17/38

17/38 sprockets made my Virago 250 faster – higher gearing is not always slower

Posted on June 19, 2013by lstrick115

I just changed (from 17/40) to 17/38 sprockets and drove it to work today with 17/38 for the first time.

As expected, it ”moves up” the speed range for each gear.  If you used to go 35 to 50 mph in 4th gear, for example, now you would go 40 to 55 mph.  A lot of my commute is 50 mph and hilly, so I was in 4th gear a lot where I used to be in 5th gear.  Fourth gear is more comfortable than before at 50 to 55 mph – 5th gear is less comfortable at 50 to 55 mph.  Fifth does not climb hills as easily as before.

So basically with 17/38 you stay in lower gears than before and use 5th more for highway use.

In my opinion,  17/38 is the proper stock setup, and 17/40 is good if your carry a passenger, have heavy accessories, or your engine is not running at it’s best.

Not expected – Here is what I found out that I did not expect:

17/38 makes the Virago 250 slower faster

It would be easy to think that higher gearing (17/38) would result in slower acceleration – it does not, since you are usually in a lower gear. Since I was driving in lower gears, the bike felt like it had more acceleration today – it felt like it had more horsepower. I was driving in lower gears than normal, revving the engine more, and driving harder than normal.  I got 71.7 mpg the first day (includes some test rides) and 77.2 mpg the second day (my recent average was 79.1 mpg)

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With 17/38 sprockets, 5th gear on the Virago 250 is most usable above 60 mph.

Miles per hour The Virago 250 greatest torque (between 4500 and 6200 rpm) is this road speed (indicated) in 5th gear: 17/38/130/stock front tire         59 to 81.1 mph

17/38/130/larger front tire         56.4 to 77.6  mph

17/38/140/stock front tire         60.9 to 83.7 mph

17/38/140/larger front tire         58.3 to 80.1 mph

Kilometres per hour The Virago 250 greatest torque (between 4500 and 6200 rpm) is this road speed (indicated) in 5th gear: 17/38/130/stock front tire         95 to 130.5 kph

17/38/130/larger front tire         90.8 to 124.9 kph

17/38/140/stock front tire         98 to 134.7 kph

17/38/140/larger front tire         93.8 to 128.9 kph

    [stock front tire  3.00×18     —    “larger” front tire   100/90-18]  

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That ↑ was the good news.

Now here is the bad news.

17/38 works so well because you can be in a lower gear – except over 65 to 70 – when you are in top gear.  Fifth gear does not climb hills as easily as before and strong headwinds affect the bike more – this is expected, but is still a downside of 17/38 – “less power” over 65 to 70 mph (because you can be only in 5th gear).

Fifth gear with 17/40 is a little stronger that 17/38.  A six-speed transmission would be cool – on the highway, you could choose to travel in either 5th or 6th gear – depending on the wind, hills, and other conditions.

For me, with 17/38 I have  more power less than 65 mph (because I can be in a lower gear) and  less power over 65 mph (5th gear).

The Virago 250 is still very good on the highway for a 250cc bike – and it has a great midrange torque for  a 250.

  Update August 5, 2013 – This morning there was a strong headwind coming to work.  Now that I have a 38 tooth rear sprocket, in 5th gear, it was bogging – reminding me of my CB160.  When I got to work, I kept thinking that I should have gotten a 39 tooth rear sprocket instead…………..

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(answer to question)

Hi, 16/38 is fine – it’s about the same as 17/40. In my opinion, 17/38 is the proper stock setup, and 17/40 or 16/38 is good if you carry a passenger, have heavy accessories, or your engine is not running at it’s best. (I think 16/38 never caught on because some people (not me) believe both sprockets should not be even numbers.)

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Virago 250 speeds-in-gears charts 17/38 and 17/40

Posted on May 7, 2013by lstrick115

  See end of post for paper tachometer overlay  you can print out and put on your Virago 250 speedometer.

I was driving to work this morning and I just happened to notice that my exhaust note was an “E” pitch at an indicated 50 mph in 4th gear.

The “E” is 82.407 Hz; multiplied by 60 equals 4,944.42 rpm. (Hertz multiplied by 60 equals rpm.)

Using this information, I made new Virago 250 speeds-in-gears charts.

(Speeds-in-gears charts already exist for the Virago 250, but I did not know if these charts were corrected for speedometer error.  My 2002 Virago 250 speedometer is 6.8% optimistist, and these charts reflect that.)

