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niethan
Nov 22, 2005

Don't be scared, homie!
I just used nail polish remover and it worked like a charm. Danke.

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GanjamonII
Mar 24, 2001

Saga posted:

IF the clamp's like the one on the older Tuono, you can fit a ytx14 just by making a spacer for the clamp and using a longer bolt. With the taller battery the seat secures it anyway, so the clamp's slightly redundant.

The clamp doesn't sound the same, the newer gen has a plastic bracket/clamp thing that is held on with two hex bolts. To move it up would require re-drilling higher up the tail section (best I can describe it) and I don't want to do that particularly much at the moment.

However I need to go back and check again how the bigger battery would fit cause this morning it had a similar symptom - it wouldn't start on the first go, turned over a couple times with nothing. I tried it again two seconds later and it fired up.

I am going to check the 'brown connector' when I get home today and see if that is toast. If so I have the bits and pieces to fix it. From my understanding this year only had one instead of two. I hope that's the case.

Also the PO seemed to use some really wet lube on the chain. I use a spray on wax thing and it leaves mostly dry crud on the chain guard and sprocket cover when it mixes with dirt etc. Whatever this guy used left wet grease type gunk everywhere. That or its got a leaky output shaft seal or something..

Hooray new bike used bike ownership!

GnarlyCharlie4u
Sep 23, 2007

I have an unhealthy obsession with motorcycles.

Proof
Determined my ballast resistor was hosed and just installed a Dyna-s instead. (Blog post)

Then as I went to put everything back together I noticed that the previous owner did something... :gonk:

On a side note, do you guys have any suggestions on how to improve my blog?
Is there anything you'd like to see more of? Does my writing in general just completely suck?

I'm going to make an honest effort to start publishing relevant and interesting content from my builds and repairs. But I could use a push in the right direction.

GnarlyCharlie4u fucked around with this message at 16:48 on Sep 19, 2011

Saga
Aug 17, 2009

GanjamonII posted:

The clamp doesn't sound the same, the newer gen has a plastic bracket/clamp thing that is held on with two hex bolts. To move it up would require re-drilling higher up the tail section (best I can describe it) and I don't want to do that particularly much at the moment.

However I need to go back and check again how the bigger battery would fit cause this morning it had a similar symptom - it wouldn't start on the first go, turned over a couple times with nothing. I tried it again two seconds later and it fired up.

I am going to check the 'brown connector' when I get home today and see if that is toast. If so I have the bits and pieces to fix it. From my understanding this year only had one instead of two. I hope that's the case.

Also the PO seemed to use some really wet lube on the chain. I use a spray on wax thing and it leaves mostly dry crud on the chain guard and sprocket cover when it mixes with dirt etc. Whatever this guy used left wet grease type gunk everywhere. That or its got a leaky output shaft seal or something..

Hooray new bike used bike ownership!

Mine came with a hidden scottoiler. Set to setting 4, which was dumping oil all over the rim! Turned it down to 1 and got out the chain wax.

Yeah, I saw the new clamp in the parts fiche - mine has a single bolt and is like an "s" shape in profile. With the 14, the clamp fits on the battery and you put a tube around the bolt (ballpoint pen for me) so the bolt-side of the clamp has something to push against.

Sure it's not the starter solenoid dying due to the PO running it on the old battery and/or running it infrequently with little charge? Might be safest to get the apparently cheaper Ducati solenoid and swap it in to make sure. Of course that might just be something I'd do due to being a mechanical/electrical idiot.

On the remote charging lead, if you can't be bothered to make those up my Optimate came with a nice setup with a rubber cap that routes to under the seat cover - you can probably buy it or something like it on ebay for $5. Admittedly $4 more than it would cost to make it from Radio Shack parts but hey.

GanjamonII
Mar 24, 2001

Saga posted:

Mine came with a hidden scottoiler. Set to setting 4, which was dumping oil all over the rim! Turned it down to 1 and got out the chain wax.

Yeah, I saw the new clamp in the parts fiche - mine has a single bolt and is like an "s" shape in profile. With the 14, the clamp fits on the battery and you put a tube around the bolt (ballpoint pen for me) so the bolt-side of the clamp has something to push against.

Sure it's not the starter solenoid dying due to the PO running it on the old battery and/or running it infrequently with little charge? Might be safest to get the apparently cheaper Ducati solenoid and swap it in to make sure. Of course that might just be something I'd do due to being a mechanical/electrical idiot.

