Oversized front sprocket safety?

[Stubby79]

Originally Posted by Daschicken

I probably don't know what i'm talking about. Either way, the larger sprocket allows for a more gradual turn around, slinging less lube.

This makes sense. Gentler curve, less articulation of each link...

[jkv357]

What is your normal cruising speed?

I have a +1 countershaft sprocket on my SVn, and it does help smooth out the cruise. Biggest factor for mileage though, is your cruising speed - the faster you go the lower the mileage. After 45 mph it's all downhill from there...

Keeping the revs lower does help, but cruising at 60 instead of 70 makes more of a difference than a gearing change will. Once you get close to 80 it's not very good at all, especially with my naked SV.

If you cruise in the 60 to 70 range, going with +1 on the countershaft may be an improvement, but +2 may put you too far down in the rev range/torque curve for best efficiency in top gear.

[Frank]

I wouldn't go crazy with gearing changes, as has been mentioned riding 5 mph slower will have a bigger impact.

If you go down a couple of teeth on the rear sprocket you could probably just remove a link or two from your existing chain. I use this calculator which helps: https://www.rbracing-rsr.com/chainlength.html

[jkv357]

Have you put in your info on Gearing Commander https://www.gearingcommander.com/ to see how much of a change it makes?

EDIT: There are really two contradictory schools of thought on the whole theory. One basically says "keep the RPMs as low as possible as much as possible, even if you need to open the throttle more", the other says " keep the throttle opening as small as possible as much as possible even if the RPMs are higher".

This thread supports the first theory - https://ecomodder.com/forum/showthre...mpg-33961.html

I've heard that Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering Book by Wolf-Heinrich Hucho supports the other.

It may be different for different vehicles (cars, trucks, cycle), so there may not be one right answer.

[Daschicken]

Originally Posted by Frank

I wouldn't go crazy with gearing changes, as has been mentioned riding 5 mph slower will have a bigger impact.

If you go down a couple of teeth on the rear sprocket you could probably just remove a link or two from your existing chain. I use this calculator which helps: https://www.rbracing-rsr.com/chainlength.html

I want to go crazy! In my car I have to be careful what gear I am in below 45 mph, the bikes are usually much lower than that. I am already in 6th gear well below that. Shifting is not a problem for me, and I will gladly trade laziness for a 7th gear!

My riding is usually done in a group, and I’m not setting the speed. That being said, highway riding is usually 65-70 MPH

Originally Posted by jkv357

Have you put in your info on Gearing Commander https://www.gearingcommander.com/ to see how much of a change it makes?

I've heard that Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering Book by Wolf-Heinrich Hucho supports the other.

It may be different for different vehicles (cars, trucks, cycle), so there may not be one right answer.

Yes, I use gearing commander all the time! My proposed 17/41 setup would be at 4111 RPM at 70 MPH, but I can’t seem to find a steel 41T rear. I may end up going 17/42 since I can find a 42T steel rear, and that would be 4211 RPM at 70 MPH. I also have hucho’s book, haven’t read it in a while though. Motorcycles are already highly overpowered and not geared tall, so I think I’m doing the right thing here. Considering the results I have gotten so far with ecomodder techniques, I will continue to be part of the low rpm high throttle crowd. SV650SF coming this weekend hopefully!

[jkv357]

Give the 17 a try - I don't think there would be any issues as long as the chain clears.

You getting a SVSF this weekend? What year is that? The dual plug heads after 2007 will most likely help efficiency.

I have the long SFV curved stacks, but the V-Strom (DL650) stacks are even longer.

This is the thread on SVRider with all the info, in case you haven't seen it lately - https://www.svrider.com/forum/showth...ight=sv+stacks - post 69 references the DL650 stacks. Post 81 has part numbers for them.

[Daschicken]

Originally Posted by jkv357

You getting a SVSF this weekend? What year is that? The dual plug heads after 2007 will most likely help efficiency.

I have the long SFV curved stacks, but the V-Strom (DL650) stacks are even longer.

That's the plan! It is a 2009 model, and even has an unmolested stock exhaust. My plan would be to get some DL650 stacks, among other things. Lots of parts to buy.

[Daschicken]

I got me an SF! It didn’t end up being the same bike as I was mentioning earlier, this one is a 2008 that has a Yoshimura pipe on it. Less than 5000 miles, unfortunately no ABS.



Going to get a baseline tank or two before doing any mods. It needs tires as the original 11 year old Dunlop D220s are still equipped.

[jkv357]

Originally Posted by Daschicken

I got me an SF! It didn’t end up being the same bike as I was mentioning earlier, this one is a 2008 that has a Yoshimura pipe on it. Less than 5000 miles, unfortunately no ABS.



Going to get a baseline tank or two before doing any mods. It needs tires as the original 11 year old Dunlop D220s are still equipped.

Congrats!

I'm glad you mentioned tires. I threw away those Dunlop 220s in 2006 when they were new with 500 mi on them - I thought they were that bad.

My son really like his Dunlop Roadsmart IIIs. I've got Michelin Pilot Power RSs on my SV, but I think I'm going to go with Michelin Road 4s when the time comes.

[jimhs]

Wow,nice bike mate!!