Hondo6

I recently found a mid-1980s Trek frame in my size. Best I can tell, it's either a 1985 or 1986 400. (Color and frame decals say 1986, but True Temper tubing says 1985. Has internal RD cable routing in DS chainstay, but I understand some late 1985 400s had that as well. Maybe it's a late 1985 frame that ended up being used on a 1986 model.)

I'm trying to get parts together for a future build, so I decided to check seatpost size. I've read that most Treks from that era used a 27.2 - but I had a loose 27.2 seatpost handy, so I checked. (Calipers say that one's 27.1 to 27.2 diameter, depending on where measured. It also fits REALLY snug in a known 27.2 frame.)

The 27.2 goes in tight as hell for about 2cm - then it becomes a "no go". I tried a verified 26.6 (measures 26.5 to 26.6) and that's very obviously too loose. Don't have a 26.8 or 27.0 handy to try.

Haven't thoroughly cleaned or honed the seat tube inside, but it's stopping so firmly I don't think that's the problem.

First question: anyone out there know with certainty what size seat post the True Temper tubed Trek 400 of that era used? I really don't want to buy another seatpost just for it to to sit on the shelf as a paperweight.

The frame also has no headbadge. I'd like to put one on it, and have found a few semi-affordable brass ones from that era (catalogs seem to show the brass with black logo/lettering one was original). But the affordable ones are kinda rough-looking.

Second question: anyone know if those brass Trek headbadges were solid brass - or brass plated? If it's the former, I think I can polish/paint/clearcoat one so it ends up looking fairly decent. But if it's plated, it's time to order a headbadge decal from Velocals before they close up shop.

Thanks in advance for any info or advice.

rhm

The following may be completely useless information, but.....

The badge on my 1982 720 was solid brass.

The model number of mine was engraved on the steerer tube with a rotary tool (dremel).

Hondo6

Thanks. I hadn't thought to check the fork steerer tube for info about the frame's model.

Unfortunately, I don't seem to be that lucky. Just checked mine and all I can find on the fork steerer tube is a stamped "TANGE JAPAN 5A".

Good to hear that about your headbadge. Hopefully someone with one from 1985 or 1986 will say the same.

BradH

I have a 1985 Trek 400. Well, that's what the serial number shows it is anyway. It has braze on DT shifter mounts and the RD cable runs through the chainstay. The catalog shows clamp on shifters and the RD cable does not go through the chainstay. There are quite a few other things about it that don't match the catalog. The seatpost is a Sugino 27.2 and that's the one that it came with.

Steel Charlie

You can have the head badge that is on an '85 frame I have for whatever it costs to send it to you. Don't know if I can get it off undamaged but I'll try.

ehcoplex 

The head badge on my '87 400T seems to be plated (ie, it's lost a lot of its brassiness when I cleaned/polished it.....).

The Golden Boy 

I don't know about the 85 400, but the 86 and 87 were 531 and therefore 27.2. I've read the same thing you have about most all Treks using 27.2.

Regarding the head badge- the 86/87 head badge is smaller and more like "printed" on brass like stock. It doesn't tarnish underneath like the 84/85 version.

They're missing the intermediary 84/85 badge which is shaped like the old version, but has the graphic without the circle

Hondo6

PM sent. Many thanks.

The generosity of folks here - with both time and vintage parts - is astounding.

Hondo6

Yeah, the True Temper frames are a bit of a "one-off". 1985 seems to be one of the few years (if not the only year) that Trek used those tubes.

I understand the 1985 True Temper frames are quite good; they're CroMo and the main tubes are double-butted. The stays are also CroMo. FWIW: fork for mine is Tange and weighs in at 695g, including the crown race.

I'd guess they simply didn't have the name-recognition of Reynolds or Columbus and hence didn't get as much respect, thus hampering sales. Which likely led Trek to go back to the more recognizable 531 the next year.

tkamd73 

Don’t know if this helps, but Trek went back to True Temper, for the 400 frame in 88. I have one, and just measured the seatpost, it is 27.2.
Tim

Hondo6

I noticed references to that and other year Treks using True Temper tubing after my last comment, so I edited it to correct the error.

I also found what appears to be a 1987 True Temper catalog online:

The Bicycle Info Project :: True Temper Bicycle Tubing Catalog circa 1987

Based on that catalog, if I've done the math correctly it looks like a True Temper frame could take either a 27.2mm seatpost (RCX tube kit, with less than 0.1mm finishing reaming), 26.8mm seatpost (RC tube kit, with 0.02mm finishing reaming necessary), or a 26.6mm seatpost (RCR tube kit, no finishing reaming required).

Or True Temper could have done a special production run for Trek, in which case all bets are off. Dunno.

Unfortunately, my frame sticker doesn't say which True Temper tube set was used. Bummer.

Hondo6

Update: finally found the archived Vintage Trek page with 1985 serial numbers. Turns out my frame is a 470, not a 400. Color and decals match those in the catalog photo for the 470, including the drive side chainstay "470" decal that's so badly faded on mine that I missed it initially. Serial number is within the range listed for a 470 of the correct size manufactured in spring 1985.

My apologies for the misleading info in the OP. I guess that goes to show just how valuable a resource the Vintage Trek site was for C&V fans.