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Gearing

2K views 23 replies 13 participants last post by  Allan 
#1 ·
Hi all.
Does anyone else have the same issue with the gearing on the F800ST as I do?
I find that at slow speeds 20, 30, and to a lesser degree 40 that if I want to stay at the said speeds, I experience not quite a judder but just the feeling that I could do with an in between gear. I always tend to ride at 20 in 2nd 30 in 3rd 40 In 4th but feel that I could do with 2.5 3.5 4.5 gears.
If I ride at 30 In 2nd it feels to revvy yet 30 In 3rd feels too high.
It’s all fine if I’m accelerating away through the gears but staying at a constant low speed as I say feels not quite a judder but a feeling of being In the wrong gear and I feel it’s down to the gearing.
 
#2 ·
I assume your figures are in miles per hour or you'd likely be stalling, not just experiencing judders.

You are riding in a gear not optimal for the speed, hence, the "judders." One gear down for the figures you provide. Aim for (roughly, as there are many variables here) high 3000's, low to mid 4000's. This range has excellent torque.

It's a motorcycle, not a diesel truck.
 
#3 ·
Ditto what Andrew says above. The 800 engine requires a higher RPM for optimal operation. In my experience (almost 10 years) if you are riding below 4,000 rpm the engine is lugging a bit.

Additional warning: in cold weather, if you are using heated gear, you will definitely run the battery down by riding below 4,000 rpm. Don't ask how I know this.:rolleyes:
 
#4 ·
I would disagree. 3000 rpm as a "shift up" point is fine until you hit about 70 km/h, depending on how hard you pull on the cable. If you want to really hammer it, stay up in the rev range, but if you're just flowing with city traffic on a warm bike - 2000-3000 is fine. The bike doesn't really start to "judder" until you get below 1500 rpm - unless US bikes are built differently for some emissions reason.

The benefit of riding like this is an even more ridiculous mpg.
That said: The gearing seems to be intended to hit metric speed limits. 4th is slightly above 2k rpm @ 50 km/h. 3rd is slightly below 2k at 30 km/h. 5th is slightly above 2k @ 60km/h. if you try to ride the bike at low revs - these are just barely above the point where the engine actually feels like you're lugging it. 3rd @30 feels too low, in danger of prematurely stretching your cam chain.
 
#5 ·
It seems from what everyone is saying that the F800ST engine is quite revvy as opposed to the CBR 600 which I sold to buy this one.
That wasn’t at all a revvy engine and would quite happily go along in the gears indicated at the speeds mentioned.
It appears that I’m going to have to change my riding style slightly and realise that the engine needs a bit of revs.
Thanks for all the replies guys.
 
#14 ·
It seems from what everyone is saying that the F800ST engine is quite revvy as opposed to the CBR 600 which I sold to buy this one.
That wasn't at all a revvy engine and would quite happily go along in the gears indicated at the speeds mentioned.
It appears that I'm going to have to change my riding style slightly and realise that the engine needs a bit of revs.
Thanks for all the replies guys.
The F800 engine has two different personalities. When I'm riding along in traffic and have no need or desire to accelerate but simply to maintain my speed, I'll often keep the rpms between 2500-3500. It's a relaxed pace I'm riding at, and I'm not expecting anything performance wise out of the engine. The other personality of the bike comes out once you get above 5000 rpms. The bike will happily rev all the way up to redline, and will actually run smoother all the way across the rpm range if you do that.

You need to adjust to what the circumstances are. As Royce mentioned, if you're in cold weather and using heated gear, then keep the rpms up just a bit to make sure you're providing enough amps for the heated gear. Riding at 2500-3500 rpms works fine on flat ground...but if you hit hilly country, you need to drop down a gear to where the bike feels smooth and not strained.
 
#6 ·
It's partly because these engines run so lean - a steady part throttle at low revs is really quite uncomfortable in how jerky it makes the engine.
However, you can make your ride much more relaxed by fitting a boosterplug or similar. This fools it into running just a teeny bit richer, but makes a huge difference in low speed running behaviour. So much so that I can happily chug along smoothly at 2500rpm in 6th gear (I tried it when I first fitted one), and then crack the throttle wide open with no judder, bogging, or any similar trait.
There are several variants of this sort of thing out there, and they really *do* make a difference.
 
#8 ·
Yes you could say they are expensive. But put it in context. Not sure about restaurant prices in England (I'm assuming England because I can't imagine our American friends using the phrase....Cor blimey!) but I took my daughter out for her birthday and the bill came to $230. So for the price of a good feed you can have a much easier time of it at low speed on any of the F800s. I have such a device fitted, and although I seldom encounter traffic nor ride in cities or towns often, I feel the benifits far outway the cost.
 
#11 ·
Excellent choice mate.