On the remote charging lead, if you can't be bothered to make those up my Optimate came with a nice setup with a rubber cap that routes to under the seat cover - you can probably buy it or something like it on ebay for $5. Admittedly $4 more than it would cost to make it from Radio Shack parts but hey.

I might have to look into that solenoid thanks. I would prefer to change it preemptively rather than have it brake down on me.

This one doesn't have a scottoiler on it.. that I can see! I got in contact with the PO this morning and he said he never cleaned it out in there, but he also never saw any oil consumption. I checked it today and its dry where I cleaned it, so I'll just keep an eye on it for now.

Im not sure if there is a standard for battery tender plugs, the ones at the battery shop are different from the plugs on my cheap autozone battery tender. I also don't have a matching plug for the tender so I'll be replacing that entirely.

Then I plan to have it set up so I can switch between the tender and a waterproof burnsmoto USB powerport for my phone so I can use GPS. I was thinking about setting up a relay to the ignition so its only in use when the bike is off, but I think that might be overkill for something I can just disconnect under the rear seat..

GanjamonII
Mar 24, 2001

GnarlyCharlie4u posted:

Determined my ballast resistor was hosed and just installed a Dyna-s instead. (Blog post)

Then as I went to put everything back together I noticed that the previous owner did something... :gonk:

On a side note, do you guys have any suggestions on how to improve my blog?
Is there anything you'd like to see more of? Does my writing in general just completely suck?

I'm going to make an honest effort to start publishing relevant and interesting content from my builds and repairs. But I could use a push in the right direction.

I read that article and being a newbie to electircal/mechanical work I had to google what a ballast resistor is and does on a bike. Now I get what it does, but it might be nice to include a couple sentences about what it does so n00bs like me can understand too.

I've read your blog before though, I can't remember how/for what but I remember the background!

dick traceroute
Feb 24, 2010

Open the pod bay doors, Hal.
Grimey Drawer
Took off the L plates. :smug:
(Passed my final, on-road, riding test first.) Still restricted to 33bhp, but considering I have MAYBE 10 right now, I think I can live with it.

GnarlyCharlie4u
Sep 23, 2007

I have an unhealthy obsession with motorcycles.

Proof

GanjamonII posted:

I read that article and being a newbie to electircal/mechanical work I had to google what a ballast resistor is and does on a bike. Now I get what it does, but it might be nice to include a couple sentences about what it does so n00bs like me can understand too.

I've read your blog before though, I can't remember how/for what but I remember the background!

Fixed. Thanks for the input. I was never sure whether or not people actually wanted to hear an explanation on how it works.
Most of my experience with the internet tells me that people click a link, want to see a pic, and will read what's there if it's <100 words.
otherwise it's "tl;dr sorry bro"

Z3n
Jul 21, 2007

I think the point is Z3n is a space cowboy on the edge of a frontier unknown to man, he's out there pushing the limits, trail braking into the abyss. Finding out where the edge of the razor is, turning to face the darkness and revving his 690 into it's vast gaze. You gotta live this to learn it bro.

GnarlyCharlie4u posted:

Fixed. Thanks for the input. I was never sure whether or not people actually wanted to hear an explanation on how it works.
Most of my experience with the internet tells me that people click a link, want to see a pic, and will read what's there if it's <100 words.
otherwise it's "tl;dr sorry bro"

I think the big issue is that people generally don't comment much on stuff. They might learn something but a "thanks for the lesson!" post is rare. It's like ride reports in this forum. They're great but it's pretty rare they generate that much commentary. I like the pictures, I personally prefer the longer posts, but I don't think that's much of a surprise to anyone that's read my posts :xd:

GnarlyCharlie4u
Sep 23, 2007

I have an unhealthy obsession with motorcycles.

Proof

Z3n posted:

I think the big issue is that people generally don't comment much on stuff. They might learn something but a "thanks for the lesson!" post is rare. It's like ride reports in this forum. They're great but it's pretty rare they generate that much commentary. I like the pictures, I personally prefer the longer posts, but I don't think that's much of a surprise to anyone that's read my posts :xd:

haha actually I was just about to say "well of course you'd like the long ones"

More pictures should be happening soon. My problem this far has been not wanting to stop what I'm doing, lose momentum and gently caress up my camera.

Hopefully I'll have the girlfriend over more often to take some pictures for me so I don't have to stop and wash my hands every time I want to click the shutter.

Everything thus far has really just been a warmup. I can't wait till I can save a couple grand and REALLY build that formula SOHC CB750 motor. The blog posts for that are going to be ridiculous.

