How does my CBX handle you ask?

Terry · Post by **Terry** » Tue Aug 18, 2009 11:06 pm

After reading this thread again; "Weaving in the high speed sweepers"

I have to relate some recent experience I had while riding my 50,000 mile 79 so everyone considering riding one or even those that already have one will know that they're NOT an unsafe bike to ride fast if properly reconditioned as you would do with any 30 year old motorcycle.

I have a stock front end but with 20w fork oil around Progressive Suspension springs with spacers (forget how long) and a fork brace. I may have raised the forks in the triple tree about a quarter inch. Rear suspension is from old style adjustable/rebuildable Konis, preload set low and the dial on top set to '4'. New(er) cush drive. I weigh about 245 w/o any gear and I'm trying a set of Avon Roadriders in stock size. Stock (US) handlebars and pegs.

An old BMW R100S or RS or?, had a nose fairing I think but no side fairings so I'm not sure, sat tall and had skinny tires and came around me while I was caught behind 3-4 cars riding thru some local twisties on the way to the coast. He really shouldn't have passed me or the cars in that section but he did, and disappeared. Once I safely got clear of the cars the road turned into a really great few miles of straights and high speed sweeper type corners. Lots of visibility and little if any traffic, 2 or 4 wheel.

I upped the revs a bit and lo and behold, I saw the BMW a mile or so ahead caught behind some cars himself! Upped the revs some more and was behind them in a shot. A passing opportunity presented itself and off he went with me right on his tail. Its not often I run into a rider that's 'game' if you know what I mean. Shifting into 5th I went around the BMW and tucking in, checked my mirrors only to see the BMW right with me! Before getting real low and leaning forward now, one last check in the mirrors and the BMW was getting smaller and smaller. I could tell he was still trying but...failing. At 9,000 or so he was a distant dot in the mirrors. At the ocean I turned south and never saw him again.

Now, throughout this little run I had the 79 running 80-90+ leaned over thru these sweepers and into triple digits on the straights with nary a wobble or any cause for concern. No see saw, no yaw effect and no wobbles. There was a little vibration though...

but I didn't scrape the pegs or my boots or any hardware. The corners weren't close enough to eachother to require any forceful turning from left to right but even in the twisties it doesn't take too much muscle to turn left and right (quickly). Direction changes at speed were not a problem.

There you have it. An early Z model in pretty much original shape with minimal mods, riding just like any good motorcycle should. I believe my 82 runs very close to the 79 at speed as well, also with similar mods.

Ride em if ya got em, they're FUN!

ericfreeman · Post by **ericfreeman** » Tue Aug 18, 2009 11:55 pm

Hi Terry

I have a new set of Progressive fork springs/spacers for my '79 and when I installed them the front end was terribly soft: I could damn near bottom the forks just pushing down on the handlebars with the brakes on! I was running ATF as per the factory manual and am wondering if this is the problem (Progressive mentioned going heavier on the oil in an email but I haven't tried the springs again as yet). I switched back to the stock springs immediately which seem fine to me. Wondering what your thoughts on this are. Thanks.

Eric

Terry · Post by **Terry** » Wed Aug 19, 2009 1:12 am

..."I was running ATF as per the factory manual and am wondering if this is the problem"

What weight fork oil did you use with the stock springs? If you just changed the ProSus springs and not the weight of the oil, and the stock springs were stiffer then something has to be incorrect with the springs you have.

ATF is somewhere between 2&1/2-5w oil I believe. I got my ProSus springs from Tims when Alex was running it...come to think of it, I sure miss Alex. Wonder how he's doing? Anyway, changed them out myself after having a shop replace the fork seals right after I bought the bike in 01. It was very mushy when I first rode it, lots of dive under braking. Still has some dive of course but not nearly as bad as before. I've heard of some that add longer spacers on top of the springs and/or add a few more ccs/ozs of oil in each fork tube too but I haven't ever experimented that way.

If the stockers work well with your weight and riding style, keep them. Most riders don't use (all) any bike has to offer anyway, me included, but for my weight and riding style I think my Xs are set up pretty well. You know, I almost never get to ride with anyone else on a CBX so maybe, I'm actually riding pretty slow and that's why I think they handle so well...

Mike Barone #123 · Post by **Mike Barone #123** » Wed Aug 19, 2009 1:37 am

Hi Terry...

No one disputes that there are early models that have handling issues and those that dont. The fact that you have one of these conditions does not mean the other condition does not exist in other CBX early models which is the key thing for us all to know.

This was my reply to this in a prior thread to give some accurate perspective to this.

