My explanation to the frame flexing

[firefly]

After installing radials 17 inch with short profile tires the suspension took a beating as now a lesser air cushion ( from the tires ) started causing more twisting forces on the frame, I thought I need a fork brace or something.
I was always unhappy with the front end stability at high speeds and felt like the front tire size 120/70X17 was being over strained by the bike's weight and big potholes to the point of thinking it might explode
I remembered an expensive mistake I did a while back when I bought a new BMW 325i, I tested the car and loved the way it handled instantly so I decided to have the dealer install bigger chrome wheels and short profile tires thinking man they look great and they did BUTT driving the car home for the first time I realized the wheel /tire thing really messed the car's handling BIG TIME at a cost of $4000, I am stuck now and will have to live with it.

Almost all frame twisting experienced by maxers is AFTER they convert to 17 inch wheels with short tire profile, the 18 inch rear wheel conversion will result in a more pronounced swing arm twisting! rarely do people with stock wheels complaint of frame twisting unless they really push the bike very hard.


The shorter profile tires reduce the shock absorbing character of the tire transmitting all the shock to the suspension to deal with it resulting in a twitchy handling and rim bending pothole effects.

This could be a good thing in fine tuning handling a LITTLE shorter profile will do the trick too much and you are screwed, I see SUVs with a 21 inch wheel and a 40 tire profile and laugh at the ignorance of its owner ( no offense to anyone) just a jab but since the vmax has only two wheels we cannot afford to do this mistake.
I finally replaced the tires with a slightly taller profile and all is perfect now, with NO significant frame twisting , fork twisting and a solid feel in corners.
I hope this long story will help fellow maxers think small incremental changes is a much better way when dealing with handling mods.

This is my opinion/experiance if it makes any sense to you use it and if not at least it did not hurt anything or anyone.
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Ford Lightning specifications

 

[mikemax04]

This is my opinion/experiance if it makes any sense to you use it and if not at least it did not hurt anything or anyone.

Very good Firefly. That's almost as good as saying IMHO

Nothing is written in stone and much has to do with the rider, his style of riding and how HE likes his Max to look and feel.

 

[firefly]

Very good Firefly. That's almost as good as saying IMHO

Nothing is written in stone and much has to do with the rider, his style of riding and how HE likes his Max to look and feel.

Mike, it is not just IMHO it is more like what I experienced and it is more objective that an opinion, we are not talking about what color is best for max.if someone had explained this to me it could have saved me $4000.
And this is exactly why I bothered to post that.
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iolite review

 

[mikemax04]

What ever you say firefly.

 

[shawn kloker]

My frame was flexing badly with stock rims and tires.That is why I have solid mounts,frame braces,gusseted frame,braced swingarm,fork brace.I did the radials last.
I think it all depends on the rider and riding style.Push it hard in the turns and it will flex.Put like a grandpa and it won't.
Ibrahim when you already have the suspension and radial upgrades you should easily be able to avoid the potholes.I never hit them and we have a million of them here.As a last resort I have wheelied over them when I could not avoid them.Stay back a little behind the car in front of you and watch the road,Give yourself some reaction time.

 

[firefly]

My frame was flexing badly with stock rims and tires.That is why I have solid mounts,frame braces,gusseted frame,braced swingarm,fork brace.I did the radials last.
I think it all depends on the rider and riding style.Push it hard in the turns and it will flex.Put like a grandpa and it won't.
Ibrahim when you already have the suspension and radial upgrades you should easily be able to avoid the potholes.I never hit them and we have a million of them here.As a last resort I have wheelied over them when I could not avoid them.Stay back a little behind the car in front of you and watch the road,Give yourself some reaction time.

Shawn, you are brutal to your bike, I am not a novice rider, I don't hit potholes all the time, some road irregularities like melted asphalt creating waves, remember I ride surface streets and that is full of road irregularities, expansion gaps & bumps of all kinds.
you use your bike as if you want to brake it while I use my bike as if I'll make it last 150K with little problems, I would never consider purchasing a bike/car or anything with an engine after you
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vaporizer manufacturers

 

[Mrmaxx]

Ibrahim, more of your

<Content edited>

 

[shawn kloker]

Shawn, you are brutal to your bike, I am not a novice rider, I don't hit potholes all the time, some road irregularities like melted asphalt creating waves, remember I ride surface streets and that is full of road irregularities, expansion gaps & bumps of all kinds.
you use your bike as if you want to brake it while I use my bike as if I'll make it last 150K with little problems, I would never consider purchasing a bike/car or anything with an engine after you

Ibrahim,I rebuilt this motor 5k miles ago myself.If it blows up I will rebuild it again.If I wanted a bike to baby and worry about it lasting forever I would be just another harley wannabe.I dig speed and acceleration---adrenaline.I am planning on porting ,new valves and springs and stage 3 cams this winter.I will never sell my vmax!

 

[firefly]

Ibrahim,I rebuilt this motor 5k miles ago myself.If it blows up I will rebuild it again.If I wanted a bike to baby and worry about it lasting forever I would be just another harley wannabe.I dig speed and acceleration---adrenaline.I am planning on porting ,new valves and springs and stage 3 cams this winter.I will never sell my vmax!

