bhpistorqintorpm

i have been contemplating converting my 4 speed RX135 to 5 speed. initially i wanted a complete conversion with 5 speed bore kit : but looking at the economics of it i decided to get only the gearbox modified (not even the new 5 speed gear box).

to begin with i was not aware of the bike's condition(i had bought it second hand last year). which bore is it running. what is the condition of the current bore. condition of the crank, gb etc. @69K on odo i was sure that bike was running on some oversize.

so i started searching around xbhp and other forums for references, insights. bugged many xbhpians again again. thanks a lot to Sandeep K Ram and Psycho for all the insights and sorry for bugging .

and one day i took off from office to attend to the bike. i had no idea where to start. went straight to J.C.Road. for some reason most of the shops were closed. then i started calling few phone numbers of mechanics that i had stored on my mobile. then got this guy online - Praveen.

jump to next week

bike stripped to the bones:




we met up on Friday morning to discuss and decide on the work that is required on the bike. after listening and riding the bike Praveen said engine seems to be in good condition but bike has lot of rattling. and i asked him if he could modify the current gearbox to 5 speed and he said it can be done and i was like . my aim was to get the engine and cycle parts in fine running condition. no cosmetic mods/restoration as of now.

so on Saturday i was there at his workshop all day.

4 speed bore:



1st oversize piston (0.25) - Goetz:



cylinder head:


gearbox side assembly:


but the 5 speed gear box conversion kit had the wrong wheel in it: so it was sent back for replacement. whole of Saturday nothing progressed.

to be continued in next post..
PS: sorry for the blurry pics: weak cellphone cam

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RX 135

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Aryan

Topic Approved.

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jd666

great going mate!! can you check and confirm whats the number of teeth on the front and rear sprockets your bike is running??

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My offerings to the gods of speed -

- KTM Duke 200
- Yamaha RXZ 5 speed

Shivanshu

Great goin bro keep us updated

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psycho 98

Nice !!! but whats the intention of running with 4 gear ratios of 4 speed and on gear ratio of 5 speed ??? why do u intend to run a 4 spd bore and head on it with 5 gears, the reason i didnt reply to your last pm is i didnt knew any mech who will do this in a proper way, thats the reason i didnt recommend any.. if you have found one then congrats ..

Please do pen down on why you choose the chow chow combo !!! what gains you looking at ???

I am not at all surprised with your set up coz there is other thread with the same set up and being given 5 star rating

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"Engine tuning is not an exact science, but with some practice and patience you'll get comfortable with your skill and be able tune for any conditions mother nature throws at you"


Still the Boss -- RX 135

bhpistorqintorpm

@Shivanshu and jd666: thanks guys

hey psycho: first thing - thanks for the PM inputs.

and about the chow chow combi:
i was not satisfied with the performance of the bike. i would always feel 'm missing something from the bike. so for that i would have to get the engine opened, tuned, bored whatever. i had no clue.
and i needed an extra cog so that the bike can be used for little highway cruising too. as such 4 speed set-up is great for city riding. and 'm always on tight budget.

in essence: i wanted to do something with this bike. so i started off. you know it is almost been 6 months i have been enquiring about this. so it is just a start: based on the availability of money and time: other things will be planned. and looks like 've found a good mechanic too

about the "my 4 speed goes one up!!" story: 'll resume soon.
-som

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RX 135

Save the endangered species!! Save the Two Strokes!!

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psycho 98

I am glad that i was to help you from 6 odd months ..

Adding an extra gear will not help in high way cruising, infact your revs will drop down the moment you hit 5th gear, coz you are running diffrent set up diffrent sproket and gear ratios in word a mix of 4 and 5 speed combo.. so you cant enjoy to the max.

"Cheap and Reliable is not Fast, Cheap and Fast is not Reliable, Fast and Reliable is not Cheap"

My only wish for you is hope u understand the ^ meaning ^ soon, i understood this rather late infact veryyyy verryyyy late, after wasting a lots of $$$$ and being conned a lot ..

