Why did HD get rid of the throttle cable?

[wayzalot]

I have been hearing about the TBW problems and keep asking myself Why not a cable.  I usually get 50,000 miles out of a cable and probably more if I lubed it.  Does anyone know why they changed.  How long until someone comes out with a cable conversion?   

[FLTRI]

A couple reasons for the TBW:
1) The rider cannot ask the engine to lug more than the engine can withstand. Less apt to cause damage to the lower end.
2) An additional box is not necessary for cruise control. Throttle is controlled by the ECM.
3) No cables to have to service.
Prolly more but that's all I can come up with right now.
The auto industry has been using this technology for years (since 1997?). You may even have a car with TBW and not even know it.
Bob

[Ultrashovel]

The "fly by wire" system is in keeping with the way that all vehicles are going - almost totally electronic. I still have a bike with the cables but I can see advantages for the fuel injection system in being able to monitor throttle position more precisely.

Like all things having to do with Harley-Davidson motorcycles, some changes will go against the grain of the old timers. There will always be some resistance to change but, like it or not, the day is coming when it will be too expensive to work on your own bike, principally due to the fact that most of the control systems wll be completely electronic and computerized and the equipment needed will be proprietary to the MoCo. They are almost there with the "Digital Technician" laptop.

[FSG]

One of my comments when HD came out with the TBW was I was looking forward to the aftermarket coming out with a Servo Motor and TBW to control a CV, I'm still waiting, it'll come eventually.

[FLTRI]

.....They are almost there with the "Digital Technician" laptop.

Well that was the idea....to eliminate the need for a mechanic...just hire a computer geek and the Dig-Tech will figger it all out.
Fortunately for real mechanics, the Dig-Tech can only read what the ECM has determined a problem which is fine for simple diagnosis, but is virtually useless for intermittent and/or failure that isn't logged into the ECM.
Bob

[One4Tone]

...I personally think it's all to do with "black box" intelligence...throttle position..may give indication of speed travel...this info would be invaluable to an insurance company in case of  an accident.....or  a particular rider's habits..(whether they acknowledge it or not)...it may in some cases,   also disable a vehicle,..like say..one may be required to pay a fine,..or pass an emmision test...no compliance?..you walk...sounds unreal?..well it's allready here, in some applications...maybe not in the motorcycle world...but it certainly in the automotive world and aeronautics...WHO'S NEXT...?...in the mean time..other reasons may be given...I think we've heard some allready...they are legitimate reasons ...but if the throttle  or a computer can be disabled...the only ride left is downhill..literally...so save your carburators and your intake manifolds.....they may come in handy some day..

[Ultrashovel]

.....They are almost there with the "Digital Technician" laptop.

Well that was the idea....to eliminate the need for a mechanic...just hire a computer geek and the Dig-Tech will figger it all out.
Fortunately for real mechanics, the Dig-Tech can only read what the ECM has determined a problem which is fine for simple diagnosis, but is virtually useless for intermittent and/or failure that isn't logged into the ECM.
Bob

Well, of course. There are some problems that won't log into the ECM. In cases where there is a code, however, the D.T. does a pretty good job on some rather esoteric problems.

Nonetheless, that day is coming, when there will be a code for literally every last thing that happens to a motorcycle. It won't take much training, either, since the person doing the diagnosis will just be a 'button pusher". We're already there on some modern cars.

[FLTRI]

...I personally think it's all to do with "black box" intelligence...throttle position..may give indication of speed travel...this info would be invaluable to an insurance company in case of  an accident.....or  a particular rider's habits..(whether they acknowledge it or not)...it may in some cases,   also disable a vehicle,..like say..one may be required to pay a fine,..or pass an emmision test...no compliance?..you walk...sounds unreal?..well it's allready here, in some applications...maybe not in the motorcycle world...but it certainly in the automotive world and aeronautics...WHO'S NEXT...?...in the mean time..other reasons may be given...I think we've heard some allready...they are legitimate reasons ...but if the throttle  or a computer can be disabled...the only ride left is downhill..literally...so save your carburators and your intake manifolds.....they may come in handy some day..

