Frame Strut - Purpose?

I've seen these many times, but never read much about their purpose. I *personally* think they are very ugly and detract from the appearance of the engine. The only thing I've read is it supports the frame head under hard braking.

My bike still has the high-speed wobble, (read about it here) and looking at maybe purchasing some Progressive fork springs. I didn't know if this frame support is associated with the wobble.

Of the various functions the frame has to perform one of the most important features is that it keeps the two wheels aligned.
The enemy of this function is when the frame flexes. The frames from Japanese manufacturers were not noted for their ability to control this until they introduced beam frames in the '90's.

Our bikes frame design goes back to the 80's and retains the thinking from decades earlier. Additionally, as the motor is rubber mounted this will allow additional flex.

So to your question (about time I hear you say...) the purpose of the bars is to reduce torsional flexing in the frame thus improve the handling.

I'm with you on the looks but beauty (or not) is in the eye of the beholder. Another way to add stiffness is to use solid engine mounts which then uses the crankcase to add torsional rigidity.

Fitting better springs will improve the front end handling provided you take the time to set the static sag but (IMHO) won't alter the weave. My money would be on over tight headrace bearings. I believe Mr Morely has a video on this.
One point to watch out for here is that when torqueing up the top yoke nut you don't put additional preload onto the bearings. Tighten in steps and make sure that the degree of 'flop' on the forks remains the same.

MaxMidnight said:

...My money would be on over tight headrace bearings. I believe Mr Morely has a video on this.
One point to watch out for here is that when torqueing up the top yoke nut you don't put additional preload onto the bearings. Tighten in steps and make sure that the degree of 'flop' on the forks remains the same.

Click to expand...

I've seen Sean's video on this and accomplished this procedure, only to produce a low-speed weave.

From what I know at this point:
Head bearings too loose = High-speed wobble
Head bearings too tight = Low-speed weave

I've taken it to a shop to check it and torque it properly - they said everything is good.

Lotsokids said:

I've seen Sean's video on this and accomplished this procedure, only to produce a low-speed weave.

From what I know at this point:
Head bearings too loose = High-speed wobble
Head bearings too tight = Low-speed weave

I've taken it to a shop to check it and torque it properly - they said everything is good.

Click to expand...

Yeah, I did the same. Simply back off on the nut a fraction and try again. Took me two additional tries and I'm only talking maybe a 1/4 turn looser and an extra 5-10 minutes to take it on a short ride between to get the perfect result.

Matt

I was cruising down the highway yesterday zipping up my jacket doing +80mph. Push the end of the handle bar hard and it comes right back to center. I've spent some time tuning and upgrading my suspension and still will tweak it a tiny bit. These bikes can perform to the ability level of most riders. It's all here on the forum, how to and where to get parts. Frame braces are something I did without anything else, at the same time. The frame is surely more rigid. I'd do it again. A stock bike should not shake or weave without mods, but like anything improvement is possible. I'd trust very few shops to address a wobble issue.

Lotsokids said:

I've seen these many times, but never read much about their purpose. I *personally* think they are very ugly and detract from the appearance of the engine. The only thing I've read is it supports the frame head under hard braking.

My bike still has the high-speed wobble, (read about it here) and looking at maybe purchasing some Progressive fork springs. I didn't know if this frame support is associated with the wobble.

Click to expand...

I like the look of the bar. Where can I buy a bolt -On bar. ? I'd put it on for sure.

jinks said:

I like the look of the bar. Where can I buy a bolt -On bar. ? I'd put it on for sure.

Click to expand...

These are from exactrep.

I normally agree w/MaxMidnight because he's got a lot of knowledge of things motorcycling. I would like to mention the move to significantly improve Japanese bike handling began in the late 1970's (I think Suzuki is usually credited w/the 1st advances for their GS750/1000 and the rotary for needle bearing swingarms and some suspension tuning capacity & better-quality components) and by 1984 Honda released the steel perimeter frame Interceptor which eventually was 500, 750, & 1000 cc (I am not including the 250 or the 700 cc tariff bike), followed by the Kawasaki 600 Ninja being the first American market aluminum frame, the Suzuki GSXR 750 & 1100 in 1986, and the 1987 Yamaha FZR750/FZR1000 (their 1st American market perimeter aluminum beam frame bikes) well before the 1990's. Kawasaki also had an aluminum frame literbike around that time but without looking it up I am not sure when, maybe 1986?

I have the frame braces that Sean sells on my bike. I was able to tell a difference immediately because they help triangulate everything.

Sent from my SCH-R890 using Tapatalk

I recently installed the weld on RMS Frame Braces and they absolutely tighten the bike right up.
http://www.rmsportmax.com/rods.html
I ran through some pretty good twisties at fairly decent speeds and could definitely tell a difference in how stable the bike was in the curves.

As for looks, I don't think mine detract from the look of the bike at all, I actually like how they look.

Is there much difference in the bolt-on style compared to the welded on ones? I've also heard that the bolt-on ones have trouble installing with a Corbin seat? Or vice versa. Is this true?

Sent from my SCH-I545 using Tapatalk

I'm sure the weld on frame braces are a bit better but the clamp on braces work fine too.
So I'd say its up to you to choose the braces that work best for you.

I like the fact that my weld on frame braces are mounted so I don't have to take them off to work on my carbs (synching, etc).
A lot of the clamp on braces look like they would get in the way for that.