Triumphrat

Billybob · 08-16-2005

Anyone have any thoughts on this?

jojje1963 · 08-16-2005

3500rpm. That will be good both for the engine and the fuel economi. Thats the rev where you have the most torque and that means the engine is happy!Higher is fine too but don't cruise at 2500.

CADIstari · 08-16-2005

For those of us with standard bonnies (no tach) what is the rpm at 65-70mph?? (stock 17 tooth sprocket and tyres)

TIA!

jojje1963 · 08-16-2005

65-70mph=
4100-4500rpm

[ This message was edited by: jojje1963 on 2005-08-16 19:37 ]

dazco · 08-16-2005

4k for me.

CADIstari · 08-16-2005

Thanks for the info....
(Daz-- does the SM have a 16t sprocket stock??)

Shorty · 08-17-2005

jojje...what are your thoughts on a decent RPM range using a 19-t sprocket on a standard Bonnie? Would 2500 RPM city cruising still be too low? Thanks for your input.

Shorty

jojje1963 · 08-17-2005

Quote:

On 2005-08-17 05:56, Shorty wrote:
jojje...what are your thoughts on a decent RPM range using a 19-t sprocket on a standard Bonnie? Would 2500 RPM city cruising still be too low? Thanks for your input.

Shorty

2500rpm is too low for the engine, as long as you are cruising it's not that bad but every time you try to accelerate from 2500rpm you put more strain on the parts than if you are at 3500. I would use a lower gear or buy a HD :-D

dazco · 08-17-2005

Quote:

Thanks for the info....
(Daz-- does the SM have a 16t sprocket stock??)

Yes, and 4k puts me just under an indicated 70 in 5th. But i can easily cruise higher. 80-80 indicated is actually very comfortable in all respects. I could have just as easily saif 3500 or 4500 or maybe even wider than that. This engine seems happy, never straining and ready to pull hard anywhere in the RPM range. The only thing to avoid as said already is lugging.

08-17-2005

This engine is a very short stroked motor for an 800cc twin. The stroke is 68mm, which converts to 2.68 inches. Cruising at 3500 RPM’s gives one a piston speed of 1562 feet per minute which is nothing for this motor. Many years ago what was considered a safe constant cruising RPM was 2500 feet per minute, which would be about 5500 RPM’s on a Bonneville engine. Today’s motorcycle engines seem to defy all the rules of years gone by, I am convinced that that engine could cruise all day at redline (7000 RPM) which is a very conservative redline. Again old school thought was an engine’s redline should not exceed 4000 feet per minute which on this engine would be just under 9000 RPM’s. Triumph has chosen to be very conservative with this engine, I am sure for them to be trouble free for years/miles to come………………Bob