It's a conspiracy!!!! 

[One4Tone]

...well i suppose "1984"  by George Orwell was a conspiracy theory..

[codyshop]

.....They are almost there with the "Digital Technician" laptop.

Well that was the idea....to eliminate the need for a mechanic...just hire a computer geek and the Dig-Tech will figger it all out.
Fortunately for real mechanics, the Dig-Tech can only read what the ECM has determined a problem which is fine for simple diagnosis, but is virtually useless for intermittent and/or failure that isn't logged into the ECM.
Bob

What good is "Digital Technician" if only dealers have one?  The fact that you and I can't buy one is criminal.   Manufacturing a vehicle that only authorized dealerships can ever fix screws the consumer to no end.  Ray

[wayzalot]

Thanks for the info.  I am stuck in the drum brake, points, and carborator era.  Not quite but you know what I mean.  My OL says I hate change.  Lucky for her she's right. 

[MaxxV4]

Hey, one4Tone:
I finally got around to reading "1984" this past Spring. I know it only Sci-Fi, but getting a little too close to the truth. It was written back in 1949 IIRC.
Mike

[CraigArizona85248]

Thanks for the info.  I am stuck in the drum brake, points, and carborator era.  Not quite but you know what I mean.  My OL says I hate change.  Lucky for her she's right. 

LOL... I'm definitely keeping my old technology.  Everytime I read about things like TBW and all the crap that just makes a bike more expensive to maintain I'm that much more commited to my 60 year old technology.  Sure, I'll compromise on some things.  I run an electronic ignition in my panhead, but that could be put back to points in about an hour if needed.

Regarding the original question... why a TBW?  I believe it allows them to more easily meet emissions requirements.  The ECM takes input from the throttle, but ultimately it determines what to do with that input.

-Craig

[frydaddy96]

What TBW problems?  Its not like there is an abundance of problems.  And how many of these supposed problems are similar to a cabled throttled?

[Micah68kjv]

I'm keepin' my old carbed bike and if God is good it'll be the only bike I need till I go to Heaven. Don't care a'tall for all the new technology and I can still wrench on my bike and do anything I want to it. Hooray for old school even if it is only a five year old bike. At least I don't need to take it to the stealer any time it develops a simple problem. CV carb is so simple a 10 year old kid can fix it.

[rigidthumper]

I believe the real reason for most of the changes is this: The engineers feel compelled to come up with something new, to justify their existence. They made it through school, got hired, and now have to produce or face unemployment. Thus, we get gizmos we don't really need.
Robin

[HV]

Massive TBW problems are much like the TC Crank run out...and  Cam Tensioner issues ... yes a few...but very little when you look at the number of TCs out there...

Aside from a few ECM connectors backing off the safety catch and making the TB not respond ....and a few user induced ( changing bars and messing up wires ) I see very few

Just this week Ive changed 7 primary chain tensioner's and a few clutch bearings ... look for these to be the next massive issues  

As for the DT... its used more for flashing updated ECM OEM Flashes....and performing Marriage ceremony's between the TSSM and ECMs and doing Birth Certificates at PDI ...it also sends the MOCO info on everything the Dealers do to any bike ...RE Flashes..

[carolinayarddog]

I average a broken cable about every year or so; good riddance

[Deye76]

I'm not against new technology, but what I don't like about the TBW is the "slop" in the grip. My cable actuated with 50,000 miles is still tight.

[Bruno-Katz Fokkerpilot]

Hey, one4Tone:
I finally got around to reading "1984" this past Spring. I know it only Sci-Fi, but getting a little too close to the truth. It was written back in 1949 IIRC.
Mike

We already have "1984" bigtime here in the UK. We now have chips in our garbage bins which tell the local authority if you`ve put the wrong stuff in the wrong bin, overloaded it, put it out for emptying too early and left it out on the street too long. The fine is up to £500. Don`t let it happen in the US.........

[IBARider]

What TBW problems?  Its not like there is an abundance of problems.  And how many of these supposed problems are similar to a cabled throttled?

