Author Topic: how stabil are yours sohc at 100 kmt (Read 4234 times)

strynboen · « **on:** October 13, 2011, 10:02:43 AM »

hey i can not drive vith one hand at handle at 100 kmt..vitaut vobbel starts..tire and bearings are good..leaks a bit fork oil bot..forks work stabil still..
problems start in rain..when i have to klean visiret on my helmet..and take one hand off..have to take speed dovn to ...85 kmt..
on my cbx..i can take both hands off handle..it runs like a lokomotive...stright a head..
hov are yours old sohc..have i a problem..or just a 40 years old bike...hope you can get it..

KRONUS0100 · « **Reply #1 on:** October 13, 2011, 10:13:18 AM »

not sure what 100mph is in mph.but mine is steady at 85mph enuff to ride with one hand, even in the corners

strynboen · « **Reply #2 on:** October 13, 2011, 10:15:22 AM »

hey think that 65-70 miles ph.. are 100 kmt

phil71 · « **Reply #3 on:** October 13, 2011, 10:17:53 AM »

if a fork is leaking, it's not working. Even if you keep it full, pressure is escaping there and it's not able to properly cushion. So if one works normally, and one is bouncy, you end up with bad handling.

jneuf · « **Reply #4 on:** October 13, 2011, 10:19:00 AM »

Solid as a rock at 100 km/h....

Could be a number of things...swingarm perhaps?

strynboen · « **Reply #5 on:** October 13, 2011, 10:20:09 AM »

hey..i vill make this forks this winter..if i get oli on the discs i vill have problems..more then i already have,,,
yes svingarm bushes are a veak point..i vill thek that..think of new tires,,, this avon i have on.. are more then 5 years..and a bit vrong dimension..to big on back

CoachDoc · « **Reply #6 on:** October 13, 2011, 10:22:58 AM »

My 550 is definitely a lot more skittish at high speed than larger bikes I've ridden, but if you don't have enough stability to ride with one hand on the bar you very likely have a problem. Wheel balanced? Check the steering head bearings, wheel bearings, front suspension to start.

flybox1 · « **Reply #7 on:** October 13, 2011, 10:45:45 AM »

Quote from: CoachDoc on October 13, 2011, 10:22:58 AM

Wheel balanced? Check the steering head bearings, wheel bearings, front suspension to start.

+1
Fresh fork oil...and check how true your wheels are while they're off for balancing.....

MCRider · « **Reply #8 on:** October 13, 2011, 12:30:12 PM »

I think it should be stable to top speed. I suspect the steering head bearings, though all suggestions must be followed up on.

Here's the test. Elevate the front wheel off the ground. Turn the fork all the way to one side. Slowly move the fork to the other side, noting how it feels. Should be smooth, not notchy. Just as you get to straight ahead pay attention. Does it feel like it drops into a notch? What I call the "dead ahead detent".

If you have this, you will never be stable. Driving straight down the road, the steering head bearings get beat into the races from each bump. Forming the detent. Sometimes its slightly to one side, as many roads have a crown in them and we always steer a little to one side to counter the slope of the road and continue striaght.

The originalbearings cannot be repaired. They must be replaced, with races. You can replace the with originall bearings, but it will just happen again. Time to upgrade to tapered roller bearings.

SKTP · « **Reply #9 on:** October 13, 2011, 12:38:21 PM »

Before my tranny died...I felt totally comfortable up to about 95mph. New Ikon rear shocks made a huge difference

dave500 · « **Reply #10 on:** October 14, 2011, 12:44:32 AM »

mines plenty stable,how worn are the tyres?when you have the forks apart go over the front end steering stem etc aswell,is your tyre pressure low?

strynboen · « **Reply #11 on:** October 14, 2011, 06:45:21 AM »

the tyre are almost finish..think i vill bay new this winter..and get them balanced..the front tyre only toutch on 2 cm in mittel..its littel higer in the mittel

think that gives the unstabile feling...the svingarm have some wear,,to make all vorse. have somthing to work vith...thanks for the good tips

are classic tire better for this bikes...not to make a oil thread..???or is it better to hoild on newer types..i run avon roadrunners now

try to click on last pic..is it normal to be higher in mittel..??

chopped550 · « **Reply #12 on:** October 14, 2011, 07:02:44 AM »

