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Discussion Starter · #1 ·
I know I'm new and It may sound stuip but does any one know how many RPM at 65 mph is on 1300.
My 1500 suzuki 65 mph is 2250 RPM, I hope the VTX is close.

Also since I don't have a owners manual I'm going to ask a stuip question. To check oil level does the bike have to be on flat ground and in the upright position.

Thanks
 

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The bike DOES have to be on level ground and it DOES have to be in the upright position to properly check the oil level.
 

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Discussion Starter · #3 ·
That's one. I kinda new that one but the other question is really what I'd like to know.
 

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Here is a large amount of information about RPM and MPH that I saved from an earlier question and answer about similar interests....I am NOT the author, I could never hold a thought this long!!! :cheers:


I just transitioned from a sport bike and miss the Tach. On the 1300, without a Tach, I am shifting as follows;

1st to 2nd at 35Mph
2nd to 3rd at 55Mph
3rd to 4th at 70Mph
4th to 5th at 85Mph

Is this okay or am I winding the gears out too much.

Please advise.



The SHORT answer is NO. You are not pushing your bike beyond Honda's limits. In fact, you have a considerable margin of safety left. However, the VTX 1300 also has enough torque to shift considerably earlier without lugging.

The LONG answer is below and I posted it once before but that was probably on the old board as I couldn't find it with a search. If you suffer from insomnia, you can try reading this before going to bed. You should drift right off!

I am a Metrologist by profession (not a Meteorologist), ie I work in the field of calibration and measurement within the Electro-Mechanical Development Lab at 3M Company so maybe this is one for me to tackle.

Here are the numbers you need to do the math. These came straight from the Honda Service Manual.

Primary Reduction Ratio = 1.935
Secondary Reduction Ratio = 0.944
Final Reduction Ratio = 2.818

1st gear = 1.900
2nd gear = 1.148
3rd gear = 0.912
4th gear = 0.778
5th gear = 0.697

Rear Tire Size 170/80-15

It doesn’t matter what a tach is reading if you have one or what your speedometer is reading either (we all know how accurate they are) because this is a fixed mechanical relationship, ie your wheel is attached to rear end gears which are connected through the shaft to the transmission, secondary gears, primary gears, and finally to the engine crankshaft. Any changes to carburetion, pipes, windshields, etc. have no effect on this relationship. Those factors may change the perceived feel and strain on the bike but this mechanical relationship is fixed. However, changing tire size or a slipping clutch would affect the outcome and on chain driven motorcycles, sprockets can be altered.

First step is to know the outside circumference of the driven tire. The VTX has a 170/80-15 tire which means it is 170 mm wide. Since the aspect ratio is 80%, that means the distance from the ground to the wheel is 170 x 0.8 = 136 millimeters. For the metrically challenged, that is 13.6 centimeters. There are 2.54 centimeters in 1” so the ground to wheel distance is 13.6/2.54 = 5.354”. Now we can calculate the the tire diameter which is 5.354 x 2 (top & bottom) plus the wheel diameter of 15” for a total of 25.71”. The tire circumference is Pi times Diameter (Pi = 3.1416) so we have 25.71 x 3.1416 which is 80.77 inches. Divide that by 12 inches and for each tire rotation, the bike will travel 6.73 feet. In one mile, the tire will rotate 5280/6.73 = 784.55 revolutions. Doesn’t matter which gear you’re in, that is always the number of wheel revolutions per mile (at least until your tire starts wearing down). For sake of simplicity, I will calculate the engine revolutions per minute for the various gears at 60 mph since it takes one minute to travel one mile at that speed. Just divide whatever speed you’re going by 60 and multiply it by these calculated rpms to determine your engine revs at various speeds within any given gear.

Since the Primary, Secondary, and Final Reduction Ratios are always the same, we’ll calculate that overall ratio first. 1.935 x 0.944 x 2.818 = 5.147
1st gear = 1.900
2nd gear = 1.148
3rd gear = 0.912
4th gear = 0.778
5th gear = 0.697

You will notice that the gear ratios for 3rd, 4th, and 5th gears are less than ONE which lets you know they are all Overdrive gears (for bragging rights, while lazily cruising down the road at 70 mph in 5th, you can tell your friends you kicked this sucker into Overdrive two gears ago). You’ll also notice that after the BIG jump from 1st to 2nd gear, the rest are all pretty close ratios. Personally I find 4th gear to be pretty much a joke. This bike could easily get along with 4 gears by dropping 3rd gear down to about 0.850 but I digress. All rpm numbers below are rounded off to the nearest 10 rpm for simplicity of reading.

At 60 mph:

5th Gear 784.55 x 5.147 x 0.697 = 2,810 rpms
4th Gear 784.55 x 5.147 x 0.778 = 3140 rpms
3rd Gear 784.55 x 5.147 x 0.912 = 3680 rpms
2nd Gear 784.55 x 5.147 x 1.148 = 4640 rpms
1st Gear 784.55 x 5.147 x 1.900 = 7670 rpms

Now, the next time someone tells you they had their VTX going 60 mph in low gear, just give them a friendly nod and walk away.

I don’t know when the VTX’s rev limiter kicks in but Honda specifies peak horsepower at 5,000 rpm so it can easily rev that high. The engine can probably safely go 5,500 but I’ll just calculate speeds in each gear at 5,000 rpm to be prudent. Kilometers per hour have also been listed for the other 94% of the world’s population.

