SBF Majesty 250/400 Cafe 2008

[br1an]

Originally posted by unocvin@Jun 23 2006, 05:30 PM

What are the advantages with the bitubo shocks? I have been playing with my shocks adjustment till I am resonably satisfied (position 3 of 5). Tyre pressure changes the characteristics too, my tyres are now inflated to max recommended of 200 and 250 front and rear respectively. I had my engine mount changed too as the rubber has disintegrated due to all the flexing, swaying and ageing as the engine is rubber mounted. My fork oil was replaced with a 20 wt instead of a 15wt (factory soec) andt I now find it too stiff ... all in all, there is a difference to me and I find it is better.

 

Anyone care to share other handling refinement done to their scoot?

basically geometric wise the majesty have engine mounted on swing arm, rear unsprung wt too high, cg too rear bias, fork and shock stroke too short, wheel too small 12" and tire profile too high. any way they are not designed for handling like bike. when i got this scooter i feel the spring is all abit on the hard side but the damping very weak it will bounch on highway. As the scoot have large compartment the sometime carry many thing so ..i think no point get the rite spring wt cos my loaden wt maybe diff day to day due to things i carry onboard. corner wise pretty all rite for scooter , high speed corner is stable only when the road is very flat .. abit of uneveness, it will ... ... feel like a boat very scary. when i first got it i put the rear preload at position 3 or lower to compansate for the lack of reboun damping, i think it was the best compromise i feel tat time. after one year i service the fork ... dunoe wat they do to it.. maybe use havier oil , i dun know. the fork suddenly feel very hard. so now my rear preload put to sec highest. was looking for bitubo cos it can be serviceable. and the preload range is much more then stock one which is about 1 cm only ... . bitubo also not damping adjustable, only advantage is wider preload adjustment and serviceable. so if serviceable there is possibility to use diff wt oil maybe even add some shim to alter the damping. now all i can to is to alter my riding style e.g move the wt forward backward, and choose the better lining in corner.

oh one more thing there seem to be a ABS sensor at my front wheel. saw on mag certain year model come wif ABS but i not sure my model come wif it or not. any way the front wheel do wheel lock pretty easily .. maybe the front too light rear too heavy ABS also no use..

[unocvin]

i have been riding on small roads, esp those with bumps and road works scars to find the limit of handling so that I won't get surprises when I ride in Malaysia ... I had the floating sensation before but after spending time doing a few things, it is pretty alright but a little "crashy" .. maybe fork oil too heavy. But on PIE/ECP flat surface it feels good at 110/120 km/h (straightline) ... but the biggest difference I experienced was after I change out the engine stay member (aka dog bone). This part is design to fail as the engine hangs off it and it allows the engine to flex and sway a bit for the sake of damping engine vibration. Mine was disintegrated and had to replace it, the scoot is 7 years old, so I wasn't surprised by that.

 

Thanks for the explanation on the Bitubo, I read that they make competition forks, shocks and fork brace for the maj 250.

[br1an]

Originally posted by unocvin@Jun 26 2006, 02:45 PM

i have been riding on small roads, esp those with bumps and road works scars to find the limit of handling so that I won't get surprises when I ride in Malaysia ... I had the floating sensation before but after spending time doing a few things, it is pretty alright but a little "crashy" .. maybe fork oil too heavy. But on PIE/ECP flat surface it feels good at 110/120 km/h (straightline) ... but the biggest difference I experienced was after I change out the engine stay member (aka dog bone). This part is design to fail as the engine hangs off it and it allows the engine to flex and sway a bit for the sake of damping engine vibration. Mine was disintegrated and had to replace it, the scoot is 7 years old, so I wasn't surprised by that.

 

Thanks for the explanation on the Bitubo, I read that they make competition forks, shocks and fork brace for the maj 250.

so u mean after u change the the engine stay member (aka dog bone) it become better or become worse?

i think the competition shock or fork will be too expensive for me .

[unocvin]

The handling is better after the replacement ... before the replacement, I am very concious about making turns, now it I feel confident. Except when it rains... maybe next thing to do will be better brake pads

[Guest bomerman81]

"engine stay member (aka dog bone)"

 

wats this???

[unocvin]

It's the piece that the engine hangs off the cross member and attaches to the chasis of the scooter. I will try to upload a diagram of it later in the day.

[unocvin]

how do I post a pic? .. i use the attachment, hope that's ok

[br1an]

Originally posted by unocvin@Jun 27 2006, 09:32 AM

how do I post a pic? .. i use the attachment, hope that's ok

i wonder wat dose this thing do .. and how it will affect the supension linkage.

[unocvin]

Not entirely sure ... i thought about it and strictly my opinions:

 

1. Vibration - single cylinder engine produces strong vibes and a common method is to rubber mount the engine to help isolate the vibes BUT

 

2. Being a scooter (engine attach to back wheel), the pivot point of the engine is also the mounting point for the engine. The pivot (fulcrum) point is the swinging up/down action like a see-saw or a normal swingarm of a motorcycle, and it is normally loaded on roller bearings to facilitate movement.

