1982 XS650 Heritage Special highway RPMs.

[itsseanjohn]

My new 1982 XS650 revs at about 5000 rpm at 100 km/h. I think it has a 36 tooth rear sprocket, and I'm not sure which front sprocket. Is this too high? I have been thinking of changing the rear to a 32 or 31. How much would that help? Any help is great, as this is my first bike and I just don't know too much about regular operations

 

[Mudgnome]

I have mine at 100km/4000rpm,so yeah if I was you change the rear sprocket.Now you are probably going to hear from someone saying you have replace everything at the same.

I very rarely put on a complete set,seems to work ok,as long as you keep it lubed.

 

[itsseanjohn]

Thanks! Is that a 18/31 setup?

 

[650Skull]

Nice bike. Should have heaps of fun.

If the bike is new to you, changing all the sprockets and chain means you are starting on your footing.

If the sprockets and chain are relatively new and in good nick then the standard link chain can carry a 32 tooth rear to 36 tooth rear. Changing to a 31 tooth you will have to buy a new chain.

18/31 = 17/29. 18 tooth front is equivalent to to teeth on the rear

Buy a 32 and 33 tooth sprocket and try them, if you gear to high you will need to rev and ride the clutch to start.

Does the bike have a drum brake mag rear wheel?

 

[jayel]

17/31 is a very good combination 104 link chain puts your 55/60 mph cruise right at where it's getting into the carb slides starting to lift (around 4200k, think mpg) the only problem with the 18T front is some interference with the shift shaft, FYI the XS650 will happily rev to above 5k just gets a bit busier in the vibrations

 

[nj1639]

I just geared the '77 to 17/32 the other day....have yet to shake her out.
The '83 is running 18/34 and for these hills, hollers and 1st gear take off, I'm liking it.

 

[fredintoon]

My new 1982 XS650 revs at about 5000 rpm at 100 km/h. I think it has a 36 tooth rear sprocket, and I'm not sure which front sprocket. Is this too high? I have been thinking of changing the rear to a 32 or 31. How much would that help? Any help is great, as this is my first bike and I just don't know too much about regular operations

Hi itsseanjohn,
PM me for my addy & phone, eh? I'm just up the road from Kindersley in 'toontown.
I'd assumed my '84 was the only year that came with the 17/36 sprockets that are just about right for sidecar work but it seems not.
I'd go 17/32 or 17/33 but as the other posts show, sprocket tooth count has lots of options and to quote Kipling:-
every single one of them is right
I'd stay away from an 18T front because of it's clearance issues and you get the same ratio change by dropping two teeth off the back as you do in adding one to the front anyway.
I'd buy sprockets and a sealed (o-ring or x-ring) chain together as a set.
Old sprockets eat new chain.
Old chain eats new sprockets.
Installed as a set they wear in together like an old married couple.
I'd also buy a Scottoiler.
Others fling a #50 Ag chain onto knackered sprockets and squirt used crankcase oil at it every second oil change.
You choose.

 

[5twins]

Carefully examine the sprockets and chain on there now. Is the chain adjustment almost used up? The sprocket teeth should have a uniform and symmetrical shape. Do they look like this? .....

If you find this stuff present, I'd replace both sprockets and the chain. A 17/32 combo should work well. I feel the 32 is about ideal on a 16" rear wheel.

 

[itsseanjohn]

Sorry I forgot which was stock. I think I will put on a 17/32 setup. 17/34 is stock, right?

 

[nj1639]

17/34 is stock for us southerners......17/36 seems to appear more in the Great White North for some reason.
Yeah, go with the 17/32 and you shouldn't be disappointed. Nice bike ya got there Lad!

