Difference in SE6 downshift under braking?

[RideOn]

I've had my Spyder RTL for 14 months, and I just made a new (to me) discovery.

If I allow the RTL to slow down by using engine braking, it frequently fails to downshift as I would expect. For instance, I was out yesterday and slowed from 55 mph down to about 30 strictly by closing the throttle. When I cranked the throttle again, the transmission was still in 5th gear and simply bogged at under 2000 rpm. I had to manually downshift to get going again, then all was well.

Next time around, I had to slow using the brakes, and I noticed the transmission downshifted as you might expect, progressively dropping gears as my speed slowed. I tried this a number of times, and every time I hit the brake the trans downshifted quickly after. If I simply coasted, it did not.

So, I'm not saying this is unexpected behavior as far as I can tell, but is it possible that using the brake pedal sends a signal to the powertrain that it should downshift as speed drops? And that simply coasting under engine braking does not automatically trigger similar downshifts? Is it just my Spyder?

This behavior was very consistent throughout my ride, although I'd never particularly noticed it before. Maybe someone else has noticed this too? There are lots of threads about shifting the SE transmission, but I've not run across this particular observation before now.

Thanks,
Bob

 

[BLUEKNIGHT911]

I've had my Spyder RTL for 14 months, and I just made a new (to me) discovery.

If I allow the RTL to slow down by using engine braking, it frequently fails to downshift as I would expect. For instance, I was out yesterday and slowed from 55 mph down to about 30 strictly by closing the throttle. When I cranked the throttle again, the transmission was still in 5th gear and simply bogged at under 2000 rpm. I had to manually downshift to get going again, then all was well.

Next time around, I had to slow using the brakes, and I noticed the transmission downshifted as you might expect, progressively dropping gears as my speed slowed. I tried this a number of times, and every time I hit the brake the trans downshifted quickly after. If I simply coasted, it did not.

So, I'm not saying this is unexpected behavior as far as I can tell, but is it possible that using the brake pedal sends a signal to the powertrain that it should downshift as speed drops? And that simply coasting under engine braking does not automatically trigger similar downshifts? Is it just my Spyder?

This behavior was very consistent throughout my ride, although I'd never particularly noticed it before. Maybe someone else has noticed this too? There are lots of threads about shifting the SE transmission, but I've not run across this particular observation before now.

Thanks,
Bob

I believe the SE trans. downshifts based on engine RPM's alone. ................. good luck .... Mike :thumbup:

 

[JayBros]

It seems to me, and this is just a personal, unscientific observation, that there is a bit of a lag when one lets the engine rpm to reach about 1,900 rpm where the engine speed downshift is actually triggered and when the transmission itself downshifts. When one applies the brakes the downshift lag does not occur. I think is has to do with the time the ECM and HCM react that is a function the design of both computer controlled modules.

 

[PaladinLV]

Standard Operating Procedure.

The 1330 Rotex is a high Torque engine. When not applying the brake, the system will not downshift until it below the point where one can throttle and that gear and resume.
Accelerating in 6th from @35 mph is not a problem but of course don't expect any ZIP!

AJM

I've had my Spyder RTL for 14 months, and I just made a new (to me) discovery.

If I allow the RTL to slow down by using engine braking, it frequently fails to downshift as I would expect. For instance, I was out yesterday and slowed from 55 mph down to about 30 strictly by closing the throttle. When I cranked the throttle again, the transmission was still in 5th gear and simply bogged at under 2000 rpm. I had to manually downshift to get going again, then all was well.

Next time around, I had to slow using the brakes, and I noticed the transmission downshifted as you might expect, progressively dropping gears as my speed slowed. I tried this a number of times, and every time I hit the brake the trans downshifted quickly after. If I simply coasted, it did not.

So, I'm not saying this is unexpected behavior as far as I can tell, but is it possible that using the brake pedal sends a signal to the powertrain that it should downshift as speed drops? And that simply coasting under engine braking does not automatically trigger similar downshifts? Is it just my Spyder?

This behavior was very consistent throughout my ride, although I'd never particularly noticed it before. Maybe someone else has noticed this too? There are lots of threads about shifting the SE transmission, but I've not run across this particular observation before now.

Thanks,
Bob

 

[ottawa-rider]

I have noticed multiple times that the transmission will downshift earlier if you're applying the brakes.

 

[BLUEKNIGHT911]

I have noticed multiple times that the transmission will downshift earlier if you're applying the brakes.

That's because when the trans. is engaged in any gear, braking will Lower the RPM's. This will activate the solenoid and it will downshift accordingly ..... Mike :thumbup:

 

[redrazor]

I have noticed multiple times that the transmission will downshift earlier if you're applying the brakes.

:agree: My 2014 RTL is Definitely quicker auto down-shifting when using the brakes. I manually downshift much of the time, however. opcorn:

 

[Pooch]

My 2021 RTL downshifts itself whether I am “coasting” or with the brakes on.
Sometimes when coasting I am surprised to look down and see the gear indicator is as far down as it shows… didn’t think I was going THAT slow.

 

[EdMat]

Maybe someone else has noticed this too? There are lots of threads about shifting the SE transmission, but I've not run across this particular observation before now.

Thanks,
Bob

Bob, I don't think your imagination is running away with you. I too have found the same thing. Rolling off the throttle and coasting, like coming to a red light when you want to coast up just as it changes, causes a downshift to the next lower gear somewhere between 1,800 and 1,900 rpm's. Same stop but needing to use the brakes causes a downshift around 2,500.

Another thing I have noticed on turns I regularly take. If I brake to around 20 MPH and during the turn stay off throttle or slightly brake it will downshift from 2nd to 1st. If I just slightly apply throttle it will not downshift.

If I can find it I had jotted down some rpm and speed figures about a year ago. Quick as I do I will post it.

 

[RideOn]

So... it seems to me my observation is mostly supported by others. However, whether braking or just coasting to a stop, the engine rpm still drops in that time, so the idea that engine rpm governs the downshift doesn't add up for me.

Here's my take:
- If I'm coasting down under engine braking, I will manually downshift to match the trans. gear to road speed. For example, at 30 mph I should be in either 2nd or 3rd to accelerate.

- If I'm using the brake to slow down, then I'll let the ECU (or whatever computer it is) do the downshifting, as it tends to pick the right gear on its own.

I suppose part of it was my expectation that the computer would intervene in all downshift scenarios, when in practice it does not; at least not at an rpm that will allow reasonable acceleration rather than lugging.

Thanks for all the input from the responders! Any other input is always welcome.

Bob

 

[Bensonoid]

Mine definitely downshifts quicker when the brakes are applied. Sometimes I'll just tap the brake pedal when it's in that sweet spot and it immediately drops a gear.

 

[RazzleH]

Mine definitely downshifts quicker when the brakes are applied. Sometimes I'll just tap the brake pedal when it's in that sweet spot and it immediately drops a gear.

My 2020 F3L too.

 

[Wahrsuul]

That's pretty much what I've seen on my '14. One of the reasons I wish I'd opted for the manual instead.

 

[RideOn]

I think I get it.

Not downshifting without using the brakes is a design "feature", not a design "oversight" or "error".

Got to love the marketing folks. :joke:

 

[Trbayth]

It's been mentioned in other threads that the SE6 (and SE5) don't auto-downshift to make life easier for the operator; they auto-downshift to prevent damage from trying to run too low a speed at too high a gear. They still expect the operator to manually downshift as appropriate, just the same as if you were riding a SM5/SM5.

The proper way to do it is to manually downshift/upshift as road conditions require.