RPM's Drop FAST on a Shift - Triumph Forum: Triumph Rat Motorcycle Forums
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post #1 of 27 (permalink) Old 06-17-2019, 01:17 PM Thread Starter
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RPM's Drop FAST on a Shift

Hi everyone.

So on the weekend I took my first long'ish ride on the new Speed Twin and I noticed that the RPM's drop very quick on a shift such that I'm jerky when back on the throttle.

I'm shifting quicker to make it smoother but has anyone else noticed that?

Maybe, it'll get better as time goes by (as finding neutral did).

Thanks
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post #2 of 27 (permalink) Old 06-17-2019, 02:55 PM
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Try clutchless shifting when at decent revs going up the box

Sent from my Moto G (4) using Tapatalk
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post #3 of 27 (permalink) Old 06-17-2019, 03:20 PM
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Yeah, think you prob just need to give it a tad more and a tad quicker. Few more spins and itíll all click into place.
Iíve been used to triples for a long time so it requires a little adjustment.
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post #4 of 27 (permalink) Old 06-17-2019, 05:11 PM
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that's what is supposed to happen when you close the throttle
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post #5 of 27 (permalink) Old 06-17-2019, 06:55 PM
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Decat. That'll greatly reduce engine braking, at least it did on my T120.

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post #6 of 27 (permalink) Old 06-17-2019, 08:33 PM Thread Starter
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Quote:
Originally Posted by Roasted View Post
that's what is supposed to happen when you close the throttle
I think you missed the "FAST" on my heading.

Ideally, the rpm's would drop at a rate such that a normally timed upshift would have the RPM's at the exact spot to enable a smooth engagement.

Many performance cars now have rev-matching (on the downshift anyway) to do just that (for those that don't or can't heel & toe).

On a previous car I had, owners inserted a restrictor (a drilled copper end plug) into one of the vacuum lines to slow the quick drops- it worked.
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post #7 of 27 (permalink) Old 06-17-2019, 11:13 PM
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It's all in the throttle and clutch control. You don't need to rev match for up shifts if you have the control between the two. It's not like your driving a garbage truck and need to double clutch in between shifts. I'd say you need more practice. I had a SV650S that had a great deal of engine brake as if you were throwing out the anchor to stop. I was jerky in the very beginning of ownership and then became smooth. Your California with its heavy flywheel probably has less engine brake than your Speed.
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post #8 of 27 (permalink) Old 06-18-2019, 12:09 AM
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Quote:
Originally Posted by SpeedTwin_Lou View Post
Hi everyone.

So on the weekend I took my first long'ish ride on the new Speed Twin and I noticed that the RPM's drop very quick on a shift such that I'm jerky when back on the throttle.

I'm shifting quicker to make it smoother but has anyone else noticed that?

Maybe, it'll get better as time goes by (as finding neutral did).

Thanks
How much does the RPM drop between shifts? I went back and looked at the Gopro of four different bikes I used in one form of racing or another. Two were Kawasaki four cylinders and two were Triumph twins with one air cooled and the other watercooled.

Even shifting quickly normally at high rpm it looked to me the bikes lost about 500 to 1000 rpm between shifts. You might do better with a quick shifter but otherwise 500 to 1000 rpm would be normal.

One technique you might try if you have not already is what I do when drag racing or riding passengers on the street. Preload the shifter by pulling up slightly with your toe on the shifter prior to pulling the clutch in to make the shift and slightly rolling of the throttle almost simultaneously.

Then quickly release the clutch and simultaneously roll on the throttle. I think I have an example I will link to this post. Hopefully it is clear enough to see.

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Last edited by retjustdad53; 06-18-2019 at 12:19 AM.
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post #9 of 27 (permalink) Old 06-18-2019, 12:44 AM
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Sounds to me like you need a quickshifter, that's the only way that you will not drop revs between gears, hold it wide open and change.
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post #10 of 27 (permalink) Old 06-18-2019, 08:59 AM Thread Starter
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It's not so much about the revs dropping guys, it's how they drop so QUICKLY.

I've tried not closing the throttle completely when shifting and that seems to help but I'll do the toe pre-load thing @retjustdad53 suggested and yeah maybe a quick shifter is what I want (never having had one)??

I've been driving stick for many, many years btw so this isn't my first go-round.

I may just record a video of it for analysis.

Thanks all for the tips!
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