JaccoW

Update 2019-July-21:
This bike is a write off. See post #6 for details.

Rear triangle is busted and bent because of a botched angle grinder job and a possible rear-end collission.

Original opening:
C&V bikes are addictive. Ever since I started hanging out here I've been scouring local Craigslist/eBay more and more for good deals on classic bikes and look into their idiosyncrasies.

While I do enjoy racier bikes I'm still Dutch and thus have trouble wrapping my head around bikes which can only fit 25mm tyres without fenders.
I also have a soft spot for drum brakes.

My current commuter bike for within the city is a 2006 Gazelle Orange Excellent in a 62cm size. While still a good bike it has seen well over 40,000 km (25,000 miles) and the rear Shimano Nexus 8-speed hub is worn out.
So I wanted a new project needed a new bike and what better than to dive into the world of classic Dutch city bikes!

History:
Most of you know Koga as a Dutch brand that started out in 1974 and until 2010 had a partnership with Miyata. Their frames were built by Miyata in Japan and then assembled in the Netherlands.
They are generally thought of as a high quality brand that builds road bikes, touring bikes and road bikes. Since the brand is expensive and generally more conservative in its color schemes they tend to attract wealthier older people and as such there are plenty of barely ridden Koga-Miyata bikes to be found in the Netherlands.

The bike:






Background info & specs:

Now mine isn't as nice as the one above (previous owner scuffed the paint with a chain and resprayed it) but it is my size! (66cm) and a short trip showed it is a solid bike with crisp shifting and which is reasonably lightweight because of the tubing used.
In fact, my aluminum Gazelle weighs somewhere in the region of 23kg whereas this one is around 17kg (brochure weight)!

Source: Koga's old brochures (which also enabled me to narrow down the model and year)

Plans:
It is actually already a pretty solid bike. I will be replacing the fenders with something that has better coverage and put on modern lights.
Some new grips and rerouting of cables and updating the ring lock to something more modern.

I prefer a dynohub on my daily bikes and will probably rebuild the front with a Sturmey Archer drum brake dynohub combo, probably the Sturmey Archer XL-FDD.
There is also an unused 90mm 5-speed hub laying in storage which would offer a slightly wider range and more stopping power over the 70mm brakes on there now.


Thanks for reading and I'll update this thread whenever I'm working on the bike.

My other project threads:

• Batavus Randonneur GL project
• Gazelle Super Licht
• Gazelle Lausanne

JaccoW

This bike has been standing in the yard (under a cover) for the last few months so it is time to start working on it again.

I have been thinking about what I want to do with this bike for the past few weeks and I think I have a good idea.
The paint is... not great and could do with a respray. I want to go with a classic Dutch bike black™ powdercoat with some accents around the lugs and probably have the decals remade in black and white. We'll see if it is viable and how much that is going to cost.

Combined with stainless steel fenders, racks and handlebars this would be my short-medium distance all-weather commuter.
Cream tyres, a Sturmey Archer 90mm XL-FDD dynamo drumbrake up front with modernized (but modified) LED lighting and it should be good to go for another 30 years.

Think classic Omafiets:


You've seen the Sturmey Archer 90mm XL-RD5 (w) hub above that I want to use as a basis for this bike. Now I could reuse the stainless steel Van Schothorst rims and I do have a weak spot for them but I think something a bit lighter and more modern might be a better fit, especially since it is a 23 (?)mm rim in the rear and a 19mm rim up front.

I think they could look great with a 36H H+SON Archetype rim. Not exactly the cheapest rim and perhaps a TB14 would look more fitting on here as they mimic the current front wheel.



What do you people think?

FlMTNdude

I like it! I don’t understand why you don’t see more chain guards in the US. But then here, bikes are not looked at for the most part as practical and to be used, but as recreation.

JaccoW

Thanks! I think you hit the nail on the head.

A recreational vehicle that's being used to ride as fast and hard as possible should logically be stripped of all non-necessary parts.

Whereas a bike used for transport needs to be as low-maintenance as possible without affecting ride quality too much.
Or better said in the case of the Dutch; it should stand up to ungodly amounts of abuse and still ride.
See my post about a 1985 consumer test of contemporary 3-speed models.

It is not uncommon to see pre-WWII bikes still being parked and used in public train stations. Heavy, single coaster brake but in all that time only the tyres have been replaced.

Came across this one last year.

JaccoW

First step: Measuring the hub!

The most important dimensions are:


So with the Archetype, which has an ERD of 595mm this comes down to 275 mm spokes on the brake side and 276 on the drive side.
Let's sleep on it and measure again in the morning.

Disclaimer: With a hub this big it is difficult to measure the exact WL and WR distances. Measure your hubs properly yourself.

Missing parts:
These hubs pop up on our local eBay (Marktplaats) from time to time, usually in a 26 inch wheel, meaning they probably came out of a cargo bike.
There are lots of people in cities using the B a b b o e Bakfiets (image) and they used to come with the SA XL-RD5(w) hub.
Nowadays they switched over to a Shimano 7-speed but kept the 90mm drums up front. I can imagine quite a few people had the wheel rebuilt to make use of the wider gearing of newer hubs or switched over to electric hubs.

Anyway the hub came to me like this:


It is missing a few of the shifter parts, most notably:

• #22: Any of the sprockets
• #23: HSL721 Sprocket Circlip
• #40: HSJ905 Fulcrum Lever w/Locating Washer
• #41: HMN128 Axle Nut
• #42: HSA650 Gear Selector Guide (Window
• #43/#46: HMN420 Guide Nut-Short
• #48-#52: Any of the shifters.

I'm leaning towards the gripshifter as I really like them in city traffic or the metal thumb shifter as they are more durable. I have read some issues about these causing mis-shifting though.



I'll probably double check the bike tomorrow to see if I haven't missed anything. Then it's time to order some parts!

Further reading:

• X-RD5 hub manual: https://www.sturmey-archerheritage.co...s/view-287.pdf
• XL-RD5(w) part list: https://hfchristiansen.zendesk.com/h...RT-LIST-XL-RD5

JaccoW

I think this might be the end of this bike.

Let me explain:

I bought this bike last winter one evening for a very cheap price (€50) and rode it home. It was a nice ride though braking seemed adequate at best but that's to be expected with 30 year old drum brakes.
With other projects having priority I just parked it and left it for later.

Fast forward 6 months and today was a great sunny day outside. I decided to take it apart to get it ready for some wheel building next week.

I started out taking apart some of the rear bits and removing the frame lock.
After I bought this bike I learned it came with a certain type of frame lock that requires brazed on bits for the frame to work. I didn't see it on mine but I figured a previous owner probably took it off.
What I wasn't prepared for however is how he did it...

My first hint was the seat stays. I mean, those should be straight right?


The other side fared a little better but still slightly crooked.


I'm also pretty sure the chainstay on the non-drive side is supposed to be straight.


It starts to make sense though once you realise how they removed the old lock from the frame... with an angle grinder and an unsteady hand. Wait a second, is that putty?


That's definitely putty but it looks like a simple brazing job could have removed it easily.




In conclusion:
My guess is this bike was first updated by removing the original lock and then rear-ended by a car, causing the whole rear triangle to bend and buckle.

Shame really, because I was looking forward to building this up with a nice pair of fresh wheels and a complete overhaul and some fresh paint.
A lightweight classic 3/5-speed commuter is all I really wanted here.

I'm probably going to strip this bike for its parts and be on the lookout for another one. The hubs at the very least should be enough to recuperate the cost of this bike.
The frame will be retired as it isn't safe to ride anymore.

On the upside; I now know a whole lot more about these bikes and what to look for.
I hear the 1996 SilverAce with its FM-1 triple butted rifled tubing might be nice. ; )

JaccoW

Velocivixen

Bummer for sure. It happens, and as you said you can keep the bits you want and put on another frame. I hope that you keep this thread updated with further projects.

JaccoW

Thanks, I will once I find a suitable successor. It will probably be a new thread but at the very least I will use this thread to tell about the wheel I will be building and probably some disassembly pictures.

alexnagui

That's unfortunate when you discover things like that.. Hope you'll find something else soon!

bwilli88 

Bummer it was screwed up by a hamhanded wannabe mechanic. I recently finished up my Opa-fiets with drum brakes and Dyno front, 5 speed rear. Rides real nice and with full fenders I plan to put on it it will be a great rain bike.

JaccoW

Your bike is starting to look great! Shame about the trouble you have getting your hands on the fenders though. Looking forward to seeing the rest of it.

JaccoW

Got everything except for the actual rim to build the rear wheel today. The rim itself was cancelled by a different shop but I will reorder it somewhere else in a few weeks.

What I did want to share is this rear wheel chain tensioning system on a later Koga-Miyata Liteace:


Instead of the more common track droput they use an L-slot to de-tension the chain and just drop the wheel right out meaning it's a lot easier to change a tyre with an IGH bike.

JaccoW

Disassembled this bike today and sawed it to pieces.

I will be selling the wheels. The Sachs hubs are a lot rarer around here than the Sturmey Archer equivalent but who knows if that actually translates into a higher price.

The fork was put aside as a spare and every little bolt was removed so I have some extras for the Koga-Miyata SilverAce. Things like the stainless steel cable clamps from the down tube and the seat tube clamp.
The headset was cracked unfortunately so that's a shame.




The insides were covered in a fine rust but would probably have been fine with a few flushes of oxalic acid. Interestingly enough you could see a big difference in tube thickness between top and bottom, meaning these were butted tubes.
No further pictures as I brought it to the local recycling plant to find a new life.

alexnagui

R.I.P.