So, I recently came into possession of an older mountain bike. At first I didn't think much of it; it had crappy wheels and mismatched parts, but as I started to scrub through the grime it started looking better and better. Chrome frame, Sugino crank and bb. Obviously I have a lot more cleaning to do, but I'd like to know if anyone could help me figure out what make it is. The serial number is M6-G4285 and it has (I believe) a 26.8 MM seatpost.



Forged dropouts, but no name on them.


Maybe someone recognizes this brake hanger/seatpost clamp?


All thats left of what seems to have been a painted on headtube decal.

Thanks,
Dan

bet it's a mongoose. the brake hanger looks right.

Thanks. It does look similar to some I found on the web, but I can't seem to place exactly what the model/year/tubing is.

85, top of the line atb pro.

old mongoose catalogs are available online. i'd find the link but my att uverse internet is so slow right now i want to punch my computer in the face.

oh, here it is. still waiting for the catalog to open.... maybe by christmas
https://www.vintagemongoose.com

i will look at my seatpost clamp tomorrow and confirm it if nobody else has chimed in

there is nice pic in the catalog that confirms it, i think.

page 6 of 8
https://www.vintagemongoose.com/pdfs/mongoose_cat85.pdf

Thats it! Thanks Chris, nice detective work. Now I just need to figure out what to do with it.

Build it or sell it. Those are your options.

What length top tube and seat tube?

I'll probably get rid if it. I have a Schwinn High Sierra that fits my mtb needs. Its 21.5" x 23".

The sharks are beginning to circle.

Check the ISO/for trade thread.

If it is a Mongoose it looks like the standard ATB model, which has bosses for regular cantilevers. At least in the catalog, the ATB Pro has the bosses mounted much higher up, for U or roller cam brakes.

interesting , i didnt think of that. though the standard atb has a bi-plain fork , at least in the year i linked to.

but, this one has those slight crescent cut outs at the top of the seat tube, where as i dont see those on the mongoose. maybe it's not one at all. or a different year given the seat collar similarity.

edit. the standard 86 atb did have a unicrown fork. https://www.vintagemongoose.com/pdfs/mongoose_cat86.pdf
and cantis

Sorry to bump, but since cleaning this bike up I've made some interesting discoveries. First is that none of the catalogs match the bike I have exactly. Mine has a unicrown fork, regular cantilever brakes (not roller cam) and no lowrider brazeons. Also, the stem seems to be 22.0, since none of my 22.2 stems fit. Any ideas? 22.0 was mostly a French thing, right?

EDIT: Its a mongoose with a non-original fork!

A lot of the early MTB's took a 21.1 stem.

Well, I felt like if I had wanted to, I could have forced the stem in there, it felt that close. A 0.2MM difference is tiny, but so is 1.1MM I guess. Maybe if I ever find my calipers I'll figure this out.

Well here she is, all built up.

That looks amazing! Love the blue rims as the only colour accent.

very cool!