Huh?  OK here's my personal stats.  40,000 miles on a TBW and it's gone to idle on me 5 times.  Once while accelerating into fast lane with a car coming up on me.  this was a one time glitch.  4 of em were in same day and I got that one fixed.  Whenever it goes to idle and you have no throttle, you shut down and reset... not fun when you're trying to get outta the way of traffic... This thing is a POS, but been saying that bout HD for 40 years...

100's of thousands of miles with cables.  Problems? ZERO

[Ridetard]

Manufacturer dependence!

[CraigArizona85248]

I have no idea what the MTBF (mean time between failure) is for the TBW.  My objection is that they have taken something that worked really well (cable controlled throttle) and replaced it with something that might work equally as well but the new item costs about 40 times more to fix if it takes a dump.  Anybody know what that throttle mechanism costs?  I've been told it's about $700 vs. what for a cable, $20?  And that doesn't even include the labor to install the part.  So you are paying a lot more but from the users perspective I don't see that you are getting any benefit from TBW.

-Craig

[harleyjt]

There's a number of reasons for TBW.  
- reduces cost
- reduces build complexity
- reduces cost of ownership - less maintenance required.  No oil and adjustment on 2 cables.
- gives engineering more control of vehicle - they can now limit the rate of acceleration, etc.
- reduces clutter for better asthetics - same as when they got rid of the speedo cable some years ago
- state of the art technology.
- integrated cruise control - no more cruise module - again less cost and build complexity and much more
 dependable.  There should now be very few warranty claims on defective cruise control outside of bad
 switches.
- probably in an overall sense, somewhat more dependable than cables. I'm sure Engineering would be
 able to prove that statistically, whether its true or not.  
- could help reduce emissions by giving engineering control of throttle.   Software could limit speed,
 throttle opening, etc for emissions purposes.
jt

[Dennis The Menace]

You hear about DBW issues because the majority of users dont post about it working.  Only a very small number of owners actually experience DBW problems, not a majority, as you may beleive.  At least, that is what my dealer told me.

As for me, I am not worried to upgrade my 07 cable bike to DBW.  Its proven technology, just look at the 1,000's of commercial aircraft using it every day transporting millions of people around the globe.  That isnt to say MoCo hasnt done a perfect job of implementing it, but same can be said for pretty much every part on a HD bike--it aint perfect for sure.

menace

[76shuvlinoff]

 My 76 has a single cable, when I bought the 09 and saw two cables I thought that was overkill but from what I read here.... life is good!

[CraigArizona85248]

There's a number of reasons for TBW.  
- reduces cost
- reduces build complexity
- reduces cost of ownership - less maintenance required.  No oil and adjustment on 2 cables.
- gives engineering more control of vehicle - they can now limit the rate of acceleration, etc.
- reduces clutter for better asthetics - same as when they got rid of the speedo cable some years ago
- state of the art technology.
- integrated cruise control - no more cruise module - again less cost and build complexity and much more
 dependable.  There should now be very few warranty claims on defective cruise control outside of bad
 switches.
- probably in an overall sense, somewhat more dependable than cables. I'm sure Engineering would be
 able to prove that statistically, whether its true or not.  
- could help reduce emissions by giving engineering control of throttle.   Software could limit speed,
 throttle opening, etc for emissions purposes.
jt

I don't buy that it reduces cost, build complexity or cost of ownership.  One replacement of a TBW will cost enough to supply you with throttle cables to outlast several bikes.

-Craig

[96flhpi]

My 76 has a single cable, when I bought the 09 and saw two cables I thought that was overkill but from what I read here.... life is good!

BTW, Yarddog - ya might wanna try lubing up the cables once in a while

[harleyjt]

You hear about DBW issues because the majority of users dont post about it working.  Only a very small number of owners actually experience DBW problems, not a majority, as you may beleive.  At least, that is what my dealer told me.

As for me, I am not worried to upgrade my 07 cable bike to DBW.  Its proven technology, just look at the 1,000's of commercial aircraft using it every day transporting millions of people around the globe.  That isnt to say MoCo hasnt done a perfect job of implementing it, but same can be said for pretty much every part on a HD bike--it aint perfect for sure.

menace

Exactly.  It's also been used in the railroad industry for many years as well. 

