tomhaegler

Having ridden a 1992 Koga Miyata Exerciser for almost 20 years now and always being a fan of the brand, I knew I wanted another Koga Miyata steel bike. In the last years I’ve gotten used to my new Cannondale Topstone (2019) gravel bike and its versatility. I rarely use it for gravel roads but it makes riding really bad asphalt roads so much better (and feels safer). So I knew I wanted clearance for 35mm+ tires. After reading old Koga Miyata catalogs and finding the “Show us your Koga Miyata” thread in this forum, I was pretty much set on finding a 1990ies Koga Miyata Touring/Hybrid bike. The problem: while Koga Miyatas aren’t that rare in my country (thanks to a big local dealer here in my town that sold loads of Kogas in the 1990ies), you a) rarely see frame sizes above 60cm and b) mostly see race bikes (25mm tires clearance max.) only.

The geometry of my 63cm Exerciser is not optimal for my close to 2 meters height, it has a really short 57cm top tube, not really optimal for a tall person with a long upper body like me. Until finding this thread, I didn't even know that they produced 66cm frames as well. But I soon realized it will be close to impossible finding a used one in my town.

BUT: After writing a post here, member JaccoW came to help. Living in the “Country of Koga Miyata”, where people seem to be a bit taller and 63cm and 66cm frames much more common, he was able to find a used 1996 “Adventure” in size 66cm not too far from his home. He kindly offered to pick it up for me and ship it to Switzerland. I’m still amazed he did it and cannot thank him enough. He even stopped at the Swiss Embassy in The Hague on his way back to get a picture of my future bike and the Swiss flag.




In the end, the "Adventure" was a perfect find. I wasn’t that keen in the beginning since it is not my favourite colorway (which would be the 1990 Traveller or 1992 WorldTraveller). But: After studying JaccoW 's scanned technical documents, I got pretty confused with the Koga geometries. All of them seem to have rather short tube tubes, even more confusing: often the top tube length stays the same for all frame heights from 60cm-66cm. Not ideal for tall people with long upper bodies like me. There is one exception: The 1996 “Adventure” is one of the (few?) Koga Miyatas that has different top tube lengths for different frame sizes - and with 60cm the longest top tube length of all 1990ies Koga Miyatas (I think).



So: What do I plan to do? As JaccoW mentioned, I wanted to build a steel gravel bike with a 1x drivetrain first. But my plans have changed: it will be a 2x “drop bar touring aka do-it-all bike” that can be used in the city, can be ridden faster without bags or can be used (as the name suggests) on multiday Adventures.

Parts: To make a long story short, as always, my bike building budget somehow starts out “as cheap as possible” and soon ends up being “only the best/fanciest is good enough” 😊 But I already have used parts and accessories from other bikes I really plan to (or at least could) use to keep the budget reasonable.

• Mavic Aksium wheelset from my old Cannondale Synapse road bike I’ve sold a few years ago. Problem: they have a 130mm spacing (129mm measured, Adventure frameset is 135mm). Using the original wheelset (135mm) would involve fitting a new freehub body - but there would be almost no axle left. So probably a new hub as well.
• used Panaracer Gravelking 35mm tires, but still OK condition
• Fabric Scoop saddle from my Cannondale Topstone (which has the carbon version now)
• Fizik Tempo Handlebar Tape I didn’t end up using for my other bike
• Tubus Vega rack (If I even put a rack on the bike)
• FSA Omega 46/30 crankset and BSA bottom bracket from my Cannondale Topstone (now equipped with Easton EC90) already changed my mind: Although the crankset isn’t bad, it’s heavy and the looks just don’t match a classic steel bike, I think.
• Cannondale Stem (115mm)
• Shimano 105 11-32 cassette or SRAM 11-36 cassette

Parts I want to use but have to buy (or already bought):

• 105 r7000 Shifters, FD and RD. Not a budget friendly addition, but I have this groupset on my Cannondale and like it a lot. The big STIs are very comfy for my big hands and the shifting is crisp
• ZIPP Service Course 70 XPLR handlebar: I’ve ridden this handlebar for many kilometers already and I like it a lot: Ergonomic top with 3° backsweep, 5° drop Flare and 11° drop outsweep. I also like the pretty shallow 115mm drop. Problem: the whole quill stem/ahead handlebar adaption problem. If I don’t like it, I’m going for a classic quill stem and maybe Nitto or Velo Orange Randonneur bars.
• I found a Shimano XT FC-M730 triple crankset which I plan to use as a 110/74mm double with TA 44/28 chainrings. Let’s see if I can get this one running with an acceptable chainline/q-factor. If not, I might have to use my FSA 46/30.
• MKS Touring Lite pedals (or using my Shimano Ultegra 6700 SPD-SL)

JaccoW

Hey @tomhaegler looking forward to seeing what you plan on doing with this bike!