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Once you have the above chart for your sprocket combination, it is easy to “make your own tach” by carefully sticking tiny numbers on the face of your speedometer.  You can fit gears 3 and 4 below the mph area, gears 1 and 2 above the mph area (on the left side of the chrome trim ring) and gear 5 above the mph area (on the right side of the chrome trim ring).  Having the 5 gears in three different sections of the speedometer make it easier to follow, as opposed to have all 5 together.  You need only numbers 4 and 6 (for 4,000 rpm and 6,000 rpm) and then you can just put in dots for the 3, 5, and 7.  How does it work?  I don’t know yet – it rained today……  (edit – it rained tomorrow, too).

Two methods – individual numbers, or an overlay. You can stick-on individual numbers, or you can add an overlay – see below.  The individual numbers are probably better if your vision is not so great.  The overlay is not as easy to read, but if your vision is really good, you might like it.  The overlay would be better is the numbers were bigger and if you put it inside the speedometer – that way, it would not hide the speedometer needle and it would be out of the elements.

My theme for this bike is “low-budget functional” – so I could not buy a tach.  I try to make parts whenever I can.  Sometimes my experiments work out and sometimes they don’t.  If it does work out, I might take the speedometer apart and put the tiny numbers on the actual faceplate.  This would be easier to do and easier to read – since now I am putting the numbers on the glass, which is maybe 10 mm above the faceplate so with different viewing angles, you get slightly different results.  (The term is “parallax error” – I just try to avoid using big words.  When I lived in Kentucky, I got a job at an electronics store, and Tim and Mark made me sell cameras instead of the “fun” stuff – that is where I learned that.)

Most people would just buy a tach if they wanted one – this idea is for someone who is short on funds.  It is easy to read (once you get used to it) and is accurate.

XV250 speedometer marked for rpm

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(Oh, I did not know about gauge overlays until a few minutes ago…..) Here are two overlays for the Virago 250 speedometer for 17/40 sprockets and stock front tire.  The outside numbers are 1st gear rpm.  The innermost numbers are 5th gear rpm. I have to print it from “Paint” to get the right size – the printed area should measure 2 1/16 inches or 53 mm wide.

(same scale as above jpg)

Cut off the blank areas so all that all that is left is mostly the numbers. Yellow highlight the 2nd gear range.  Green highlight the 4th gear range (don’t cover up the numbers).  At this point, it will look something like this: If you tape it on the glass of your speedo in just the right position for your sprocket combination, it will be accurate.  For example, for 17/40, position it so that 5,000 rpm in 3rd gear lines up with 40 mph  (17/38 would be 42 mph).  After I use it a while, I will post a more accurate one, but this one is fairly accurate.

(If your friends laugh at it, tell them the no-cost paper tachometer is more accurate than the bike’s speedometer.)

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  edit 6/13/13 – The idea above ↑   is for someone who is short on funds or just wants to have a tach’s function without paying for it.  Of course, a real tachometer – a round one –  would be better…..

Bobster’s Virago 250 with tach

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Fix the Virago 250 gearing !   Changing sprockets (gearing) on Yamaha Virago 250 to 17/38, 17/40, 17/42, etc.

Posted on August 17, 2011by lstrick115

i   –    5 Votes

The stock sprockets on the Virago 250 are 16 teeth (Front) and 45 teeth (Rear).

Yamaha sells this model worldwide; the gearing is probably fine for some areas, but for travel on “high” speed paved roads, in my opinion the stock sprocket choice is way too low.

   For any Virago 250 that is running strong, I would go with 17/38, 17/40, or 17/42 depending on your driving conditions.  If you have changed your rear tire size, that could affect your decision also.

Examples:  If you seldom carry a passenger and don’t have many hills in your area, 17/38 could be good choice. If your bike has extra weight due to added windshield, saddlebags, etc. and heavy rider, you might go 17/40, or 17/42 if your area is hilly.  If you have a hilly commute but intend to go to smaller rear tire (120/90-15), 17/38 could be good choice, since the smaller rear tire will give you the equivalent of 17/39.

I changed my Virago 250 to 17/40.  It’s a different, better, more useful bike now – more like a real motorcycle should be.  Instead of going through the first four gears by 30 mph, I get to actually use the transmission like on most bikes.  The motor is less revved up.  Taking off from a stop is absolutely no problem (I am 210 lbs or 95.5 kg).  The stock 16/45 takes off super easy but this is because it is the wrong gearing – taking off with 17/40 is no harder than with the average motorcycle.  Yamaha was not doing beginners any favors with the “granny” first gear – people should learn how to take off on a motorcycle with normal gearing.

