4speed or 5speed

[dutchtwinshock]

is a 4speed box from a 360 or 414 stronger as a 5 speedbox from a 250 vb/ve/vf?
i want to put a 5speedbox from a 250 vb in a 360h7.

has someone a picture of a 4speedbox?

Maarten

[cappra]

The 4 speed has bigger gears, one less shift fork, larger slider disc's.

[mx250]

So the question is; the VB, VE and VG 5 speed is the same as the VR (in size if not ratio)?

[dutchtwinshock]

Thanks for the pictures ,I see the 4 speed is much stronger.
Now i think the 5speed(250) will not hold up the power from 360 h7(has plenty ps)
I gona look for a 4speedbox ,maybe impossible.

i am thinking when i can`t find one i wil let produce a stronger 5speedbox .

http://www.mpe07.co.uk/

Which wil fit a modern sprocket .I contact him he told me he could made it for about 800euro
Yes thats not cheap but you can race further on for the next 15 years.


The vr 5 speed is the same as the later models 5speed, but the gears are a little wider,and the first 3 gears are non fixed to the shaft

[cappra]

In order to fit the 6 speed transmission into the 360 cases, Montesa
had to reduce the size of the gears to an average of 10mm in width,
about the same size as the 250 gears.
I have done a few of the 5 speed conversions into 360 VB's without
any problems. (414 might be something else!)  I think the 250 transmission
would hold up fine in place of the 360 Enduro's trans.

Thanks for the link to that website.  I might see into getting some of the
non existent Montesa gears reproduced.  Mainly the kickstarter gears for
the Cota 123/200 series.  The guy looks to do fantastic work.

[dutchtwinshock]

yes indeed ,and he takes away the fear for running out of parts a little bit.

I will give the 5speed tranny a try.Did you do the conversions also with the late model 5speedb. VB-VG. Because the vr tranny looks stronger(little wider gears) i can choose i have a vr and a ve 250 tranny

 But i like the idea of reproduce parts, special a new strong 5speed for all monty lovers.
because i like these bikes ,not they are rare or vintage but because they are so simple and effective.
There is not one part to much on it.Compare it to modern 4stroke bikes which are a hell for the amateur sideline drivers.
I think there is a gap in the market to reproduce a new vintage montesa/maico/cz/....like mx bike whith discbrakes.
it would form a new class mx.ers(sorry a little off topic)

I also planning to lasercut rear and front sprockets

[All Things 414]

Honda XR sprockets go straight on the splined Montesa shafts. All you need is the boss off an old Monty sprocket to go over the top of the Honda one.

[dutchtwinshock]

okay!
also a good idea for the rearsprocket?

On solomontesa they think they are made off gold

[cappra]

I have done both a VR transmission and a VB 250 transmission in the conversions.
The main problem I have been seeing in the 5 speed transmissions is the tendacy
to pop out of gear.  This can be traced to looseness in the slider disc's, and gears
on the shaft.  The transmission are not blowing up, they are just wearing out!
There is just too much looseness in the whole assembly.   Montesa must have been
aware of the problem as the introduced a spring loaded mechanism in 1979 that worked
very well, but did not really address the problem of the gearbox.  The 4 speed transmission
did not have these problems due to the elimination of one shift fork, larger gears and larger
slider discs. (less rocking on the shafts)   If I could adapt the spring loaded mechanism
to the 4 speed gearbox, it would be almost a perfect trans!  Wonder what it would
cost to have Moore Engineering made some of the shift drums for the 4 and five speed trans.

[dutchtwinshock]

I don`t know if the shiftdrum is heat treated(harded) .If not you could bolt on a camsplate with a little pin for holding it in place.
Like most bikes have.
Can adding a stronger spring (rightside) solve the problem?