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Handling question/ tire question

schwinnman67

schwinnman67

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Guest
I finally took my 86 out for a ride today and noticed a few things that seemed odd. If I hit a raised groove/crack in the road, the front didn't track very well. Also, noticed it doesn't turn very well.

Tried looking up tire info here, but still a little confused. What is the correct tire size (or what size would be better) and what would be a good tire combination (front and rear)? What is the correct tire pressure? 


Thanks
 
A stock front tire for that 86 should be a 110/80-18.
The stock rear for all models is a 150/80-16.
Radials were stock in the later years.
But I've run bias tires for a while now and can't tell much of a difference in handling.
I tend to run 41 psi front, 42 psi rear.
You might see if there's a fork brace for your application.
That made a noticeable improvement in the tracking stability from my experience.
I recently found myself in a situation where I needed a front tire replacement while on the road.
As I rode away from the shop, the new tire felt mushy, uncertain and I hated the thing.
I found that the shop put in the recommended 36 psi.
I inflated the tire back up to 41 or 42 psi.
Ahhhh, that's was more like it!  :)
You might also check the condition of your steering head bearings.
Too loose (clunky), too tight, dry, rusted, wore out or 'notched' races will give you steering issues. 
 
I see your in the Colorado area.  I just went through there a couple of weeks ago.  Myself, and the 2 other riders I was with experienced an strangely similar problem over tar snakes.  A wondering wiggle in curves and on the straights.  Very unnerving to say the least.  I'm on C10 running a fairly new Michelin PR3 up front and a Shinko 777 on the rear and had never felt this so consistently before on other roads (TX, MN, AR, OK).  The other riders were on a K16 with fairly new PR4's and a C14 with also fairly new Pirelli Demons.  Just throwing that out there for comparison.  BTW, I'm on my 4th set of PR3/777 and really like the combination (~11K front [38psi], ~9K rear [42psi]).  Whichever tires your get, shop around.  Even on-line dealers drop their prices now and then.  Also, be sure to inspect wheel, steering head and swing arm bearings while you're in the process of upgrading your tires.
 
  You might want to check the front motor mount bolts . If these are loose the front steering will wander. The right mount needs to be tight and the left bolt usually needs spacer washers between the motor and the frame and tightened.  Check the rear mounts also.
 
What Mettler1 said.

My bike was solid with all of the maintenance I performed over the Winter.  I had installed Murph's front tip over bars with no shim previously since there was not one in the left top motor mount nor a nut when I removed it for installation.  I had not read up on the shim problems beforehand. 

Well, my bike was tracking great with no shimmy until earlier this month.  I thought I might need to make some adjustments until I saw my upper left motor mount bolt working out of the air vent during a ride!!! :-\  It had snapped due to no shim.  I replaced it including a washer for a shim and now no more shimmy. :beerchug:
 

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I feel like a total dummy..... Checked the tire pressure  25 in the rear and 28 in the front. I reset them to 40, what a difference!!  Rides a lot better, even with a worn out rear.

Now, the next question... I noticed that these have air suspension, but there is only one Schrader valve on the front. Shouldn't there be 2? What pressure should the fork be at? The front seems a little soft.. 
 
schwinnman67 said:
I feel like a total dummy..... Checked the tire pressure  25 in the rear and 28 in the front. I reset them to 40, what a difference!!  Rides a lot better, even with a worn out rear.

Now, the next question... I noticed that these have air suspension, but there is only one Schrader valve on the front. Shouldn't there be 2? What pressure should the fork be at? The front seems a little soft..
Click to expand...

There is a "crossover" tube located down on the froks, just above the bottom tripple tree.... only one air valve...
Forks should never excede 7 psi, so you need a specific air gauge that reads below 20 psi, a bit tricky to find, but available.. the hard part is getting the forrect air pressure, don't even attempt a compressor, a small bicycle hand pump with quick release works best.

Rear shock can take 50 psi max, same story, don't try a ompresor...  most of us heavier people will run about 35-45 psi, and the damping stem set on 3.

Do yourself a favour tho.. go to Murphs kits site, and pick up the Progressive springs for the front... they are the cheapest improvement for an 86 thru 94 air assisted fork replacements, then you can forget about adding air to the forks, and the seals will last exponentially longer... you will see an improvement in the way they feel also, without going big$$ on spefial springs and emulators.... which can come later if you decide to hang on to the bike a while...

 
I have put 1000 miles on my bike in the last couple of weeks...but have had similar concerns.the bike had been in a damp shed before that.fork seals replaced and most things nipped up.new tyres ...replacement rear second hand shock .i also noticed that the engine mounts and linkages were in need of attention.lose and no grease.iam slowly working through the bike as I also have a uneasy feel on the bike..having a look at the swing arm bearing soon..and headstock ...not played much with the tyre pressures still running 36 41...but iam 160 kg fat Guy so might have to upgrade the shocks...but as standard these bikes can carry 200kg ...so I still have room for a very small wife .ha.
 
Danny, sounds like you're going in the right direction looking at air pressure.  What tires did you install?  Just curious about load ratings and possible sidewall flex causing that uneasy feeling.
 
Im gonna throw out my 2 cents on tires. I bought my 03 a few months ago and it needed a rear tire. It had a less worn Shinko Verge on the front. I work at a small shop and we sell ALOT of Shinkos. Ive got the 244s on my KLR 650 and 705s on my 08 Triumph Bonneville Scrambler convert. I love these tires and the price is right. I installed the Verge radials on the front and rear. Went to one of Arkansas premier sport bike roads push mountain rd and alot of other twisty Ozark roads the next week. As a old sport bike rider i rode the Connie WAY faster and harder than the old girl was meant to. These tires are great and the price is right AND they make the sizes for the ole pig. Im done  :great:
 
At the moment I am running avon tyers and 7 psi in the front and 48psi in the back.  The front end has a wobble when you take your hands off the bars.iam thinking that the rear swingarm bearings need replacing or greasing. .or could be the head bearing. Will get back to you and let you know what I find.
 
