5-6 speed KTM transmissions

[garrettccovington]

Next Tues. I'm gonna get my hands on bolt and take it over to my friends shop and make the 30mm "Dog Leg Pointed bolt" I don't have and try it out.  I have questions i.e. where is neutral, does the spacing gear ratio, between gears change, is it worth it, etc.?

G

72 six-day

[brian kirby]

I checked the bike when I got home and with some embarassment I announce that it has 6 speeds. I've been riding this bike for a year and had no idea it had a 6 speed transmission. [)]

Brian

'72 Berkshire

[454MRW]

It just makes the transmission effectively a 2-6th gear transmission. It does not change the ratios. By selecting the appropriate sprocket combination, the effective 5 speeds can then be utilized for MX use. All of my KTM 250-400 engines have been 6 speeds, although the later versions, starting somewhere around 1977 or 1978-early 1980 can be limited to 5 speeds by the addition of the longer dog point bolt. The proceedure is also outlined in my 1980 MC250 Users Handbook.
Both are listed in the 1978 Engine Repair instruction Manual 0561-080203 m8x20 & 0561 080303 m8x30. Remember the transmission must not be in 1st gear or neutral when installing the longer screw, or the gear shift drum could be damaged.
There has always been what I refer to as a "false neutral" between 2nd and 3rd gear, which I am assuming would be the neutral in a 5 speed configuration. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S

[rob w]

I fail to see any reason why I would pass on the option of using every gear the transmission has to offer.

[garrettccovington]

I agree, why not use all the gears available.  I thought maybe it changed the gear ratio's between all the gears.  I think I'm still gonna try it though.

G

72 six-day

[Larry Perkins]

I think the 5 speed thing is because in most MX situations if you gear for the start so you can use 1st then you never reach a speed to get in 6th and if you gear for topend to be right in 6th then first is too low.  Personally I like the 6 speed geared that way and then do 2nd gear starts and have 1st for an off-road bailout gear.  This gearing situation arose because the bikes were designed for enduro & Six Day type events and on a road section the high 6th gear was a blessing.  Just not many 80 mph sections on an MX track.

Larry P

[brian kirby]

That is exactly what I was going to do Larry, gear it for 2nd gear starts and use 1st as an emergency bailout. Its too tall right now for 2nd gear starts.

Brian

'72 Berkshire

[joe novak]

Hello,  My daughter and son have a Suzuki JR-50. It is sold as a single speed, centrifugal clutch.  The bike actually has a gear shifter which needs to be shifted into gear to engage.  I have read and seen advertized on Ebay Suzuki JR-50's which have been converted to a two speed bike.   I understand that the first gear is blocked out, and that only second is used.   Some have unblocked first gear and have made a two speed bike out of it.   Anybody know anything about this conversion?  Thank you,  joe

[Ernie Phillips]

6-speeds give you lots of versatility: Enduro, Hare Scramble, MX, and Desert on one bike.  The Penton designed machines excelled as a one-bike-that-can-do-it-all!   However, when you look individually at specialized disciplines such as open class Moto Cross, the Maico's with their linear powerband and slick 4-speed gearboxes are legendary.   While the riders of the peaky machines are jabbing the shift lever ... the Maico rider just pulls away.  Back in the day as well as now, the '72-'74 open class Maico's allowed average riders to achieve better than average results by providing predictable power delivered via an optimized gear set.  In the hands of experts; Ake, Adolf, Werner, Gerrit ... these guys cleaned house with 4 speeds in the early 70s Trans-AM events.  If KTM would have had the time and resources, I believe the Mint MC-5 would have had a proper 5 speed (different ratios than the 6-speed).  Of course then the name "Mint" would have to be changed to ... "Carlsbad"?

Ernie P.
Chattanooga, TN

[brian kirby]

A 4 speed transmission is lighter too which makes those Maicos easier to push back to the pits when the break down. I know this from experience.

Brian

'72 Berkshire

[Bob Marsh]

LOL, not much lighter, but a pound or two..I guess any amount helps when you are pushing[8D]

[tomale]

The maico 4 speed works fine for most MX races but two years ago I was wishing I had a 5 speed. I had the bike geared as tall as I could. It was so tall in first gear, it was like a 2nd gear start. There were places on the track that I had to slip the clutch in first gear to keep from stalling it in a tight hairpin, but there was a section that had a 75 yard straight followed by a sweeper and then another 75 yard straight.. I was passing everyone in the tight stuff but the bikes with the 5 speeds would leave me in the dust...on those long straights. I was wishing I had brought my MC5 but alas, there was no room.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[Mike Lenz]

In 78 they went to the drum with the pin sticking out farhter that could be blocked out to lock out first.  It is easy to know if you have one of these engines because the bolt is 8mm(the threads), not 6mm like the old ones.  Prior to 78 they blocked out first a different way (lack of a pin in the drum)so this bolt change thing wont work.  I have made up a paper on how I have done this to the older engines.  If interested email me at [email protected].