Do you ever coast in N at higher speeds? Trans clunk hard when shifting back into 2nd?

[nitroheadz28]

Sometimes I goof off and want to relax my hands/ back/ shoulders when I'm approaching a red light an eighth of a mile away and there is no one behind me, riding up to it with no hands on the bars. Or I just want to coast without engine braking/ holding the throttle open.

Sometimes I want to adjust part of my gear while I'm on the go and need both my hands.

On both occasions I shift into N while coasting at 40-25mph, sometimes a light turns green before I can slow down completely, and as I shift back into 2nd no matter if I do it firmly or softly it clunks HARD. If I preload the shifter and ease it in, the lever bounces for a second before catching- as if the gears are trying to mesh together. If I do it firmly, it goes clunks quickly into gear.

I'm assuming that the reason for this is because the engine/ trans speeds aren't matched up after engine RPM drops? I haven't tried rev matching in this case yet- but I can assume this is the main reason? I've been too apprehensive to try it for fear of grenading anything.

If I can't get it to shift properly with rev matching next time I'll stop doing this for fear of damaging anything, but I just wanted to confirm in case anyone has similar habits.

I have a habit of coasting a lot in neutral with my 5/6 speed cars and of course there is no issue/ danger with this. This is my first sequential gearbox vehicle.

 

[Gary in NJ]

I believe that this is a bad practice. From my understanding this is hard on the syncros.

 

[FinalImpact]

Throwing the safety aspect aside and going with the gear box - I would advise against it.

If you must -> Rev match it and shouldn't throw parts from the case!

Roughly speaking Rev Match to:
40 mph ~ 86XX RPM in 1st gear
40 mph ~ 59XX RPM in 2nd gear

Info here: RPM, Gear, Sprockets, Tire = Actual Speed!

 

[ChanceCoats123]

I believe that this is a bad practice. From my understanding this is hard on the syncros.

I don't believe constant mesh trans have syncros. I think dogs was the word you were looking for. :thumbup:

 

[Marcin]

I think You would get better if You drop into first. I've read somewhere that it's easier to drop down from N that up.

 

[FinalImpact]

I believe that this is a bad practice. From my understanding this is hard on the syncros.

FWIW: the ratchety, clunk clunk clunk followed by the BANG is the clutch dogs going in to the gears against their will. Although this is a full constant-mesh box, it has no syncro's to aid the alignment of this process of the gear in motion.

Think of it as a binary process. 1 or 0. In or out. A couple pics...

Clutch dogs go into gear directly!

These (Clutch dogs) go into the recess in the mating gear when selected!

Recess in mating gear for Clutch Dog engagement.

From: Broken my gears :-(

 

[nitroheadz28]

Roger that, thank you gents!

FWIW, dropping down to first going over 25mph is perfectly smooth with a proper rev match (Though its very rarely necessary).

I've only done this a handful of times so far, the first 2 times were when I was still noobing around and accidentally downshifting a gear too much until I hit neutral.

Will refrain from doing this in the future :thumbup:, my trans shifts as smoothly as an FZ6 can and I want to keep it that way.

 

[Gary in NJ]

I don't believe constant mesh trans have syncros. I think dogs was the word you were looking for. :thumbup:

Right. That's why the transmission shifts easily without a clutch, where as to do the same in a car I have to rev-match.

 

[Red Wazp]

I love coasting, no handed even better down a twisty mountain road (not too steep mind you) but all my bikes will do the clunk into second so I usually slow way down below 20 mph before putting the bike back into gear. Helps avoid the clunk which can't be good for the dogs.

On a side note I have a friend break the chain on his DRZ400 some years ago in Death Valley. I towed him with my KLR650 up Wild Rose Rd. to Emigrant Pass where he coasted non stop 19.5 miles to Stovepipe Wells.

I went back a year later and clocked the mileage with my FJR to be sure. He even passed a slow car as terminal velocity for him was 47 mph.

 

[FIZZER6]

Sounds like you need a throttle lock! If you need to fidget with your gear though , just wait until you stop moving, shift into neutral, foot on the rear brake and do what you need to do, then away you go.

 

[nitroheadz28]

Sounds like you need a throttle lock! If you need to fidget with your gear though , just wait until you stop moving, shift into neutral, foot on the rear brake and do what you need to do, then away you go.

Awww thats no fun!

I will look into those for long distance riding, not a bad idea for the interstate. Sometimes the mind wanders looking ahead, you look down at the speedo and you're speed has crept up 15mph more than you had it

 

[2old2ride]

Why not leave it in 2nd and coast that way. If it starts to stall pull the clutch. I try not to stop for red lights. I'll leave her in 2nd and 'walk' her to the light. normally I can catch the light going green without stopping. This, done as often as possible really increases gas mileage. Just be sure to watch your six. You don't want to audition as a hood ornament for some old woman in her Buick that thinks the world will end if she doesn't catch the light red.