Waggle in the bars is usually the fault of worn tires. A good test of that is to let the bike coast down from ~60 MPH with your hands off the bars. Things can go wicked very quickly around 45 MPH under those conditions.

All that being said, years ago I was told the C10 uses the same head bearing set as the old Ninja 900 and the C10 is quite a bit heavier. The bearings need to be snugged at the 600 mile check but are hardly ever given any attention. Regardless of what is causing your waggle you should snug those puppies up. The races on my 86 were dented by the time I got around to them - Not Good.
 
I have new tyers.but might put 41 in the front as iam only running 36 at the moment. .I do think that I have a issue with the rear swinging arm bearings and also the linkage that is connect to the frame as these are the only ones I haven't dealt yet. As the rest of them were dry..and needed a good clean
 
Check steering bearing/head looseness. Put bike on centerstand, get on bike and have someone pull down or put weight on passenger seat to get the front tire off the ground. If handle bars fall to the left or right and bounce off the steering stops then you are too loose.it should take the weight/force of a 1/4 - 1/2 lb burger to push or pull the steering to the stops. It should feel smooth without any feel of notchiness through the full range. Be careful when taking the weight or shifting weight forward on the centerstand as it may rock off the centerstand with any forward movement.
 
36 psi in the front is plenty adequate as far as avoiding bar waggle goes but I'd run 38-40 psi up front just to help the tire last longer. it's good to check out all those bearings you are talking about but your best bang for the buck will be the head bearings.

Keep us posted on your progress.
 
I have been riding bikes for 35years and in my experience if something is happening at the front ,it's probably something wrong at the back as with  bearings ...but saying that any information from fellow bikers is a must.as every bike has its own little quirks.. especially one that has an engine that is used as a stress member  ..so I think a start at the front and work my way back and check everything in between..iam not looking forward to the swingarm..as I have been told they are a bugger to remove...ha
 
I  suspecting that the engine mountings are loose as the front left side will not  tighten up and I've got a feeling I may need to put a washer on the nut..I'll let you know tomorrow night.
 
Remove all linkages and inspection.found slight play in the lower one.but not anything bad.greased them up and popped them back in .swingarm was fine no movement.front engine mounts were removed and cleaned,found that there was a hard  substance in the  Threads.which was giving me the  impression they were  fully locked up but they were not.... removed and cleaned .had the bike out for a short ride found there was an  improvement ..but still have a  wobble from the front..not as bad but still there. But what I have noticed is that the rear shock might be leaking air..only a couple of psi over a week or two..
 
schwinnman67 said:
I feel like a total dummy..... Checked the tire pressure  25 in the rear and 28 in the front. I reset them to 40, what a difference!!  Rides a lot better, even with a worn out rear.

Now, the next question... I noticed that these have air suspension, but there is only one Schrader valve on the front. Shouldn't there be 2? What pressure should the fork be at? The front seems a little soft..
Click to expand...

Any time you ride feels squishy or it seems to be giving you some unpleasant feedback - the first and most likely culprit is tire pressure.  A drop of just a few pounds can make a big, very noticeable difference.  I run both tires at 42
 
Correct air pressure in a tire works wonders, as does correct suspension set up.  The earlier models used air and the latter have preload adjusters.  Another thing I've noticed with C10s, some people replace the 110/ front with a 130.  Mine had one when I purchased it (very used!), and the preload was wound out to the minimum.  The bike steered and handles like an overloaded truck.  I put a 110/ on the front and set the static sag properly.  The bike handles like my old '86 model did when new....a revelation!
 
All IIRC, so YMMV. :)

The spec for putting in a shim is around 0.7mm gap prior to tightening.  I grabbed a handful of fender washers that fit over the bolt then jammed them in the space until no more would fit. 

This mount clamps the engine into the frame.  If there's too much gap, the bolt ends up taking the weight across it and either shears off, stretches, or just stays there well enough to look good but not really do anything.
 
schwinnman67 said:
I finally took my 86 out for a ride today and noticed a few things that seemed odd. If I hit a raised groove/crack in the road, the front didn't track very well. Also, noticed it doesn't turn very well.

Tried looking up tire info here, but still a little confused. What is the correct tire size (or what size would be better) and what would be a good tire combination (front and rear)? What is the correct tire pressure? 


Thanks
Click to expand...

Until I did my 17" conversion this year I ran the Avon AM-26's for almost 5 years. They are probably one of the best handling bias ply tires out there. And they come in C-10 sizes. Ask anyone who has followed me through the twisties and they can attest to that. They make the correct C-10 sizes for older and newer models.
(Front) Specifications and Options

Brand Avon
Front / Rear Front / Rear
Tire Size 110/80-18
Bias / Radial Bias Ply
Rim Size 18
Tube / Tubeless Tubeless
Speed Rating V
(Rear) Specifications and Options

Brand Avon
Front / Rear Rear
Tire Size 150/80-16
Bias / Radial Bias Ply
Rim Size 16
Tube / Tubeless Tubeless
Speed Rating V
Product InformationCustomer Reviews (90)Specs & OptionsQ&A
Product Details
This bias-ply Avon tire is perfect for commuter and traditional motorcycles. It has a large contact patch for excellent grip at all lean angles and an interrupted center groove to resist tracking. V Speed rated (149mph / 240kmh) across the entire range.


 



 
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