danmar

I just finished refurbishing this bike and I'm trying to learn more about it. The internet has very little info to offer and I'm beginning to suspect that this may be a fairly rare and special bike. Is this perhaps a Grant Petersen build? Has anyone seen one of these before?

Here's what I know:

This is a 25” Kabuki Diamond Tourer 21 speed c. 1989
CroMo tubing and fork - no serial numbers
Shimano Deore rear derailleur stamped M (1988) rd-mt62
Suntour XC 9000 front derailleur stamped EK (1988)
Suntour forged dropouts
Phil hubs laced to Araya 27” alloy rims
ST (Specialized) “flag” 170mm cranks (made by Sugino) stamped I-3 and h-11 (1988 and 1989)
Gran-Compe center pulls
SR Royal stem

This came to me with swept back flat bars and cheap thumbies, which I've swapped out for bullhorns and Suntour stem shifters. I've also installed a new seatpost and a vintage Brooks Pro saddle. I'm intending to make this my go-to touring bike, but I'd like to know its value so I can choose how many locks I need to carry.








Thanks in advance for your help.

ramzilla

Interesting bike. With center pull brakes, 27" wheels and, some Suntour bits I'd guess that it's older than 1989. Could be that someone replaced the FD & RD with newer items. Plus, by 89 most bikes were wearing unicrown forks. I also thought that the Kabuki named bikes were big in the 70's and disappeared sometime around 1980 or so. It's a nice bike with good touring geometry. Nice chrome details. You might get $275 in the right market.

danmar

Ramzilla, I think you might be right. It probably was upgraded in the late 80's. I just can't find much info on the Diamond Tourer. The only Kabuki catalog available online is from 1982 and it's not in there. The few pics I've seen of other DTs look older and don't have the same flashy lugs. Also, it doesn't have the weird forged aluminum lugs and quill seatpost which every other Kabuki I've seen has. Definitely an odd bike.

cycleheimer

It is without a doubt from around 1974/75. The 1977/78 DT model looked like the photo I posted, but bright metallic orange was more typical. Not a touring bike by refined 1980's standards, but a decent bike. The Diamond Road was their top model back then (70's), followed by the Diamond Touring in their old catalogs. You can find a Bicycling magazine review of the Diamond Road online. Most of the Kabukis you see are entry-level, since more people buy the less expensive bikes. The Submariner with Stainless steel main tubes was really sharp back then, especially in the light metallic blue, but still upper entry to lower mid-level. Being comfortable with the frame sizing and ride is the main issue. Drop bars with SunTour bar-ends is the way to go!

BRIDGESTONE=TIRES

cycleheimer

Or​​ange DT (1978?)

danmar

Cycleheimer, I saw your pics in another thread and I just found a blog with links to the Bicycling article about a '74 Skyway (another odd bike--disc brakes!). See love, laurie: ryan's new road bike. This skyway has a similar color scheme and decals as mine. So, I guess it's a '74 with significant high-end upgrades from 1989.

cycleheimer

Definitely mid-70's. The upgrades could have been done later than 1989 using older parts at the time. C. Itoh was the importer. Nice bike. You don't see too many of them, especially from the mid-70's. I have owned a Skyway, a Hill Topper, a Submariner and a Super Speed. I actually used the Skyway for commuting, and put up to 40 miles a day on it in total. I had thousands of miles on it when I sold it, but still looked and rode like new. I always wanted a Diamond Road, but they seem to be pretty rare. They were also pretty expensive when new, which is why I didn't own one. I was very happy, though, to own the DT.

T-Mar

I concur that the frame is mid-1970s. It's definitely pre-Peterson and from the era when Bridgestone was still being distributed in the USA though C.Itoh. As noted, the bicycle has been almost completely rebuilt, with the exception of the brakes. I'm really surprised that there isn't a serial number. If you want to investigate further you can remove the fork, as there may be a date code on the outside of the steering tube.

Literature of the era places Diamond Tourer below the Diamond Road and Diamond Track, so it was considered 3rd in the hierarchy. Still, it was a $350-$400 bicycle in it's day, depending on the exact year. It's interesting that the frame is painted in Sweet Tangerine, which was the colour typically reserved for the Diamond Road in the mid-1970s.

The tubeset is unspecified but Bridgestone's traditional partner was Ishiwata, so that is the leading candidate. Ishiwata. Touring frames of this era typically used slightly heavier gauge tubing, so it is probably Ishiwata 024. The seat post diameter may provide a clue, provided the replacement post was properly sized.

