Hey all, recently brought my bike back home from school and it consisted of 4 hours of 80 mph highway riding. Now, I was stupid and didn't check my oil level before riding, but checking it the next day, it was dry, which I was going to attribute to the bike burning oil while sitting at 7k+ rpms for 4 hours. Regardless of if this is the cause or not, I'm thinking of switching my front sprocket to a 17T when I have time just for the simple reason that it should drop my RPMs about 1k when cruising on highways.
My main concern is that I definitely do a lot of spirited, twisty riding, so I'm looking for impressions on how a 17T affected your guys "fast" riding if it did at all. I'm actually fine with the less low-end grunt, because one thing I hate about the 15T is I find myself having to shift like mad from a stop if I want to get up to a 45 cruising speed.
Also, I'll have to look back to date, but I think I have like 6/7k miles on this front sprocket (I also replaced the rear sprocket and chain at the same time), so would switching mean I'd have to replace both sprockets again or would it be ok to just change the front?
Although I like the standard gearing on my 02 GS I did suggest the possibility of using a 17 or 18T front to help with the high speed oil consumption on well used GSs in a recent post with no response. I still think it's a good idea, we did a 500 mile interstate day once at a pace a little higher than usual and I was down to the add mark when we got there. Later the same month a 400 mile first day at our 70-80 mph indicated usual pace resulted in no loss of oil or any added for the whole 1500 mile trip including another 400 mile interstate last day. I had a 14T front on my 97 GS then and think a 17T would have eliminated the oil usage at the higher pace on the first trip.
On the front sprocket change, I've never replaced a rear sprocket on any bike but have replaced the front every 2nd or 3rd or so chain change with no problem. Might reduce chain life a bit but there are so many variables I don't know for sure. :dunno_black:
My brake/chain record:
http://www.gs500.net/gallery/data/500/GSbrakechainlog.jpg
You drive a 500cc bike, if you want to get to 45mph in one shift get a bigger bike. Shifting through 6 gears to get to cruising speed is half the fun on these bikes :) Gives you the illusion that you're going faster. Even going up to an 18T isn't really going to make you shift less. You'll find it annoying having to slip the clutch more on starts. It is quite a torquey bike so you won't lose too much bottom-end.
Maybe try going to 20w50 oil first and see if it slows down the high-speed oil burning problem. I think the burning oil problem has more to do with the higher and constant load on the engine at highway speeds rather than the specific RPM. But that's just me, what do I know...
As I have posted on other threads here, I have been running 18/37 for over two years and love it. The upside is a very relaxed feel at highway speeds, less vibration through the bars and a very slight improvement in fuel economy. The downside is slightly slower pick-up in 1st gear and the need to slip the clutch on steep uphill starts for the first 5 metres (yards). Once above jogging pace there is little difference in feel until you reach 6th gear. Yes, in 6th, it struggles a little on steep hills or into a head wind but I just drop to 5th which is now almost exactly the ratio of standard 6th. In essence I have gained a "7th gear". I wish that I could do the same on my Honda but it is shaft drive.
On the subject of oil consumption, my K9 has only done 18,oookm but has never needed a top-up. As suggested by Wagoneer I do use 20w50 over the Summer period as it often gets to 40C+ here (104F+) during that time. I have found over the last two Summers that the thicker oil makes a very significant improvement in gearshifting and clutch operation. For the cold weather I go back to 10w40 or more usually 15w40.
Macka
I've literally just swapped to a 17t front sprocket this past weekend. Bike feels fine. Smoother at higher speeds say circa 60-70mph. no issues on pulling away and general riding. Still happily bimbling around London city in 3rd/4th gear at low revs. Will fill up on the way home to see what mpg it is giving. Doing a 400mile round trip this weekend, so will be able to see if the gearing is better for the longer trips. I also just topped the bike up, and will be take a spare 1lt with me for the trip.
So Prmas, don't tell me you've got a CX too?
Jools
Quote from: Wagoneer on November 04, 2013, 08:13:30 PM
Maybe try going to 20w50 oil first and see if it slows down the high-speed oil burning problem. I think the burning oil problem has more to do with the higher and constant load on the engine at highway speeds rather than the specific RPM. But that's just me, what do I know...
Unless the engine is an old high-miler its more likely the oil has evaporated rather than burnt off. GS5 engines are very prone to this on long runs at constant speeds and loads. Fill it with a low volatility full-synth for the journey back and if the problem is evaporation you wont loose as much.
There are simple tests you can do. Look for oil traces running out of the drain hole on the underside of the can. Run your finger around the inside of the can end after a long run, if it comes out wet and gooey you are burning a significant amount of oil. You can also hold a sheet of white paper a few inches off the pipe end with the engine running, if its burning oil it wont be long before the paper gets soggy :thumb:
No Jools, it is an NT700 Deauville which I use for touring. In fact, on the 15th I am heading off on a 2000+km/9 day tour with two mates. They will be on a Honda Shadow and an older Suzuki 1200 Bandit. The GS is my "just for fun" bike. It is a beautiful evening in Melbourne right now and I have just returned from a little ride around the suburbs and down to the beach on the Suzi. It loves the cool evening air and I really like riding at night. :cool:
Macka