[Vinish]

Besides the "red line" rpm limit, is there also a max speed (mph) limit built into the bike computer?

 

[nate6966]

Besides the "red line" rpm limit, is there also a max speed (mph) limit built into the bike computer?

I've never hit a governor on my F - all the way to redline in 5th

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[Wigit]

I'm curious how fast the 1800 could STOP when it's at top speed.:shrug: This seems like a FAR more important detail to me. I love torque, I love getting up to speed, but speeding doesn't interest me these days. I guess I'm gettin' old.

 

[nate6966]

I'm curious how fast the 1800 could STOP when it's at top speed.:shrug: This seems like a FAR more important detail to me. I love torque, I love getting up to speed, but speeding doesn't interest me these days. I guess I'm gettin' old.

Very good question! I would say it will stop a lot quicker than a 1300

Don't hate me cause I have two front rotors and a multi piston rear caliper!

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[Wigit]

Maybe. That's entirely possible. I locked up both front and back earlier this week on dry pavement in an emergency stop.(really hot woman on sidewalk distracted me from stoplight) I skidded for a bit. She smiled.

 

[PaXman11]

I just want to clarify something for future members who desire to post here...
The VTX carries the same engine, transmission, and gearing in all versions of their 1800 (C,R,S,T,N,F). The 1300 also maintains the same engine, transmission, and gearing for all versions (C,R,S,T)
While I can't offer input on the 1300, I know the 1800 from the factory is capable of reaching red line in all 5 gears (no bags/no windscreen/one rider) given enough road and proper conditions.

Now follow this close... the same RPMs (red line) will turn the same transmission gears the same number of times. Every transmission on every 1800 will spin the driveshaft the same number of times at the same engine RPM. The same final drive gears will translate that spinning driveshaft into the same number of rotations of the wheel/tire. In essence - every 1800 has nearly the same top speed!!! (allowing for different rear tire circumferences as different models have different tire sizes)

The formula: speed = engine RPM * transmission gear ratio * final drive gear ratio * rear wheel circumference
NOTE - Horsepower and torque are not factors in top speed, they are factors in acceleration. They can only impact top speed where the engine is able or not able to reach red line in top gear

Here's the variables that are possible and common that actually change your top speed:

1. Different size rear tire = larger diameter tires will travel longer distances in the same number of revolutions, thus allowing higher top speed (assuming you don't oversize the tire for the engine's power)
2. Different final drive gear set - - it is a common mod to swap the final drive from a 1300 onto an 1800. I haven't done this so I can't answer the exact impact to top speed, but this gear change provides a different multiplier in the speed equation
3. Different red line - - adjusting the RPM at which the computer hits the rev limiter will change how many times the motor turns over, thus changing the speed equation
   • Note that red line is set by Honda due to design of the cam, lifters, valves, balance, etc. Higher red line requires more precision and machine work to internal engine components
4. Different transmission gear ratios - - I've never heard of this being done on a VTX.

So, with that little walk through in mechanical engineering, we now return to the tall tales of top speeds.

***** One last caveat - If you've completed the Di-Lithium Crystal upgrade in your aftermarket warp core, you should be able to achieve warp 9.4. Not the 9.8 that PaXman11 is claiming. He's a liar. :icon_poke

But those Ferengi lyin' bastages assured me I could do 9.8! On a serious note, the faster you (appear to) go, the more error the speedo's have w/o corrective devices to zero them. As far as stopping ability, I have that covered too, w/ a darkside putting more rubber to the road on her backside translating to quicker stopping.

 

[Vinish]

Very good question! I would say it will stop a lot quicker than a 1300

Don't hate me cause I have two front rotors and a multi piston rear caliper!

Sent from my... wait - No free advertising here!

If you are saying this because of the dual front brakes, I will disagree that this will have an impact in a "normal" isolated emergency braking situation. With the single front rotor/caliper, you can exert enough force to lock up the front wheel. If you can do this, then it is impossible to get any additional braking force. The maximum amount of braking force that can be used is the amount just short of what it takes to lock up the wheel. If a single rotor/caliper can lock up the front wheel, then that single rotor/caliper system can also exert the maximum braking force.