>>>>>>

Hummmmmmm....I agree there needs to be a better and more complete perspective on this. Here is my attempt on this based what I have experienced and can confirm with first face to face discussions with other CBX owners and actually observed when riding with or behind other stock/near stock early model CBXs over the last 30 years.

Early model confirmed handling issues that I know personally about and have heard from other owners:
1. Weaving on straights at 85+ mph does happen

2. Near or total tank slappers on straights at 85+ mph does happen and is more likely to happen going over a subtle undulation in the road on the straightaway.

3. Near or total tank slappers in sweepers at 75+ mph does happen and is more likely to happen going over a subtle undulation in the turn.

My 80 started the handling bad habits at about 3,000 miles and within six months each item (1-3 above) occurred.

Early model confirmed reports related to not having handling issues that I have heard from other owners
1. Not every early model has these issues....infact some owners report not having any of the handling problems stated above

2. Not only have there been many owners that have reported none of these handling issues but there are documented cases where stock/near stock early model CBXs withy 35mm forks were infact road raced with success.

Accurate Perspective
I believe the above is an accurate perspective........the perspective that every current and future CBX early model owner should know. In the end it all comes down to CBXers stating a problem and everyone having their say....then we all decide what if anything we want to do about the problem for ourselves, if anything.....and that is the value of this forum to each of us.

My "On The Record" Declaration Related to Stock Early Model Handling
I will formally go on record in saying if you have a stock or near stock early model CBX and go above 85mph on straights or 75mph in sweepers...... you could be risking your life.

The Fix
The fix is easy and not expensive. Late model 39mm forks to fix the wobbles .......and when you are at it install the Race Tech Gold Valve for a massive improvement in front end feel and handling performance. Keep the early model brakes or upgrade them when you do this or later.

My Personal View
We each have our own personal view of the CBX and mine starts with the simple concept that Honda defined what the market, design, handling and performance objectives for early model CBX and these did not include owners limiting the speed to 85mph on straights and 75mph in sweepers due to handling issues. Fix the handling issues and ride the ride on the CBX the way Honda intended was my approach. It all worked out.

Nor have I ever accepted the concept that an ole early model CBX that handles should avoid street group rides or track days where newer bikes are the norm...and guess what... this also has worked out every single time ...and to the great surprise of a few on these rides with the newest/latest/greatest bikes of today

In saying all this...I want to emphasize this is my view on my 1980 CBX ....and .....the neat thing is each of us can have our own view(s) and none of them have to be the same......and we all can still get along.

I want to personally thank everyone for their views on this topic and ofcourse all other topics like this on our forum.....this is exactly what being a CBXer and being a member of ICOA is and always has been about. Sharing, helping and friendship.

Mike

Terry · Post by **Terry** » Wed Aug 19, 2009 2:46 am

Thanks Mike. I think I've read that a couple times now. You keep leaving out one fix though, the one I just listed. Thousands of miles have proven it to be a pretty good 'fix' and not at all expensive or labor intensive. And its certainly not scary to ride fast.

"I have a stock front end but with 20w fork oil around Progressive Suspension springs with spacers (forget how long) and a fork brace. I may have raised the forks in the triple tree about a quarter inch. Rear suspension is from old style adjustable/rebuildable Konis, preload set low and the dial on top set to '4'. New(er) cush drive."

Your fix below is (not) the only fix and (is) much more expensive.

"The fix is easy and not expensive. Late model 39mm forks to fix the wobbles .......and when you are at it install the Race Tech Gold Valve for a massive improvement in front end feel and handling performance."

And I'm not saying your fix is not better than mine but to add this declaration,

"My "On The Record" Declaration Related to Stock Early Model Handling
I will formally go on record in saying if you have a stock or near stock early model CBX and go above 85mph on straights or 75mph in sweepers...... you could be risking your life,"

seems a bit...harsh

I realize I don't have experience with several different CBXs but I've never heard of these before now,

1. Weaving on straights at 85+ mph does happen
2. Near or total tank slappers on straights at 85+ mph does happen and is more likely to happen going over a subtle undulation in the road on the straightaway.

Tank slappers and weaving (in a straight line)? just for going over 85, or could it be because of bad tires, incorrect tire pressure, tires out of balance, bad shocks, sticky brake pads, warped rotors, weak fork springs, weak fork oil, uneven amount or not enough fork oil or......all of which that would be present in most any thirty year old motorcycle? Is it really just the CBX? Did only the CBX exhibit these tendencies even when new? Not the early 903 Kaw? Not their 750 triple?

Not Triumphs or Nortons or Beezers of the same vintage? Not Guzzis or Sportsters?