When I was working for Chrysler and we first introduced this technology on the new Hemi, I braced myself for a barrage of complaints and allegations about runaway cars and complaints that the throttle was the reason I had a wreck, etc etc.  It never happened.  In fact, the very few issues we had, generally dealt with the vehicle not wanting to accelerate.  Much the same as what some have posted here.  It really hasn't been a problem and for the most part is very reliable. 

I'm not scared of it at all. My only beef is that now they - engineering - can program in how they want the vehicle to respond - engineering now has the power to "make you" take you foot off the throttle.   They can limit how hard you hammer the throttle as well. This can be beneficial as it will help the automatic transmission's life expectancy.  It can help with engine life as well - just try matting the throttle in neutral now and see what happens.  She's only going to go so high, and thats it.   
jt

[hotroadking]

TBW is just one more natural progression in the advancement of the EFI systems at HD

remember MM? couldn't idle worth a crap, hot, cold, leaks, tps what a PIA, and everyone bitched
then delphi, better, better control, less idle problems single bore intake better design runs well

Now TBW - less parts ie cables and cruise control module and cable - gone.  

JMO TBW is part progressive tech, part EPA/Emissions control.

HD in order to give us our beloved air cooled engines must take as much control over the efi delivery and burn rates as well as exhaust in order to maintain the air cooled engine in production....

So far I havent' had any issues with the 09's TBW but I admit I let the 08 get on the road for the bugs to get worked out first, never , ever buy the first year of production, you're a beta owner....

Corvette has had TBW for years and you don't see them running out of control, Yamaha's liter bikes all have tbw the 600 might as well and those are 160 HP 180 MPH race bikes...

Also  if the mo co engineers can slow the rate of acceleration,  the aftermarket will figure out how to improve it....

[wavlovr1]

if you have ever tried to adjust the throttle plate opening to coincide with the twist at the throttle on a TBW bike the answer is obvious. At lower throttle positions TBW controls the amount of actual throttle plate opening. Now just consider that (1) the bike is set to run lean as hell to meet emmisions specs, (2) the TBW is used so far on only the heaviest harley models.

When the TBW is set to open the blade at the same rate as the throttle twist, you get major pinging. The timing is too advanced for the mixture of fuel provided on that heavy bike. Either you richen up the mixture or retard the timing to solve the problem. I believe that TBW is the only way HD could get decent performance with adaquate timing on the heavy bikes while still maintaining an EPA compliant exhaust. JMO, jimbob

[Ultrashovel]

if you have ever tried to adjust the throttle plate opening to coincide with the twist at the throttle on a TBW bike the answer is obvious. At lower throttle positions TBW controls the amount of actual throttle plate opening. Now just consider that (1) the bike is set to run lean as hell to meet emmisions specs, (2) the TBW is used so far on only the heaviest harley models.

When the TBW is set to open the blade at the same rate as the throttle twist, you get major pinging. The timing is too advanced for the mixture of fuel provided on that heavy bike. Either you richen up the mixture or retard the timing to solve the problem. I believe that TBW is the only way HD could get decent performance with adaquate timing on the heavy bikes while still maintaining an EPA compliant exhaust. JMO, jimbob

That's a very good explanation. It makes sense that under certain conditions a linear applicaton of throttle does not provide optimum performance.

[hotroadking]

That's a very good explanation. It makes sense that under certain conditions a linear applicaton of throttle does not provide optimum performance.

Does that mean that the CV carbs slide was a good idea to control air flow velocity  LOL

[Ultrashovel]

That's a very good explanation. It makes sense that under certain conditions a linear applicaton of throttle does not provide optimum performance.

Does that mean that the CV carbs slide was a good idea to control air flow velocity  LOL

Absolutely. That's one good reason why a bike with a CV will start much easier than a bike with a regular sidedraft carb. The air is nicely controlled until needed. That's also why drilling a larger hole in the slide and cutting the spring down so the slide will open faster is counter-productive. People do like to tinker with them but they are really just fine if left alone other than calibrating them to a particular bike with a different needle and jets if necessary.