The Adventure should be a pretty sweet bike once built up, especially as a drop bar tourer. Almost made me hesitant to send it your way. Luckily I have the 1999 Koga-Miyata Adventure to keep me company, even though it isn't my size.
Last I saw of it it was packed up in a small box.

Steve B.

Interesting that these are branded as "Koga Miyata" as they are essentially Miyata bikes that were for a period sold by Koga, a Dutch company. Somehow some of these ended up in a warehouse in Salt Lake City, where either Miyata or Koga had spare frames set aside as potential warranty replacements. In '97 or so, they put these on sale, a dealer was American Cyclery in San Fransisco, where I purchased my City Liner for $175 in 1998. It was a butt ugly lavender and pink, I had it painted a more pleasant green a while back. Its a full blown touring bike, even has a mount on a seat stay for a generator. I am just now starting to actually use mine for loaded touring, at which it excels at. Its been a commuter mostly, though it did take me on the Bike Tour of Colorado in '99. Its my best fitting bike.

tomhaegler

Unfortunately the downtube has a small dent and a bit of corrosion already. I wanted to make sure that there are no cracks and stripped the paint (and unfortunately a bit of the logo). But: Everything seems to be fine. I sanded down the rust and put some rust converter on it afterwards to prevent further corrosion.


dent after rust conversion

To cover it up I used a "Dupli Color" car repair pen - unfortunately they didn't have the exact same color. It's not beautiful, but it works for me. A friend once had a dent pulled and the color professionally restored at a car shop - looked incredible. But cost him 400 EUR. This was no option for me



Maybe one day I restore the logo - given that somebody could provide me with the original pink/gold decals. No luck so far.

tomhaegler

Small update. Installed some components:

• Neco bottom bracket
• 105 r7000 Shifters, FD and RD
• Shimano XT FC-M730 crankset with 48/28 TA chainrings on the inner and middle position
• Fabric Scoop saddle
• ZIPP Service Course 70 XPLR handlebar
• Ultegra SPD pedals
• Blackburn bottle cages
• Mavic Aksium wheelset (squeezed frame from 135 to 130mm)
• Panaracer Gravelking SK 35mm tires

Not sure about the STX Canti brakes. I ordered some really cheap XLC Mini V-Brakes (25 EUR for both incl. brake pads) which should work great with the 105 road shifter...maybe wait for those to arrive and install them first. Then testing and handlebar tape to finalize the build.
Maybe, I also try to find a 0 offset seatpost 26.6/26.8mm - but not easy to find. I'm pretty much as forward as I can be now...

tomhaegler

Some additional thoughts on the drivetrain:

The beautiful Shimano XT FC-M730 crankset is amazing. Originally a triple crankset with 110/74 bcd, it can be used as a double using only the inner two positions (really low gearing) or the outer two positions (smallest possible chainring 33t).
I'm using the inner two positions with 44/28 and a 113mm Neco BB (+ 2mm driveside spacer) this results in a chainline of 41.5mm and not too bad Q-factor of 153.8mm. When using the outer two positions, one can easily use a 109/110mm BB and bring the q-factor down to 148 or lower!

A 41.5mm chainline sounds strange, but is not bad at all, as I found out. It positions the big ring about in the middle of the cassette - exactly what I wanted. Because 80% of the time I will be using 44t front and the full range 11-36 in the back. For climbing I can use 28 / 25-36). So it's basically set up like a one-by crankset with the option of super low bailout gears.