Oh, and I had a lot of fun with that BMW

alimey4u2 · Post by **alimey4u2** » Wed Aug 19, 2009 3:42 am

I was very interested in what Shiro Irimajiri had to say on the handling in the CBXexpess. "Smaller Japanese riders wearing slim leather suits, riding flat on the tank". I know I have put on weight due to "finally" quitting the smokes....

Mike Barone #123 · Post by **Mike Barone #123** » Wed Aug 19, 2009 9:31 am

See Reply>>>>>>

Terry wrote:Thanks Mike. I think I've read that a couple times now. You keep leaving out one fix though, the one I just listed.

Thousands of miles have proven it to be a pretty good 'fix' and not at all expensive or labor intensive. And its certainly not scary to ride fast.

"I have a stock front end but with 20w fork oil around Progressive Suspension springs with spacers (forget how long) and a fork brace. I may have raised the forks in the triple tree about a quarter inch. Rear suspension is from old style adjustable/rebuildable Konis, preload set low and the dial on top set to '4'. New(er) cush drive."

Until now Terry I did not know of your fix. I did all of the parts you stated except the cush drive and it did not work for me. Actually in the original post I did I forgot that I did install Progressives also ...I will fix that. Reply>>>>>>

"My "On The Record" Declaration Related to Stock Early Model Handling
I will formally go on record in saying if you have a stock or near stock early model CBX and go above 85mph on straights or 75mph in sweepers...... you could be risking your life," seems a bit...harsh
Reply>>>>>> Maybe, but one CBXer budz went to the hospital and the other nearly killed himself on Rt150 at Marlinton right in front of me over this issue. I would rather state the consequences that could happen if one has an early model that has these dangerous handling traits....rather than go to funerals or hospitals wishing I had

I realize I don't have experience with several different CBXs but I've never heard of these before now,

1. Weaving on straights at 85+ mph does happen
2. Near or total tank slappers on straights at 85+ mph does happen and is more likely to happen going over a subtle undulation in the road on the straightaway.

Tank slappers and weaving (in a straight line)? just for going over 85, or could it be because of bad tires, incorrect tire pressure, tires out of balance, bad shocks, sticky brake pads, warped rotors, weak fork springs, weak fork oil, uneven amount or not enough fork oil or......all of which that would be present in most any thirty year old motorcycle? Is it really just the CBX? Did only the CBX exhibit these tendencies even when new? Not the early 903 Kaw? Not their 750 triple? Not Triumphs or Nortons or Beezers of the same vintage? Not Guzzis or Sportsters?

See Reply>>>>>> The issues I described started at about the 6 month mark after I bought the 80 or say six months .....not recently at the 29 year mark. The fix I stated worked toward for 10-15 years and finally got me there.

I think it is important people know about all fixes if their CBXs has the handling problems stated......also I want everyone to clearly understand not all CBXs have these handling problems and hope for my contribution on this I have treated all these areas fairly and accurately based on my personal experiences and what I have observed in other CBXs or been told by owners of CBXs

In the end there are hundreds of things related to tires and all that can cause any bike to not handle right or even be dangerous....but for CBXs the common thing for all early models that weave and have other dangerous handling traits is the 35mm forks. I think dialog like this is the absolute best this site can offer fellow CBXers....in the end they can read all of this and decide for themselves what if anything to do ....and we can provide better help/opinions than that

Oh, and I had a lot of fun with that BMW

EMS · Post by **EMS** » Wed Aug 19, 2009 10:20 am

Terry wrote:
Oh, and I had a lot of fun with that BMW

That may have been a little lopsided competition. The BMW R100S had only 70 hp in its best form. If you don't run away from it with a CBX, you may be running on only 4 cylinders..

Mike Barone #123 · Post by **Mike Barone #123** » Wed Aug 19, 2009 11:39 am

alimey4u2 wrote:I was very interested in what Shiro Irimajiri had to say on the handling in the CBXexpess. "Smaller Japanese riders wearing slim leather suits, riding flat on the tank". I know I have put on weight due to "finally" quitting the smokes....

Hi Larry....we have had the Iramajiri article for some time now for the Xpress....I read it a couple of years ago and now do not have the new Xpress since I am in NC...but I am thinking you are saying his interview did state something like the Japanese test riders did not have handling issues with proto CBXs as above or in other areas of this interview.

My feeling is having just Japanese test riders for the CBX might have been a mistake since the bike was not to be sold in Japan or only in countries where the riders were small and light. With 2/3rds or so of the CBXs headed for America the weight of riders in the USA should have been considered in testing proto CBXs.

Actually some of the CBX road/comparison tests way back then clearly documented the handling issues we have listed in out posts here.

