The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: MrRiden on October 20, 2007, 04:16:11 PM
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All,
Got into an unfamiliar sweeping left hand bend too hot and had to get off the throttle rather quickly. My '82 R65LS began to wobble in the manner of a petite tank slapper tho' not completely out of control. I got back on the gas and it stabilized. It did this once more making me enter turns very cautiously and add power when the turn exit was in view for the rest of the ride. This werked fine. I'm thinkin' that it is time for the long neglected steering head adjustment. I'm not a real aggressive rider and I've gone too deep too fast before and had nothing like this happen. Any other mechanical gotchas I should look at?
thanks'
Rich
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Rear shocks.
Fork oil.
Tyre pressures, particularly front.
Tyre condition.
Frame mount studs tight.
How were you loaded (the bike that is!!!!)?
Notchy, dry, tight, loose, grease hardened head bearings.
That'll do for starters.
Bill.......................;-)
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Hey Bill you missed crappy road surface...
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Rear shocks.
Fork oil.
Tyre pressures, particularly front.
Tyre condition.
Frame mount studs tight.
How were you loaded (the bike that is!!!!)?
Notchy, dry, tight, loose, grease hardened head bearings.
That'll do for starters.
Bill.......................;-)
Good list! Let's see:
BMW fork oil should be up to level but I have 'nuff to drain & refill to be sure.
Tires 30 front 32 rear just checked. Good non cracked tires with plenty of tread.
Frame mount studs... um, not sure, you mean engine mount? will have to check!
No luggage to speak of, just my tank bag with a Gator Aid, first aid kit, maps and my cheater glasses.
Bearings don't seem to be either stiff or notchy, I suspect a bit loose, no play but this bike tracks rain grooves like a blood hound! Made me want to try a damper but I want to go the standard route first.
Shocks are Hagons at the lightest preload & I weigh about 160-170 somethin'.
Swing arm bearings just greased. I'll check the engine mounts, fork oil, and head bearings. Also will look for a St. Christopher medallion.
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Rich, you may want to experiment with different tire pressures. I was using 30-32 psi for quite some time, and it was suggested to up the pressures and see what I thought of it. I now try to keep the pressures in the 34-36 psi range on the front and rear. If you are going to remove the bearings and races, I've got the next 5 weeks off of work, and I like to see how to remove and install the steering head bearings, because I've got 80,000 miles on mine, and I'm sure they are in need of replacement !
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I agree with Bob on the pressures, unless you are about 90 pounds wet! ;) I know both of my R100s would be rather squirelly with those pressures...
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Yep, higher tyre pressures certainly flattens out those squirrels, along with the rabbits, gophers, rats........................
Bill................;-)
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Heh! [smiley=evil.gif]
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Tire pressure, among the other factors that folks have pointed out could certainly contribute to this,
though I think that your rear shocks may be set a bit too light/squishy or are adjusted to be underdamped.
Another argument for running a bit higher tire pressures is NASA's findings on hydroplaning speeds.
It was determined that, all other factors being equal, the hydroplaning speed of a vehicle was a
function of the tire pressure - specifically 9 X (sqrt(P) where P is in PSI = Hydroplaning Speed in Knots.
So running a bit higher tire pressures, especially if you live in wet climates or where water onthe road
is common, can help reduce the potential for hydroplaning and associated loss of control.
Now this DOES NOT MEAN pump up your tires to 50 PSI, nor does it mean that you don't have to slow
down in wet road conditions - it just can provide you a bit more margin for safety.
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I've never noticed hydroplaning on my bikes, just in cars. It's really fun in front wheel drive cars.
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Bob and esteemed R65 owners,
I'm going to go after the bearings first as I've not been there yet. I've P!$$ed away this weekend so will make an attempt next weekend after visiting The Cycle World International Motorcycle Show http://www.motorcycleshows.com/. I'll use SueCanadas guide which calls for a second person so Bob I'll pm you 'bout that.
