Top Speed, Tach and false neutrals

[awaffa2003]

Hey guys, i'm running into a few problems and i think montmil may be able to help on this one 4 sure.

1st: what's the fastest you guys have been on your '65's? i've heard that a properly tuned R65 can cet close to triple digits, the most i've heard of is 105MPH. on my way to gillette, freeway speeds were at about 75, but one time i wanted to see how fast i could get it going and i topped out at like 86ish, going downhill... to say the least, i was dissapointed. what are these machines good for?!

2nd:MONTMIL, my tach still isnt working, help! i called trail tech and they sent me a resistor tach wire, now the thing wont even go above 5000 when i went screamin down the road today, 5th gear @ 80MPH. is this normal? I've never had a working tach, even the stack one was broken before i got the bike.

3rd: false neutrals SUCK! someone tell me why they happen and/or how to stop them. when i get into one, i feel like i'm somehow grinding my gears so i slow down and it goes into gear by itself. is this bad for the bike cuz it's happening a lot every time i ride and i'm not wanting to screw up my transmission.

Thanks in advance.

[mikethebike]

I may be reading between the lines here but I suspect that you are expecting too much from an R65.  The design of the engine and gearbox is very basic; agricultural even and was not really meant for high rev slick gear changes as found on later machines.  I may stir up a hornet's nest with my opinion but there it is.  False neutrals occur when the gears are not synchronized into mesh and the gear spins freely before being fully engaged (often caused by trying to engage gears at inappropriate revs/speed).  I found that with the BMW box you can put pressure on the shifter just prior to using the clutch, the gear then slips into mesh as the clutch is used.  Hope this helps,
Mike

[steve hawkins]

My 1979 R65 will top the ton...just.  Calibrated digital speedo rather than optimistic original fitment.

Here is the thing - hold your gears and use the whole rev range - expect to be at 90+ in fourth and still accelerating.  5th is an overdrive, change up too early and you will lose your momentum.  If you started accelerating in 5th at 75mph you will never get there.  Gears - use them.

Also, do you have a fairing or luggage?  Both will go against you for outright top speed.  Weight and drag.

A post 81 bike will change sweeter that a pre 81 due to the flywheel weight.  You have to be very positive on both however, when you change gear.  The gearboxes are effectively the same.

Get out on the freeway with your chin on your tank and try again......see if you don't start grinning...

Steve H

[montmil]

Yo, Harrison... Have you tried "toggling" the Vapor set-up between the "2-stroke and 4-stroke" program? Remember that the Beemer generates a wasted spark on the cylinder going thru the exhaust cycle. The tach's inductive pickup may be tricked into thinking you're on a two-stroke R65. Play with it and see what you can discover. And post up on that resistor tach wire, OK? I'd be interested in the results.   Monte

[nhmaf]

My '82 LS has buried the speedometer (85 MPH) and still had more left - if your bike is in good tune and not pushing a big fairing or got a bunch
of luggage on its tail it should be good for 100-105 MPH near redline in top gear.   As others have posted, if you're fighting a headwind, going up much of
an incline, or not hugging the tank you will have a tough time getting there, and use all your gears and RPM range.

[Ed Miller]

Mine will nearly red line in top gear on a long flat stretch, which is somewhere around 105.  With my Windjammer and big saddle bags I'm not sure it's the smartest thing to do.  

[awaffa2003]

I KNEW it had to go faster! maybe somethin's messed up...cuz even today, 86 tops, going downhill...hugging the tank. maybe i need a propper mechanic, i've been takin it to this indie guy from our club, runs a "shop" in this spare garage. i want to do my own work, but i have no idea where to start, nor do i have special equipment such as a lift and things. anybody have any tips? i'm still runnin the K&N's with no change in jetting, about the only real thing i've done to effect performance. maybe instead of forkin out all that money to make it look cool i shoulda made sure it ran well...although it took me to gillette and back problem free (2100 miles).

ok now for the false neutrals, had to do a quick merge today, i was stopped, pulled into the street, almost out of the 90 degree turn i shifted into second, freaked the crap outta me cuz i popped a lil wheelie doin it. shifted into 3rd (false neutral) now this truck is on my bumper while i'm revving away. dont have time to let it clunk into gear by itself, so it took 2 "shifts" to get into 3rd. this is a huge problem!!! is it me just trying to shift too fast or am i grinding my gears off???

Montmil, resistor wire is no good, i cant get it above 5000 when i'm actually riding but in neutral, i can get it up to 7400ish, which i think is redline. maybe it's right. i wish i could mount up a working stock tach and compare...totally and completly in the dark on this one as i have no past reference.

[montmil]

well...although it took me to gillette and back problem free (2100 miles).