1st gear 5000/7670 x 60 = 39 mph (62 kph)
2nd gear 5000/4640 x 60 = 65 mph (104 kph) (yes Patricia, there is a Santa Claus and it is possible to go over 60 mph in 2nd gear)
3rd gear 5000/3680 x 60 = 82 mph (131 kph)
4th gear 5000/3140 x 60 = 96 mph (154 kph)
5th gear 5000/2810 x 60 = 107 mph (171 kph)

For what it’s worth, if the VTX can reach 120 mph in 5th gear, it will be spinning 5,620 rpm.

:drunk:
 

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wow did u read that??? interesting.....
 

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Discussion Starter · #6 ·
wow did u read that??? interesting.....

I did I did and I think I found my out my answer it's about 500 RPM more than my other bike, Not bad better than the bike I just sold it tached 4200rpm at 65
 

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I put a Baron tach on my C I also have a Speedohealer to get TRUE mph readings

3200 rpm is just about 70 in 5th
3000 rpm is +-65 in 5th

Before the speedohealer the way the bike comes from the factory
3000 rpm was about 72

The bike was off by 9.2% now things read true...

Have not really paid attention at lower speeds as I cruise town at the speed limits posted and use lower gears and keep things at about 2500 rpm

at 85 to 90 mph I am doing about 4000+/-

Jim
 

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RPM VS road speed is not the real concern it's the piston speed that really matters as that accounts for most of the stress and friction in the engine. The valve train is not much of a concern as engine speeds are low for an ohc design. If you want to compare engines look at how far the piston travels per mile as well as the mean piston velocity (acceleration and mass for bearing load).
 

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I am thinking of getting a Baron tach. Are you happy with it? Does the needle jump at all?
I like mine everythng jumps at idle - very steady at speeds...

Make sure you solder the connections to the spade lugs... IF they come loose you have to go in and reconnect - remove the tank... it will be shaley if the connections are not tight...

Jim
 

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Discussion Starter · #12 ·
I like mine everythng jumps at idle - very steady at speeds...

Make sure you solder the connections to the spade lugs... IF they come loose you have to go in and reconnect - remove the tank... it will be shaley if the connections are not tight...

Jim
I used shrink butt plugs, also can use a female to 2 male adapter. Mil standard 2000 says not to solder unless you have clamps with one inch away to hold wire. With my 35 years of wiring. I've seen wires break right at the solider joint. Or you can use butt plugs with shrink tubing on top with 1/2 inch to each side of the end.

If you need female to 2 male adapter PM me and I'll send you some. That would be the easiest way to go.
 

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I used shrink butt plugs, also can use a female to 2 male adapter. Mil standard 2000 says not to solder unless you have clamps with one inch away to hold wire. With my 35 years of wiring. I've seen wires break right at the solider joint. Or you can use butt plugs with shrink tubing on top with 1/2 inch to each side of the end.

If you need female to 2 male adapter PM me and I'll send you some. That would be the easiest way to go.
I spoke to a tech at the company and told him I was having problems with my tach, was not responding correctly - he asked me if I had soldered the connection at the spade lug, I told him I had CRIMPED it (I knew it was tight) He said disconnect it from the coil and solder the wire joint, I did and have had no problems with the spade lugs to date... 10k miles so far
The wires are secured at the post with wire ties connecting them all together to keep them from moving...
GOOD info always looking for information about connection problems... nothing more frustrating than a loose connection or an intermittent ground wire...

Jim:choppersm
 

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Discussion Starter · #14 ·
Well I quess I've been crimping things wrong for 30 yers now and don't know what I'm doing.
 

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Well I quess I've been crimping things wrong for 30 yers now and don't know what I'm doing.
Hey it was not said to demean you in any way, I think you’ve taken this too personal... :nope:

I am only 1 person here... are we not allowed to have an opinion?

Not sure how OLD you are, (doesn’t really matter) I have been in the business for a while - my second job has been for more than 35 years and I started it after 12 years of electronics in the Navy... So I too understand WIRES, NUTS, BUTTS, BULLETS, most Connectors, wire splices and SOLDER...:hmm2:

Maybe you woke up on the wrong side of the bed today... or is it’s too cold to ride - not sure why you have taken my comments personally - I only posted what I was told, by the Baron Tech...

Jim - have a great day man!
BTW -- Stress Kills -- be careful and cool off a bit... Get that blood pressure down... :bleh:

I am "Older and Wiser" well according to the patch on my vest anyway... :choppersm
 

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I put a Baron tach on my C I also have a Speedohealer to get TRUE mph readings

3200 rpm is just about 70 in 5th
3000 rpm is +-65 in 5th

Before the speedohealer the way the bike comes from the factory
3000 rpm was about 72

The bike was off by 9.2% now things read true...

Have not really paid attention at lower speeds as I cruise town at the speed limits posted and use lower gears and keep things at about 2500 rpm

at 85 to 90 mph I am doing about 4000+/-

Jim
Where did you get your speedohealer?
 

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2009 VTX 1300R, Long Island NY
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Where did you get your speedohealer?
You're probably not gonna get an answer -- was posted May 9, 2008. o_O
I have the SpeedoDRD (several years old) and have the Baron tach (recently installed). I recently posted info about it and how to install on a 1300. Mine works perfectly, no flutter. Model BA-7570-00. Ordered mine thru Amazon: $182. But shop around (JP Cycles). It has made me shift a little better.
(y)
 
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