Also note that 11-36 is not recommended with the 105 r7000 rear derailleur (11-34 rec.), but works flawlessly. Also the 44/28 - 11-36 is a bit above RD capacity, but no problem either. Of course 28t and 11-19 in the back is not really possible/optimal.

tomhaegler

I finished the bike this weekend and went for a test ride. Short version: incredible. I like those 13EUR Mini-V-Brakes by XLC. Work really well with my 105 STIs and come with road brake shoes. I did about 1200m altitude over 45km and was surprised how good the bike felt. Especially absorbing the bad roads compared to my aluminium bikes! And the long 1072mm wheelbase makes for a really stable bike. I wasn't keen on the simple colourway in the beginning but I have to say: it looks amazing. In bright sunlight it is almost dark purple, in the shade more of a darker red. The gearing seems to be great as well. While I spun out in 44-11 sometimes (which I expected), I really like the 44/28 - 11-36 setup. But only a loaded tour with around 20kg+ will tell if it works Now I need to find a 26.6 seatpost with less offset...
And of course: thanks again JaccoW for your help!

EB_AZ

This has turned into one beautiful bike after one very engaging build process. Thank you for taking us along with you as this project has unfolded tomhaegler and I hope to see much more of this bike going forward.

tomhaegler

For those interested: The build incl. pedals and bottle cages weighs close to 11.4kg. Not too bad for a 3.9kg steel frame (incl. fork). But of course far from my (secret and probably in hindsight totally unrealistic) 10kg goal. I know, this is probably the wrong place (I'm a member of the "Weight weenies" forum) and build to talk about weight, but just for the sake of it, here are some possible upgrades that could bring the weight down a bit more:

• wheelset, switch for DT Swiss PR1800: save 200g
• tires + tubes (Panaracer 35mm total 740g vs Conti GP5000 32mm 560g, 2 x butyl tubes = 200g vs TPU Tubes = 80g) : save around 300g
• cassette: 50g max to be saved...
• crankset: FC-M730 175mm = 520g & 110g for both chainrings and about 250g for the Neco BB = total 880g. vs Easton EC90SL (46/30) = 555g + BB (100g) = total 655g: save around 225g or Dura Ace crankset = 690g (50/34) + BB (77g) = total 780g, save 100g.
• saddle: buy carbon version of Fabric Scoop Radius: save 150g
• Shifters: 105 r7000 = 620g for both, Dura Ace = 537g for both, save 80g

So: I'm looking at a total of max. 500-600g to be saved which results in a total rider + bike weight difference of laughable 0.55% (91.4kg vs 90.9kg). but then, a sub 11kg weight would be niiiiiiiice!!! (at least psychologically)

Piff 

You aren't planning to spring for an aluminum cassette, are you? Of all the weight weenie things I feel like those are the least useful splurge.

CMAW 

Nice build, bike looks fast almost despite itself. Re: the seatpost, you can have the original 0° seatpost of my Terraliner, if you can wait until september.

tomhaegler

Haha, no. I wouldn't do that!

tomhaegler

It is actually is really fast! I was surprised...I rode some Strava segments (climbs) I usually ride with my 7 or 8kg bikes...wasn't much slower. Sometimes even faster (probably new bike motivation)
Could you send me a picture of that Terraliner Seatpost?! Thanks a lot!!

EDIT: I suppose it's that one?


BTW: Why is it so hard to find 26.6mm seatposts?

CMAW 

Yes, that's the one, I'm touring right now. Needs some cleaning up but 100% functional.

non-fixie 

Great result. Well done!

tomhaegler

What do you think, I'm not sure. Black seatpost/stem or polished aluminium? Or a mix of both like it is right now?

Rage

Looks good.
I’m gonna go with Snoop and say, “murder was the case.”
Plus one for black seatpost and stem.

tomhaegler

great. Still have the "Murder was the case" vinyl in my shelf.

Rage

I got it on cd. Kinda wish I had it on vinyl, too.
We share the same taste in bikes and music haha.
Looking forward to pics when you’re done murdering the bike…

JaccoW

That turned out great!

Looks like a very fun bike in and around the mountains over there. My guess is this is about as light as can be with vintage gravel bikes.
How is the ride over rougher terrain?

As far as I know all Koga-Miyata bikes use a 26.8mm seatpost and Ergotec should make some in black.

Any better pics in the sun?

tomhaegler

Thanks - will post better pictures (with a proper camera) soon. I didn't test it on rougher terrain yet, but the feel on bad roads (lot of potholes etc.) was great! About the seatpost diameter: strange enough, I tried to fit my 26.8 Kalloy seatpost I have on my Koga Exerciser - didn't really fit (only with a lot of force). And the seatpost that came with the Adventure is labelled "26.6" ...?!

JaccoW

So how 'bout dem pictures?

tomhaegler

soon😅 I haven‘t forgotten!