The dual rotor/caliper is useful in cases where there could be too much heat buildup such as extended downhill braking or multiple hard uses of the brakes in rapid succession such as in racing or very fast riding through the twisties.

In a single isolated emergency braking situation, heat buildup in the rotor/caliper is not an issue. Given that the maximum useful braking force can be reached with both the 1300 brake system and the 1800 brake system, what will determine stopping distance is primarily the skill of the rider. But, since the question is about the mechanical aspects of the bike, then (assuming equal riding proficiency) what will make a difference is the weight of the bike and the friction between the tire and the ground. An 1800 weighs more which hurts its braking distance but it has wider tires which should help its braking distance.

In summary, it is really hard to say which bike would have the advantage in braking distance but the dual front rotor/caliper on the 1800 is irrelevant in the situation being discussed (single instance emergency braking).

 

[Vinish]

Others in this thread, I believe, have spoken of hitting a speed limiter separate from the red line rev limiter. I don't own an 1800 and would not go that fast if I did so I certainly cannot confirm this based on personal experimentation. I'm also too lazy to go look though 21 pages to see if my alcohol addled recollection is accurate. Someone help me out. Is there a speed limiter as well as a rev limiter on an 1800?

 

[nate6966]

Others in this thread, I believe, have spoken of hitting a speed limiter separate from the red line rev limiter. I don't own an 1800 and would not go that fast if I did so I certainly cannot confirm this based on personal experimentation. I'm also too lazy to go look though 21 pages to see if my alcohol addled recollection is accurate. Someone help me out. Is there a speed limiter as well as a rev limiter on an 1800?

I have an 1800 and I confirm that there was no speed limiter reached prior to reaching red line in 5th gear

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[nate6966]

If you are saying this because of the dual front brakes, I will disagree that this will have an impact in a "normal" isolated emergency braking situation. With the single front rotor/caliper, you can exert enough force to lock up the front wheel. If you can do this, then it is impossible to get any additional braking force. The maximum amount of braking force that can be used is the amount just short of what it takes to lock up the wheel. If a single rotor/caliper can lock up the front wheel, then that single rotor/caliper system can also exert the maximum braking force.

The dual rotor/caliper is useful in cases where there could be too much heat buildup such as extended downhill braking or multiple hard uses of the brakes in rapid succession such as in racing or very fast riding through the twisties.

In a single isolated emergency braking situation, heat buildup in the rotor/caliper is not an issue. Given that the maximum useful braking force can be reached with both the 1300 brake system and the 1800 brake system, what will determine stopping distance is primarily the skill of the rider. But, since the question is about the mechanical aspects of the bike, then (assuming equal riding proficiency) what will make a difference is the weight of the bike and the friction between the tire and the ground. An 1800 weighs more which hurts its braking distance but it has wider tires which should help its braking distance.

In summary, it is really hard to say which bike would have the advantage in braking distance but the dual front rotor/caliper on the 1800 is irrelevant in the situation being discussed (single instance emergency braking).

I really do hope you're not saying that breaking power is equal simply because you can lock up the brakes. Once a tire is locked up, you have decreased the friction between the bike and the road, decreasing the stopping power. If that logic was correct, then the Chevy Citation I had in high school had maximum stopping power as well - comparable braking power to a similar weight race car? I think not.

Regarding weight, the 1800 weight ranges 778 to 804 and the 1300 is between 678 to 748. That's only 3-18% heavier in the difference in weight.

Yes, having two rotors on the front increases the ability to apply brakes without locking up the tires, thereby decreasing stopping distance.

While I concede the fact that I have not witnessed or read about any comparison of stopping distances between the two bikes, I doubt that the lower weight offsets the increased braking power enough to have a better stopping distance with the 1300.

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[Duug]

Others in this thread, I believe, have spoken of hitting a speed limiter separate from the red line rev limiter. I don't own an 1800 and would not go that fast if I did so I certainly cannot confirm this based on personal experimentation. I'm also too lazy to go look though 21 pages to see if my alcohol addled recollection is accurate. Someone help me out. Is there a speed limiter as well as a rev limiter on an 1800?

