My bike…1974

[MarkPBG]

OK, on my last 10 hour ride, i wanted to check out the high speed stability. I noticed a very slight wobbly pushback from the front end at around 95 MPH. By 105 it was more noticeable. Around 115 it seemed a bit excessive. At 125 it made me feel like i was going to get into a tank slapper if my attention slipped for one second. I'm going to get the wheel trued, check the balance (it has some wheel weights on it now) and maybe consider changing the stem bearings, front wheel bearing, and adding a fork brace.

It's not normal for a bike to misbehave at 125 like this, or is it just because it's an old bike and all the old bikes had this problem?

p.s. This engine SINGS at 7500 RPM! It sounds so smooth! :)

[TOOLS1]

That bike should be stable way past 120mph. It could be the tire, balance, or wheel true. Bearings would be noticeable at lower speeds also. Fork brace would only come into play at high speed cornering, or extended tubes. These bikes were plenty stable without them.
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[MarkPBG]

Yeah, it didn't seem right to me either. I'll check the tires, balance and true....then I have to check my other new problem. THe chain contacts the center stand. The center stand stop can be adjusted, but there seems to be excess slack in the chain, and the original rear sprocket is showing the beginnings of tooth wear. I may just change them out before the long trip to Barber. :)

[shinyribs]

Everyone tells me that 125 mph is about the max for one of these bikes running perfect in stock trim. I tend to disagree. AFAIK,my '76 F is bone stock. Engine wise,that is. I've checked my Vapor speedo with 3 different gps's and it shows dead on the money. I've had mine past 135 with no issues. Once,at about 120 my backpack started doing weird things,but the bike did fine. I can turn loose of the bars at 100 mph with complete confidence.

I'd agree with checking the rim for true. Mine used to have a bit of a hop in the front end that balancing never seemed to fix. I checked the runout and it around .060'' up and down,.040'' side to side. I got it to within .020'' in both directions now and its fine. My SOHC is waaaaay more stable at speed than my DOHC,though the steering is heavier. It's a trade off.

Be careful being speed racer. And if you think they sing at 7500 wait til hear it at 10,000. Simply beautiful.

[shinyribs]

Oh, and as far as fork braces go,make sure you get a real fork brace. I know you know the difference. I put a tweak bar on mine and it does nothing at all. Dead weight unless you're running long forks. If you do run across any good deals on actual bolt-on fork braces let me know,please. I haven't found the time to make one yet but I'm super interested in getting one.

[MarkPBG]

And another little problem cropped up. My main stand stop has apparently lost a piece and now the center stand goes too far up and the chain can rub on it. I removed the center stand until I get a replacement or fabricate another piece to stop the stand where it's supposed to. Old bikes.....they'll keep you on your toes for sure. :)

[MarkPBG]

I'm going to get a new set of sprockets and chain when I do the front and rear bearings. I found out why mine is so quick....not sure of the front sprocket size, but the rear is a 43 tooth aluminum piece, so it's definitely been changed from stock. I'll probably order new cush drive rubber blocks too, since the rear will be apart for the bearings. Those little rubber blocks are expensive! But I don't want to put used ones in if i am going to go through the trouble of having them changed. Lots of little bugs to work out before the road trip! :)

[TOOLS1]

I have never seen a bad cush drive rubber. 43 Tooth is pretty small for a rear sprocket, and would be for top end, not acceleration.
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[MarkPBG]

I miscounted, the rear is a 45 and the front is a 16. If the charts I read online are right, this gives me a 2.81 final drive ratio compared to the stock 2.67 with a 18/48 combo. This might be why my engine only turns 4k at 65MPH. Also, the front and rear bearings have been peened, so they are not original, but I don't know how long ago they were changed. I may just put new ones in anyway while the wheels are off. Next week these new problems will be fixed, then I just have to wait for the next one to show itself! :)

[shinyribs]

No need for a chart buddy.

Just divide your rear gear by your primary gear. Just like ring and pinions in an auto diff.

And I higher numerically gear is actually deeper gearing. 2.81 is deeper than 2.67. Your current setup would cause higher rpms compared to stock.

