KOBA Shift Kits.

[terry]

Hello All. I get e-mails to my PENTON web site wanting to buy a KOBA shift kit. Anyone know where some might be?

Thanks
PENTON Motorcycles
Terry Everett/Ohio
//www.pentonmotorcycles.com

[terry]

Thanks to Glenn in Cal. for e-mailing me and letting me know about some kits for sale.

Terry Everett/Ohio
PENTON Motorcycles

[adrian_goold]

Just reading over this post, can you explain what the koba shift kit is?

Regards,
Adrian Goold #101
http://www.ozktm.com

'73 175 Engine Rebuilding.
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[terry]

Hello adrian
I never had a KOBA shift kit, and to be honest I am not familiar with them. I will take a stab at it though. I think the selector shaft was machined and they rounded off the lobes. This made a positive shift when the detents fell into the grooves. Also the shift key was machined at an angle on each side and on both ends.

Thanks Again
PENTON Motorcycles
Terry Everett

[john durrill]

Terry, Adrian,
 We have some adds for the Koba kits in some old dirt bike magazines. It looks like from the add and pictures that the kit used springs in the same way a Hodaka does to compress when the key ( Steel balls in the Hodaka engine) does not line up with the slots in the gears.
 Something like this.
You shift say into second. The shifter mech. assembly rotates and locks into second gear position. The slot inside second gear, that the shift key slides into, locking the gear up, is not lined up exactly with the key. The result is a false neutral even though the shift hardware has advance into the second gear position. You can get around this for the most part by holding the shift lever at the stop a tiny bit longer each time you shift.
 The Koba kit would do the same thing with 2 springs. One for up shifts and one for down shifts. There should be a right hand wound and a left hand wound spring in the kit . After you shift , if the slots are not lined up, a spring compresses, the Key under spring pressure will slide into the gear as the slots align   . All you do is shift and release the lever like you would on most tranny designs.
 We looked at the adds for this kit back in the day and decided not to try it because the gains were not enough to off set the losses for enduro and trail riding. Most of our customers were trail riders and enduro folks. Once you get an understanding of whats going on in the tranny. Apply that to how you shift the Sachs engine bikes, we found we don t miss anymore shifts with a Sachs engine than we do with any other bike.
 The stock setup is stronger and simpler. For MX it might be enough of an advantage to make it worth while. As long as you can get replacement parts for the kit and it will hold up for long enough between services.
 If you bang on the shifter and or hold the shifter at the stop too long, on a Hodaka type design the springs will unwind. That leaves you with a tranny that wont shift worth a dime no matter what you do till the spring or springs are replaced.
 The Hodaka type shifter is a very good system you just need to use it like it was intended to be . The down side ( we though at the time ) is the kit was not designed with the rest of the tranny so you have to modfie the factory parts to fit. Our thinking was if the factory had designed it in, then you would have a stronger setup. All the parts would be built with the kits parts included in the design and a stronger tranny ( over a modified) would be the result.
 Does anyone in the group have any experience with the Kit under racing conditions?
John D.

[six dazed]

hi john,back in the 70's i raced mx on a six days with the koba kit.if i remember correctly there was a slight improvement if you were a quick shift type of guy.however,this i remember clearly-the shift from 1st to 2nd-usually on the way to the firstturn(hi ron!)was still problematic.you still had to take your time and think about that shift and as you said hold it a hair longer.i used my heel on the way back to the footpeg with my foot to shift to second but tried it both ways and it was still a hit or miss(literally)proposition.patience was golden,but its hard to be patient in the heat of battle.this one drawback,plus the fact i worked for a honda dealer convinced me to get a cr125 when they first came out.anyway,is the kit a huge improvement?i doubt it.the penton when new, shifted at least as good as the koba kitted motor.i think proper adjustment and maintenence are the keys as well as getting used to the way it shifts when set up properly and find what works best for you.and of course fresh selector keys etc..doug wilford's explanation of the gearbox and its workings and adjustment is very helpful.that was in a previous question in this column,hope it wasn't lost in the crash..there's my 2 cents,ric

ric emmal

[OUCWBOY]

I raced MX back in 69 and 70 with my Six Day and as long as you had the adjustment correct, I never had a single problem.

Donny Smith

[six dazed]

donny you're right,when the bike i raced was new and adjusted it worked great.only after time and a dimwitted teenager's abuse(yours truly) did any problem pop up.i'm just not sure the koba kit improved anything.it was my sponsors bike and he had kit installed.   ric

ric emmal

[wolfmanonapenton]

I have two new Koba shift kits still in packages with instructions that someone should reproduce them? They were better for racing,because bike I rode shifted more positive and was'nt as finicky as far as if you had to hit the shifter hard or laid it down? and shifting was smoother and did'nt feel so much retenshion on top of foot puting in and out of gear and find neutral was easyer when needed than finding more when unwanted?with the standard that you had to ajust more often unless you're kit was'nt installed right to begin with?anyone interested let me know?[8D]

[terry]

Hello Wolfman.  I would be very interested in getting them reproduced. Please contact me. my web site is  
//www.pentonmotorcycles.com

I have people waiting in line for the kits.

Thanks Again
PENTON Motorcycles
Terry Everett/Ohio