Shawn, you are lucky you can build your own motor, it saves a lot to do the work yourself, but for many of us poor suckers we take it to a shop or a dealer to have it fixed, I love acceleration and adrenaline too but with a different kind of riding, that doesn't mean I enjoy my bike less than you, we are just different riders that happened to love the same bike and that is cool with me, you are a drag racer while I am a lane splitter we get our fun differently and also set our bikes differently so what is great for me could be the worse thing for you , this is why everyone modifies his bike differently.
I noticed that every thing I said about modification you have the opposite on your bike, hey as long as you like your bike and I like my bike this is really all that matters.
In general you are much harder on your bike than I am on my bike which is really none of my business anyway.
Ride fast & safe that is all what matters.
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Yamaha VMX1200

 

[Buster Hymen]

Ibrahim, more of your BS, <snip> give it a rest already.

None of this crap on this forum. If you want to act like an asshole, stick to the Yahoo groups.

 

[mikemax04]

None of this crap on this forum. If you want to act like an asshole, stick to the Yahoo groups.

Way to go Buster. Glad to see someone jump in and weed out the trash talk.

 

[shawn kloker]

Ibrahim,No hard feelings here.The vmax is many different things to different people.

 

[firefly]

Ibrahim,No hard feelings here.The vmax is many different things to different people.

Shawn, I have no hard feelings at all, I understand riders are very different and use the max in different ways, my bike is a commuter bike with an attitude, a cigarette holder, a note pad holder, a clock
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roor bong

 

[Robbarrie]

I honestly can't imagine the tires having anything to do with frame flex. The flex is caused by torque and a little movement due to the rubber motor mounts....It's got nothing to do with tires, don't know what your thinking. If you install solid mounts and add a frame brace it will limit the twisting of the frame and the solid mounts will limit the amount of engine movement. If one was to scrap the stock frame and buy a special reinforced frame, might not have to do the other mods. By that would be going totally overboard wouldn't it.

 

[firefly]

You are right about frame flex due to engine torque but also consider the frame flexing due to lateral forces exerted on the frame during turning and encountering a bump, this is a different kind of frame flexing, this can be exaggerated by low profile tires & stiffer suspension.
what connects the frame to the road is the suspension and tires.

I honestly can't imagine the tires having anything to do with frame flex. The flex is caused by torque and a little movement due to the rubber motor mounts....It's got nothing to do with tires, don't know what your thinking. If you install solid mounts and add a frame brace it will limit the twisting of the frame and the solid mounts will limit the amount of engine movement. If one was to scrap the stock frame and buy a special reinforced frame, might not have to do the other mods. By that would be going totally overboard wouldn't it.

 

[Robbarrie]

IMHO

I think the key word is exaggerated, if your given'r while going over a bump your going to feel a jumping motion, as your wheel looses traction and from the frame flex your one track alignment of the front and back wheel my not be perfectly on center. This may also give you a shift in weight transfer when the tire makes contact with the ground again. However, if one could measure it - it would only be for a fraction of a second. The question is : will the type of tire make a difference ?
Maybe very slight, again I think this would be extremely small and may not matter what tires you have. I don't really know it's just more of a guess.

 

[firefly]

Robbarrie, I have experimented with several tires sizes/profiles bias and radials, I noticed a rubbery feeling in dips, bumps, wavy road irregularities and freeway expansion gaps.
this is what I found, low profile front tires make it hard for the suspension to absorb shocks and makes the shocks transfer to the frame causing flexing, Low profile rear tires are brutal on my back since all the shock absorbing is left for the shocks to deal with.
I do not have frame braces or an after market fork brace and don't think I'll need them. the correct fork setting to my weight and radial tires that have a 70 profile for the rear and 70 soon to be 80 profile in front did the trick for me, IMHO my bike behaves like I want it to behave! its not a sports bike and not a clumsy cruiser either.
Note: different riding skills, style and bike use demand different settings but all demand a well tuned suspension! to get the most control = pleasure out of the max.

IMHO

I think the key word is exaggerated, if your given'r while going over a bump your going to feel a jumping motion, as your wheel looses traction and from the frame flex your one track alignment of the front and back wheel my not be perfectly on center. This may also give you a shift in weight transfer when the tire makes contact with the ground again. However, if one could measure it - it would only be for a fraction of a second. The question is : will the type of tire make a difference ?
Maybe very slight, again I think this would be extremely small and may not matter what tires you have. I don't really know it's just more of a guess.

 

[shawn kloker]

When you are really cranking on the torque hard in the turns the frame is definately flexing.Specially with out any mods(solid mounts,frame braces).

There is not much that isn't done to mine now,and I can still flex the frame at top speed on the highway weaving between traffic.It does however not flex anywhere near where it used to before.

This is probably not an issue if somebody doesn't ride the way that I like to.Stock everything is probably fine to ride around legally at the speed limit and an occasional straight line high speed blast.

We have alot of hills and sweeping turns here in western Pa. I know my bike is not a sport bike but it does handle very well now.Getting it to stop,now is my biggest concern and maybe a steering stabilizer.

 

[mikemax04]

When you are really cranking on the torque hard in the turns the frame is definately flexing.Specially with out any mods(solid mounts,frame braces).

There is not much that isn't done to mine now,and I can still flex the frame at top speed on the highway weaving between traffic.It does however not flex anywhere near where it used to before.

This is probably not an issue if somebody doesn't ride the way that I like to.Stock everything is probably fine to ride around legally at the speed limit and an occasional straight line high speed blast.

We have alot of hills and sweeping turns here in western Pa. I know my bike is not a sport bike but it does handle very well now.Getting it to stop,now is my biggest concern and maybe a steering stabilizer.

Shawn, have you had your swingarm braced yet? They tell that it also contributes to flex during hard acceleration.

 

[shawn kloker]

Ya,Its braced.I did it at the same time as my solid mounts and new swingarm bearings.Frame braces helped the most in my opinion.I did it last to mine.