The thread where I ask questions about my new R65L

[Tony Smith]

Been checking prices (US Dollars)

Shorai drop in replacement for R65 - $72.53 on special $275.95
http://www.batterygiant.com/motorcycle-battery/BMW/R65/LFX27L3-BS12

An eBay seller at $202.00
http://www.ebay.com.au/itm/Lightweight-Lithium-Powersports-Battery-DLFP-50N18L-A-for-84-95-BMW-R65-Apps-/311406487191

Same battery at $250
http://www.ebay.com/itm/Lithium-Battery-BikeMaster-DLFP-50N18L-A-BMW-K100-K75-R100-R60-R65-R75-R80-R90-/361303015792


Now we are cooking, LiFePo4 at $171.
http://www.batterystuff.com/powersports-batteries/LFX18L1-BS12.html


Getting there - also LiFePo4 and $150
http://www.batterystuff.com/batteries/ss51913.html


And these guys have a price range of $404 right down to $105.
http://www.revzilla.com/parts/1980-bmw-r65?page=3


Ok, I found myself wondering why the price difference, obviously there is a price point for LiIon batteries and the newer (and cheaper) LiFePo4 batteries. But why the range?

Then it clicked - the number of cells and whether those cells are merely hooked up in series or, with a greater number of cells, if they are wired series/parallel (the second having the obvious advantage of lower individual load per cell) - depending on price a 12V Lithium battery will have 4 or 8 cells (the standard output of a Li based cell is between 3.7 and 4.2 volts).

I have two thoughts.

Before I bought any Li based cell  I would want some real-world results based testing as to how long they last and what they are like in service. Even more so on a battery from the bargain basement end og the spectrum. I well remember my first foray into AGL, that battery lasted a whole 9 months, well at least it was cheap. It also failed on a wet cold day (the wet is usual the cold is not for where I live) and doing a one-man push start on even something as benign as an R65 isn't fun when you are nearly 60.

[misterpepper]

http://shoraipower.com/lfx14a2-bs12-p66

Purchased on amazon for $128.33 shipped. It is a motorsports battery, designed for starting duty, 8 cell for better cranking. This one is a small form factor, so to put it in the battery tray you need to put some foam or something in there to hold it (it comes with lots of foam for this). I probably should have gotten the L2 version instead of the A2, because the polarity makes more sense. Some other brands to consider are Antigravity, Ballistic, WPS and Earth X.

Regarding cell count, you are correct. You need enough cells in series to get the correct (~12V) voltage, but the cells can only provide so much cranking power. To increase cranking amps they add cells and wire them series/parallel. Some manufacturers use round cells, and others use prismatic (rectangular) cells. You can get the batteries with a case/housing that is a drop in fit for the battery you are replacing, or you can get them with a case designed to just fit the "guts" inside. The direct replacement ones typically cost more.

[misterpepper]

Question 4: my driveline has a real rubberband feel to it. I don't like it. I assume this means the spring or anti-shock parts are worn out. Can I replace the driveshaft with one from an earlier airhead that does not have this feature? Is that wise, or would it be better to replace the worn parts instead? Is there some way of diagnosing what exactly the problem is short of opening it up?

[nhmaf]

If you put the bike on the centerstand, gearbox in gear, and raise the rear wheel off the ground - how much rotation/play do you feel before you detect the resistance of the engine?   Put the gearbox into neutral and rotate the wheel back and forth - does the amount of slack seem similar?

The spring in the cush drive on the later driveshafts is pretty stout.. they seldom break but when they do, one usually can feel a significant "clunk" if it is broken and the ends separate & come together.    It will require a good size press/spring compressor to service - if you want to try to take on that challenge.
But first, be sure of your diagnosis

[misterpepper]

My center stand is missing the spring(s) so I have it zip tied up out of the way for now, but I'll figure out how to get the rear wheel off the ground to check it out. Looking elsewhere on the web it seems the driveline "cush" spring can wear out. Is this common? I would imagine that a properly functioning driveshaft spring should only rarely be felt and only under abusive acceleration or shifting. Am I wrong to assume this? I feel the lash under all but very gentle acceleration.

[Barry]

It's not common for the drive shaft shock absorber spring to  break or wear and if it did I don't think it would produce a rubber band feeling so I'd say you are correct in assuming it should be relatively unobtrusive. Could it be something else you are detecting like clutch slip ?

[montmil]

Just a thought here...

