Yamaha Starbike Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
Hey everyone, I know this topic has been beaten to death, but something I havn't seen anyone suggest is changing the gears themselves in the transmission.

Would anyone be able to tell me if its possible to swap the actual gearsets in the transmission to get a lower 5th gear ratio? I thought maybe swap in a fourth gear set in with the input and output being reversed. This would give a 5th gear ratio of .858 instead of the .966 that comes from factory

The other thing is while I have seen that people say you cannot use the vstar 1100 or 1300 final drives, what about them does not work?
 

·
Super Moderator "Loose Nut"
Joined
·
9,530 Posts
The concept of your idea is great.. My question is what is the end results you are aiming for. While the 650 is a great bike, horse power will limit a 1.12% overdrive ratio you are suggesting. The cost of doing this swap would be high unless you had a donor bike. The 650 and 1100 engines have a higher cruise rpm than a lot of bikes due to their designed power band. With my 1100 I can cruise at 80 mph for hours without any issues. If you want a lower rpm cruising bike I suggest you get a larger bike. As far as final drives they are unique to each size bike. There are many 650 owners here and I'm sure they will chime in.
 

·
Registered
Joined
·
6,851 Posts
I love the way my 650 cruises at 50 to 60mph. The bike feels like it would run forever at 55mph.

On the highway with the windshield on the bike at 80mph the throttle is really cranked. Pushing the RPMs lower at the same speed will give you less HP.

If you really want to ride the interstates look at a VS1300 or Roadstar size bike.
 
  • Like
Reactions: Diogenes415

·
Registered
Joined
·
4 Posts
Discussion Starter #4
I don't do a whole lot of highway driving, very little actually, just a short jaunt to work in the morning at 80km/h (posted limit, but we all know that isn't the speed I'm going :p)
The cost isn't a big deal, I have access to lots of wreckers and I'm sure I'd be able to find a ruined transmission, its just whether or not it'd be possible.

And as for the final drive, what makes them different? I did some searching and they appear to be the same, at least cosmetically. The four mounting bolts are in the same configuration and the shaft appears to be the same size. Is it the spline onto the wheel that differs? Or something else?
 

·
Super Moderator "Loose Nut"
Joined
·
9,530 Posts
And as for the final drive, what makes them different? I did some searching and they appear to be the same, at least cosmetically. The four mounting bolts are in the same configuration and the shaft appears to be the same size. Is it the spline onto the wheel that differs? Or something else?
The part numbers are all different, check web sites for oem parts. Manufacturers do use a lot of parts from one model to another, but part numbers stay the same. Here is a good link for part cross reference between the Vstar models, didn't see final drive but just about everything else is listed.

Fitment Chart
 

·
Registered
Joined
·
4 Posts
Discussion Starter #6
The part numbers are all different, check web sites for oem parts. Manufacturers do use a lot of parts from one model to another, but part numbers stay the same. Here is a good link for part cross reference between the Vstar models, didn't see final drive but just about everything else is listed.

Fitment Chart
I get that the part numbers are different, but that only makes sense because the gear ratio is different. But if it mounts onto the frame without issue, and splines onto the wheel, I don't see why it wouldn't be a feasible option?
 

·
Super Moderator "Loose Nut"
Joined
·
9,530 Posts
If you have access to lots of wrecks I suggest taking a tape measure and micrometer to compare. If it's doable keep us informed. From my past experience at times the effort doesn't equal the results. That's why manufacturers make different models for sale.
 

·
Registered
Joined
·
909 Posts
I get that the part numbers are different, but that only makes sense because the gear ratio is different. But if it mounts onto the frame without issue, and splines onto the wheel, I don't see why it wouldn't be a feasible option?
I highly doubt that the transmission components can be swapped over to a 650... it's transmission by design is smaller and lighter and doesn't have to be as beefy as the larger bikes to cope with the power and torque. I have yet to see any components swap so easily from one model to another and thats after decades of building frankenbikes. The one and only time I've seen such an easy swap is with the taller CB200 fifth cluster fitting into the CB175... but then they were basically the same motor/tranny.

Enjoy the 650 for what it is. It has a motor designed to be revved and will do so safely at greater than interstate speeds all day. If you want a low-revving road tractor then you should buy one.
 

·
Registered
Joined
·
6,851 Posts
Look at the stock 650 HP curves on the website: https://www.pacificcoaststar.com/pcs/yamaha_dynos.htm

the stock engine produces 33HP at the tire from 5200 rpm to 6200 rpm, which is 75 to 89mph with the stock ratio in 5th gear.

If you put a higher gear ratio on 5th, you will shift that curve up (HP vs mph), giving you less HP in the jump between 4th gear and 5th.

To get the same acceleration between 55mph and 75, you would have to wind the bike out to its redline in 4th up ~70mph. Between 55mph and 70 you would be reving the hell out of the engine in 4th gear, so that you could have it spin a little slower in 5th gear. Every hill you hit you would have to kick it back down into 4th and hi-rev it again.
 

