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hey u techie guys cud u plzz tell me the diff b/w single downtube frame and double cradle frame
which one is better and wat is +ve and -ve points of both
which one is better and wat is +ve and -ve points of both
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~~I LiVe My LiFe a QuArTeR MiLe At A tImE~~ -
Single downtube frame - CBZ , Karizma
Double downtube cradle frame - Pulsars , RX series , KB100 , KB125 , Fiero
There are 2 tubes that support the engine from below thus taking the weight of the engine . In Shogun/Shaolin , the single downtube splits into 2 tubes again to suppport the engine from below .
In Bullet ,CBZ and ZMA , the engine is not supported from below , the engine is the load-bearing member of the chassis .
Modern foreign bikes also have the engine as stressed member .
Overall its the stiffness and strength that matter , however you get it .Man will occasionally stumble over the truth, but most of the time he will pick himself up and continue on. -
Hey rEd, I've read that double cradle frames are better than single downtubes as far as the stiffness and rigidity are concerned. But I don't want to sound like a typical Pulsar guy yet again and state something like "yes, double cradle frame is much better than single downtube. That's why Pulsar has it and most others dont!". Just kidding!
As Ricci said, if even modern foreign bikes can use single downtubes with the engine as a stressed member, both configurations should have their own plus and minus points. Waiting for a real tech guy to put down all the points though! - MAX.
Some men have thousands of reasons why they cannot do, what they need is one reason why they can.Comment
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Cant really say which is better. Some say Cbz is a better handler than the pulsar and along with they say that double down tube is better in handling, so you see the conflict?
Single downtube has the adv of less weight and using the engine as a stressed member gives the weight advantage.
Double cradle chassis gives more rigidity but compromises in weight.
But the anomaly still remains between CBZ and Pulsar.
The doulbe cradle chassis of the RX series has been proved to be one of the best on indian bikes in terms of handling.
Guys what do you think?LIVE LIFE FULL THROTTLE!!!!!! VROOOOOOM!!!!Comment
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Teknically speaking, if u get 2 bike models (1 each of single tube nd double dwn tube), hold the steering part in one hand and rest of d body in the other and give it a twist, a double dwn tube wud prove 2 b much stiffer nd wud budge d least, wen compared 2 d single tube model. Thats'll abt handling (influenced by rigidity) , wen confronted with torsional forces. As regards handling many other parameters play an important role. Pulsar has a dbl dwntube, ZMA single, but ZMA is the better of d two in handling. But put a CBZ (SDTube) thru some quick left-right turns nd u might notice it lacking in rigidity (even though CBZ is still s'posed 2 b the better handler of the two). So d +ve point of DDTube is rigidity, -ve is higher power 2 weight ratio. Vice-Versa 4 SDtube cradle. Handling characterisitics depends on the rest of the chasis, suspension design etc.____.~^~._.~^~._.~^~.____
____BEND IT LIKE ROSSI____Comment
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i have heard double cradle chassis r better than ddtube.more flexibleComment
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I don't think that unwilingness in left-right turns is a sign of less rigidity , rather it indicates more directionals stability .Man will occasionally stumble over the truth, but most of the time he will pick himself up and continue on.Comment
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When comparing double cradle and singe downtube the double cradle frames are more stiffer and stable. Other than the type of frame handling depends on like rake,trail, wheelbase etc.
Nowadays racing bikes use a different kinds of frame other than these two, like twinspar, deltabox, trellis etc. But during the 70s and early eighties, when doublecradle/singlecradle types where in use, most of the racing machinery had double cradle frame rather than single. And that makes sense.
During the hundred cc brigade of yore the bike with the best stability was KB100/125. RX is also a good handling and more nimble than the KB. And the Suzukis were the ones i didn't like in handling dept.Suckin\' gas and haulin\' a**!Comment
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LOL tell this to nav tht kb/rx have good handling.as per him rx is wobbley and unstable.\'87 High Torque RD 350B
in first gear,6000 rpm,whack the throttle.Comment
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R U guys sure that the ZMA (and all Single Downtube bikes) use the engine as a stressed member?