 

[nitroheadz28]

Why not leave it in 2nd and coast that way.

Because its wasted momentum, I'm all about efficiency

 

[FIZZER6]

Because its wasted momentum, I'm all about efficiency

Actually, coasting in a higher gear so there is only slight engine braking as you decelerate can actually save fuel because fuel injected engines cut fuel while engine braking with closed throttle. :thumbup:

I coast in 4th or 5th from speed down to about 2,500 rpms before I pull in the clutch and shift down.

 

[FinalImpact]

Right. That's why the transmission shifts easily without a clutch, where as to do the same in a car I have to rev-match.

It may seem this way but that's not quite why. Notice the PEG section of the Clutch dog and its actual area being very small (pic's ^^), almost like dowel?? Notice the Mating Gear sections recess and how LARGE the opening is? That provides degrees of rotation which equals opportunity to engage. It doesn't have to be perfectly aligned to enter and engage the opening, thus its pretty easy to hit the window.
- Well unless the gears ARE STOPPED and not Moving, i.e. at a light and cant get it into gear.
- Also this is where are trans picks up all the rotational slack. Well that and the drive chain out back.
-->> Quick Video. Constant mesh, beveled gears (not straight cut), has brass synros and 5 speed. [ame="http://www.youtube.com/watch?v=IKywZ730JFs"]Gearbox operation with clutch - YouTube[/ame]


A typical cage trans is in or out. You have to have the clutch dogs lined up perfectly to engage a gear. Thats where the brass synchronizers come into to play. Once gear selection begins, pressure is applied to the brass. The brass helps adjust the speed of the gear to match the speed of the counter shaft by dragging it to the counter shafts speed.

However - when a cage is setup to race, guess what they do - No Syncros! They look like box from our bike. Look here A T5 setup for racing; Page 2 - Modified T5 Transmission - Gear Set And Dyno Test - 5.0 Mustang & Super Fords Magazine

I love coasting, no handed even better down a twisty mountain road (not too steep mind you) but all my bikes will do the clunk into second so I usually slow way down below 20 mph before putting the bike back into gear. Helps avoid the clunk which can't be good for the dogs.

Me too, but as said below, in higher gears so the fun lasts longer without slowing down! There are some places with some pretty good corners and that makes it more better! :thumbup:

PS - Longest coast without ignition/engine assist was in 65 Chev Corvair - 22.5 Miles off a mountain. Was nearly crawling a few times but made it into town which no one had done. It was playful teen competition! Twisted mountain road and some corner speeds were over 70mph!

Actually, coasting in a higher gear so there is only slight engine braking as you decelerate can actually save fuel because fuel injected engines cut fuel while engine braking with closed throttle. :thumbup:

^^ :thumbup:

 

[FinalImpact]

From another post: Why can't I get my bike in gear while stopped?

From: Is this normal - Won't go into gear while stopped?

This is normal and here is the technical explanation. In short the gears don't go in at a stop as they physically can't fit the peg in the hole until the gears rotate a small amount.

See the gears here (bottom of pic, last two gears); the clutch dogs must fit into the recess in the opposing gear to lock it in. When you're stopped and the clutch is disengaged, sometimes the cogs rest right on the ridge separating the recess thus it will not drop into gear until you:
A) roll the bike moving the output shaft.
B) release the clutch moving the input shaft.

Make sense?

JJD952 transmission

 

[Gary in NJ]

Thanks FI for very informative posts. One of these days I'll have to take a crack at disassembling and reassembling as transmission. It's the only way I'm every going to truly understand the relationship between all of the components in a transmission.

 

[FinalImpact]

Thanks FI for very informative posts. One of these days I'll have to take a crack at disassembling and reassembling as transmission. It's the only way I'm every going to truly understand the relationship between all of the components in a transmission.

Worked in a transmission shop for 6 years, so I picked up a few things along the way but that was some time ago. Also, tore stuff apart all my life. :thumbup:

 

[greg]

it's also safer to keep it in gear, so you can accelerate out of trouble should you need to.

As said above, if it's engine braking then it will use less fuel than being in neutral and idling.

Personally I change down as I slow, so that I am in the right gear all the time. I only change to neutral if I know I will be stopped for > 5 seconds.

 

[ChanceCoats123]

it's also safer to keep it in gear, so you can accelerate out of trouble should you need to.

As said above, if it's engine braking then it will use less fuel than being in neutral and idling.

Personally I change down as I slow, so that I am in the right gear all the time. I only change to neutral if I know I will be stopped for > 5 seconds.

I agree that's a good general rule. Most of the time, I'll just hold the clutch in and stay in gear. I'd rather be ready to go if need be than let my hand rest for a few seconds.