·
Registered
2001 V-Star XVS650 Custom
Joined
·
3 Posts
So I am on the same page as [email protected]. I dont want a bigger heavier bike mine is fine. And when on the freeway I dont need an abundance of pickup. Just want the bike to not sound like the seams are blowing out. I will attempt the 1100 final drive on my bike for certain. But the opening off the transmission and all that I do not believe will be a help. Why well it already has been said. If you adjust just the 5th gear in the transmission, well you either will be tacking it into the red when up shifting from 4th, or you will be bogging it to much once shifted to 5th unless you start at second and incrementally bring up each and every gear after. 3, 4, and 5th. Then and only then will it not affect you drastically.
But the final drive in all honesty is the way to go and Soon I will post how this goes. Let you know. have a great day and remember to.
Always Keep the Shiny Side Up!
 

·
Registered
Joined
·
146 Posts
The final drive on the 650 and the 1100 are completely different animals. They will not swap without major and costly customization. Would probably be cheaper to just upgrade to the 1100. The 650 and the 1100 are very similar in their riding and handling characteristics. jmho
 

·
Registered
2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
Joined
·
714 Posts
Final drive ratio is nearly the same for the 1100 and 650; 2.909 vs 3.071. According to another user who is going to fit cast wheels off the 1100, the 1100 hub will bolt up to the 650 swingarm. At 60 mph you will drop rpm from 4200 to just under 4000, or 5% less. You will also need a new hub from the 1100, which also means going to disc brake. Or a machinist may be able to convert your hub to take the splines off a generation 1 Virago 750 or 920 - it has been done the other way around.
 

·
Registered
Joined
·
4,883 Posts
So I am on the same page as [email protected]. I dont want a bigger heavier bike mine is fine. And when on the freeway I dont need an abundance of pickup. Just want the bike to not sound like the seams are blowing out. I will attempt the 1100 final drive on my bike for certain. But the opening off the transmission and all that I do not believe will be a help. Why well it already has been said. If you adjust just the 5th gear in the transmission, well you either will be tacking it into the red when up shifting from 4th, or you will be bogging it to much once shifted to 5th unless you start at second and incrementally bring up each and every gear after. 3, 4, and 5th. Then and only then will it not affect you drastically.
But the final drive in all honesty is the way to go and Soon I will post how this goes. Let you know. have a great day and remember to.
Always Keep the Shiny Side Up!
The 1100 sings pretty good at 65mph also i don't go much over that.
 

·
Registered
2001 V-Star XVS650 Custom
Joined
·
3 Posts
Well thank you for your technical and experienced input. I will probably still keep and ride my bike around town. Not long highway rides for sure. And that's only because I custom built this baby. These is some pics.
96230
20200614_192941.jpg
20200614_192957.jpg
20200614_192941.jpg
 

·
Registered
Joined
·
4,883 Posts
Don't get me wrong guys have taken them cross country. Jspree has 100,000 on his. They are are just designed to run higher rpms. Even my 1800VTX i was looking for 6th gear. I am just a cruiser not a speeder.
I like the look of your bike. 650s will go forever. I have 36000 on my 1100 and expecting another 60,000.
 

·
Registered
Joined
·
146 Posts
Great looking bike. Back in the day a "big bike" was a 750. I took a Kawasaki kz 400 from PA to FL without a second thought. I know what you mean though I parted with my 1100 Silverado in favor of a Roadstar Silverado to reduce highway rpm's.
 

·
Registered
2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
Joined
·
714 Posts
Personally, I want as few rpms as possible when cruising because I find high revs stressful. In my experience, most bikes are geared too short. This is due to performance; ideally, you want the engine to make max power at max speed. But how many of us actually do top speed runs? And the price is that we carry more rpm than needed for cruising.

Still, for a 40 hp 550 lb 650cc motorcycle, the XVS650 spins quite slowly at about 4100 rpm @ 60 mph IIRC. However, if I could, I would have dropped rpm to about 3500 rpm at 60 and lived with the reduced performance. The 71 hp 500 lb XJ650 Seca turned 4500 rpm at 60, and it fired twice as often, making it sound far busier than the Dragstar. And an R6 will turn about 5500 rpm at 60 - and many will rather sit in 3rd or 4th gear at 60 because they think 5500 rpm is lugging the engine 🙄

There is a reason I do not own fours anymore, and high rpm that sound even higher than they are is the reason for that.
 

·
Registered
Joined
·
1 Posts
Hey there...

This can be stupid, or can be smart... But I really dont know.

It is possible to decrease cruising RPM, If you are able to increase the height of your tyre...

Vstars uses a 170/80-15 rear tire. And It seems that It doesnt exists a 170/90 or 170/100 tire.

But in a National fórum, years Ago, I saw a Guy putting a 200/70-15 tire.
The problem is that the rear Wheel is only 3.5 inchs wide. So the 200 tire does not get larger when mounted.
But It really gets taller!!!!

The only thing that can compromises It is rear fender. Depending on wheight, tire can stcratch the inside top of the fender.

This is probably way cheaper and easier to try then a final drive swap, and may ending same result...
 

·
Registered
2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
Joined
·
714 Posts
Your theory is correct. The difference in your example is very small, though; theoretically 136 vs 140 mm in height. Or about 3%. Not much, especially since you will need a new rim to fit the wider tire.
 
1 - 19 of 19 Posts
Top