Montmil, resistor wire is no good, i cant get it above 5000 when i'm actually riding but in neutral, i can get it up to 7400ish, which i think is redline. maybe it's right. i wish i could mount up a working stock tach and compare...totally and completly in the dark on this one as i have no past reference.

I'd say you've got a very reliable 25-year old BMW motorcycle. 2100 miles without a hiccup is spectacular! Me? I'd leave it alone.

Could be there's some other issues going on within the engine internals as to your performance questions. Have you ever done a compression test on the cylinders? If cylinder compression is below spec, you'll see a deterioration in performance but your reliability won't be effected too much. This is going to generate your tachometer questions and answers. Testing is easy. Get your indie to assist. I've done this on several engines powering various vehicles. You may solve your riddle.

Don't fret. Enjoy.

Monte

[nhmaf]

As to the false neutrals - when was the last oil hange in your gearbox ?    I'd certainly make time to do it, and carefully check the magnetic drain plug when you first pull it out to drain the oil.  Look closely - if it has what feels like a small amount of "fuzz" or "paste" on it, this is some very fine metal bits which is more or less normal.  If you see or feel any "chunks" ( a chunk being something grittier or with pieces larger than typical "toothpaste" consistency), this could indicate that you've got something wearing out abnormally quick in the gearbox.

BMW's don't shift quickly like a Japanese wet-clutch bike will, either.   As mentioned before it helps to preload the shift lever just a tiny bit before the shift, and the shift has
to be pretty deliberate & definitive - a casual "flick" of the toe will not do.

Perhaps a fresh gearbox full of clean 90W-100 gear oil (don't need to go with synthetic, but you can if you like - but be prepared for the possibility of some leaking seals if you do) will set her all right again and reduce your false neutral problems.   Of course, it wouldn't hurt to pull the transmission and check/clean/lubricate the
input shaft splines and clean&lube the pushrod/piston/throwout bearing at the back of the transmission either.   After doing these things to my bike, it shifts much nicer
than it did previously, and adding on Justin B's very robust shift selector rod helped too !    Perhaps this is a good project to try with your mechanic friend.    IF you guys
need pointers, just let us know !

[Justin B.]

I can't add much other than to reiterate that it ain't gonna shift like a Jap bike and if you try to make it shift like that it'll bite you and cause you grief.  You must "preload" the shift lever and it helps to "blip" the throttle on downshifts.  I can't get a decent 1-2 upshift out of any of mine but the rest of the gears are OK.  I found that synthetic 80w140 helped just a little...

As far as performance, the K&N pods may be hurting you as I have read some knowledgeable folks indicate they hurt performance.

[steve hawkins]

I am also running the pod filters, the biggest oval ones I could find and there is no doubt they still hurt the top end performance.  I do struggle to make it to that 100mph with them on.If you have the small connicle air filters, I am sure you will be restricting the airflow somewhat.  

But I am not interested in being there even on my Cafe Racer.  Being caught do 100mph in the UK is an instant ban (1 year) and that is not funny.  I am more interested in the 50 -80mph bracket. Having said that, I would be disappointed with 86mph as a top speed.  

I would refit your airbox and see if that makes the difference, before doing anything else.  While you are at it make sure your pod filters are clean before you refit them.

Let us know how it goes.

Steve

[nothing]

Shifting is not easy on these bikes, but two things will make all the difference: Preload and Follow-Through.

It's been said before, yes I am being redundant but I hate seeing a tranny abused.

Preload: Put just a little pressure on the shift lever BEFORE you pull the clutch, and keep that pressure consistent, and the shift lever will pop right into the next gear when it is ready - try it, you'll be pleased.

Follow-Through: Keep that pressure on the lever until you are fully finished with the shift and the clutch is fully released, then and only then you can relax your toe. This will help it stay in gear when you get back on the throttle.

Preloading is also the way to happy downshifts.  [smiley=beer.gif]

[Justin B.]

But, even with correct technique you can't (at least I can't) expect a non-synchro gearbox to shift lightning fast or light as a feather.

[nothing]

Well, with proper technique my shifts are light, slightly heavier than a feather. And lightning fast wouldn't be proper technique, at least the technique that works for me - it is a process and takes a beat or two to execute correctly.

I'm certainly not saying I nail it every time, but when my shifts go wrong I can usually see where my technique was at fault - it's been a long time since I've felt the urge to blame it on the machine. I'm rather proud of the improvement, actually.

[mikethebike]

Forgot to add that a gentle release on the clutch will add years to the life of the transmission.  No chain (or cush rubbers)on R65's  means that there is a direct drive to the wheel, with only the clutch itself and a slight dip in the suspension to take up the drive.  With a quick clutch release you may have a kick in the wallet to go along with the kick in the pants!  To some up on the clutch use - fast in-slow out! (Works in other areas of life too I am told!)