Kabuki12

I have a 1976 Kabuki Diamond Formula that I bought new. it has more of a race geometry than the Diamond Tourer. It came with Suntour/diacomp components. I still have it although it is now full Campy (period correct). I think the Diamond Tourer and the Formula were pretty much the top of line for Bridgestone/ Kabuki in those days. When i asked Grant P. if he knew what tubing was used, he said that he remembered the bike but it was before his involvement with Bridgestone. Mine had a decal that said plain Gage CrMo and that 's it. He DID say that he really liked the fork radius that was there, what ever that means? I hope this helps. Joe P.S. mine has vertical dropouts

T-Mar

There was no Diamond Formula in 1976, according to my literature. In 1976, Bridgestone and C. Itoh formalized their long standing relationship, with C. Itoh's American bicycle division becoming Bridgestone-Kabuki. Bridgestone bowed out circa 1977 and the line was pared down, with the Diamond Road, Diamond Track and Diamond Tourer being eliminated. Wishing to retain a prestigious Diamond model, the Diamond Formula was created but it was essentially a slightly upgraded version of the 1976 Hilltopper.

Regarding the the tubeset, my literature only refers to it as "Chrome-Molybedenum 0.9MM for main tubes". The only stock Japanese tubeset that matches this description during the era was Tange #5 . Of course, this is only for one particular year of the Diamond Formula variants, though even as late as 1982 the advertisements for this model do not mention butted tubing, only referring to a "CRMO No. 4130 frame". Pending further evidence, Tange #5 would be the leading candidate.

Kabuki12

You may be correct about the year . I might have purchased it a year or two later than my memory tells me. I disagree with the Diamond formula being just slightly upgraded from the Hilltopper bike. The tubing wasn't anything special , but the geometry is a lot different. The Diamond Formula was a brazed lug build while I think the others as in the Submariner were pressed together with cast pieces. I bought my wife a Submariner the same year I purchased mine and it was a completely different bike. Mine was around 22 lbs and hers was very heavy somewhere around 28 or so. I purchased mine from a guy locally here who had a bike shop and also built his own racing frames. His name was Stan Johnson and we became really good friends. You can look him up if you don't know his name. He told me the Diamond Formula was a good move for me just getting into that type of cycling, understand that my previous bike was a Schwinn Varsity! He ordered it for me as he didn't normally stock them , but assured me it was a quick , light bike. I still ride it , although more for sentimental reasons, it IS a very tight frame and performs quite nicely. I doubt the Hilltopper is any thing close. Thank you Joe

ramzilla

[QUOTE=danmar;20414166]I just finished refurbishing this bike and I'm trying to learn more about it. The internet has very little info to offer and I'm beginning to suspect that this may be a fairly rare and special bike. Is this perhaps a Grant Petersen build? Has anyone seen one of these before?
Here's what I know:
This came to me with swept back flat bars and cheap thumbies, which I've swapped out for bullhorns and Suntour stem shifters. I've also installed a new seatpost and a vintage Brooks Pro saddle. I'm intending to make this my go-to touring bike, but I'd like to know its value so I can choose how many locks I need to carry.

You're going to have to try harder at restoring old bikes. Looks like you missed a couple spots or, you put about 1000 miles on it since you restored it. Be good. Have fun.

T-Mar

Please note that I said it was a slightly updated 1976 Hilltopper. which used a brazed, plain gauge, CrMo frame. The geometry was very similar, if not identical to the Diamond Formula. My point was to emphasize that the Diamond Formula did not replace the previous Diamond series models, such as the OP's Diamond Tourer, but was a new and lower grade model, despite its position at the head of the lineup.


If you want to know the year of your frame, it should be easily determined from the serial number. While C.Itoh and Bridgestone had terminated their co-ownership by this time, Bridgestone was still the contract manufacturer of the early Diamond Formula models.

danmar

[QUOTE=ramzilla;20418520]Ok, yeah, I mispoke. I haven't gone in for the full restore yet but got it working again. Cleaning, waxing, new cables, new chain, tires, etc. New QRs on the way. One of these days I'll get in these and polish those hubs. Really I was too excited to ride this to fuss over it too much.

jtyr71 

Except for the color, it pretty perfectly matches this catalog that I believe is 1974. In this catalog the Diamond Tourer is listed as literally "The top of the line Kabuki!." The Diamond Road and Diamond Track seem to have been introduced in the 1975 catalog.

jtyr71 

By the way, this eBay auction shows your bike's predecessor, what I would extrapolate/speculate is a 1972 or 1973 C. Itoh Diamond Tourer: https://www.ebay.com/itm/302289312070

Notice that the CrMo sticker is the same as that used on the 1974 and 1975 Diamonds.