Motorcyclists that are perhaps late in discovering the simple pleasures of owning an Airhead BMW, particularly those people that have only ridden more modern bikes, find and or imagine all sorts of concerns about the Airhead transmission and drive line. Operating an old Bavarian tractor takes a bit of getting used to.

A certain amount of driveline lash will always be there. Careful shifting, by matching revs to road speed and gear selection, pre-loading the shift lever and holding the lever in position until the complete gear change has been made will eliminate most, if not all of, gearbox clash.

Then there's that large, relatively heavy, automotive-style flywheel that doesn't want to slow down. The clutch adds its own flywheel effect.

Transferring drive to the rear wheel adds more opportunities what with spline gears and the crown gear.

A different world from the hi-tech Japanese and newer Euro bikes. I shift my Triumph Triple with an entirely different style.

[wilcom]

Motorcyclists that are perhaps late in discovering the simple pleasures of owning an Airhead BMW

So true Monte............. I came from worn out Nortons when I went "Beemer".  That ol' used R50 with the funny forks was worlds ahead of anything Norton. It was quiet & smooth in comparison.  If you went from a modern rocketship 4 cylinder bike to an Airhead it would scream tractor with every mile.

Once you figure out you can't pass anything, anywhere...... it becomes a VERY nice tractor LOL

[montmil]

Copy all, Joe!  [smiley=thumbsup.gif]

[misterpepper]

The only other bike I've owned was a Yamaha TW200. Japanese yes, high-tech no. But it was a wet clutch with probably relatively little mass to the flywheel.

I don't think any springs or parts are broken, hence the rubber-band feeling and not clunking of some sort. It may very well be user error, but it seems to me that a correctly functioning driveline wouldn't behave the way mine does. Accelerating in 1st gear is a little like a novice stick shift driver with the torque from the engine loading up the lash in the driveline, then the driveline catching up and releasing it's stored energy and repeat a few times until the bike and engine settle into the same pace. At speed there are no issues unless I flog it a little, probably due to the lack of torque in higher gears to load the driveline.

[montmil]

Golly gee whiz! So much Airhead knowledge in such a very short time. Impressive.

[decorn33]

For what its worth, if you are certain that the rotors are below minimum in their grooves, then replacements do seem warranted, however my original disk was grooved just like the ones on your LS when I was exploring my options. I found an outfit called Truedisk LLC. Motorcycle Brake Rotor Resurfacing, (www.truedisk.net). They are in Michigan, a fellow named Tom Tokarz runs the place. I had the rotor back in about 2 weeks - looking as good as new. Much cheaper than having the rotor replaced by Spiegler, (as long as it can be resurfaced.) If you are not certain, Tom will evaluate and respond before any work is done.

[misterpepper]

I've been riding the R65LS more lately, mostly due to the fact that my car crapped out on me. Riding it more has pushed me to address some its issues. I have new tires on the way and brake rotors and pads have shown up. Ideally I will be converting to tubeless when the new tires go on, so I probably need some stems and maybe a way to ream the stem hole. I figured out that my voltage regulator wasn't putting out enough volts to keep my lithium battery happy, so a new adjustable regulator is on the way. I've been going through and doing all the tuneup adjustments to the valves, timing and carbs. It's running much smoother now. I need to find time to lube all my splines and bearings to improve the shifting and steering. All my electrical is working now. I really wasn't planning on this being a standard mode of transportation until after I had a chance to pull the engine and transmission and go over all the little stuff first.

It's a fun bike to ride. I haven't had it up to freeway speeds on account of the old tires. I get some wobbles if I take my hands off the bars at about 30mph. Hopefully new tires solves that, but I still need to check the head tube bearings. I'm understanding the "rubber cow" nickname better. What are the best ways to combat the flex? I can tell that my front forks need some attention, and my rear shocks don't look like any of the currently available options I've found. I'll have to post a picture to see if anybody recognizes them before I replace them with something else, because the rear suspension needs attention as well. Oh yeah, and my speedometer died on my first longer ride. It's been fun, though.

[Bob_Roller]

What was your decision on brake rotors

With the front fork brace you have installed, I don't think the fork is flexing, possibly more tire condition/balance issue, steering bearing adjustment .

[misterpepper]

Fork brace is actually off right now, as well as the front fender. That probably has something to do with it. I'll check that steering is tight and report back after the new tires are installed.

What tire pressures are you guys running? I've heard that airheads like higher pressures, around 40psi. I'll be running dual sport tires (Pirelli MT90-AT) which would typically be run at lower pressures around mid 20's for on road. What would you guys run for 80/20 street riding on dual sport tires?