 

3. Since this pivot point is also the mounting point for the engine and being rubber mounted, it is not going to be able to swing like a roller bearing swingarm and so,

 

4. The "dog bone" takes over most of the flexing and swinging duties of a conventional swingarm. The rubber material is not filled in 100% comapred to those of the cross member, there are gaps built into it that allows it the space to deform/compress/stretch as the engine swings up and down and unfortunately also flexes sideways. That's why most (if not all) scooters doesn't handle the same as a motorcycle. With exception of a few like a Tmax (mid mount engine) and Nexus which is solid mounted on bearings and not rubber.

 

5. The rear shocks basically just help control the engine/rear wheel swinging by damping it.

 

On my scooter, the rubber in the dog bone disintegrated and affected my handling, basically the scooter doesn't really want to turn smoothly. The feeling I can associate it with is like a badly underinflated rear tyre when riding a motorcyle.

[br1an]

wow very informative.. thanks for the detail explaination. now i know more about scooter. must meet up wif u one day for kopi to talk bout it. i am very new to scooter. the internal is covered up very difficult to see wat is going on.. by the way here u get those diagram ?

[unocvin]

Those diagrams are from the factory service manual (should be the same use by HL mechs)

 

My scooter is maintained by a car mechanic (i used to drive) who have the factory manual .. he has adjusted my valves clearance, replaced every wheel bearing, serviced my brakes, replaced the variator cam, spacer and slider and of course that "dog bone" as well as engine and gear oil. It is straightforward with the manual to follow.

 

I buy the parts and he charge me labour, most times I hang around to learn too... definitely more affordable than service at bike shop (bike shop mark up on spares and sometimes smoke you into changing things that isn't necessary) and DEFINITELY cheaper than HL (i know bcos my dad's Maj when for some service) ...

 

Anyone needs to know more about Maj 250 beneath the plastics, let me know. I try to look up his manual or answer with what I already understand..

[br1an]

with the amount of work done on ur majesty.. it must be runing smooth like brand new .... all these work .. though only pay for manhour.. still come out to be a big sum

[unocvin]

.. yea, spend a bit, but necessary expenses lah. But that was my objective anyway - buy the cheapest in a reasonable condition and then spend on replacing all the worn parts and hopefully trouble free for the next 3 years and just carry out monthly maintenance ..

 

Been doing some search and found that the FI Maj 400 redesigned the engine mounting to have 2 "dog bones". Yamaha call the internal rubber "compression rods" and works like how I imagine it to from my earlier post. ..

[br1an]

do u go any outing?

[william_liu]

Think can ask bomerman81 to rename this thread as "SBF Majesty 250 Cafe", looks like a good thread with valuable info sharing and should be made into a 'Cafe'!

 

[Guest bomerman81]

Originally posted by william_liu@Jun 28 2006, 07:02 PM

Think can ask bomerman81 to rename this thread as "SBF Majesty 250 Cafe", looks like a good thread with valuable info sharing and should be made into a 'Cafe'!

 

ok will convert it.....

 

then can chat anthing under sun here oso other then valuable info.....

[Guest bomerman81]

Originally posted by br1an@Jun 28 2006, 06:27 PM

do u go any outing?

can can mayb can try to have 1 lah.....

 

anyway we all majesty mah.....

[Guest bomerman81]

how abt having a kopi session on sat 31/06/06???

 

interested??

[Guest bomerman81]

KKFC Kopi session

 

Date: 1st July 2006

 

Day: Saturday

 

Meeting Place & Time:

KKFC @ 2100hrs

 

Confirmed list

 

1) bomerman81 ( 81253090 )

2)

3)

4)

5)

6)

7)

8)

9)

10)

 

 

PS. Anybody oso can join juz a kopi session for riders to discuss about ur passion and hobby.......

 

:cheer:

[unocvin]

u mean 1st July? ...

[Guest bomerman81]

Originally posted by unocvin@Jun 29 2006, 09:40 AM

u mean 1st July? ...

 

juz edited!!!

[Guest bomerman81]

Originally posted by unocvin@Jun 29 2006, 09:40 AM

u mean 1st July? ...

so u joining???

[unocvin]

..i wouldn't mind .. but I have visitor from overseas .. so, I can't confirm .. but if the meet up is firm, I can drop in after finishing whatever it is i need to be doing that evening .. PM me your contact number so I can call you on Sat evening..

[Guest bomerman81]

Originally posted by unocvin@Jun 29 2006, 10:09 AM

..i wouldn't mind .. but I have visitor from overseas .. so, I can't confirm .. but if the meet up is firm, I can drop in after finishing whatever it is i need to be doing that evening .. PM me your contact number so I can call you on Sat evening..

ok will edit the post with my hp no. in ok.....

[william_liu]

You got fierce competition for your outing on that day....

 

namely: ENGLAND VS PORTUGAL!

 

:bouncefire: