Throttle Progressivity - Why???
(Background stuff) Okay, so a few years back when I was (over half serious) pondering getting a new/newer bike I stopped at a the dealer over on Crystal River. After a brief chat with one of their staff, I decided to take a test ride on a 2012 Police model FL. The point of this was that I'd been happily riding a 1987 FLHTP for the past 20 years ... So I thought - WTF - lets try an apples-2-apples comparison of what I might be missing...
The first thing I noticed was while trying to launch the damn thing was that it appeared to have absolutely no low-end torque/power/anything what-so-ever. It kept trying to stall every time I let the clutch out...and no amount of throttle twisting seemed to get it to stop acting like a Kawasaki with varnish in the tank..
Now this was much apposed to the bike I'd just rode in. My 87 was "double tall" in that I'd gone up two teeth on the front pulley as well as going with a Rev-Tech close ratio tranny...yet it would happily launch off idle two up without any sigh of strain or hesitation.
After almost stalling the damn thing about 9 time, I finally got it to - half heartedly - crawl off its own ass and get me out of the parking lot. And once I got it above 2,000RPMs it started to act like it just might not be a totally gutless POS ... But the behavior seriously bugged the shit out of me.
A week later, we were at Destination Daytona when I first laid eyes on Trixie. Now while she too exhibited some of the bizarre limp throttle shenanigans...it wasn't nearly as bad as the police model 12 ... So I allowed for the learning curve, bid my old dragon farewell, signed the papers, and rode her home.
So now that she was in the garage on my turf, I got the SEPST connected and commenced to diving in and having my wicked way with her... (yes I am having just a little bit too much fun with this - Sue me...).
(More on point - end of background stuff) The first of the screen shots -(hopefully)- attached below is the Stock Throttle Progressivity map that goes a long way towards explaining why the new school FBW throttle is such a Japanese style PITA. Because until the engine somehow manages to wander up to 2,000RPMs the riders throttle input is virtually irrelevant.
Engine speed 1,000 RPMs
Rider throttle input WFO
Throttle plate position: 23% ??????????????
You gotta be shitting me right? ...Nope.
While I'm tempted to wonder why many folks say these TC engines are "happier" above 2,500-3,000RPM ... Looking at the TP map - to me - makes for more than just a bit of a 'Well Duh!' moment ... because that right where the stock map finally turns the poor damn thing loose to run properly wild..
The second screen shot is what I did to eliminate this nonsense...and I gotta say the (basically) stock 96" TC is perfectly happy - even two up - from 1,500RPMs on.
Sure it'll lunge forward from 3,000RPMs much harder for "spirited" riding...but I have no problems passing in 6th from 2,000RPM with the flattened TP map that actually gives me what I ask for...when I ask for it.
So what I'd really love to know, is WTF is this horribly performance hobbling Throttle Progressivity nonsense actually intended to do??? I've sarcastically referred to its behavior as 'Traction Control' in the past ... Primarily as I'd found it virtually impossible to get the thing to spin the tire - without getting completely ridiculous - even in the rain. But the flattened TP map fixed that "problem" rather quickly.
Is TP just a sad attempt at making these beasts Squid Safe ... Or is there a quasi more practical reason for its (annoying) existence??
Scarlet Red 2010 Road Glide Custom named Trixie - She's a flashy little minx..
Basic black 1981 Tour Glide Classic named Alice - She's a sleeper project.