Dunno where the actual redline on the 1800 is b'cuz It didn't come equipped with a tach. However,...it does have what I understand to be a rev limiter. Mine and a few others have been reported to come into play when the indicated speed of 144 is attained. At that time the motor pretty much goes into a "stall" of sorts.
If there's a seperate "speed" limiter,...this is the first I've heard of such.

As for riding to WOT. I don't recommend it to anyone. I only do cuz I'm a special kind of stoopid sometimes but, fully aware of the risk and carefully pick my places to run it up,...and then only sans other traffic.

The real charm of the power these HOnda have is in low end torque.

 

[nate6966]

Dunno where the actual redline on the 1800 is b'cuz It didn't come equipped with a tach. However,...it does have what I understand to be a rev limiter. Mine and a few others have been reported to come into play when the indicated speed of 144 is attained. At that time the motor pretty much goes into a "stall" of sorts.
If there's a seperate "speed" limiter,...this is the first I've heard of such.

As for riding to WOT. I don't recommend it to anyone. I only do cuz I'm a special kind of stoopid sometimes but, fully aware of the risk and carefully pick my places to run it up,...and then only sans other traffic.

The real charm of the power these HOnda have is in low end torque.

My 1800F has the digital tach (which I don't entirely trust the accuracy of) and it consistently reads about 5,500 when the rev limiter causes the engine to stutter and cut power, regardless of gear. This is the very same feel you get when you reach the 140+ readout on the speedometer in 5th gear.

 

[nate6966]

.... An 1800 weighs more which hurts its braking distance but it has wider tires which should help its braking distance.

In summary, it is really hard to say which bike would have the advantage in braking distance but the dual front rotor/caliper on the 1800 is irrelevant in the situation being discussed (single instance emergency braking).

So I checked it out and apparently those brake upgrades on the 1800 actually significantly impact braking distance.
As documented here - http://www.mcnews.com/mcn/technical/2012JanPerfIndx.pdf - the braking distance from 60-0 in ft is:
VTX1800 = 109.47 ft
VTX1300 = 122.0 ft

 

[Vinish]

I really do hope you're not saying that breaking power is equal simply because you can lock up the brakes. Once a tire is locked up, you have decreased the friction between the bike and the road, decreasing the stopping power. If that logic was correct, then the Chevy Citation I had in high school had maximum stopping power as well - comparable braking power to a similar weight race car? I think not.

Regarding weight, the 1800 weight ranges 778 to 804 and the 1300 is between 678 to 748. That's only 3-18% heavier in the difference in weight.

Yes, having two rotors on the front increases the ability to apply brakes without locking up the tires, thereby decreasing stopping distance.

While I concede the fact that I have not witnessed or read about any comparison of stopping distances between the two bikes, I doubt that the lower weight offsets the increased braking power enough to have a better stopping distance with the 1300.

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Yes, that is exactly what I am saying. Having two front rotors does NOT help you stop quicker than with a single rotor provided 1) you are talking about a single emergency braking situation and 2) you are able to lock up the tire with both a single and a double rotor system. I am also NOT saying that locking up the tire gives you the most braking ability. As you note, quite the opposite. You get terrible braking when locking up a tire.

Instead, what I am saying is that the maximum braking ability occurs when you apply enough force to barely NOT lock up the tire. This is, of course, what ABS does. It applies the maxium possible force that does not lock up the tire. If you were able to do this yourself and it is my understanding that highly skilled riders can do this, then you would achieve maximum braking force. As I said, this occurs right before tire lock up. Since you can lock up the tire with either the single or double rotor system, this means that you can reach AND EXCEED the optimum lever force and hence the optimum braking force with both the single and double rotor. If you can exceed the optimum with both single and double, then this obviously means that you can also reach the optimum with both single and double rotors and, hence, achieve exactly the same stopping distance with both single or double rotor.

The real value to a double rotor system is, as I previously noted, the ability to spread out the heat amongst two braking calipers/rotors in situations where you need extended or repeated braking such as long downhill runs or racing.

Once you agree that you can lock up the tire with both a single and double rotor system, then the maximum braking ability (shortest stopping distance) is no longer a function of the number of rotors but, rather, depends on other factors like the bike weight and friction between tire and road. Of course, this all assumes an equal skill level of the person riding the one and two rotor bike.