Saga
Aug 17, 2009

Z3n posted:

I think the big issue is that

Man TOO LONG!

polystyrus posted:

Took off the L plates.
(Passed my final, on-road, riding test first.) Still restricted to 33bhp, but considering I have MAYBE 10 right now, I think I can live with it.

Congrats on your mod 2...excellent! :rock:

Now you can represent King's Road stylee - S1000RR with a restrictor kit and matching leathers.

Nidhg00670000
Mar 26, 2010

We're in the pipe, five by five.
Grimey Drawer

GnarlyCharlie4u posted:

My problem this far has been not wanting to stop what I'm doing, lose momentum and gently caress up my camera.

This is me. Whenever I bring the camera before I change oil or adjust valves or whatever, I only remember I brought it when I'm all done and go :doh:

As for what I did on my bike today, I adjusted the chain on the SV. Of note is that the chain and sprockets are less than a week old, changed by the shop I bought it from (it's still under warranty). Yesterday I noticed that the chain was like a guitar string... :downs:

Nidhg00670000 fucked around with this message at 20:36 on Sep 19, 2011

sirbeefalot
Aug 24, 2004
Fast Learner.
Fun Shoe

niethan posted:

I rattlecanned my KLR today, it looks p good from afar


But I used the wrong kinda tape for masking so it's got a lotta bleeding


Whatever, it's a KLR

I know, I know, whatever, its a KLR and you cleaned it up anyway, but next time lay down a coat of the base color once you mask off, and it will seal the edges of the tape before you put the second color on. Works wonders.

VV Even with blue or green tape I'll occasionally get bleed. Even a clear spray that matches the base sheen works.

sirbeefalot fucked around with this message at 03:46 on Sep 20, 2011

Queen_Combat
Jan 15, 2011

sirbeefalot posted:

I know, I know, whatever, its a KLR and you cleaned it up anyway, but next time lay down a coat of the base color once you mask off, and it will seal the edges of the tape before you put the second color on. Works wonders.

Or if you use the special (expensive) blue painter's masking tape, and be sure to run your finger along the edge. If all I have on hand is normal masking tape, I'll do what you said.

Snowdens Secret
Dec 29, 2008
Someone got you a obnoxiously racist av.
Got the first service done. The auto-self-check showed that the throttle bodies were out of sync, which may explain some low-rpm jerkiness I've noticed. Unfortunately, while the desync can be picked up through the OBD2 port under the seat, getting to said throttle bodies to adjust them involved lifting the tank, removing the battery, airbox, and ECU. All in all, an educational experience.

Also, I already knew my rear tire pressure monitor didn't work, but now I've found out either my front monitor reads 8 pounds high or it's reading the back sensor as the front - probably the latter, although Lord knows how or why. Either way I've got at least one new sensor on the way under warranty.

E: A Speed Triple
vvvvvvv

Snowdens Secret fucked around with this message at 19:55 on Sep 20, 2011

KozmoNaut
Apr 23, 2008

Happiness is a warm
Turbo Plasma Rifle


Snowdens Secret posted:

Got the first service done. The auto-self-check showed that the throttle bodies were out of sync, which may explain some low-rpm jerkiness I've noticed. Unfortunately, while the desync can be picked up through the OBD2 port under the seat, getting to said throttle bodies to adjust them involved lifting the tank, removing the battery, airbox, and ECU. All in all, an educational experience.

Also, I already knew my rear tire pressure monitor didn't work, but now I've found out either my front monitor reads 8 pounds high or it's reading the back sensor as the front - probably the latter, although Lord knows how or why. Either way I've got at least one new sensor on the way under warranty.

What do you ride, some sort of space ship? :v:

GanjamonII
Mar 24, 2001

GanjamonII posted:

I might have to look into that solenoid thanks. I would prefer to change it preemptively rather than have it brake down on me.

This one doesn't have a scottoiler on it.. that I can see! I got in contact with the PO this morning and he said he never cleaned it out in there, but he also never saw any oil consumption. I checked it today and its dry where I cleaned it, so I'll just keep an eye on it for now.

Im not sure if there is a standard for battery tender plugs, the ones at the battery shop are different from the plugs on my cheap autozone battery tender. I also don't have a matching plug for the tender so I'll be replacing that entirely.

Then I plan to have it set up so I can switch between the tender and a waterproof burnsmoto USB powerport for my phone so I can use GPS. I was thinking about setting up a relay to the ignition so its only in use when the bike is off, but I think that might be overkill for something I can just disconnect under the rear seat..

