Framebuilders - fork spacing

I'm about to make a fork and I'm wondering if there's any particular reason why the fork needs to be more narrowly spaced than the rear dropouts? I would like to have the spacing in front and back be the same so that it would be possible to switch the front and rear wheel if this was at any time desired. Any reason why I should not do this?

I'm about to make a fork and I'm wondering if there's any particular reason why the fork needs to be more narrowly spaced than the rear dropouts? I would like to have the spacing in front and back be the same so that it would be possible to switch the front and rear wheel if this was at any time desired. Any reason why I should not do this?Because unlike the rear, the front hub doesn't have a cog/cassette so there's nothing for the chain to go around? Are you planning to push this thing with your feet or just coast downhill?

What kind of front hub are you thinking of using? All regular front hubs use 100mm spacing between the axles.

I did a quick check of the date and yup I was right - it isn't April 1st. I thought I'd blacked out for three months until I checked.

As weird as this post might sound, there IS a mountain bike that uses rear hubs for both front and rear wheels. The name will come to me after I hit "reply". The bike is a snow/sand bike and uses monster wide rims and tires and they use a rear hub up front to get as much spoke width as possible.

surly pugsly

the idea is a rear hub flipflop hub on both wheels. switch between 4 gears, and backup if it gets stripped and the nearest bike shop is a thousand miles away.

i'm not a frame/wheel geometry guru, but if your rear wheel isn't offset, it should work just fine. Seems like running 2 wheels with flipflop hubs would do it.

This is actually not a completely daft idea. If you ran two dishless hubs of equal width, on a singlespeed for example, you could have two flip flop hubs with the potential of having 4 rear cogs.

Why you'd want to do that though I'm not quite sure! :D

^ almost the idea of a pugsley

instead of the 4 gears it allows to to have 2 gears + disc brakes.

the idea is a rear hub flipflop hub on both wheels. switch between 4 gears, and backup if it gets stripped and the nearest bike shop is a thousand miles away.

Another fopaw to avoid durring your construction is to make the droppout diameters large enough for rear axles.

Will there be any problem with having a dropout slightly wider than the axle in it as long as the axle is bolted securely?

A guy in my 'hood built a fixie with that setup. He used QBP part # FS2251 front dropouts and opened the wheel slot up with a file to accomadate the extra axle diameter. Looks cool but the last tine we went riding together I was getting pissed with him about stopping to swap or reverse wheels or otherwise fiddle fart with the wheels whenever the hills got steep.

Will there be any problem with having a dropout slightly wider than the axle in it as long as the axle is bolted securely?

What velonomad said.

You can use rear hub up front, but be prepared
for the axle to be bigger. Most roadish front
axles are 9mm and most rears are 10mm.

do it Seggybop! its a good idea and you shouldn't think twice about it. having an interchangable front and rear wheel is a good idea for touring in desolate regions and also a good idea for having more interchangable gearing for a one speed.

Sure you'll have to widen the slots for a 10mm axle but so what.

I might whoop one up for myself just for the heck of it.

More people should build thier own stuff.

CK

Will there be any problem with having a dropout slightly wider than the axle in it as long as the axle is bolted securely?

Greater risk of bending an axle with the longer moment you put on it. Since you probably have more weight on the rear than the front anyway, the front isn't likely to be the more likely source for an axle failure. With flip flop hubs, I would think you've already minimized that risk to begin with.