lewtwo

I have been looking at bikes and bike frames for about a 18 months now. Looking for a lightweight, double triangle, long wheelbase, steel (cromo or better) frame with a true horizontal top tube (as in road bike), horizontal rear dropout (as in IGH hub not derailleur) , cantilever brake bosses, curved fork, front and rear dropout eyelets suitable for 700Cx35 wheels/tires. The closest thing I have found is something along the lines a "Handsome Cycles XOXO" but if is for 26 inch wheels. At this point I am convinced such an animal does not exist.

REALLY STUPID QUESTIONS:
1) What defines a mountain bike frame?
2) Contrast a road bike frame with a mountain bike frame.
2) Why can one not find a frame that has both horizontal rear dropouts and cantilever brake bosses?

jade408

I am not an expert, but 35mm tires + road bike do not really mix. Hence the smaller tires used kn some frames, which keave addiitonal clearance for fenders and tire width.

This is likely in the right neighborhood: San Marcos Frame Set | SOMA Fabrications

Look for "touring" and "randonneuer" bikes to get more of your requests in.

lewtwo

I can live with somewhat smaller width tires --- actually plan on 30 or 32 but wanted a little room for error.
Heck, I can live without any of it (and probably will), but it drove my interest in the attached questions.

Looigi

Seven Cycles.

Canker

Surly has a few that might work in their pavement line lke the check/cross check.

lewtwo

The Surly's are interesting but the questions remain ... particularly #1 and #2 .

MRT2

Try these out. I think they both tick off all your boxes.

Space Horse | All-City Cycles
Camargue Frameset - Camargue - Frames

njkayaker

Geometry (related to rider position) and frames built to withstand more bashing (and, likely, more stiff). Basically.

Mountain bike frame also allow for much wider tires.

lewtwo

non-horizontal top tubes.

MRT2

Confused. Both these framesets have horizontal top tubes.

jade408

Try this: ES | SOMA Fabrications

MRT2

Nice, but it has a vertical dropout.

lewtwo

Look at the last picture on at the bottom of the referenced URL. The top tube slopes down from the head tube to the seat tube.

MRT2

Very slightly, but not much. Now this is a sloping top tube road bike.
AnyRoad CoMax (2015) | Giant Bicycles | United States

lewtwo

I already have something of that extreme: https://www.bikesdirect.com/products/...G3_dsl_800.jpg
(the picture is of the small frame ... the large frame is worse)

By " true horizontal top tube" I mean 90 degrees to vertical, not 89 or 88, 87....

If I see a sloping top tube then I think heritage is mountain bike, compact frame: responsive but also stiff and heavy (relative to a lightweight road bike).
That was the reason for questions one and two. Plus the aesthetics are not as pleasing.

fietsbob

fat tire capacity
Road is using narrow high pressure tires
A) you are not looking back in time far enough| B) you are not willing to hire a framebuilder to change Vertical dropouts for The other style .?

C) You came here expecting other people to do the searching for You.

lewtwo

No, I wanted to explain why I was asking the questions.

I think that the answer is a bit more complex than tire size. I have my own hypothesis but I have been known to be wrong on more than one occasion so I thought it best to ask for some other opinions.

Deontologist

Hardly any road bikes have horizontal top tubes anymore.

If you really want a frame with a horizontal top tube you're going to have to look at old road bikes bikes. Start around 2005 and go back.

jade408

Willing to accept 650b? Here is something: Polyvalent MK3 Frame and Fork - Frames or https://store.velo-orange.com/index.p...-frameset.html

lewtwo

I was actually more interested in answers to the question:
1) What defines a mountain bike ?

As far as the 650B is concerned, I am more likely to compromise on the brake bosses.
It is a long term project so I am not in a hurry.
I may possibly spot a 20 year road frame from ebay that comes close.

Elvo

Ridley X-Fire - 2014 - Custom Bikes / Frame Only | Competitive Cyclist

What do I win?

MichaelW

Surly Cross Check has your features.
H dropouts have been out of favour for decades. Only a few touring bikes have them , for singlespeed backup use. My old Bob Jackson World Tour used to have H-Dropouts but now feature V-Dropouts

Also check out sliding vertical dropouts, which are superior to H-Dropouts for adjusting tension.
Disc brakes have superceded canti brakes on many modern tourer.

steve0257

My generalizations of the difference between the two is the purpose they are designed for.

A mountain bike would be optimized for agility and handling at low speeds in tight places, but a road bike would be optimized to track well and be stable at higher speeds. Playing with the head angle and fork rake?

Also, I feel road bikes would generally have higher gearing than mountain bikes. Again, that is a function of how the bike is intended to be used.

tcarl

A mountain bike frame is going to be much sturdier and stronger (and therefore heavier) due to the rougher nature of use.