Goddamnit my new bike DOES have some sort of oil leak. The area I cleaned off yesterday is wet again today. Its coming from somewhere covered by the frame and side panels/tank. When I get home I'll get in there to find it. The leak is reasonably small - nothing dripping on the ground, so I hope its something minor. Or at least cheap to fix. The PO says he knows nothing of it.

edit2 - parts fiche says that there is a bunch of oil lines and some sort of junction up from where the leak appears to be from. Hopefully that is it as the stock clamps on the oil lines on these bikes are notoriously lovely and should be replaced with hose clamps.

I'm a little annoyed at the shop I paid to do the prepurchase inspection, in retrospect I shouldn't have been such a muppet and looked it over more closely myself I probably could have caught it.

Edit - on the plus side I haven't had any other starting issues and I still love the bike, though the front tire is a Dunlop D208 from 2007 and I felt it pushing a little on the one proper corner on the way into work today...

GanjamonII fucked around with this message at 21:16 on Sep 20, 2011

Saga
Aug 17, 2009

GanjamonII posted:

Goddamnit my new bike DOES have some sort of oil leak. The area I cleaned off yesterday is wet again today. Its coming from somewhere covered by the frame and side panels/tank. When I get home I'll get in there to find it. The leak is reasonably small - nothing dripping on the ground, so I hope its something minor. Or at least cheap to fix. The PO says he knows nothing of it.

edit2 - parts fiche says that there is a bunch of oil lines and some sort of junction up from where the leak appears to be from. Hopefully that is it as the stock clamps on the oil lines on these bikes are notoriously lovely and should be replaced with hose clamps.

I'm a little annoyed at the shop I paid to do the prepurchase inspection, in retrospect I shouldn't have been such a muppet and looked it over more closely myself I probably could have caught it.

Edit - on the plus side I haven't had any other starting issues and I still love the bike, though the front tire is a Dunlop D208 from 2007 and I felt it pushing a little on the one proper corner on the way into work today...

Did they check the clearances for you? In which case misting all over everything with no drips is possibly valve cover gasket, and probably the front one which is harder to access. If they popped it off and damaged the gasket, that's how it would happen. Same story if the PO had the clearances done pre-sale.

It would be slightly weird for it to be the oil lines as they don't have to come off for any routine servicing task I know of. But still, very small jubilee clips to the rescue!

Mine really likes the 2CTs it came with, but then it bloody well should for what 2CTs cost! Neutral right the way through corners, very good grip, turn in on the quick side - though not as quick as a Roadsmart - but with excellent stability. Which obviously you want with these bikes given what the front end is doing out of every corner!

They're almost good enough to make me ignore the fact that they were made by Michelin. My Hornet came with a set, and I can say the traction and handling characteristics seem even more useful on the Aprilia.

That said, I'm not paying 300 pounds for tyres, so I'm going to swap onto part-worn BT023s for the winter and spring when the rear finally dies.

Saga fucked around with this message at 07:14 on Sep 21, 2011

GanjamonII
Mar 24, 2001

Saga posted:

Did they check the clearances for you? In which case misting all over everything with no drips is possibly valve cover gasket, and probably the front one which is harder to access. If they popped it off and damaged the gasket, that's how it would happen. Same story if the PO had the clearances done pre-sale.

It would be slightly weird for it to be the oil lines as they don't have to come off for any routine servicing task I know of. But still, very small jubilee clips to the rescue!

Mine really likes the 2CTs it came with, but then it bloody well should for what 2CTs cost! Neutral right the way through corners, very good grip, turn in on the quick side - though not as quick as a Roadsmart - but with excellent stability. Which obviously you want with these bikes given what the front end is doing out of every corner!

They're almost good enough to make me ignore the fact that they were made by Michelin. My Hornet came with a set, and I can say the traction and handling characteristics seem even more useful on the Aprilia.

That said, I'm not paying 300 pounds for tyres, so I'm going to swap onto part-worn BT023s for the winter and spring when the rear finally dies.

When I got it had a brand new Q2 on the back, so I'm putting a matching Q2 on the front. I have them on my SV and liked them well enough, plus they are drat cheap.

Though given the rate these bikes are meant to eat tyres I'll bet I'll have plenty of opportunities to try out different brands..

Tamir Lenk
Nov 25, 2009

GanjamonII posted:

Goddamnit my new bike DOES have some sort of oil leak. The area I cleaned off yesterday is wet again today. Its coming from somewhere covered by the frame and side panels/tank. When I get home I'll get in there to find it. The leak is reasonably small - nothing dripping on the ground, so I hope its something minor. Or at least cheap to fix. The PO says he knows nothing of it.

edit2 - parts fiche says that there is a bunch of oil lines and some sort of junction up from where the leak appears to be from. Hopefully that is it as the stock clamps on the oil lines on these bikes are notoriously lovely and should be replaced with hose clamps.

I'm a little annoyed at the shop I paid to do the prepurchase inspection, in retrospect I shouldn't have been such a muppet and looked it over more closely myself I probably could have caught it.

Edit - on the plus side I haven't had any other starting issues and I still love the bike, though the front tire is a Dunlop D208 from 2007 and I felt it pushing a little on the one proper corner on the way into work today...

Once you remove the side panels and tank, set up a remote fuel tank (or use a long fuel line from your separate tank).

Clean up the oily area. Then spray some athlete's foot spray (the white powdery residue kind) all over that part of the engine. Run the bike at idle for a minute or two, or put the tank on and ride around the block a few times.

The foot spray will show exactly where the oil is coming from with a nice brown spot.

HTH

GnarlyCharlie4u
Sep 23, 2007

I have an unhealthy obsession with motorcycles.

Proof
Again, not my bike but I still did the work.

http://gnarlywrench.blogspot.com/2011/09/joeys-k3-is-out-on-road-god-save-us.html

Basically I got her roadworthy now.
There are still a few little things to fix up like a missing passenger footpeg and apparently it won't do over 50. But at least it runs.

I'll be doing a plug chop this evening and double-checking the timing.
Along with adjusting the rear brake and swapping the stock handlebars back on.

Clubmans are uncomfortable? WHO KNEW??? /sarcasm

Z3n
Jul 21, 2007

I think the point is Z3n is a space cowboy on the edge of a frontier unknown to man, he's out there pushing the limits, trail braking into the abyss. Finding out where the edge of the razor is, turning to face the darkness and revving his 690 into it's vast gaze. You gotta live this to learn it bro.

GnarlyCharlie4u posted:

Again, not my bike but I still did the work.

http://gnarlywrench.blogspot.com/2011/09/joeys-k3-is-out-on-road-god-save-us.html

Basically I got her roadworthy now.
There are still a few little things to fix up like a missing passenger footpeg and apparently it won't do over 50. But at least it runs.

I'll be doing a plug chop this evening and double-checking the timing.
Along with adjusting the rear brake and swapping the stock handlebars back on.

Clubmans are uncomfortable? WHO KNEW??? /sarcasm

Should have left the side covers as is. Orange deco stylin'.

Ziploc
Sep 19, 2006
MX-5
Instead of messing around trying to get the stripped sump drain retapped I decided to say, "gently caress it" and get a new sump plus everything I need to do the change on my 02 Bandit 600 this weekend.

I have a new sump, oil cooler banjo bolt copper seals, sump gasket, sump plug alum crush washer, and new header gaskets.

Any tips? Tips are very welcome.

Tamir Lenk
Nov 25, 2009

Pulled off the front brake and will flush it out and reassemble with my sexy new SS line and new pads tonight.

Bled out the rear brake, but I think I can drill out the broken bleeder with the brake on the bike. One of the bolts holding that brake in place is wire-secured (the swing-arm connection), so I want to avoid messing with it for fear that I will gently caress up the reinstall. I did remove the rear brake line, including the hard channel portion, so I can replace it with a single SS line.

Got some speed bleeders to go into the new brakes. Hopefully that will make it easier to fill the new lines.

GnarlyCharlie4u
Sep 23, 2007

I have an unhealthy obsession with motorcycles.

Proof

Z3n posted:

Should have left the side covers as is. Orange deco stylin'.

trust me I really wanted to but they were actually sprayed matte black over that. I tried as best I could to remove just the black but alas.

It's okay though I've got another more hosed up set of sidecovers I'll be removing the black from. Hopefully I'll do better this time.

I really like that Sunrise Orange paint though. It kills me that some asshat just sprayed matte black over what once was a beautiful bike.

GanjamonII
Mar 24, 2001
Wired up a relay and burnsmoto USB power socket, and put on the arkon cell phone mount. Its switched by the license plate light, and uses an SAE connector which lets me switch between this and the battery tender at will.
It all works without setting fire to anything too! Total cost around $60 for everything including mount and random wiring, connectors and heat shrink tubing.