 

[PaXman11]

Maybe, some of us need to look back on our motorcycle safety training courses to the part where they discuss and practice "Threshhold braking", or that point where you reach just short of a full lock-up situation. If you haven't taken the course, research the term, and then maybe do some practice for your own peace of mind and safety.

 

[Duug]

Maybe, some of us need to look back on our motorcycle safety training courses to the part where they discuss and practice "Threshhold braking", or that point where you reach just short of a full lock-up situation. If you haven't taken the course, research the term, and then maybe do some practice for your own peace of mind and safety.

I've been riding for 50 years. Owned over 16 various motos. Up until a few years ago I had 3 in the garage. My current Xc, a Vmax I had since '91 and a Vulcan 1500 since '96.

The braking in the vulcan was kinda soft and slow to respond but, the bike was so slow i didn't worry about it. I eventually sold the vulcan. No regrets.

The Vmax brakes response was immediate and hard,...it would endo if only front got slammed. The front and back werent linked so it was easy to slide and skid around. I liked that.

The HOnda brakes are truly awesome. Tho' I didn't like the linked aspect at first, It made itself very welcome after having to use'm to their fullest capacity. Very smooth but, firm. The thing stops on a dime!

Maint',...keep'm clean inside and out. Keep the pins clean and lubed.

 

[nate6966]

...Once you agree that you can lock up the tire with both a single and double rotor system, then the maximum braking ability (shortest stopping distance) is no longer a function of the number of rotors but, rather, depends on other factors like the bike weight and friction between tire and road. Of course, this all assumes an equal skill level of the person riding the one and two rotor bike.

Look - differences between the 1300 and 1800 brake systems are:
- 1300 has a single front rotor with a 2 piston caliper on the front wheel while the 1800 has two rotors and two 3-piston calipers on the front
- 1300 has a single piston caliper on the rear and the 1800 has a double piston caliper
- the 1800 has the linked brake system, activating the center piston of both front calipers along with the rear caliper when the foot pedal is depressed.

We both agree that these are the differences in brake systems.

I've already identified the weight difference in a previous post - between 3-18% varying due to models of the bike.

Tires vary as we all know.

Using the same rider or at least skill level is demonstrated by MCNews here:

http://www.mcnews.com/mcn/technical/2012JanPerfIndx.pdf -

the braking distance from 60-0 in ft is:
VTX1800 = 109.47 ft
VTX1300 = 122.0 ft

Argue tire size all you want or reasons why all you want - I'm just pointing out that I'm not the one saying that my 1800 can stop better than a 1300.

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[Vinish]

I'm making absolutely no statement on the 1300 vs 1800 braking. All I'm saying is that two rotors is NOT superior to one rotor for a standard emergency braking situation for the logical reasons I have already outlined. It is really simple science/physics/logic.

 

[nate6966]

I'm making absolutely no statement on the 1300 vs 1800 braking. All I'm saying is that two rotors is NOT superior to one rotor for a standard emergency braking situation for the logical reasons I have already outlined. It is really simple science/physics/logic.

I understand your logic, but I still have a mental block about it. Additional rotor allows for additional brake pad contact patches giving additional friction to stop. While one rotor can still lock up the tire, I don't believe that provides all the stopping friction that a second rotor and caliper can provide at the moments prior to lockup.
I also understand completely the instruction and practice of Threshold braking. But that instruction is to maximize your bike's braking power, not equalizing every bike's braking power.

So, instead of relying upon my own understanding (while I had several college classes in engineering and physics, it wasn't my major or my occupation as your profile says you are an engineer) - I turned to other sources to figure out where my gut feel was coming from and to confirm that the reason behind racing bikes having two rotors was simply reducing brake fade...
Here's what I found that further gives me a tough time understanding your claims...
http://www.superstreetbike.com/how-to/removing-front-brake-rotor-doesn%E2%80%99t-affect-stopping-distance-mythbusters

I'm not trying to be combative, obtuse, troll, or even trying to just be right. I just want to understand where the significant stopping improvement is coming from on the 1800 given the extra weight yet similar tire sizes to the 1300.

 

[Hiramsaint]

As far as the speed and braking thing go, all I can safely add is this: