I want to build a commuter porteur bike and would appreciate some help selecting a frame. I don't know much about frames etc but have read that a low trail Randonneur frame would be ideal, thus me posting here instead of the commuting forum.

Here are my requirements:

* horizontal drops for an internal hub (sram automatix). How effective are the adjustment screws on the drops that frames such as the polyvalent have ? Worth it or are they a gimmick?
* able to accommodate coaster brake - needs a strong rear triangle ?
* geometry conducive to heavy front load - is low trail the only requirement here?
* Possibly front disk brake it rains a lot where I am but I know this adds weight and complexity. Might be able to get away with rear coaster brake and front cantilever
* Cantilever/disk brakes to allow for fenders
* Fender room and attachment points
* Wheels...not sure if 650B gives me better options for commuting tires
* Doesn't need to be especially light
* As cheap as possible given the above requirements - I want as little money as possible chained up on the street

It seems like a VO polyvalent is an ideal candidate except for the cost...

What exactly am I looking for here ? Could I buy a cheap hybrid or mountain bike frame 2nd hand and then get a raked fork separately to get low trail while keeping costs down ?

Any help appreciated.

Nick

I moved this here from randonneuring, since nobody was going to answer there.

Modifying an existing bike to get low trail isn't going to be easy, you're probably talking a custom fork. The industry really isn't making many low trail bikes. And 650b is still a niche size for road tires.

With your set of requirements, I'm afraid you probably are talking an expensive bike, you probably have to compromise.

You mention both low trail forks and disk brakes. That's a rare combination. I only know of one non-custom fork on a production bike that offers it, the Elephant Bikes National Forest Explorer. There are porteur racks for it too. It doesn't come with horizontal drop-outs at the rear though and might be outside your price range.

I think a All City Nature boy disc probably gets close, not low trail though. From what I've heard, low trail is one of those optimizations that you can probably live without. I want to put a porteur rack on my commuter, which is high trail. That isn't stopping me, the problem is that I would have trouble parking it

I answered here... Merge?
https://www.bikeforums.net/utility-cy...me-advice.html

Anyway, I thought the Republic Socrates covered many of the needs of the OP. Most IGH hubs with coaster brakes are 3 speed, although Shimano does make an 8 speed version.

Trail is the ground plane distance between the Head tube axis line and a plumb line from the front wheel axis .

by increasing the fork rake/offset you can reduce the trail .. Get the Actual Trail Data and compare that, rather than brand names .

FWIW My 2 Folding bikes , A Bike Friday Pocket Llama and a Brompton are low trail Geometry ..

the handling Seemingly Improves with weight over the front wheel.

Great thanks for moving the post unterhausen and thanks for the fork and wheel advice. What do you think is expensive ? $1000 ? I was hoping to be able to do something like pick up a second hand bike with the appropriate frame, wheels and front brake and just swap out the rear wheel for one built with the automatix for a total cost of no more than $500. So something like this ($300) for example:

Yeah I figured that combination would be rare. I'm happy to sacrifice the disk if I have a drum at the back.

Those Elephant bikes look sweet !

Please do merge it if you know how. Not sure if that means people in the utility bike forum won't find it here when it's merged ? I figured they might know something about frame geometry and front loads. Thanks for your reply I responded to it there.

This one might work but not sure if fenders will fit