The socket itself is ziptied to one of the clip on mounts the previous owner installed. I want to find a more permanent solution to the mounting but I also don't want to cut any of the plastic or anything like that so need to play with it a little.

infraboy
Aug 15, 2002

Phungshwei!!!!!!1123
I did about 166.2 miles on the zx6r before filling up.... I put about 4.480 gallons in the tank and I believe the tank is about 4.5 gallons :v

2ndclasscitizen
Jan 2, 2009

by Y Kant Ozma Post

infraboy posted:

I did about 166.2 miles on the zx6r before filling up.... I put about 4.480 gallons in the tank and I believe the tank is about 4.5 gallons :v

Pfft, I once put 17.65L in to my Gixxer's 17.5L tank. Although I did run out on the highway and managed to juuuuuuuuuuuuuust coast up an off-ramp and rolled to a stop just short of the petrol station.

GanjamonII
Mar 24, 2001

infraboy posted:

I did about 166.2 miles on the zx6r before filling up.... I put about 4.480 gallons in the tank and I believe the tank is about 4.5 gallons :v

My fuel light came on at 80 miles yesterday.

Saga
Aug 17, 2009

GanjamonII posted:

My fuel light came on at 80 miles yesterday.

86.3. Gotta love it. Also, my back 2CT is disappearing at a prodigious rate.

babyeatingpsychopath
Oct 28, 2000
Forum Veteran


Saga posted:

86.3. Gotta love it. Also, my back 2CT is disappearing at a prodigious rate.

188. This up from 136 a few weeks ago. Carb tuning is fun! 200 miles on a tank? Yes, thank you very much!

Now to get my sprockets and get the MPG up higher (lower revs @ highway speed).

Queen_Combat
Jan 15, 2011

babyeatingpsychopath posted:

188. This up from 136 a few weeks ago. Carb tuning is fun! 200 miles on a tank? Yes, thank you very much!

Now to get my sprockets and get the MPG up higher (lower revs @ highway speed).

Changing sprockets does not increase fuel economy on the highway. You may be turning a lower RPM, but it requires a set amount of energy to get you going at 70mph (or whatever speed); you can't magically make it require less energy to do so by lowering engine speed. If you change sprockets, you may be lugging along at a lower RPM, but your throttle will have to be open just] a little bit wider to compensate. On engines that are already low-RPM cruisers, doing so may bring the engine into an unsafe "lugging" territory, where heat from the amount of increased gas used per stroke (compared to the same amount of air per stroke) can cause damage, especially on air-cooled engines.

The only way changing sprockets to achieve a lower RPM on the highway can help is if, for whatever reason, your engine is already cruising at a damaginly-high RPM on the highway, but most bike manufacturers take this into account when designing them.

My favorite quote on the subject: "MPG is related to the amount of fuel that needs to be burned to haul a specific load at a specific speed, which is mostly to do with overcoming drag and friction. Those factors will not significantly change with revised gearing."


Science!

Queen_Combat fucked around with this message at 20:20 on Sep 23, 2011

Z3n
Jul 21, 2007

I think the point is Z3n is a space cowboy on the edge of a frontier unknown to man, he's out there pushing the limits, trail braking into the abyss. Finding out where the edge of the razor is, turning to face the darkness and revving his 690 into it's vast gaze. You gotta live this to learn it bro.
Alright, most of this is incomplete.

Geirskogul posted:

Changing sprockets does not increase fuel economy on the highway. You may be turning a lower RPM, but it requires a set amount of energy to get you going at 70mph (or whatever speed); you can't magically make it require less energy to do so by lowering engine speed.

There are more factors here than just the amount of energy that it takes to go that fast. Gearing affects how much power you make at a given speed, so if gearing your bike higher moves it closer to peak torque for a given throttle opening, then you can actually have to open the throttle less to maintain speed. This is more true on thumpers and twins, but still true overall. Gearing can change the efficiency of the engine at a given throttle opening and speed.

It's worth noting that partial throttle values aren't shown in a dyno graph. The ideal engine efficiency for 10% throttle might look quite different from the peak torque for 100% throttle due to the effects of compression ratio, cam timing, etc, when you're not wide open.


quote:

If you change sprockets, you may be lugging along at a lower RPM, but your throttle will have to be open just] a little bit wider to compensate. On engines that are already low-RPM cruisers, doing so may bring the engine into an unsafe "lugging" territory, where heat from the amount of increased gas used per stroke (compared to the same amount of air per stroke) can cause damage, especially on air-cooled engines.