"vibrating" sounds like a tire balance issue. And your tires look like they are totally shot. It can be compared to a car that the steering wheel shakes at highway speeds. My little 550 is a dream to ride at 70+mph, even as a hardtail.

strynboen · « **Reply #13 on:** October 14, 2011, 07:04:58 AM »

its are more a wobbel in hole front..not vibrasion

Gordon · « **Reply #14 on:** October 14, 2011, 07:05:05 AM »

If you like the Avons then stick with them. The design of the tire isn't what's causing the problem, although the wear may be contributing. I ran Avon Roadrunners on my 750 until they stopped making them and have now switched to the Avon Roadriders. Similar tread pattern but they come in standard sidewall sizes so you can get a better stock fit than with the metric Roadrunners.

Peacefrog · « **Reply #15 on:** October 14, 2011, 08:09:52 AM »

My 750 would develop a wobble/vibration right around 65-70mph. My fork seals need replacing, my tires are about 6 years old but look pretty good. Don't seem to have bad bearings. I fixed the issue by using a good pressure gauge to fill the tires. 5 psi made little difference in city riding, but on the freeway it was enough to scare a new rider (me).

ofreen · « **Reply #16 on:** October 14, 2011, 09:16:30 AM »

Your tires are worn out. The front has a significant crown to it and the rear is flattened in cross section. That is not a good combination for decent handling. They appear to be old, too, so the rubber no doubt has lost some compliance. New ones will probably eliminate you problems. What pressures are you running in them?

crazypj · « **Reply #17 on:** October 14, 2011, 09:27:50 AM »

100km is 62.5mph.
The only time I've seen CBX really bad is with oversize front tyre.
All the CB's I've ever had or ridden (except one hardtail chopper) were completely stable to 100MPH
(when everything was in 'reasonable' condition)
Check swing arm bearings and chain adjustment as well as balance of BOTH wheels
BTW, that's 'normal' wear pattern for AVON.
Try 'old style Continental rib tyre (as fitted to old BMW's, I think RB112?)
I really liked them on my 550, they have a 'limited slip' capability when you get near limits of lean (but hang in there real good when you go a bit further

)
BTW, you English is far better than my 'mastery' of any foreign language (I's still learning 'American' English

)

BeSeeingYou · « **Reply #18 on:** October 14, 2011, 09:37:54 AM »

Quote from: ofreen on October 14, 2011, 09:16:30 AM

Your tires are worn out. The front has a significant crown to it and the rear is flattened in cross section. That is not a good combination for decent handling. They appear to be old, too, so the rubber no doubt has lost some compliance. New ones will probably eliminate you problems. What pressures are you running in them?

And get za proper size. Zay look oversized for za rims and while zay may fit zay vill wear badly.

fire113 · « **Reply #19 on:** October 14, 2011, 09:41:01 AM »

Quote from: strynboen on October 14, 2011, 06:45:21 AM

are classic tire better for this bikes...not to make a oil thread..???or is it better to hoild on newer types..i run avon roadrunners now

...I am using BT45, that tyre is very good in combination with the CB750.

Good luck...Georg

crazypj · « **Reply #20 on:** October 14, 2011, 09:49:15 AM »

I think either you swing arm bearings are worn or rear wheel is slightly out of line (you can see wear pattern on chain, shiny on right side of roller, greasy on left side)
If you sit offset on bike (almost everyone does) it could either compensate or compound effect?

Franky · « **Reply #21 on:** October 15, 2011, 10:16:54 AM »

Hej!

Min 77'er CB550 er stabil til mindst 130.

Har iøvrigt købt Bridgestone BT45 dæk her: http://mynetmoto.com. Firmaet er vist fra Cypern, men gode priser og hurtig levering!

(To the non-danish speakers: My CB550 is stable to at least 130 km/h and I ride BT45's)

strynboen · « **Reply #22 on:** October 15, 2011, 10:23:39 AM »

hej tror også det bliver det valg..

think it be bt..

DavePhipps · « **Reply #23 on:** October 15, 2011, 01:05:26 PM »

My bikes is oddly steady at 100kph. My swingarm bushings are worn and rear wheel bearings need replaced, but that doesn't seem to affect the front too much.
I used to wobble at all speeds then I got new tires and aligned my forks. One tube was 1cm higher than the other.
After that no more wobble

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Author Topic: how stabil are yours sohc at 100 kmt (Read 4234 times)