Renthal bar brace - Why do I need one?

[Commuter_Tim]

I have renthal gold bars with one of these on the bandit...
https://thumbs.ebaystatic.com/images/g/iXgAAOSw37tV--X7/s-l225.jpg

What purpose does it serve, are the bars made of some soft alloy that demands it?

My google skills are failing me.
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The above post is most likely nonsensical.

I ride a Bandit 600... badly.

[bamt]

It gives you somewhere to mount your GPS?

I like the honesty of bykebitz.

[Commuter_Tim]

[M.C]

I don't have one on my renthals. I thought they were to strengthen the bar, but from what I've heard they just cause more vibration.

[c_dug]

I have one on my Fazer bars - never even considered why to be honest!
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[Rogerborg]

[Teflon-Mike]

It's a bit of 'Legacy'... you almost certainly don't need it.

Whey back when, before the sport of Moto-Cross got metricized and was called 'scrambles' in good imperial English feet and inches, virtually all competition bikes were home built 'specials', created from a standard road bike.

Incidentally, the term 'chopper' now applied to raked fork 'Easy Rider' style American customs, originated in england, and the practice of 'chopping' the frame to reduce the wheel-base and make it nimbler off-road at low speed; Hence such specials gained the descriptions a 'Trials Chop' (job).. which crossed the atlantic with the the flood of Brit-Bikes to the USA in the export drive to reduce the war debt in the 1950's. The new generation of US rider's who bought Triumphs and Aeriel's and the like, looking for technical help to keep the things running, shunned by the incumbant Harley & Indian dealer's, turned to British motorcycling magazines for inspiration, and discovered the 'Trials chop' in the process, inspiring both the boom in US dirt-biking as well as the technique of frame 'chopping' perverted to stretch the wheel-base for an impractically long 'Easy' rider US Custom.... but I detract.....

Chopping an old Brit road-bike down to make it shorter for off-road use, it was common to fit a short petrol tank and push the seat forwards; foot-pegs would usually be moved from under the engine towards the front of the cradle, up and back, rather like a Cafe-Racer's rear sets, to somewhere more directly under the saddle near the swing arm spindle to 'centralise' mass when 'feet-up' stood on the pegs rather than sat on the seat.

But that puts the bars very low on the head-stock, so the rider is crouched over to reach them; hence bars were 'raised'.

Easiest way to lift the bars, is to bend up a bit of pipe with a taller U section in the middle where they clamp to the fork yoke.. especially if you were going to bend up a new pair of bars to make them wider for more leverage on the rough anyway.

HOWEVER.... road bars and trials bars would normally have something in the order of a 2" or 3" 'lift' in the U, as that increased and bars almost as tall as the 'american Ape-Hangers' reached 5-6" or so, so it was noted that when you turned them... they twisted! This was made more apparent in British scrambles or US 'cross-country' events, where the bikes were being 'raced' over the rough, rather than ridden considerately and with skill and dexterity....

Easiest way to stiffen up these long wobbly handles was to brace between them, and that was originally done by brazing a stiffening tube accross the top of the U of bars which were usually in them days still steel.

As off-road sport diverged into separate disciplines, with 'trials' becoming modern Enduro and 'Observed Section' Trials, and Scrambling becoming Moto-X, the deep-braced handlebar went to MX and Enduro...

In 'Observed' Trials, such deep braced handle-bars were never as popular as in dirt racing; lower bars kept the rider weight low and pulled him forwards over the bars spreading the weight between wheels for control; and the sport didn't find such advantage in monster amounts of suspension travel and huge ground-clerances, pushing foot-pegs ever higher, demanding ever taller handle-bars.

In Scrambles, though.. they did!

Aluminium handlebars, came along.... oooh, in the 1980's ish.

My Montesa Cota is a 1981 example, based on Ulf Karlsson's 1980 world Trials Championship bike.... noteable asside, it was Montesa's only WTC victory before they were assimilated into the mighty Honda corporation to build melody mopeds.. it was also one of the last WTC's taken on a twin-shock machine. As such, my old cota aught to represent the pinicle of T-shock evolution... and to be fair it does display a fair bit. for maximum ground clearance the frame is 'Majestied' the lower frame rails 'chopped' out, the engine used as a stressed member between the down tubes and the swing-arm; It also boasts a lot of aluminium parts, like the wheel rims, fork yokes, engine steady, petrol tank; though that was for UK market models to comply with current C&U regs... RoW got a one piece fibre-glass seat/tank unit to save weight, and it was such a 'feature' for the era most of them are actually stamped 'Montesa - Akront"...

Remember The thing's first, and only ever (daylight) MOT had just expired expired when I bought it in 1986, and It still has little 'features' like a rubber insert around the clutch and brake cable nipples in the handle-bar levers to counter criticism over alloy levers that they'll 'wear oval' round the cable! At that time, people would retro-fit steel levers to compers that came with allow ones, because of such fears and concerns and folk telling me how much 'better' steel levers and steel handle-bars were, because you could bend them straight on a section if you bent them in action, where alloy would just snap, when you crashed! (which I did a lot off, I must confess!)

Wasn't until 1995 when I bought a pair of Renthal's to try and alter the riding position a bit, I actually discovered that the cota had 1" diameter tube bars, rather than 7/8".. and I had to shim the bar-clamps to fit'em! Stripping off the levers and twist grip also revealed how they had 'knecked' the bars back down from 1" to 7/8" at the grip to take standard grips and controls!!! but again I detract a little

'Fat' 1" bars are a pretty recent innovation, re-invented by the yanks, as they discovered the material and started applying it to 'choppers', as a way to make tall alloy bars stiffer.....

Renthal, famed for popularizing alloy bars... stuck with the 7/8th standard, as that was what would most easily fit most bikes as an after-market component, and tackles the stiffness issue with higher grade aircraft grade alloy tubing, and the 'clamp-on' bar-brace, where welding a second tube accross the U as had been common on steel bars would have weakened the metal and made it more likely to crack than less....

There you go... that's the 'legacy' of how they came about.

Evolution of MX, ironically saw bar heights start to shrink again in the late 80's as ever longer travel suspension begged ever longer forks pushing the head-stock higher and higher, reducing the 'need' to fill that gap with pipe....

Loads on them from ever taller jumps, that had begged that longer travel suspension, turning the sport from a cross country race into a display of areal acrobatics, IMO, though still meant that the bars benefited from a bit of stiffening, and so they remained, even though the loads were now up and down and trying to flatten the bars, rather than torsional trying to twist them, front to back.

For road use?

The brace is probably utterly unnecessary; the bars are unlikely to be so tall that they flex when you steer, and if you crash down hard enough on them to try and flatten the shape, very often... you probably have bigger things to worry about than whether the bars will fatigue fracture!

More widely adopted on road bikes as a fashion item in the Street-Bike era of the middle 90's, they were fitted as a cheap way to fix up a lost the fight with the street sports-bike, compared to buying exotic multi-adjustable after-market 'clip-ons' or OEM replacements, as well as to ease the uncompromising riding position of a racer-crouch a little.

The bar-brace was usually retained, as it came with the off-road bars as standard, and as a feature, denoted they were genuine alloy competition bars, rather than cheap steel 'patern' replacements out of the Moto-Fiz brochure that supplied the carbon effect tax disc holder and anodised allen screw kit for the fuel filler!!!!

So, you bin teffed again... the purpose and the history of the alloy bar brace in one!!!
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[talkToTheHat]

Note the bulge on each end of the central bar, ideal for clamp-on accessories like the satnav, camera, phone holder, heated grip controls...
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Bandit. does. everything.