Looking forward to being able to nip across the channel and pick a few bottles up from where that's produced. But until things improve over here, we'll have to be content with what the local off licence can provide us with.

Happy daze.
[emoji898]

Sent from my moto g(8) power lite using Tapatalk
 
#13 ·
'The old man' your original question was a fair one and your thinking to adjust your riding style is worth trying. There often seems to be new F800 owners here, so this is my experience from being around rotax engines for many years. Rotax designs and builds performance engines. With good maintenance, the F800 engine can run at 75% of redline mile after mile, all day long, day after day. In fact race engine builders have a term they call "killing it with kindness". Over lugging an engine has detrimental mechanical effects like rod knock (wrist pins), crank bearing wear, piston and valve heat wear and while lugging a motor you're building more internal cylinder heat all while your oil pressure is at its lowest. A certain amount of reciprocating engine mass actually helps an engine last longer. So, we riders may feel the bars are buzzy or it doesn't get as good of fuel economy, the truth is the engine runs better at a little higher rpm. So back to your original post, if your F800st is feeling revvy in 2nd gear at 30mph it's probably not hurting anything. I spend lots of time between 3k and 4k without a worry. Everyone should ride their motorcycle in a way that's comfortable for them, but the rotax engine has no complaints being pushed a little.
 
#15 ·
I'll back XR1000's opinion. As he says, many of us came to the F800s after many miles/km on very different machines. In my case nearly 40 years on BMW airhead twins. It took me quite some time to overcome the reluctance to hold it at much higher revs than I was used to. And against what my intuition was telling me, fuel economy actually increased. The aforesaid however, does not help with 1st or 2nd gear slow speed riding (in slow moving traffic etc). My personal experiance with an AF-XiED unit is that it has mostly cured my bike's tendency "snatch" at low throttle openings. Oh yeah...IanA. I know Tassie wines beat the hell out of that French dishwater, but what's a father to do when trying to impress his daughter as a man of the world?
 
#16 ·
On my first extended ride, I am impressed with the ability to "lug" down between 2-3K rpms and pull away. I didn't try WOT at those rpms, just letting it pull away. My Tiger 800 was not nearly as good at those low rpms, but was superior on top. I have had quite a few bikes in the past, and it pulls like a bigger twin, to me. Weight to HP ratio probably helps a lot. I will say it feels smoother in the higher rpm ranges (above 4k). So far so good!
 
#17 ·
dencof. Most riders are not complaining about accelerating from low revs/low speed. Indeed as you say, as long as the throttle is rolled on steadily, the F800 performs well. The surging most complain about is at low constant speed/low throttle openings, as in lane filtering, road works ect. This is where the O2 sensor modifiers have the greatest affect.
 
#18 ·
Thanks Redned. I have not been in that situation with the bike yet. I have taken a late night ride, with no one around and experimented with speeds/gears to see and feel what was comfortable with the bike, but didn't try steady state 20 to 30 mph at 2-3k rpm. Is this a known issue with all 800s or particular years? I appreciate learning from you that have experience with this machine. dc.
 
#19 ·
dencof. From the amount of posts it seems to be common over the whole F800 range. The main reason for this occurring is that, to meet EU/US environmental regulations, the fuel/air mixture at idle and low throttle openings is set very lean. So when just tootling along and slightly opening the throttle, the injectors fire in a lot fuel. The bike lurches forward, you back off the the throttle, mixture goes lean and the bike drops speed dramatically. This makes progress at low speed difficult to control. As I and others have said, the O2 modifiers fool the ECU into richening the idle mixture, making (certainly in my experience) low speed running much more managable. Others may be able to give a more detailed explanation.
 
#20 ·
Hi , as a newish F800ST owner (1 year ) I have started to notice the “ snatching “ at low revs when rolling back onto the throttle as described I the above post. I’ve never heard of O2 modifiers and would appreciate some more information if possible. Where can I get one and , as a reasonably competent home mechanic , could I fit this myself. I’m in Derbyshire UK
 
#21 ·
Allan. There are a number of O2 modifiers on the market. Some are very simple and cheap.....basically just a resister in the sensor circuit to change the voltage the ZFE sees. From a number of threads on this site, the bikes computer soon figures out that it is being tricked and any effect these modifiers had soon disappears. The more expensive units involve electronic trickery that the computer doesn't seem to detect. I use one, it's been on the bike for some years and is still producing the desired effect. Search the net and and you should be able to find them. Most of the good ones cost between $200A and $400A
 
#23 ·
bmwroadsterca. My mistake..it was early in the morning here. However, reading Allan's post, I gathered that he wasn't "au fait" with the whole O2 concept so tried to keep it fairly general in my discription. Many so called O2 Spoofers are indeed only air temp spoofers and it is these that the engine management system (CPU?) soon learn to ignore. These are usually the cheaper alternatives. True O2 sensor modifiers are usually much more expensive.
 
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