Shaft Drive Klunker bike

Hey Ratters,

I'm working towards my first completely scratch built bike.
And I thought; Lets share the whole process!

At the moment I am working on setting up and arranging my workshop, since I'm slowly working towards building frames for customers.

Regarding this bike I had in mind: I have five brand new shaft drives in boxes. Three 'singlespeeds' or 'three speeds' and two with an threaded rear sprocket.

Two types: Right is for regular hubs like the Shimano CB-E110 or Nexus 3.

At the moment I am doing lots of inquiry! Measuring, calculating and looking for good mountainbiking geometries.

The shaft drives 'chainstay length' is fixed, so that is why I can't build a long chainstay (belly mounted BB) cruiser with this.

Right now I am figuring out the measurements of this shaft and how I build a durable frame with this.

Unfortunately VERY fat tires won't fit, probably a maximum of 2 inches, depending on wheelsize.... which is dependant on the internal gear ratio....





Measuring the dropout width.


BB shell.


My sketch of the bike.
A looptail, shaft driven klunker bike

I intend to use CroMo tubing.

Little update:

I checked the intended dropout width in multiple ways: In my alignment jig and by assembling/adjusting the rear hub.




Shimano CB-E110 hub.








I also checked the Ratio: 1:2
1x crank turn = 2x wheel turning.

Tire clearance is meh. We'll see what we can do with that.

Bottom bracket shell is machined. Only a section to be removed that has to be milled:




This is how the bottombracket shell looks in the BRIK bikes (a Dutch brand that sells bikes with shafts).




Youtube video link

Since the 'open section' of the bottom bracket, especially in the corners, has a higher level of stress and tension, I decided to thicken the ends and have that part a lot stiffer.
I purposely designed the open section with a radius, so that tensions do not concentrate too much in a 90 degree sharp angle.

The bottom bracket is a 51,2 inner diameter (almost the same as a US BB) and 57mm outer diameter on the thinner section. The ends are 60mm. So a central wall thickness of 2,9mm

I don't think this will be a light bike, but then you have more energy downhill

ifitsfreeitsforme said:

Neat. I've wanted a shaft drive bike for twenty plus years.

Are you designing with Creo?

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Well, I might be open to selling a frame/bike when its done
I am indeed designing with Creo Parametric! How did you recognize it? Solid Works is common too

ifitsfreeitsforme said:

I could tell by the font. I use Creo at my job (senior drafter at Colt).

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Very cool! At my employer, we work with Creo Parametric and the Windchill system for drawing data storage.
In general, it works really good. I can even work from home and log in to a virtual desktop (the machine at my work does the heavy lifting then).

Shells are done, but I think I need to check the inside angles again and remove a bit more:



No problem ironing that out. You can see the gaps and the shell that can go more to the right.



CroMo tubing is here too!

Working on a geometry sketch.

Seat tube will be 28mm.
Chain- and seatstays 15mm.
Downtube 35mm.
Top tube(s) 28mm.

I'm preparing the bender for a 15mm loopytail.

The next days I will have a lot to do:
Saturday I'm enjoying a day at the Dutch mountainbike museum (800 bikes!).

Monday I will attend brazing class.
Looking forward to this!

SwissGuy said:

I just can't wrap my mind around the fact, that the Netherlands as the very definition of a flat country has a MOUNTAINbike museum...

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What should it be called then?
FLATainbikemuseum
The Dutch always are excited about something they don't have

I will post pictures of some of the 800/900 bikes they have in a thread here on RRB soon. It will be picture heavy then!

In relation to this topic:
Look what I found in the museum:

B1 bicycle. 26". They use these in a dusty mine since a chain gets dirty fast.




Seeing that last picture. It seems that its (the BB) welded first and then machined for the shaft protruding from the frame when assembled.
Also little tire clearance.

At the mountainbike museum I met a guy who is also enthousiastic about Klunker bikes. We met via a Dutch marketplace and he saw one of my project on RRB's I believe. We decided to meet at the museum and ride
He also met Paul from Atomic cycles last year. Incredibly cool.
We had fun and he seems a great guy. We'll probably ride again!

This was his ride:

1952 Schwinn Hornet with Araya's and a Shimano CB-E110 coasterbrake. Beautiful to see it on the mountainbiking trails

moleman said:

Super interesting! I wonder, how difficult would it be to widen the bottom bracket? Like, a longer BB axle and an outboard left side bearing? That might allow for wider tires....

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I thought that too!
Well, the gearing has a certain angle to allow the shaft to move 'outwards' to the dropout width.
I don't know, what will happen when I change that angle (I need new housing for the bearings and, such).
Also the BB width will change. Which, all in all, might pose quite a challenge.

But I do have more shafts (sets) lying in my shack, so I can experiment with another bike.
Maybe even fabricate a bike with open bearings (sealed industrial) and open shaft. I've got plenty of ideas!

My bottom bracket shells (2x) are done and fit perfectly! (pictures below)
Now I can concentrate on the geometry of the Klunker bike and start with tube bending/notching and such.
First I need to re-arrange my shed, since bike building and bending stuff requires space

If anyone has a great geometry suggestion, I'm open to it and exploring.

Is this XL geometry interesting perhaps?
I will compare it to my current klunker, which I like but has a little bit short top tube.
The chainstay is obviously fixed on this shaft drive (445mm).

