SF Cyclotouring

Ride reports and other ramblings from a San Francisco cyclist.


GT Tachyon. A Great Idea that Happened Too Soon.

According to this forum posting, Bill Duehring was the VP of Product at GT around the time the GT Tachyon was produced (later he was promoted to COO). Props to this guy! Who is he? Where'd he go? [Update: Looks like he's at Felt Bicycles now...]

Now read the text contained in the purple block in this catalog scan. I'm assuming Mr. Duehring wrote this, or at least was influential in authoring it. You might want to mentally substitute "650B" for "700D" since those wheel sizes differ by only about 3mm in radius:

Some quotes from the above:

...manufacturers and consumers alike assumed everyone wanted an ultimate off-road machine. Well, assumptions can be wrong...

Why doesn't anyone make a bike that's as tough as a mountain bike, yet as functional on the road as your old ten-speed?

Such sensibility and practicality is rare in today's bike market!

Now check out the other page of that catalog scan:

Note especially the inset photo of the front fork dropout, featuring adjustable offset:

New design Cross fork with adjustable offset offers four different front wheel locations and lets the rider choose.

I argued for exactly this type of multi-position dropout on the KOG list during the initial discussions about the design of the P/R frameset, but Kogswell instead decided to offer multiple fork options instead of this convenient design.

Now oogle the bike:

Hot damn!

I remember these things sitting on the floor of one of the shops I worked in during the early 1990's...I dismissed them due to the funny 700D wheel size, and the fact that they were (ugh) "hybrids". Ugh, indeed -- if I knew then what I know now, I'd have held them in as high regard as I do now. Of course I want one!

Apparently GT also made a few tandem models using the 700D wheelsize as well...



Blogger blackmountaincycles said...

I believe this bike may have been an attempt to circumvent the high import duties imposed on mountain bikes. Mountain bikes are hit with an 11% duty rate while "road bikes" with larger diameter/skinnier tires are only charged 5.5%. Raleigh did something similar in the 80s when they (re?)introduced 650B mountain-like bikes.

Very cool find, though. Should be a fun project.

And Bill Deuhring is definitely one of the smartest guys in the industry that you never hear about.


12:01 PM  
Blogger Jim G said...

Hi Mike,

Thanks for the comments --interesting to hear about the import tax on MTBs (I didn't know that)! Also, I was wondering if you knew of Bill Deuhring at all...

FWIW, that Tachyon pictured isn't mine, just a photo I found online.

12:10 PM  
Blogger Jim G said...

Mike, another thought: are current 29ers and 650B/"27.5" MTBs immune from the higher import duties? Thanks!

12:16 PM  
Blogger blackmountaincycles said...

The import duty thing is skewed because back in the 80's Huffy and Murray were still making bikes in the states and lobbied for higher import duties on the type of bikes they were producing (BMX bikes are also hit with 11%). Now that they don't make bikes in the states...

29ers are hit with an 11% rate. There are bke weight and tire width parameters that it doesn't meet.

12:40 PM  
Blogger Tarik Saleh said...


I think they would have been a great idea if they actually came with rims that you could get tires for now. Ryan aside, it is a really bad fit trying to get 584 or 590's on a 700d rim. Lord knows I tried when I fixed one of these up for a local shithead a few years back. It had the 700d but not the adjustable dropouts. Luckily I found some NOS 700d tires via the boblist. Its akin to Riv offering 603 rims and then pulling back on the tires in 2 years...
It was sort of almost there, but I think the 700C bianchi all terrain bikes were even more prescient...

8:44 PM  
Anonymous Flynn Joffray said...

Yeah this bike is pretty cool. notice the suntour command shifter, pretty awesome. a bike before its time. The one I had was a pain when the tire popped though...

9:45 AM  
Anonymous Anonymous said...

Someone ought to get a hold of Bill Duehring and see if he's aware of the 650B wheel movement.

I would really like to trade my 26" Felt FS rig in for another one with 650B wheels.

Mike, do you know him?

5:02 PM  
Blogger blackmountaincycles said...

I've met Bill and talked briefly over the years. If Felt is anything like the bike company they should be, they are already aware of everything that is going on.


7:38 AM  
Anonymous Anonymous said...

This is a little late, but thought I'd add a comment. I built one of these up with 650B wheels, and it rides great. Here's a link to the thread I started on it, with photos: http://forums.mtbr.com/showthread.php?t=416402

6:21 PM  
Blogger Morgan said...

Does anyone have any idea about how much a early 90s, maybe even late 80s model of a GT Tachyon would be worth, or how much it cost originally?

My boyfriend inherited one from his godfather and it was recently stolen from his car, and he would like to get money from his insurance to get a new bike, but we have no idea how much they cost! Please help us not participate in insurance fraud!

9:50 AM  
Anonymous Anonymous said...

I owned one of these until it got stolen. It was an interesting concept but the components were far from bombproof and mostly unique to this bike as near as I was able to determine. Suntour also ceased operations shortly after this. The tires were a royal pita to find. The frame was on the heavy side as most "Garbage Truck" steel frames from this era were. It wasn't a bad bike but could've been much better.

7:36 PM  
Anonymous Dean said...

To morgan,

I spent around 600 some bucks in the early nineties for mine. I still have it and still ride it, I feed it 26 1/2 tires. Mine is the black and purple splatter paint job

5:16 AM  
Blogger Syke said...

Funny. I was just given one of these, in very bad condition, this afternoon and discovered your blog while trying to figure out what the heck I had. After discovering that 700D tyres aren't available anymore, I figured this is God telling me to start playing with 650B's.

Guess I've got a nice winter project.

7:28 PM  
Anonymous Anonymous said...

...hey guys...I'm not sure how old this thread is, so apologies if I've woken up an old sleeping dog...point is, while poking around in my bssement, I happened to find a pair of RM20 700D wheels...they're on what appear to be Sun hubs, no name OEM stuff, really...there's one broken spoke in the rear, otherwise they're in fantastic shape...available to anyone who can use'em, I can relace'em with fresh DT's onto your hubs if you like, or ship'em as they are for you to have your favorite tech work'em up for you...feel free to contact me at rc-mobile(AT)rogers(DOT)com...

8:19 PM  
Blogger Ray Lofton said...

I just picked up onew of these in excellent condition for $40 at a thrift store in Maryland :o)

11:04 AM  

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