-)

Sometimes I wish I got a 250 but the low end torque on demand with the 650 is such a great thing I don't know if I could downsize now. I also just like knowing I'm faster than %99.99 of cars out there.

I do occasionally get up to 80mph when traffic allows, let's say... 15-20% or so of my weekly commute. So I think I will try to rig up some sort of tail box.

I bought my sv650 for $1300 working with a salvage title and have gone through it, even adjusted the valves which was a $&@& to do (shim under bucket). So at this point with my current mpg, I don't think a smaller bike/scooter would ever pay for itself.

I'm thinking full valence front fender, chop off rear mid guard, get a tapered tail box, maybe some aero mirrors? And a big tank bag.

Have you overhauled the carb recently? Jet it as lean as you dare. If it is a CV carb similar to a DR650, the slide & slide guide gets worn. I went from about 45 to 55 on my DR with new slide guide, needle and main jet.

Ohh good idea bikenfool, I think they are very similar. I really haven't touched the carbs. I would def want to get a temp gauge first, I always wonder how hot it runs.

Usually I pay no attention to the speedo/tach tonight I took notice of my usual driving habits, traffic was basically stopped the whole way through Hollywood and the valley. I averaged 30-35mph splitting lanes, never drop below 20mph and stick in 4th gear for most of it.

A set of flat slide carbs is gonna be hard pay for itself if you dont factor in the added bonus of a funnier ride ...

But I wonder if they do exists as downdraught as it is the SV setup IIRC ?

Checking the carbs is a good idea. Because you are running at a pretty small throttle opening most of the time, carb sync is going to be important - so I would check it.

The SV's idle mixture screws are a !#$% to get to, but that's another thing that you want set properly to get good MPG. Having it set lean, and jetting lean in general, isn't necessarily better. I would think you would want to adjust the idle mixture to get the highest RPM idle in your case - then set the idle to about 1200 or maybe slightly less.

There were some article on Craig Vetter's website that mentioned testing that was done back in the 80s with leaner jetting, and that it didn't help MPG. It just made the engine run poorly so you opened the throttle more.

That would be conditions for streamlining the scooter.

Smaller drive sprocket? That will increase your RPMs at any given speed. Larger drive sprocket or smaller driven sprocket should lower RPMs.

I was planning to bump my drive sprocket up a tooth on my 650R, but I rarely ride it any more as I have to shuttle the kids around too much so I'll be selling it soon.

I'd say there is an even simpler one. Simplest aero mod... is a tight tuck. Most of my riding over about 40mph I have my chest on the fuel tank. This typically gets me about 10% over sitting upright. Precise numbers are tricky to sort out with as tiny as the fuel tank is.

How much do your tires per mile cost, maybe better focuse somewhere else.

He did say that, didn't he?

As darcane stated, if that's the case (smaller front/countershaft sprocket), it's not helping you get better MPG.

I have gone to a 1T larger front/countershaft sprocket, mostly for the 500 RPM drop it gave on the hwy and the smoother range it put the engine in at those speeds.

I would at least go back to a stock sprocket (15T) and maybe try a 16T - they aren't expensive.

Oops I meant 1t bio get drive sprocket, but I haven't installed it yet. Looks like it will be fairly soon as I noticed my chain has quite a bit of play.

This tank I've been tucking any time above 40mph so well see where that gets me.

The tires, I think they were like $40-50 each. They seem to be lasting ok

How many miles on the chain? If it is getting worn, you'll want to change that too. As it wears, the chain gets longer and will chew up sprockets quickly.

Yikes, I don't know! It's the one it came with, so at least 10k miles, could be original at almost 50k miles! I think I have the new chain in the garage with the new sprocket. Looks like I have my weekend planned out for me.

And I don't know how to sync carbs. I only have delt with single carb setups or fuel injection.

A simple way to synch carbs.

Back off the idle stop adjustment screws so they are not in contact with the linkage, where you can put a feeler gauge in both and measure the same clearance without moving the idle stop levers.

Adjust the screw that connects the pirmary linkage (fixed) to the secondary linkage (adjustable), so you get the same measurement at both idle stop screws. This measurement will be greater that your initial measurement but should be exactly the same from one to the other carb. Add feeler gauge leaves until you get both sides identical.

regards
mech

Would the engine even start and run with the intake cam retarded that much?:eek:

I had a 1999 Triumph Adventurer (with the 885cc engine), I got 51mpg from that with average driving (but no traffic jams). First thing I did, I tossed the stretched oring chain and got a non-oring one which I think helped a fair amount due to the low friction. I added a home-brew chain oiler (total parts cost was about $15 IIRC) which kept the chain looking nice. The bike might have been a bit oily in back but I didn't care.

