Staton Robin Subaru crank shift kit

MaxPower said:

Staton sells regular old square taper crank arms that are the same as the ones I'm using. The problem is that there is no dish to the smallest sprocket. A flat sprocket only allows you to get the sprocket butted up to the adapters flange and not over hang the flang with a dish. Most front sprocket sets have a dish for this very reason.

Click to expand...

My bottom bracket is 2.630" inches wide and with the 27 tooth ring almost butted to the right side bottom bracket bearing carrier the front chainring gears are almost perfectly centered with the rear 7 speed cluster casset. Guess I was lucky.

Do you have any spare room between your most outboard gear on the rear casset and the frame tube/dropout? If so, you could spacer the the rear casset more in the outboard direction to get better alignment.

My philosophy is to look at these motorbike kits as "universal" kits made to work on all different types, styles, and variaty of bikes.............not everything is going to fit up perfectly because of the "universal" nature and some adjusting, tweaking, cutting, and fitting is going to be necessary for different bike types. ............Don

MaxPower said:

dtj6ppc, do you have any wobble in the front sprockets when you pedal? I've got some but I don't think it's enough to pop the chain off though.

Click to expand...

Yes, I originally had an unacceptable amount of wobble and/or runnout in the front ring assembly and asked Staton about the easiest fix for this problem.........he suggested sending the front ring assembly back to him for adjustment, I was too anxious to get the motorbike up running and didnt want to wait for shipping and repair time, so I bugged it out myself.

The wobble seems to be caused by tolerance stack ups between the various, freewheels, rings, and spacers, turns out that this front gear/freewheel ring assembly is fairly complex with all the different components assembled together into one unit.

I think the fix is to assemble all these different components in relation to one single control part which would be the "axle with woodruf key".

I am just guessing, but it appears that Staton is assembling all the individual parts independantly and not onto the "axle" in a controlled manner, I dont know this for a fact. But, when I disassembled my unit (very difficult because of the locktited thread assemblys and high torque rates) and re-assembled using the "axle" as the control surface reference component, all wobble or runnout disappeared, and the gear system shifts flawlessly without hesitation and without deraillment from outer most rings.

The locktite and the need for a super heavy duty freewheel dis-assembly socket are some of the reasons that Staton recommends return for re-adjustment if wobble or runnout is present.

Personally I hate wobble and runnout even if it does not cause bad shifting or chain deraillment, something about a gyrating gear mechanism just rubs me the wrong way when I have to look at it constantly, especially when the rest of the motorbike is working flawlessly...............Don


I think the following 2 photos of the inner and outer keyed spacer areas best illustrates the different alignments that caused wobble/runnout, and dissappeard when re-assembled using the "axle" as a control feature;

Just my two cents .
I have used awful-ly made crank spindles. They are just slightly wrong , the taper or lack of it the bearing support spacing, bent, erc.
These guys are not newbies when shifter kits are used.
They sell three different crank spindles that are properly sized and made.
134 mm, 135mm, and 158 mm.
Sick Bike Parts LLC - Performance parts for your motorized bicycle

Thats dax also sells a good one.
157 mm.
Page Title

From my experience it makes a difference if the engine driven sprocket , and crank drive sprockets align perfectly. As well as the crank to freewheel setup at least on the bottom . From the derailuer to the crank sprocket.
I do not like pulling off on the sidewalk to put it back together at all.

Staton uses two guides for his unusually long drive chain.
I use a strong spring loaded idler wheel with a rollerskate wheel.

MaxPower said:

Is this too much wobble? Dailymotion - wobble 2 - a Auto-Moto video

Click to expand...

Looks to be borderline functional to me.................probably wont cause front chainring derailment but will require bigger gaps in front ring shifter mechanism for proper functioning.

Aesthetically it looks wrong, and probably promotes earlier chainring and chain wear. You do not strike me as the type that likes less than correct functional hardware..............Don

MaxPower said:

Almost done! I'm still waiting to hear from Staton about the wobble.

Click to expand...

Just about there, looks good, I know you must have given it a short test run by now.

After looking at your bike photo, the one thing that needs to be fixed is that the gearbox to bottom bracket chain needs to be routed "underneath" the first "idler pulley" and not over the top as you now have it located. This will allow the chain to contact about 80 percent circumference of the gearbox output gear and greatly reduce the possibility of chain/gear jump.

Also, noticed that you bolted the tensioner bracket arm common to the gearbox front cross bolt where as Staton designed the arm to be located in the "U" bracket hole about 2 inches lower (disregard my statements if these were done intentionally to try something different)........review other support photo's to see these differences.......Don

MaxPower said:

He told me a story of one of his customers doing it and having it sent back to him for repair. I'm guessing that was you dtj6ppc.

Click to expand...

No, it was'nt me, but almost could have been because of the amount of locktite and tight thread fit that almost makes it impossible for anybody to dis-assemble.

Hope he figures out a way to get the assembly together "wobble free" from the factory, seems like other customers are having this problem also..................Don

MaxPower said:

I talked to Staton about the wobble. He said that It will straighten out a little after it gets warn in. .

Click to expand...

Good luck with that, the way Staton has put these front ring assemblys together nothing short of a high explosive is going to change the way they track.

Let us know how things work out...........Don

MaxPower said:

Finished the bike today. Post pictures tomorrow.

Click to expand...

How well does it ride, have you figured out the proper shift technique for smooth shifting without the gearbox destroying slam-bang effect?.........Don

MaxPower said:

Pictures as promised. First impressions: The 33cc engine is quite weeny. I'm used to my 80cc harbor freight engine. I only have 2.5 hrs on it so maybe the it needs to be broken in. I haven't pushed it hard yet but I've been up to 20mph. The transmission is making a lot of noise. Sort of a wining grinding noise. It's most likely getting broken in too. Can anyone else confirm this? Will it quite down after some time? I'm very impressed with the one pull starting of this motor. It's also easy to pull and I can start it while siting on the bike. The gas tank is small and I only got about 20 miles in my first tank. I'm going to get a fuel bottle for reserve. Shifting is quite easy if do it right. Let up on the throttle, shift, and slowly increase throttle. If you shift too soon however, you will get a jolt and could possibly brake something. Maybe it could fix my wobble.

Click to expand...

Excellent job Max, you have more accessories on that bike than many motorcycles that I have owned!

You did a great job of centering the gearbox directly over the rear wheel, much better than I did.

Yes the 33cc is small but bullet proof reliable, starts everytime all the time. Owning one of these is like owning a multi-speed tractor trailer with alot of gears, you keep shifting thru all the gears until you get to the rpm that you want to motor/pedal at, there is a gear for all occasions whether it is mountain climbing or cruising along the flats.

Gearbox whine does not go away because of the use of straight cut gears as opposed to bevelled gears..........its a cost thing, although Staton says his new 16 to 1 gearbox, straight cut gears also, is alot quieter, I believe because the gear speeds are reduced due to the ratio difference between reduction and drive gears.........maybe some other person with the new gearbox can confirm this................Don

MaxPower said:

I have the 16 to 1 gearbox

Click to expand...

At first I was a little distracted with the gearbox whine (identical to a manual transmission car when shifted into reverse gear) but eventually came to the conclusion that it was a non-issue because of the over-masking exhaust noise also produced at higher rpms.

One of the gearbox whine benefits is that it is a good shift indicator, if the whine noise is too noticable it is an indication that the throttle speed is too high and needs to be reduced before shifting.

Max, how much weight are you going to be pulling with rider, bike, motor/gearbox, trailer, and contents?.........Don