This doesn't take into account that there is a reduction in the number of times that the engine injects fuel, so while you might have to open the throttle more, overall, your consumption can be lower if the RPM drop is higher than your loss in power.

The lugging scenario is hugely unrealistic on just about any modern bike. You'd have to change the sprockets upwards of 30%+, and at that point you're hitting the physical limitations of actually fitting sprockets in there. A lot of modern cruisers are belt drive, too, so larger gearing changes on a belt drive run into other issues (like having the wrong size belt all of the sudden.

quote:

The only way changing sprockets to achieve a lower RPM on the highway can help is if, for whatever reason, your engine is already cruising at a damaginly-high RPM on the highway, but most bike manufacturers take this into account when designing them.

[quote]My favorite quote on the subject: "MPG is related to the amount of fuel that needs to be burned to haul a specific load at a specific speed, which is mostly to do with overcoming drag and friction. Those factors will not significantly change with revised gearing."


Science!
Drag and friction do not. Engine efficiency and performance does. If your engine is 10% more efficient at lower RPM, that's going to show up as a measurable change in gas mileage.

Some guys on 250s see upwards of 80-90mpg on bikes that are geared taller. Impossible with the stock gearing. Check ninja250.net or any other site where people actually care about gas mileage.

KozmoNaut
Apr 23, 2008

Happiness is a warm
Turbo Plasma Rifle


EDIT: wrong thread.

KozmoNaut fucked around with this message at 23:13 on Sep 23, 2011

Queen_Combat
Jan 15, 2011

Z3n posted:


This doesn't take into account that there is a reduction in the number of times that the engine injects fuel, so while you might have to open the throttle more, overall, your consumption can be lower if the RPM drop is higher than your loss in power.

This is the key sentence, right here. It all depends on engine design - whether or not a change in gearing, and reduction of fuel intake strokes, is offset by pumping losses.

Your example of "many 250's" applies, as they are generally geared for more torque at lower speeds to offset their lower engine displacement and make them more responsive and torquey at lower speeds, but they suffer at the higher ends because of that. If you lengthen their gearing, you're moving their peak efficiency (and torque curve) up, which may increase fuel economy at higher speeds but decrease low-end power. An engine designed for highway cruising will not benefit nearly as much (or may actually suffer a detriment), for the reasons I stated earlier. The power has to come from somewhere - you can't just get OMG FREE MPG INCREASE without trading something. There are many factors to take into consideration, like the torque/hp relationship for each and every engine. You don't just throw sprocket increases at engines without thinking it through.

And yes, the lugging scenario is very applicable, even with modern bikes, without a "30% increase" in sprocket size.


EDIT: VVVVVVV We will have to agree to partially disagree, then. We've both said things that agree with each other, but differ in other aspects. I won't clog this thread up with any responses re: sprockets/gearing/fuel economy, but thank you for your replies.

EDIT 2: VVVVVVV It's not an argument against changing sprockets and gearing as a whole, either.

Queen_Combat fucked around with this message at 02:07 on Sep 24, 2011

Z3n
Jul 21, 2007

I think the point is Z3n is a space cowboy on the edge of a frontier unknown to man, he's out there pushing the limits, trail braking into the abyss. Finding out where the edge of the razor is, turning to face the darkness and revving his 690 into it's vast gaze. You gotta live this to learn it bro.

Geirskogul posted:

This is the key sentence, right here. It all depends on engine design - whether or not a change in gearing, and reduction of fuel intake strokes, is offset by pumping losses.

You will see a reduction in gas mileage if you shorten gearing, and an increase if you raise it on every motorcycle I've ever ridden. Most modern engines are geared with an eye towards acceleration, not the best possible fuel mileage, and are more than powerful enough to continue to carry a motorcycle with a minimal increase in throttle application when you lengthen the gearing, but a 10% or more decrease in RPM. This is more true on standards than it is on sportbikes, as they tend to be geared much shorter from the factory, but even sportbikes will see consistent changes as noted from modifying gearing. I've personally recorded consistent changes when gearing has been modified on my bikes, around 5-8 mpg depending on overall design for changing up or down a tooth in the front. This applies even more on bikes that have big, wide torque curves and high efficiency at low RPM, such as a bandit 1200 or most big displacement V twins.


quote:

Your example of "many 250's" applies, as they are generally geared for more torque at lower speeds to offset their lower engine displacement and make them more responsive and torquey at lower speeds, but they suffer at the higher ends because of that. If you lengthen their gearing, you're moving their peak efficiency (and torque curve) up, which may increase fuel economy at higher speeds but decrease low-end power. An engine designed for highway cruising will not benefit nearly as much (or may actually suffer a detriment), for the reasons I stated earlier.