I don't think so. Agreed that the Bullet uses its engine (more so Gearbox) as the stressed member, but all other bikes don't do that. All other bikes have the mass of the engine so small that stressing it will be crazy. And then U have the Rubbed mounted engines to cut out the vibes ..can't be stressed.
I guess the ZMA (like other single downtube bikes) like the Caliber 115 as well has a normal (and not stressed engine).
On the other hand...the Bajaj Byk, is neither a single or a double downtube bike. It has no Downtube at all. The Sheet metal chassis takes all the stress and holds up that horizontally mounted engine. And so that the byks don't look something like bikes with a cut off chassis, they have 2 dummy downrod tubes goin down. Interesting stuff.2003 Bajaj Pulsar 180 DTS-i (first gen, spoked 18" wheels)
2005 Ford Fusion+
2006 Bajaj Wave 110 DTS-i
2010 Bergamont Tronic SportComment
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byk and splendor use a backbone type chesis.yes karishma and cbz use engine as stressed member.\'87 High Torque RD 350B
in first gear,6000 rpm,whack the throttle.Comment
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Stand corrected Rajnish! Checked up an earlier issue of OD last nite.
But also reminds me, most scooters and scooterettes have not only the engine (and transmission) as the fully stressed member, but also form a part of the suspension itself (most notably the swingarm) which is actually the final drive (belt or chain) housing.
In the classic Vespa/Bajaj layout, the engine and gearbox itself forms the swing arm (there is no belt or chain final drive).
And regarding the back bone, the Splendor uses the arc welded tube type chassis as do most Indian Motorbikes. But the Byk was the only bike (leave aside step thrus) to feature a monocoque (spot/seam welded) chassis.
BTW: what kind of Chassis does the Yezdi have?2003 Bajaj Pulsar 180 DTS-i (first gen, spoked 18" wheels)
2005 Ford Fusion+
2006 Bajaj Wave 110 DTS-i
2010 Bergamont Tronic SportComment
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actually the splenders and cd series use the backbone type only.tht's wht the type is usually called.yezdi uses a single downtube type frame.some more figures for roadking-
Maximum Speed : 120 Kmph
Acceleration : 4.1 secs. (0 to 60 kmph)
Max. Gradability : 25 with flying start of 20 kmph in 1st gear.
Ignition Timing : 23 +/- 2 BTDC at 3000 RPM
Spark Plug : Mico W 225Z or MODI CHAMPION L 82 Yc
Gap Setting : 0.7 mm to 0.8 mm
JIKOV 2926 SED, PACCO P :
Main Jet 96
Pilot Jet 50
\'87 High Torque RD 350B
in first gear,6000 rpm,whack the throttle.Comment
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Amazing Stats Rajnish,
Just imagine what a 4 decade old bike could do! That too with just 4 gears!
It still can beat the sh** out of most new 4st bikes!
BTW, what was the Power output of those twin exhaust machines?2003 Bajaj Pulsar 180 DTS-i (first gen, spoked 18" wheels)
2005 Ford Fusion+
2006 Bajaj Wave 110 DTS-i
2010 Bergamont Tronic SportComment
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sorry my post was incomplete,here r rest of them-
Type : 2 stroke, Air Cooled
No. of cylinders : one
Bore & Stroke in mm : dia 70 x 64
Cubic Capacity : 246.30 cc
Compression Ratio : 8.2 : 1
OUTPUT (BHP) : 16 at 5000 RPM
Torque : 2.43 Kgm at 4250 RPM
Starting Primary Kick (can be started in any gear by depressing the Clutch)
Length : 2000
Height : 1100
Width : 750
Weight (dry) : 134 Kgs
Kerb weight. (Incl. Fuel ): 144 Kgs
Wheel Base : 1350
Pay Load : 130 Kgs
Front Wheel Spindle Max. Load : 75 Kgs
Rear Wheel Spindle Max. Load : 199 Kgs"
Quarter mile was below 18 secs.\'87 High Torque RD 350B
in first gear,6000 rpm,whack the throttle.Comment
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