2 stroke shift kits on vintage bikes?

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silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
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northeastern Minnesota
After seeing and reading about BarelyAWake's Rollfast build I find myself dreaming of a shift kit. I admit to having a very limited understanding of how these work and had discarded the idea once it seemed they were only appropriate for newer type bikes with gears and a derailleur. Then I saw Barely's and have been thinking since how nice it would be to have power at lower speeds and to have lower engine speeds when cruising at 20 or 25 mph... and quieter because of that. Where I am for the winter in the Cotaktin Mountains of northern Maryland there are many hills, a few of which I can negotiate with my 39 Elgin and many which are too much for just the engine and midway up it is time to peddle till my pants catch on fire and tongue is hanging out. It occurred to me a few weeks ago that it is a good recipe for a heart attack to be climbing some of these hills. But with a shift kit... well I could go anywhere and not have to plan my route according to grade of hill.
So, the short of it is this: What are the options, what must one do assuming the bike is powered with a HT 2 stroke and the original wheel has a coaster brake? Let's say you are planning a build from scratch, on a budget, and want a vintage bike with a shift kit? What's the best way and what's the poor boy way or is there no poor boy way? We're talking about a bought shift kit, like the one from SBP. Let's say it is that one. And the bike is a classy old single speed with a coaster brake. What must be changed?
SB
 

camlifter

Active Member
May 4, 2009
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acme labs marion ohio
in order to have a shift kit bike you must first have some gears to shift, so a single speed is out unless you want to make it into a multi gear bike. i think that would cost more than a new multi speed bike. or you could do the 3 or 5 speed hub as an intermediate transmision like i did on the 3sp jack shaft build, thats a lot of work though and requires welding and fabbing brackets. probably best to start with a multispeed bike. then everything would be in bolt on kit form.
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
camlifter,
I'm sure it does make the most economic sense to use a newer bike, but lets say you really want it to be vintage and are starting with a frame, can't weld and have your feeble old heart set on a shift kit from SBP. Does anyone know if the old 2 speed Bendix hubs would work? Were they strong enough? The way those were engaged was to let off the peddling for a moment, bump the coaster brake and resume peddling. If one of those would work then you could still have a coaster brake, yes?
SB
 

Ghost0

New Member
Mar 7, 2008
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Bellingham, WA
A coaster brake set up in any form including the bump shift set up is not possible with the Shift Kit. Reason being is that with the front freewheel you cannot pedal backwards. Well you can pedal backwards but it does not move the chain in a reverse direction to engage the coaster or bump shifter. Hope that answers your questions. The ultimate may be to use a Nuvinci but that kind of throws the budget out the window. Some provisions would also have to be made for a rear brake.
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
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northeastern Minnesota
I just went to SBP and can see that the bendix hub won't work because of the front free wheel. And I see that the nuvinci variable speed hub is a mere $600.00 which is a wee bit over budget. So it looks like either a manually shifted internal rear hub strong enough to hold up to now being a motorbicycle or somehow adding a derailleur from a newer bike which sounds like a major can of worms. It also means that a vintage bike designed originally for a coaster brake now needs a new braking system.
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
A coaster brake set up in any form including the bump shift set up is not possible with the Shift Kit. Reason being is that with the front freewheel you cannot pedal backwards. Well you can pedal backwards but it does not move the chain in a reverse direction to engage the coaster or bump shifter. Hope that answers your questions. The ultimate may be to use a Nuvinci but that kind of throws the budget out the window. Some provisions would also have to be made for a rear brake.
Ha, I think we were typing at the same time. Your website made things pretty clear if I had been paying closer attention the first time I investigated. Nothing is ever as simple as you want it to be, but what a sweet ride Barely came up with. There is nothing like a vintage bike in my view, so I am not deterred and want to pursue this. I don't yet know which bike... maybe one I already have like the 50 Panther which has Pat's prototype "motorbike' tank. It could be a Worksman newsboy I have without a motor... not vintage, but can look vintage and has the same problems to work out. Or maybe a nice old 1930's Elgin men's bike I don't have yet, but something special. This is for next winter, so I am researching and picking brains now so that I have a plan. This is for me, not to sell, so I don't really care how much work it is. Thanks for your input. That shift kit is the cat's meow.
SB
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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up north now
Can't you just mount up a back wheel with a 5-7 speed cog and a derailuer? You might have to make some minor mods, but I'm just talking out my ass now...
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
I don't think the idea was to get rid of the coaster bake so much as is was to have a rear wheel with more than one speed.
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
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northeastern Minnesota
Can't you just mount up a back wheel with a 5-7 speed cog and a derailuer? You might have to make some minor mods, but I'm just talking out my ass now...
It sounds like this would be the cheapest way to go. I'm going to do some creative staring at one. Any idea what modifications you'd need to do?
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
A 3-speed internal geared hub with drum brake would also work, I believe, like a Strumey Archer.
I think this is what BarelyAWake did with his. As I recall he bought the hub by itself and had it laced to a wheel in a bike shop. I wonder if one is available ready made on a sturdy wheel. I would guess if you wanted heavy duty rims and spokes it would need to be custom done. It seems to me he said the hub was on the large size. The internal hub would look the most appropriate with a vintage bike, I would guess. I would think three speeds would be adequate. Do you know of anybody who has done this with either a Worksman newsboy or the Schwinn Panther. I'm kind of leaning toward the Panther for this shift kit. Along with a front springer, your gas tank and the nice lines of the Panther it would make a sweet ride.
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
GhostO,
I'm still not real clear about the starting procedure with the shift kit, but understand it is different and a simple bump start is not possible. I'm partial to pull start and have two bikes running centrifugal clutches. Can you tell me if the crank arms with the shift kit would need to be changed or modified to accommodate the additional width of the pull start and automatic assemblies? I'm sure there are others who would be interested in the shift kit for a bike originally designed for one speed, like the Worksman newsboy or any of the fifties and earlier cruisers. It would be good if we vintage types had a clear set of options to pick from in making a conversion. When I think of a kind of perfect cruiser, the shift kit is right near the top of the list. Thanks for your expertise.
SB