[MarkPBG]

It looks like I got this scheduled at just the right time. I think I got every single last mile I possibly could have out of this chain....what do you think? LOL

[TOOLS1]

Just put a master link there, and you can get another season out of it.
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[shinyribs]

Wow. That is a thin chain. I had a thin chain like that once...never again!

Glad that didn't turn ugly on you. Good catch

[MarkPBG]

Getting the new chain and sprockets on it now....also putting on the top carburetor boots that protect the thing coming out of the top, and the rear air box connectors that join the carb to the airbox. No more vacuum leaks for me! :) Put new rubber on all the foot pegs, shifter, kickstart lever, etc. Changed all the light bulbs, and I'm installing the ignition switch power relay, headlight switch power relay, and headlight power relay. Decided to change the fork fluid too, and put the drilled rotor on. This bike should run absolutely great for my trip. Only the weather or an accident will be of concern. :)
Waiting on my el-cheapo Amazon saddlebags, tank bag, and tail bag to arrive. Around $125 for all of them. Even if they only last a few trips, I'll be happy with that. :) Going to see how my car GPS works for the trip. Got a battery connection kit for my Garmin. I'm trying to find a mounting kit for my phone to shoot video on the road, why buy a dedicated thing like a gopro or contour? I have an app that lets the camera take a picture at set time intervals, or using the GPS in the phone, at set distance intervals. That could make a cool stop motion video of a trip. Hmmmm.
Already have an AMA membership so towing and gas are covered, as well as trip insurance. :)

I ....may....have a bit of an overplanning problem. lol

[shinyribs]

Overplanning is impossible!

A stop motion trip video would be awesome.

[MarkPBG]

I decided to go ahead and get an alarm system so I don't have to worry at the hotel. Going to hook that up this weekend or next. Couldn't find another 16 tooth front gear through my local shop, so we decided instead of 16-45 (2.81 ratio) we'd get a 17-48 (2.82 ratio) for almost identical RPM@MPH, and a much heavier solid chain. (I've heard tales of rubbing with an o-ring chain) I don't mind periodic oiling, and from what I hear, they're tougher if you frequent a lot of dirt/sand roads (which I do). The bigger gears will also reduce wear and tear on the chain since the diameter of the circle that the chain has to wrap around won't be as tight.  Supposed to be wrapped up by Friday, so I can make our local club bike meet on Saturday, and the Distinguished Gentlemans Ride on Sunday. (Miami to Ft. Lauderdale and back to Miami....over 75 riders on all kinds of bikes, wearing suits!) Should be a blast.

[MarkPBG]

Rear swingarm bushings are bad, overnighting a set so my new chain doesn't wear out quick and it will be ready for the Saturday show and Sunday ride.

[MarkPBG]

Mechanic failed to overnight them. Won't be riding to Barber this year. Oh well, I can bring my better camera gear!
I wouldn't trust it even if the bearings did get here on time, as my ignition switch just failed, and I found 3 potential shorts in the wiring harness while tracking it down. So, I'll wait until after the show, put in the new wiring harness, and all the power relays. (Headlight power, starter button, and ignition switch power relays)
THEN the bike will be done......

until I find something else. lol

[shinyribs]

See you at Barber! The Water Buffalo is going up for sale there. Bring cash.

[MarkPBG]

LOL, not buying another just yet. I'm not done pouring money into this one! :)
I was going to leave tomorrow morning by bike, but looks like I'll be driving the car this time. My ignition switch just melted. My head stem bearings shipped out late and won't arrive in time, and my tires are just 1/8" away from the wear bar, and they're soft compound, so they need changing before a 2000 mile trip. :(

Oh well, more room for camera gear! :) I'll get tons of saleable shots, I'm sure. I can't believe I couldn't find anyone that's going that wanted to share a room to save money! The one I have reserved has two beds and ran just $300 plus taxes for the 4 nights (10th - 14th)

If you see me, I'll be the fat bald guy with the nikon camera gear. I'll likely be wearing my black boonie hat to keep the sun from burning me to a crisp. See you there!