There are no motorcycle engines that are really "geared for highway cruising". We're not talking about Camaros with an overdrive 6th gear that puts you at 1800 RPM at 65mph.

You don't change the torque curve with gearing changes. You change the thrust at the wheel, but you don't change the engine torque by modifying gearing. Changing gearing does not modify low end power. It changes where in the powerband you are at a given speed. Taller gearing reduces acceleration and RPM at speed.

The closest that you'll get to "engines designed for highway cruising" is bikes with peak torque at low RPM. These bikes will generally see the best gains from taller gearing as they're operating closer to peak efficiency at low RPM, so pumping losses that you mention are minimized. The bikes that see the worst gains from longer gearing are heavily top end biased ones, (yamaha R6 comes to mind), where your engine is operating nearly entirely out of it's powerband when you're at freeway speeds. Even then, you will still see MPG increases, they're just smaller overall.


quote:

The power has to come from somewhere - you can't just get OMG FREE MPG INCREASE without trading something. There are many factors to take into consideration, like the torque/hp relationship for each and every engine. You don't just throw sprocket increases at engines without thinking it through.

And yes, the lugging scenario is very applicable, even with modern bikes, without a "30% increase" in sprocket size.

You're not getting "free MPG" out of gearing changes. You're reducing the acceleration of the bike, and depending on where the gearing changes put you in the powerband at high speed, could be increasing or decreasing top speed.

Look at gearing commander. Your lugging scenario is really not applicable. A 2010 sportster needs the gearing 43% taller to get the cruising RPM at 65MPH to drop below 2k. Even then, you'd probably still be ok, as redline on that bike is only 6k, so you're operating at 33% of overall RPM, which is fine. Same is true of a VRod, with a 30% difference in gearing, you're still cruising at 2900 RPM at 65 MPH vs. stock which would have you at 4100 RPM. Those redline at 8k or so, so you're still fine at 2900 RPM. The manual for the ninja 250 recommends that you're in 6th gear by 28mph, at a total RPM of 3.5k for a bike that revs to 14k. You're just wrong here on the lugging scenario. You don't have to believe me though, go plug numbers into gearing commander. Throwing anything under a 30% gearing change at any motorcycle isn't going to cause you to get into any level of RPM that could be considered dangerous.

You're incorrectly weighting the various factors that go into gas mileage vs. gearing on a motorcycle. Having to increase the throttle a small % doesn't compare to dropping 10% or more off of your cruising RPM, which is a direct reduction in gas burned. If I've got 1.1 gallons of gas and you've got 1 gallon of gas, I'm going to go a lot farther than you even if I use 20% throttle rather than 10% throttle.

Z3n fucked around with this message at 23:22 on Sep 23, 2011

Snowdens Secret
Dec 29, 2008
Someone got you a obnoxiously racist av.
The argument that changing sprockets does not affect fuel economy would also mean that driving down the highway in 4th gear gets the same efficiency as 6th.

BaKESAL3
Nov 7, 2010
So I changed my tires out on the gixxer today. Dealer's supply company screwed up the order so I ended up with a Sportmax Q2 on the rear(loving awesome), and a Pilot Road on the front. I'm afraid these two different types of tires are a horrible idea.


Then when I got home I guess I didn't put the kick stand down enough because it folded back and I dropped the bike. Scuffed my frame slider and cost me my shift lever so I did the logical thing. I ordered some nice Yana Shiki rearsets off Ebay.

BaKESAL3 fucked around with this message at 09:58 on Sep 24, 2011

NinjaTech
Sep 30, 2003

do you have any PANTIES
I had a hell of a time with my front tube. I had to take the tire off three times and patch 4 punctures. Then of course since I have awesome luck, the valve started leaking. This tube is just adamant about not holding air. Ruined my plans of riding to the peak in capital forest today.

I'm hoping costco's tire center is open tomorrow so I can try to get a new schrader valve put in.

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babyeatingpsychopath
Oct 28, 2000
Forum Veteran


Took the valve cover off, but can't get it out of the frame to actually check the valves. Is there a trick I'm missing? The book just says "remove cylinder head cover" by removing all the bolts.

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