You could think of the change to 17/38 as a transmission change – it is like you discarded 1st gear (which is too low anyway) and added a 6th gear.  It is not really accurate to say 17/38 will result in lower power or torque, because you would probably be in lower gear.  5th gear with the stock 16/45 is about like 4th gear with 17/38.                          -Les S.

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Choice of sprockets is an individual decision, but the information below might help you decide which combination is best for you:

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Negatives:
1) Your Virago 250 is not running as strong as when it was new.
2) Half of your riding is in hills, and half is fairly flat highways.
3) Your bike has a windshield, saddlebags, and possibly other heavy accessories.

Positives:
4) You do not carry passengers often.
5) Your weight is 175 lbs. or less
6) You have the stock size rear tire (130/90-15).

Based on this, I would go with 17/40.

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Negatives:
1) Half of your riding is in hills, and half is fairly flat highways.
2) Your bike has a windshield, saddlebags, and possibly other heavy accessories.
3) Your weight is 200 lbs. or more

Positives:
4) Your Virago 250 is running very strong – as strong as when it was new.
5) You do not carry passengers often.
6) You have the stock size rear tire (130/90-15).

Based on this, I would go with 17/38.

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Negatives:
1) Half of your riding is in hills, and half is fairly flat highways.
2) Your bike has a windshield, saddlebags, and possibly other heavy accessories.
3) Your weight is 200 lbs. or more
4) You have a larger size rear tire (140/90-15).

Positives:
5) Your Virago 250 is running very strong – as strong as when it was new.
6) You do not carry passengers often.

Based on this, I would go with 17/40.

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Negatives:
1) Most of your riding is in hills; the rest is flat roads.
2) You carry passengers fairly often.
3) You have a larger size rear tire (140/90-15).

Positives:
4) Your Virago 250 is running very strong – as strong as when it was new.
5) Your bike does not have windshield, saddlebags, and possibly other heavy accessories.
6) Your weight is 165 lbs. or less

Based on this, I would go with 17/40.

(Due to the larger 140/90-15 tire, this is equal to 17/39)

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Negatives:
1) Most of your riding is in hills; the rest is flat roads.
2) Your bike has a windshield, saddlebags, and possibly other heavy accessories.
3) You carry passengers fairly often.
4) You have a larger size rear tire (140/90-15).

Positives:
5) Your Virago 250 is running very strong – as strong as when it was new.
6) Your weight is 165 lbs. or less

Based on this, I would go with 17/42.

(Due to the larger 140/90-15 tire, this is equal to 17/41)

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The chart below shows the number of links needed for each sprocket combination.

http://www.cyclechaos.com/4um/f27/virago-250-front-rear-sprocket-upgrades-15285/index2.html

See link above – the chart below used the data from this link.

Some sprocket combinations can use two different lengths – the shorter length will have the chain adjusters more forward, and the longer length will have the chain adjusters more back. Sprocket combinations can sometimes use two different chain lengths because chains can vary somewhat in length (used chain vs new chain and different brands of chain.)

16/45 stock ………………………………………… 114

16/43 – 4.6% higher gearing 0/.5 …………. 114

17/45 – 6.2% higher gearing 0/.25 ……….. 114

17/44 – 8.6% higher gearing 0/0 ………….. 114

16/41 – 10% higher gearing -2/0 ………….. 112

17/43 – 11% higher gearing 0/.25 …………. 114

16/40 – 12.5% higher gearing -2/.25 ……. 112

17/42 – 14% higher gearing 0/.5 …………. 114

16/39 – 15% higher gearing -2/.5 ………… 112

17/41 – 17% higher gearing -2/.25 ……….. 112 . .. 112 tight or 114 loose

17/40 – 19.5% higher gearing -2/0 ………. 112 .. 112 Chain will fit perfect, with full adjustment available

17/38 – 25.8% higher gearing -2/.5 ……… [b]112[/b] .. 112 Chain will fit 1/2 back, so might run out of adjustment before worn out

17/37 – 29.2% higher gearing -2/.75 ……. [b]112[/b] .. 112 Chain will fit 3/4 back, very little adjustment available

17/36 – 32.8% higher gearing -4/0 ………. [b]110[/b] .. 110 Chain should fit perfect, with full adjustment available