__________________
"Engine tuning is not an exact science, but with some practice and patience you'll get comfortable with your skill and be able tune for any conditions mother nature throws at you"


Still the Boss -- RX 135

bhpistorqintorpm

very well said: and i never dispute that. and that is the reason i did not post this thread on the other forum.
about conning.. nope nobody has conned me : it was my choice. infact i was told about all the caveats. 'll cover that all in my write up.
some thing urgent came up in office: not able to complete the story.

and about dropping out of power band on highway.. actually i don't know how one 'll take it: but actually lower engine revs are good for me and i feel it is easier cruise like that.. and any day i need to just shift one down to reach that 4th gear: sprocketing remains the same(wanted to reveal this in the story )
and yes i do understand that i can't enjoy it to the max: like a true 5 speed but this is better than what i had before.
thanks for the wishes

and @Aryan, thanks for approving the thread: i completely forgot that this is a new thread and needs approval

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RX 135

Save the endangered species!! Save the Two Strokes!!

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bhpistorqintorpm

as Praveen was scouting for the right gear wheel: i was told to come on Tuesday morning and pick up the bike. but as it should happen: bike was not ready by Tuesday.as his shop is pretty far from my place, i could n't visit in person either. finally i get a call on Friday and i was confirmed that the required spares have been procured and i can come and oversee the work on the bike. till this time the bike was in the same condition as shown in the pics above. on Saturday i reach his shop by around 11.30 and i see this:
lower end of the bike neatly laid out in parts:



crank:



and... gosh my phone dies off: i forgot to recharge it yesterday night i hurriedly buy a new charger: put it on charge. meanwhile work on the gearbox assembly is in progress. everything was being fitted in neatly- even as a RD owner comes with a broken gear lever and another guy with his Karizma. after directing them about 'next' steps and cordially turning down few other service requests: he resumes work on gearbox. condition of the bike:
1. the bike is running first oversize. 2. condition of the bore is good: doesn't require rebore
3. crank is in good shape/condition. no play.
4. a spring and for the clutch release mechanism was worn out: changed: culprit for earlier hard gear shifts.
5. clutch plates changed: pressure plates ('m i using the correct word?) are in good condition..(voila my fone is back to life)


after gearbox was ready: engine was decarbonized. assembling of all the other components started. as required new seals were used with different grade of grease/paste. after lower end: top end was mounted on to it: this assembly essentially the engine goes into the chassis


with all the fluids in place and the big, black cat-con silencer was mounted. now as the assembly was still in progress i had to leave his premises because of my friends. we had to go somewhere. work was carried on till 10.30 in the night and later i received a SMS that i can collect the bike on Monday - Sunday being an holiday. I had spent almost complete day at the mechanic's place.

finally i collect the bike on Tuesday morning.
Now the bike has:
1. New spark plug : NGK
2. New Kicker
3. Stock 4 speed sprockets at the front and rear
4. Bike chassis paint touched up at few places: (rust due to acid leak from battery)

i started the bike and engaged first and started moving.
at first bike felt light and gear shifts were lot smoother. i went up to 4th and increased the throttle input to increase the revs and locked on to 5th. neat. bike was cruising clean in top gear. all the engine vibe problem were attended to. overall i was happy with whatever i experienced in that short ride.

after returning from the test drive, Praveen told me that i'll experience false neutrals for few kms say up to 500 kms. after which we would have to change the gearbox oil: and at that time it would be fully synthetic oil. the final ratio is not very tall when compared to 4th gear,but it still a lot easier on revs in the current sprocket set up. we discussed the sprocket change too. but for now both of us were happy with the stock set up. later we might go for more teeths at rear for top end if that is what i want. we are not sure how the bike will perform then: it is all based on trial and error.

other option of gearbox was short ratio gearbox : if i am not wrong this is the stock 5 speed gear box. this would have definitely worked out much costlier.

current situation: bike is running fine. it's been around 150 kms after doing the mod. chain needs to be tightened and i keep hearing some metallic sound occasionally apart from chain cover sound. got to have it checked.

final outcome i am




phew that's a looong post and sorry for the poor quality pics.
this was jsut the engine overhaul and gb mod. 'm planning for cosmetic restoration a little later. chroming, painting, new panels, monogrmas

cheers,
som

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RX 135

Save the endangered species!! Save the Two Strokes!!

http://www.facebook.com/group.php?gi...&v=info&ref=mf

mav1234

Nice one bro.. changing from 4 gears to 5 really requires skill, if anything goes wrong then time and again you will face problem.

Hats of to the MECHANIC and you too ..

Keep us updated about how you feel after this change.I mean any discrepancy you are finding after the change has been done..