My personal opinion is that the standard 42 mm CV Keihin is the best bike carburetor ever built. I ran one on my former Shovelhead for more than 10 years with never so much as a burp. They were widely used on the Japanese big four prior generation bikes to good adavantage.

One good example was the GL1500 Honda Goldwing (1988-2000 6 cylinder). They had two Keihin CV's side-by-side and that gave them a truly seamless performance - almost as good as fuel injection. Harley also made good use of them as we all know.

If I ever get another older HD, I will run another CV carb. They are great!

[truck]

I had a Harley with TBW back in the 60's (you know the kind). The wire broke, but I was able to ride home by working the carburetor linkage with my right hand by reaching down under the tank.
TBW is nothing new, it's come full circle, just like the secondary drive belt.

[wayzalot]

I just like dependabe equipment.  my throttle cable lasted ove 50,000 miles and when it broke (by the throttle) I took off the adjuster and grabed a handful of cable and made it home.  Simple is more dependable.  Now if you will excuse me I need to adjust the aluminum foil on my rabbit ears on my black and white zenith. 

[FLTRI]

That's a very good explanation. It makes sense that under certain conditions a linear applicaton of throttle does not provide optimum performance.

Does that mean that the CV carbs slide was a good idea to control air flow velocity  LOL

Absolutely. That's one good reason why a bike with a CV will start much easier than a bike with a regular sidedraft carb. The air is nicely controlled until needed. That's also why drilling a larger hole in the slide and cutting the spring down so the slide will open faster is counter-productive. People do like to tinker with them but they are really just fine if left alone other than calibrating them to a particular bike with a different needle and jets if necessary.

My personal opinion is that the standard 42 mm CV Keihin is the best bike carburetor ever built. I ran one on my former Shovelhead for more than 10 years with never so much as a burp. They were widely used on the Japanese big four prior generation bikes to good adavantage.

One good example was the GL1500 Honda Goldwing (1988-2000 6 cylinder). They had two Keihin CV's side-by-side and that gave them a truly seamless performance - almost as good as fuel injection. Harley also made good use of them as we all know.

If I ever get another older HD, I will run another CV carb. They are great!

I had a Harley with TBW back in the 60's (you know the kind). The wire broke, but I was able to ride home by working the carburetor linkage with my right hand by reaching down under the tank.
TBW is nothing new, it's come full circle, just like the secondary drive belt.

[04glide]

I just went back to a carb. When my 04 FI bike was totaled and I bought the 03 I was real happy to have a carb again. I just added pipes and tuned the carb myself. Cost me $17 and it is running great. 

[carolinayarddog]

"BTW, Yarddog - ya might wanna try lubing up the cables once in a while" 

Thanx 96, but I'm way ahead of you.  I even soaked one in a coffecan of oil overnight before I installed it.  I wash the bike regularly and I suppose all that extra moisture shortens the life

 

[wayzalot]

I just went back to a carb. When my 04 FI bike was totaled and I bought the 03 I was real happy to have a carb again. I just added pipes and tuned the carb myself. Cost me $17 and it is running great. 

Exactly how I feel.  I guess there are two kinds of motorcycle riders.  Those that like the new technowlagy (which is great when it works) and those that like the reliable, be able to pull over and adjust and go type.  Now I might get hammered for saying that but I think there are two kinds.  My buddy rides his 47 knuckle like he stole it.  Once in a while we have to stop and fix or adjust something but lots of fun.  

[CraigArizona85248]

I already did that.  It only took a second because my lawn is so small.  Damn hooligans!  And if I catch that kid up the street I'm gonna hold him down and cut his hair.  Damn hippies!

-Craig

[redrokit8]

I have an '09 w/TBW and never had a bike run better.
There is no 100% touble free product that is mass produced.
It's human nature to reject change. We're creatures of habit.
If you don't embrace new technologies, that's ok. Stay with what you've got.
If given the chance, you should experience the new tecnologies as a bases for your beliefs / objections. Then you'll know for sure if it's for you or not.