Triumphrat

klem · 12-05-2012, 12:52 AM

I have a Triumph T100 Bonneville with an 18 tooth front sprocket Im thinking about replacing it with a 19 tooth sprocket is there any reduction in engine revs at cruise speed with the 19 tooth and if so how much would it be if any?
Cheers Klem.

ozbon · 12-05-2012, 01:58 AM

I think the general consensus is, 19T In top gear a reduction of about 500rpm.

John

klem · 12-05-2012, 02:30 AM

That is a nice reduction i have always felt that they rev a bit to high at cruise speed the reduction in engine load on the open road would be good.
Are there any downsides to the 19 tooth sprocket?

ozbon · 12-05-2012, 02:43 AM

It'll reduce your chance of winning a drag off the line, but you'll get a little extra top end speed.

denbow · 12-05-2012, 05:33 AM

With a 19 T you'll be 3380 rpm @ 60mph, 3940 @ 70 and 4500 @ 80mph in 5th gear according to the chart.

I ran 17, 18 and opted for the 19 for its relaxed cruising speed and slightly better fuel consumption. It also stopped me feeling for another gear at 50 mph.
No noticeable lack of acceleration detected...just hang onto each gear a bit longer.

shrini23 · 12-05-2012, 08:58 AM

OT:
18T has 106links on 525 chain so if I go to 19T how many link do you guys that I need to buy.,
Also what is a good 19T out in the market..
I tried ebay and cannot find a 19T for a triumph scrambler

larrykahn · 12-05-2012, 10:17 AM

4000 rpm fifth gear 68 vs 72 mph. By my guess on the speedo reading anyway. Worth the change.

denbow · 12-05-2012, 11:13 AM

You don't need to add any links, there's plenty of slack in the adjustment to accommodate a 19. I jumped from 17 to 19 without issue.
Renthal are one of the most common sprockets. Try Ebay UK , I'm sure you'll find one on there for under £20 + shipping.

biker222 · 12-05-2012, 11:46 AM

Here is a great gearing calculator.

Located Here: http://gearingcommander.com/

WindTherapy · 12-05-2012, 11:50 AM

British customs, bella corse, and New Thruxton all sell sprokets.