Nhmaf, I will also try more preload on the shocks and experiment with higher pressures (34/36 to start?). You site NASA and hydroplaning which made me smile at a bit of Irony. When this happened I was on my way to a little breakfast spot called the Space Age Lodge. Excellent pancakes. http://www.roadsideamerica.com/tips/getAttraction.php?tip_AttractionNo==76
As for hydroplaning, well, it happened on a stretch of road on Az 238 http://www.americansouthwest.net/arizona/sonoran_desert/national_monument.html
but your point is still taken! Thanks for the guidance!
rich
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Rich, if your near tank slapper happened on AZ 238, I doubt that the road surface was a contributing factor, that has to be one of the smoothest roads I've ridden on. Rich, did this happen in one of those sweeping turns about 20 miles or so east of Gila Bend ? That was a great road, until every jack-a$$ going to or from San Diego, found out it is about a 75 mile shorter drive than using I-10 to I-8.
A co-workers kids have named it 'DEAD COW' road, it's one of those areas known as 'open range', no fences to keep cattle off of the road, and it's a hilly and twisting road in some areas. Needless to say the amount of dead cows on that road is downright scarey, I refuse to ride or drive it in night conditions.
Rich the Space Age Restaurant is one of those roadside 'attractions' that everyone needs to see, a few years ago they had a fire in their kitchen, and on the sign out in front of the burned out building, they had put up, "WE'VE BEEN ATTACKED BY ALIENS".
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Next time I'm in AZ I will have to go looking for that restaurant. My wife and I did at least manage to get
out to Meteor Crater last year - we had to help with her brother's wedding in Phoenix so we didn't have alot of
free time... :(
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nhmaf, this restaurant/hotel/motel, is located in Gila Bend, Az., you can't get much further out in the middle of nowhere than Gila Bend, Az.. If it wasn't for fact that motorists needed fuel between Yuma, Az. and Tucson, Az., I doubt that it would be in exsistence today !!!! But the aforementioned restaurant is quite a curiosity from the outside ! Best to visit before or after the HOT season !!
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I've never noticed hydroplaning on my bikes, just in cars. It's really fun in front wheel drive cars.
Two years ago going up the hill at a high rate of speed out of Chatsworth GA in a driving rain storm following a FJR1300- the front end started moving right of its own accord (with the crown of the road) rolled off the throttle and dropped 20 mph and it stopped. Took a couple of deep breaths and slowed down some more. Thank God I was going uphill. :-/ :o :-[
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Whew, werk week over!
Yea Bob, It was on the first and second big sweeper. Hit the first at... um...well I'll plead the fifth cuz I'm not sure what felony speeding is here but as I said I did get off the gas abruptly. There was a fatal accident to view on the return trip so I won't be so callous net time I go for the 'flying saucer' breakfast. This is a really nice / dangerous road. I've got some automotive issues with the pink haired töchter car but I'll give a shout when I get down to the bearings.
rich
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Rich,
The posted speed limit is 55 mph, and I normally do 65 mph with no problems at all.
One of the biggest problems is the drivers of cages, I have been passed by vehicles doing approximately 40-60 mph faster than I was doing.
A lot of those vehicles were towing trailers with off road vehicles on them, and motorhomes with trailers.
It's a common 'by-pass' to get to the Imperial sand dune area just west of Yuma.
Also becoming a well known short cut to San Diego. Knocks about 75 miles off of the I-10 to I-8 route.
The road opened in late October '99, and for the first 2-3 years, you saw more cattle than vehicles.
Just give me a shout when you do the bearings.
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Just a quick aside to the road discussion....when I did the cleaning and lubing of LRB's steering head bearings, I knew they needed something done as I wobbled literally around corners and I can see now that if I had ever entered a corner too hot, it would likely as not caused a tank slapper! The only thing I knew was that the steering was stiff and it got stiff suddenly. A little perplexing Rich as you say your steering is not stiff?? Hmmmm. Can't hurt to clean 'em up though that's for sure.