If it were my size I would buy it.

T-Mar, what do you think about the Suntour parts and date on that eBay bike? Does my guess make sense?

T-Mar

My leading candidate would be a 1971 model. 1971 was reportedly the first year for C.Itoh bicycles in the USA and extant samples of 1972 models typically have the "Guaranteed World's Finest Precision Bicycle Mechanism" decal on the down tube. The 1973 version was not available in orange, according to my spec sheet. The 1973 model name as "Tripping", I kid you not!

I'm assuming your component comment relates to the presence of the Spirt derailleur and friction shift levers, as opposed to more appropriate Compe V and Power Shifters? The levers are sitting over a decal, which would be atypical, and there there does appear to be the outline of a clamp further up the down tube. While this suggests the levers may have been replaced, this may not be the case. I have seen other high end C.Itoh of the era with the same levers and front derailleur. Consequently, these parts may be OEM and simply a cost concession to hit a slightly lower target price.

It's also worth noting that C. Itoh was marketing a high end competition bicycle prior to 1975. My 1973 specs list a Professional Road Racer model with a double CrMo tubeset and tubular wheelset. I've seen samples with serial numbers dating as far back as early 1972. Given the existence this C.Itoh model, it seems strange that Bridgestone did not offer a Diamond Road at the same time.

jtyr71 

Here's a beat-up and modified Diamond Tourer from Craigslist. Note the replaced fork and bent frame. Also notice it has the same CrMo sticker.

jtyr71 

Oh and here is the other one I've found:
Kabuki Diamond Tourer
https://vue.usc.edu/images/kab1.jpg
All have the same CrMo sticker.

jtyr71 

I'm adding this amazing craigslist find to this thread because I think these bikes are closely related, and it's valuable to see them together:
https://newjersey.craigslist.org/bik...152756544.html
This is the first time I have EVER seen a real-life example of a 1975 Kabuki Diamond Road!!!

Orange paint and chrome lugs are similar to the 1974 Diamond Tourer, but this bike has numerous distinct features that clearly make it the even more rare 1975 Diamond Road. Check out the pics:

jtyr71 

The seller has been super helpful and responsive. T-Mar here is the serial number and one more photo showing the rear stays:


I think the Japanese characters are highly interesting. What do you make of this bike T-Mar?

jtyr71 

Lastly here are snaps of my 1975 Kabuki catalog.

If it were a 23" frame I'd be on my way to pick it up now!

Orange Bike Guy

Hey Everyone,

JT reached out to me about my bicycle and I was pleasantly surprised to learn that there is an awesome road bike community online!
I got the bicycle in Fort Lee about 9-10 years ago and unfortunately it never really fit me. It fits someone who is 6 foot and up.
As you can see in some of the pictures I jacked up the handle bars to compensate for my height.

I know the cannondale seat is aftermarket and when I originally got it there were leather straps that attached to the pedals.
I don't know if I still have them but I can look, It almost looked like a Japanese old wooden sandal/shoe.

The serial # is A623524
Under the serial I can make out Asian characters and then : OHTS - there are two more letters but it's hard to identify.
When I get back home I can take better pictures.

I am unsure if I want to sell the bike now however, it really doesn't fit me and If someone would like it here I would be more happy selling the bike to someone in this community that can appreciate it than someone on craigslist.
If there are certain pictures you'd like let me know!

Orange Bike Guy

The pedals were like the Diamond Tourer DT-3K

On the break release adjusters there used to be a little rubber cap as well.

The tube and tire both need replacing in the back.
My brother said when he was riding it the tire rubbed alittle on the frame however that could be bad alignment when I was fiddling with the back tire OR when I used to ride it it used to bump in the back and I think it was because the tube was pinched and that is probably why it doesn't hold air anymore.
I am unsure really however if anyone wants to come over and take a look I am more than happy to do that.

ramzilla

Wow! Japanese quality at it's finest!!!!!!!!