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14 teeth front sprocket advice 390 adventure

5155 Views 25 Replies 9 Participants Last post by  alexgreateffort
I changed the front sprocket from 15 to 14 teeth and here is my thought.

Personal information:
2021 390 adventure with aluminium top box and side cases;
220lbs man often riding 2up.
70% city riding and 30% motorway riding (50-75mph, usually 60mph cruising)

First of all, Gas Mileage is not affected, if you are bothered by 1mpg difference, go get a 125cc scooter.
Stock gearing is OK, dont change if you dont want.
Here is just my opinion.

Q: why changing from 15 to 14?
A: stock 1st gear is too tall and I feel the clutch is over stressed at stop and go traffic.

Q: is 14 teeth solve the problem?
A: kind of, 14 provides 7.1% lower gearing/torque. it is noticeable at start up but the RPM at highway is increased significantly. (the mpg is not affected much, not noticeable.)

Q: pros of 14-45 setup?
A: 1.better startups. 2. a lot fun when riding wide open throttle and in moutain area. 3. can changed to 6th gear at speed of 45mph (a usually speed of chinese expressway, 15 45 is terrible at 45 mph because 5th is too low and jerky and 6th gear is too tall and engine runs rough below 4000rpm)

Q: cons of 14-45 setup?
A: 1.too much gear changing,25 mph at 4th gear intead of 3th, 40mph at 6th gear.

Q: RPM difference?

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Q: if 14-45 is too much of upgrade, what about 15-46/ 15-47?
A: 15-46 is not noticeable of change.
Highway tourer, 90% highway riding:
1.one person with luggage, stock ratio.
2.2up with luggage,15/47
2.2up racer? 1290 R instead

Mixed rider, 50-50 city and highway
1.one person with luggage, stock ratio or 15/47.
2.2up with luggage, 15/47 or 14/45.

City rider, 90-10 city and highway
1.one person with luggage, stock ratio or 15/47 or 14/45.
2.2up with luggage, 14/45 or 14/46.

Q: 14-49 setup?
A: U R Nuts. I believe if the bike is geared too low, you will feel when you twist the throttle, the engine waste all the energy reving up instead of pulling the bike forward.
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I also only go up in the front to relieve the chain a little and went down in the rear to ride at the same speeds in lower revs.
I hardly ever ride in towns/cities and mostly longer distances in a row, 350 - 450 km/day so no need for me to lift the front wheel.

16T front for me, stock 45T sprocket on rear. I wanted better 6th gear performance, cruising capability on highway. ~120 km/h here on the local highways.
I do?

300km/day on a duke? man you have a titanium butt:cautious:
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