I sketched a CAD geometry for reference (I will do it a bit differently when I feel like it) and I started with the first tube miters and alignment.


57mm BB saw.


I marked the spot on the assembled BB and started aligning in the JIG.


Very tight tube mitre! Love it!


Not fully clamped yet, I need to clean and check a few things first.
The BB and seat tube alignment JIG parts can't be aligned since the BB is not centered here. The shaft drive piece is off centre.

Example:

Example.

Oh yea, forgot the geometry:
(Crude sketch)

I am not entirely sure if I keep the chainstay looptail like this. Now it looks like and elevated chainstay.
The left chainstay can be different and attached to the bottom bracket.....



Comparison I hand sketched before.

rickpaulos said:

http://www.commuterbicycles.com/incline.htm

I found Incline shaft drive bikes are still listed for sale, whether they have them or it's a outdated website?
My guess is they made a batch of them in the early 2000s and are still trying to sell the old stock to recoup their investment.
Yet another case of reinventing the wheel. Shaft drive bikes were invented over 130 years ago. Those were all 1 speed, single tube tires and no brakes. Like they ever went fast enough to need brakes or there were things to not hit. ie, no cars, trucks or busses or even that many people out and about. I recall the drive shaft assembly on the Inclines was sold as a kit to oem manufacturers with few takers. I think there was a euro based company selling bikes where their are year-round commuters in lousy weather.

I bought a Incline Newport (the all red bike) about 18 years ago. I recall I got it on sale so it was much cheaper. Shaft drive 3 speed with 26" wheels. I thought it would be a good winter commuter in the upper midwest. All stainless steel, polished aluminum, plastic or powder coated aluminum frame. There were a couple parts that rusted up, one that I remember were the screws that held the plastic bell housing on, pretty minor. Anyhow the gear ratios weren't good and there is no way to change that. The old saying about 3 speeds was correct. Too High, Too Low and not quite right. With no option to change sprocket/cogs you are stuck with the factory ratios. I only rode it a few times and I though it was really slow and heavy feeling. The 7 speed ig hub version might have been a better choice but those were 700c only. Not good for our lousy local streets. My wife commuted on it for a winter or two and then refused to ride it anymore so i sold it. She's back to old school 21 speed mountain bikes for her year round townie. I have to change the chain & freewheel & brake pads & cables every year or two.

After reading the blogs at Arron's IGH hub service, it's clear that the newer Shimano Nexus 7 speed hubs with the seals still need periodic servicing. Combining with a shaft drive, the bike still isn't a never-needs-any-maintanence bike which is probably a primary selling point to some buyers.

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Wow, I love to see that old website, brings back memories American websites and products were great back then, can't describe it since it encompasses quite a lot.
Could be indeed outdated, some websites they 'list' or refer to are already into another business. I see Breezer bikes on there also.

Shaft drive bikes are indeed old. When the hype started around the 'Ceramic Speed' bike, which is nicely fabricated and built by the way, then many people thought it was the first shaft driven bike ever. That is how strong a marketing campain can be. But that Ceramic Speed principle is already thought out in the 1890's somewhere. Only the methods of fabrication, the shifting mechanism and materials changed in my view.

Sounds like you had fun and some stories with your Incline Newport
Yes! The gearing....... the ratio on two of my shafts is 2:1.
Generally I like my 44t-22t ratio on my 26" cruiser bikes, but I need a second gear when I really go fast. This bike will be a Klunker with a single speed coasterbrake.
Maybe the next one will be a bike with a Sturmey Archer S2C kickshift. We will see.

In the Netherlands there is a company named 'BRIK' which sells pretty cool 28" shaft driven bicycles. Reviews say they are a bit more heavy in motion, but not huge.
Since my bike has relatively thick wall CroMo tubing it is heavy in weight and cycling. A perfect leg day bike

I bought five of these shafts in one sale and at least two sprockets are suited for hubs with a 'three notch' driver (sprockets with three notches).
The others have a gear which is threaded, has no ratchet pawl function, and since the gear is pretty wide and thick... you can't screw a locknut on the hub. I can't think of where it is used because:

• On a fixed gear it will turn itself loose when braking.
• On a coasterbrake it will turn itself loose when braking.
• It does not fit on a 'modern' derailleur cassette spline system.

We'll see when we get there and used those shaft drives!

rickpaulos said:

After reading the blogs at Arron's IGH hub service, it's clear that the newer Shimano Nexus 7 speed hubs with the seals still need periodic servicing. Combining with a shaft drive, the bike still isn't a never-needs-any-maintanence bike which is probably a primary selling point to some buyers.

Click to expand...

I see what you mean. My internal hub (Sturmey Archer S2C) that I use for commuting in rain, dust and snow needs a service once a year. I clean the dustcaps and the internals. But my bikes never stay parked in the rain for many hours. I ride about 4000 kilometres per year with the commuter.
A hub with industrial sealed bearings and a drum brake or disc brake might do the trick in regards to low maintenance.

I now realize that building a shaft driven bike comes with its limits, like gear ratio, tire thickness, geometry fixes (chainstay, dropout and BB) and with only able to choose square tapered JIS cranks.

I should assembly a crank on there with a sprocket. People see that bike and they will think: Where is that chain? Then you drive off