Additionally, I took part of an lenghty interview of Shiro Irimajiri with a MC Journalist friend of mine and this did come up in the 3-4 hours we talked to him at Marysville.....he stated the 35mm forks were on the early model CBXs to save weight.....then looked down .....for a second .....which to me meant he realized this ended up being a mistake.

From a personal stand point Larry.....I know my weight made this handling issue worse....but yet again...once the 39mm forks were installed all of this went away on my CBX ....which tells me that this fix will work for CBX riders of which all weigh less than I do

The more documented fix attempts we have with results, the more cornclusive this will be and as such be a great benefit for decades into the future for all CBXers

Another good ref to recheck on this handling topic and what Honda knew or thought before the X was released is the one with the three Honda Engineers that was in a prior Xpress......again.........I read this over lots of time in the editing process back then... but as usual forgot all of it now......

EMS · Post by **EMS** » Wed Aug 19, 2009 12:46 pm

In 1978, the 35mm fork was a standard in the industry. Honda actually made an intermediate step to 39mm, with a 37mm fork on the CB900F in Europe that wasn't even available in the U.S. And the fact that the early CBX "wobbled" and "flexed", is not just to be blamed on the fork alone.

Terry · Post by **Terry** » Wed Aug 19, 2009 1:14 pm

EMS wrote:
Terry wrote:
Oh, and I had a lot of fun with that BMW
That may have been a little lopsided competition. The BMW R100S had only 70 hp in its best form. If you don't run away from it with a CBX, you may be running on only 4 cylinders..

Yeah it would have been closer if I had my old CB750 which was bored to 852ccs, jetted and piped, but it was still fun!

Don · Post by **Don** » Wed Aug 19, 2009 1:17 pm

You have to give some weight to the things the lead engineer on the project has to say . . . . especially when he has Mr Irimajiri's credentials

"The CBX was a commercial success, but also a faiilure as we were not able to give the bike the correct road-holding that it deserved"

"I remember the first tests on the CBX with test riders in America. They were complaining that the bikes were wobbling and shaking alot and we could see from the side of the track that they were moving and suffering of tank slappers"

"The problem was that our Japanese riders had found the same troubles. They modified their riding style and tried to adapt it to the bikes"

"Honda factory knew how to make engines, but in our minds, frames were not that important"

It's a pretty well accepted fact that ever since the first big test at Willow Springs in 1978 that the CBX had a great engine and the bikes major shortcoming was in it's handling. That said, if 20 weight fork oil and a set of Koni shocks makes it do what you want/need it to, then all's fine . . . . you needn't do more. For the many others who have noticed the same things Mr Irimajiri speaks of, more steps may be necessary to get to a good handling, fun to ride bike

Unsafe? I'd never say that. A box stock CBX easily outhandles most any Harley Davidson product ever made and there are millions of those on the road everyday . . . . it would be unsafe to try to keep up with a CBX in the twisties on your Harley - But that doesn't mean we can't make small changes which make big improvements to our CBX's and enjoy them all the more

Don

alimey4u2 · Post by **alimey4u2** » Wed Aug 19, 2009 5:49 pm

Words of wisdom Don...

Mike Barone #123 · Post by **Mike Barone #123** » Wed Aug 19, 2009 7:52 pm

Don wrote:
Unsafe? I'd never say that. A box stock CBX easily outhandles most any Harley Davidson product ever made and there are millions of those on the road everyday . . . . it would be unsafe to try to keep up with a CBX in the twisties on your Harley - But that doesn't mean we can't make small changes which make big improvements to our CBX's and enjoy them all the more

Don

Hi Don

I agree with all you said......buttttt there is one major diff between HD and the CBX in terms of being safe.

Harley never designed their bikes to top out at 130mph, be the superbike of that era, do the quarter mile in mid 11 seconds and handle when they were introduced. Owners and everyone else knew this about Harleys of that era including the motorcycle press.

The CBX on the other hand was designed to do all these things.......and as such is unsafe with its handling issues given its top end speeds approaching 130mph which no stock Harley could come to in 1979 or for the most part...even today..

Mike

Mike Barone #123 · Post by **Mike Barone #123** » Wed Aug 19, 2009 8:05 pm

EMS wrote:In 1978, the 35mm fork was a standard in the industry. Honda actually made an intermediate step to 39mm, with a 37mm fork on the CB900F in Europe that wasn't even available in the U.S. And the fact that the early CBX "wobbled" and "flexed", is not just to be blamed on the fork alone.

Every CBXer that put 39mm forks on an early model CBX did not have the handling, weaving or wobbling issues at speed after that. Not a coincidence.

It is simple concept ...solutions that solve issues and work.... trump what Honda, Honda engineers, Honda test riders or anyone said at the time or now that has not fixed the problem