Frame Bracing

My race bike has bracing at the rear pivot and steering neck but the swing arm & fork is unbraced. It doesn't handle too bad either. I wont be bracing one...I personally think you should assess the need, depending on what else you've done and allowing for modern tyre technology & gross weight  ;)  Rob
 
Hey Padlock

Here's some proper head bracing ............. ;)

Just down the road from you too.

                    Cheers
                            Matt

 

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hochkoenig said:
I never had any Speed Wobble even at topspeed with my 1200, rides like a Train with Ceriani Forks
Click to expand...

Never had any wobbles on the street too. On the bowl with "G"s at some of the fast NASCAR road race tracks here in the USA with a 36t rear sprocket and high revs.. that's another story. Stiff Cerianis up front..no problem. The swingarm would flex in the back though.It would twist under power...easy fix.

Old school thinking was if it is shaking up front..the cause comes from the back of the bike. If it is shaking in the back of the bike..it comes from flex in the front.

 
My 3C handles fine too, almost no additional bracing involved.

The headstock was repaired and braced to prevent further cracking, the swingarm pivot area and the axle are as they left the factory.  Swinger has been replaced with a RGS unit, not for the strength but for the length, also left in stock condition.  A MR1 fork takes care of keeping the front wheel in line under hard braking.  The 38mm Ceriani forks are a bit weak for a bike of this calibre and the Marzocchis no more than marginal once brakes, wheels and tyres have been uprated.  Theoretically, forces induced to the frame must now be more than with the stock forks and swingarm due to reduced flexing, but the frame is more than up to it.

Imho, triple wobbles have a lot more to do with suspension set-ups than frame flexing.  I get to ride quite a few diffent triples and have found, quite frankly, that about 80% of these handle shite.  Sagged springs, too hard springs, no damping, damping akin to a steel rod as well as a good mix of these conditions back to front is very common.  An understanding of chassis set-up basics is often sadly lacking, so no real surprise.  Funnily enough, fancy fork braces and braced or aftermarket swingarms seldom make matters better :D.

piet
 
well - yes and no...

I have upgraded my bike over the years a lot while no welding was involved but a box type swingarm (K&J in Germany) and a fork brace on the standard 38mm Marzocchi (which had a good service but no fancy parts in it like gold valves etc.). I switched from the AG Strada to Konis and had 90% of what I wanted and a bike that handled so much better. But then, I changed to GSX-R rims - oh what a difference with those BT012SS this made... Added YSS shocks on the rear (which are a bit longer than the Konis) and had a bike that handled almost as good as a 20 years younger one (Honda VFR from the 90's). What a difference...

Headstock still original, swingarm-pivots, too, as well as the front fork. For a race-bike, I would consider a longer headstock and a thicker fork with more adjustments, but for street-usage, this is more than you'll ever need if you want to stay half way legal...
 
As Piet says, back in the Days a Italian Moto have to be hard, and feel like a Oakboard.
As harder as better, our poor spinediscs!!  :(
This was done because of lack of good Damping in Frond and Back...
But good fun also... 8)
 
Here you go Julian, the head stock on my Mk3 Motodd frame


PB281473.jpg
 
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