 

[nj1639]

Hi itsseanjohn,
PM me for my addy & phone, eh? I'm just up the road from Kindersley in 'toontown.
I'd assumed my '84 was the only year that came with the 17/36 sprockets that are just about right for sidecar work but it seems not.
I'd go 17/32 or 17/33 but as the other posts show, sprocket tooth count has lots of options and to quote Kipling:-
every single one of them is right
I'd stay away from an 18T front because of it's clearance issues and you get the same ratio change by dropping two teeth off the back as you do in adding one to the front anyway.
I'd buy sprockets and a sealed (o-ring or x-ring) chain together as a set.
Old sprockets eat new chain.
Old chain eats new sprockets.
Installed as a set they wear in together like an old married couple.
I'd also buy a Scottoiler.
Others fling a #50 Ag chain onto knackered sprockets and squirt used crankcase oil at it every second oil change.
You choose.

Now Fred, don't be scoffing at the #50 ag....lol......there has to be some merit there, haven't heard about any limbs lost to one yet....unlike them pants grabbing, leg tearing offen' three point hitches....

 

[weekendrider]

Well I happen to use both ag and motorcycle chain.
I wouldn't mix them but to each their own.

 

[Royboy]

17-32 absolutely perfect.

roy

 

[fredintoon]

nj,
back in the day ag chain was all she wrote but although modern bike chain runs on the same sprockets it's 4 times as strong and lasts 4 times as long.
It also costs 4 times as much.
Chainwise you break even but the sprockets wear away too so you lose out there.
If the extra chain & sprocket swapping work is a curse or a blessing depends on how much you like getting your hands dirty.
And, um, AFAK a 3-point hitch connects a tractor to a farming implement so although I know you are picking at me it don't work unless I understand it, eh?
5twins,
130/90-16 and 110/90-18 tires have just about the same outside diameter so 17/32 will work OK on either.

 

[realgone]

Ditto.
I had a 1980 special that had the 17/36 gearing. It was ridiculous.
Michael Morse recommended not going smaller than a 32 to avoid clutch drama in hilly areas (not a problem in SK).
I also think going smaller than a 32 could make things a little snatchy in slow tight turns in urban driving where 1st gear might be too short.
Anyway, I was very happy going with the 17/32.
I sprung for an 0-ring chain at the same time, glad I did. Less stretching, fewer adjustments, and it seemed quieter.

 

[5twins]

Fred, do a little playing around on this web site and you'll see there is a difference between the 18 and 16 .....

http://www.gearingcommander.com/

I have several 18" wheels. I have a 32 on one, 33 on another. I prefer the 33. I feel it suits the 650's power characteristics and output better than the 32. Punch some numbers in at the above web site and you'll see a 16 with a 32 is almost the same as an 18 with a 33.

 

[fredintoon]

hi 5twins,
nah, the gearing site wants to feed cookies to my computer so I ain't gonna open it.
However, my mathbox sez the OD of a 110/90-18 is 25.7" while the OD of a 130/90-16 is 25.2"
Or, a bald 110/90-18 is the same OD as a new 130/90-16.
So, yeah, as you say, a one tooth difference in the rear sprocket will balance the two.
What's more important for a potential wheelswapper to know about is the handling difference.
The narrower 18" tire lets the bike corner better.
The fatter 16" tire keeps the bike steadier in a straight line.
The BC twisties are better with an 18"
Straight line Saskatchewan does better with a 16".

 

[CDNTX650]

I wouldnt go below 32 either. 17-33 or 32 would be good, or even to stock murican 34. Getting into head winds means you will have to keep it in 4th anyways. These arent great highway steeds. 100km/h plus is fine. But if your looking to cruise at 130 in a 60km/h head wind it can be a fight, as there isnt much hp to battle that wind.

Kindersly eh, im from regina.

Also, i would change your gears as a set with a new chain. No point chewing up a new sprocket with worn chain.

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[weaselbeak]

5000 rpms is too high at 60mph on these bikes. Change the sprockets. As for ag chain, I used a bunch of it playing with a trike and the stuff is junk. 4400 lbs tensile strength. The weakest motorcycle chain is like 6600, many upwards of 9-10000. Don't waste any money on that slappy, noisy crap.

 

[CDNTX650]

Ebay oring chains are a good buy if you dont get effed on shipping. I run an ebay one on mine.

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