Keep in mind even if you have to replace a non-oring chain twice as often as an oring one, you are probably still ahead in dollar terms.

Don't worry too much about your fuel cost, just enjoy your SV. You are still getting double the mpgs that everyone else out on that road is getting, maybe more.

Camshaft sprockets are usually 36 tooth so a teeth sprocket delay is 10°.

The inlet advance before top end center is usually 30° and delay after bottom end is 50° ish.

Atkinson timing engine as seen in a Prius is 15° to 0° advance and 90° to 105° delay, thanks to a cam phaser.

That being said, there is a thread in the Motorcycle section wich name is "Atkinsoning motorbike engine" where one guy tried a one teeth delay on a big Kawi engine to no avail and the conclusion was the carbs can't cope with back flowing, which is the whole idea of the Atkinson cycle.

So far it is just a maybe that an injected engine would do better in this respect ...

http://<a href="http://s1187.photobu...connor/128.jpg[/IMG]
This is a tail piece I designed for my city bike.

The image doesn't show I'm interested in seeing what you came up with.

Also, how do I get my fuely to show up in my sig like that?

See http://ecomodder.com/forum/showthrea...ture-2117.html

And here's Grant-53 's picture for ya:
http://i1187.photobucket.com/albums/...connor/128.jpg
If you click on Reply at that post you get the BBCode in that post too, whether functional or not.
Whenever you see something in a post that you'd like to do too just hit Reply and study the code :)

Saw his photobucket link does show up in a browser but it is a page; you need to copy the actual picture address (right-click on it) and paste that between these [IMG][/IMG] tags to make it work.

Thanks!!

A little update, for a few weeks I was tucking anytime over 45mph. There was about a 10% increase in effeciency. But it was hurting my neck/shoulders. I have decided that it isn't worth the 50 cents or so I'd save daily. especially where I depend on my strength in my current line if work. So now I'll occasionally tuck in to reduce turbulence especially at speeds over 70, but I'll have to look into and aero tail box for long term use. Thanks!

Hi Saturndude... I've posted my modifications to my 02 SV650 and my mpg gains. Before the extreme modification I got about the same. I have tried other modifications related to some of my other research you can see here that put it 52 to 55 mpg. (That proto-bike is an extreme example of mpg and available power on tap of course) With the current mods and practical driving (key here) I have my best now at 64.3mpg with the SV. With many hills I should add between here and Santa Fe NM. In city driving is best with the turbo mods due to less throttle and and I was able to lean out the bike anyway. Gearing helps in your case btw I'm sure you all ready know. Less effort from the engine and running 15.5 to 16.6 AFR will never hurt anything and at sea level you wont hardly feel the power loss. I can go on but just thought I'd make mention you can get better mileage with some tuning details. Also Graig Spears (Spears Racing) makes the advance timing keyway that will help as well with MPG. Talk to some of the guys at SVRider.com, some of them with carb SV's are getting mid 50's as well with some good tuning techniques.

Cool I think I'll look into slightly leaning out the carbs next.

This weekend I installed a new chain and two new sprockets. I decided to stick with the o-ring because I want to reduce required maintenance. And I swapped the sprockets from 45/15 to 44/17. It feels fine and I'll post back results once I run through a couple tanks. Unfortunately I don't usually have a chance to get up to speed so well see.
Also, I ordered a second rear pillion passenger seat and plan on constructing an aero tailbox around it.

For best mpg, I would recommend a 150 CC, 5 speed transmission,double overdrive motorcycle.
I tried the Roketa 127, best i got is 96mpg at 60mph tailgating trucks, and 120mpg at a constant 35-40mph.
127cc is too small for highways, and made to go 35-45mph, however it's for speed step through gearbox with clutch started slipping, and acceleration was sluggish (a WOT departure was very similar to cars departing from a red light)
Therefor a standard 5 spd gearbox is just the right thing for small bikes of <200cc.
A thumper or single cylinder is most efficient, more so than a twin cylinder, and excellent for <200cc engines.

a single cylinder 150 cc engine, with a 5-speed transmission, & a double overdrive doing roundabout 3000 rpms at 45 miles per hour, will be the closest results you can get to a hundred MPGs, while at the same time, downshifting doing 7-8k rpm allows you to go to about 60 miles per hour at ~70mpg.

Trying to keep the rev range between 2500 and 3500, at your regular cruising speed maxes out mpgs. I usually change +1t front, and -5t rear, or the equivalent of 7 to 8t down on the rear. Most bikes come with a ~16/41t, and mpg is directly affected by sprocket tooth change. Going from a 16/41 to a 17/36t should increase mpg from 50 stock to 60mpg (a change of just under 20%).
Upshifting 1 or 2 gears should give you very similar gear ratio as a stock gearing final gear, so you could do almost the same top speed in 5th or 4th gear.



For prolong highway rides of 65mph tops, you will need A 250 cc engine, single cylinder at 85mpg peak, 75mpg @75mph.

if you ride a lot of highway and interstate, at speeds over 75 miles an hour, you will need a 500 cc engine minimum. a 650-750 cc engine is recommended if you are doing more than one hour at interstate speeds a day.

All of these are best with a ptwin engine, fuel injected, but some modern vtwins also get good gas mileage.

Honda engines are better than suzuki engines. They have lower peak rpm, but higher low end torque, which is excellent for eco riders, and those that want to make their engines last.
For high performance, lower mpg, Kawasaki engines are quite good.

your gas mileage, when fuel injected, can be between 66 and 75 miles per gallon on a 500-750cc engine.
On most carbureted engines it's a good 15% lower

Some of the smaller bikes are offering a 6-speed trans. Bikes with 125 to 150cc are not as common as 250cc machines. See the latest Vetter Challenge results where 'low&slow' topped 175 mpg on his streamlined 250cc Ninja. A 150 cc at 3000 rpm and a 50cc at 9000 rpm are moving the same amount of A/F mixture. Key factors in fuel efficiency are compression ratio and air drag.

Rider comfort is a persistent problem. The individual's settings of handlebar height and reach are a function of arm and torso dimensions. Build the bike to fit you. Once you have your body position optimized your shoulder height will determine the vertical dimension of your fairing. Max width is at the shoulders so the cross section would be an inverted egg shape. Vetter just updated his fairing tail section see Chapter 83 at craigvetter.com

If I had an opportunity again, I'd love to try modding the Sym Wolf150.
A very nice, simple, and mod friendly bike.

Most 150cc or below bikes are chinese bikes, with their inherited problems of screws falling off while riding, chrome rusting, 3-5k miles before a valve adjustment (2k miles on the 50-100ccs), low engine life expectancy, bad electrical cable wire harness, etc...

The Sym Wolf 150 is Korean, not inheriting all those chinese flaws, and probably the perfect city commuter.
It can go on highways, but not too far. Forget interstates on this. It would be dangerous, unless going on the right lane tailgating trucks to reach 65-70mph.
It's a great tradeoff between power and mpg, hitting just right in the sweet spot for city rides.
eco modders would love doing sprocket changes to rev that 150 in the sweet 3k rpm range, while doing a nice 30-35mph, clutch allowing you might be able to get it to do 3k rpm @40mph, surpassing 110mpg when cruising comfy.

The Honda Rebel 250 slightly has too much power in the city, while just not enough for the interstates (7.5k rpm @ 85mph when ducked forward, or 6k rpm @75 mph is about the best you can get out of it, though it generally only can get 65-75mph reliably top speed, accounting for head wind and hills).
It's a great Highway bike, and with the correct gearing great for going 40-55mph all day long, and mpgs surpassing 85mpg. A great number, but not great enough, when 100+MPG is achievable!
It's engine is a lot better than the Suzuki GS500 in terms of low end torque, and low RPM performance.

The chinese bikes stock have 80+mpg, and can be modded for 100+mpg, but they have no oil filter, and their oil consumption is quite high.
from both an environmental and economical point of view, they aren't very good investments at all in the long run.
The increase in oil changes, offset all gains done in fuel MPGs.
The increase in valve adjustments, and repairs on broken parts will catch up on you in the long run. Their lower resale value makes them worth nickels at the end of their lifetime, which often is only 1/4th that of a Japanese bike.

For that reason, without trying it before, I'd probably nominate the Sym Wolf 150 as the perfect econo-bike for the city.

It'll be perfectly possible to mod any 125 to 150cc to do over 150mpg, but when gearing becomes too tall, it no longer becomes a practical bike to ride in city traffic.
Too tall gears cause bad acceleration, and difficulty departing from a dead stop.
Wind drag on small bikes increases exponentially from 35mph onward, so your sweet spot for max mpg would be 35mph on a 100cc, 40mph on a 150cc, 45mph on a 250cc (trying to keep revs between 2.5 and 3k rpm.

I checked the Sym website for information on the 2015 models. The bikes are now from Taiwan and the 250cc fuel injection bike is a 6 speed rated at 25 hp and 96 mpg.

How much?