RPM vs MPH

One more question for today. In an effort to figure out if this bike is still stock or modified, could someone please give me the stock gearing ratios so I can calculate enging rpm as it equates to speed. Or better yet just tell me what engine rpm should be for say 40, 50, 60, 70, & 80 mph.

1985 XJ550

TIA

 

If it's gearing was modified, it was only done by changing the sprockets. You can simply count the teeth on both and look up in the Yamaha parts fiche and confirm that way. I can tell you that my 550 Seca is turning about 5K at 60MPH. Not sure if Secas geared like Maxims though.

 

On my Maxim the rpm (in 5th) track pretty close to the mph. maybe a tad less/ But I understand the Seca has six gears.

 

The following graph will tell you what you want to know. For example, at 6000 rpm, in sixth gear, you should see about 110 km/hrs (68 m/h).
From TwoWheels Magazine, May 82 review of the XJ550RH. Found in the XJ cd set.

 

That is a lot of gear and a lot of rpm's to only be running 68 mph.

 

1982 yamaha xs400j in 5th gear like kontiki said tach is a tad lower than the speedo but not by very much. @ 70 mph I seen the tach at about 7000rpms after that its all a blur to me. these things are surprisingly fast when you want them to be and you don't even have to red line the thing

35 mph = 3300 rpms

 

My apologies, yes the 550 Seca is a six-speed. So anything I can tell you is apples-to-oranges. Maxim owners will have to fill in the blanks.

 

lol

sometimes i wish i had 6 gears.

 

6th gear, 50mph, I'm right at 4k rpm

Haven't really paid attention to any one other than that, most of my commute is a 50mph zone, but I'll try to pay attention next time I'm riding

 

I can add to that, but like PaulT, it's a six-speed Seca 550: (all in 6th) 5Krpm=60mph; 6Krpm=72mph; 7Krpm=84? (speedo pegged) 8Krpm=??
9Krpm=?? probably around 108mph I'll let you know when I get a different speedo...

 

The 550 Maxim has a 6 speed transmission also.

 

I wonder if there's a way to put a 6 speed in these bikes? Or gear them differently without having sprockets to change....My buddy with a xj650 maxim has the same problem, too many rpm's for the speed. This may be one for an expert I guess, and that's not me.

 

AHHH...pardon my lack of XJ "crossover" knowledge. I THOUGHT all 550's were essentially mechanically the same, engine-wise. Are the 550's the only XJs that are chain drive? Obviously, you can't change SPROCKETS in a shaft-drive bike. I think the underlying problem is that us Americanos aren't used to having the "lump" spinning such high R's in a "cruising" situation...I kinda like it, sounds like an F1 car gearing down when I come to a stopsign...the MOTOR (550 anyway) seems to like it too, like I said it is definitely "happier" (smoother, quieter) running at 6K rpm than it is at 5K. Another argument for stock exhausts...

 

Paul and Fitz, thanks for the feed back. This bike runs the same RPM/MPH in 6th as you posted.

I am sure at this point it is stock through and through. As I am un-familiar with this model I had a lot to learn. Thanks.

 

Left work in a hurry the other day


3rd gear, 8500 rpm = 60mph

 

60 in 3rd, on a six-speed bike. And you guys wonder why the 85mph speedo frustrates me...what also amazes me is that this thing (550 Seca) will pull right up to 9000 before it starts to even SLIGHTLY run out of steam, and in any gear...

 

I've started taking a lower gear on the long 2 lane hills to/from work. Initially I was shocked at how well the bike responded, but now I'm just enjoying having something that will twist 8-10k.


Neutral, 0 rpm = 0mph :lol: