Anyone hand make fenders?
 

Greetings frame builders, I usually hand out in touring and folding bikes, so first post over here for me.

I'm in the process of purchasing a new bike, it is a folding Bike Friday New World Tourist. I have always wanted some Honjo Hand Hammered Fenders, http://www.jitensha.com/eng/fndrs_e.html. However I have pretty much moved to the realm of 20" wheels and they do not make fenders in this size.

The only option I found, which are beautiful, are wood fenders, http://www.woodysfenders.com/store/. However a local rider has the flat fenders, which I do not like and the compound curve ones are $:twitchy:$ expensive. I love those compound fenders but $180+ is outa my range atm with the new bike purchase.

So does anyone have a link to anything nice or to directions on doing their own? I have a local metal artist that will allow me to borrow space, tools and advice, but he is very busy so I'm trying to limit it to space and tools.

On a side note, anyone here ever build a folder?

The only reason I have never made fenders is because I hate the way the flat ones look, and I wasn't sure I could bend wood in a compound curve. The compound curve fenders I have seen before were laminated and carved, which may be how the ones in your link are built

I have never seen directions. If you are going with metal, you probably can find enough information to learn how to do the job in the sheet metal literature.

I've only seen the carved laminated compound curve fenders as well, although I think they have been made with a large heat press similar to what is used to make skateboard decks.

Sorry Jim, flat ones are a snap to make but lack on looks and the compound ones are beautiful but a backache of labor.

Thanks guys, luckily I mentioned this to my local shop owner today. He immediately said that he had a buddy in CO that had done some and has promised to find me some pics and see if the guy is interested. Problem isn't solved but I have a decent lead now.

I would think it would be pretty easy to make compound curved wooden fenders with thin wooden laminates laid up in two or three layers of thin veneer strips 90° to each other and 45° to the longitudinal plane of the fender in much the same way cold molded wooden boat hulls are made using the wood epoxy saturation technique (WEST System) pioneered by the Gougeon Brothers. You could make the mold out of several pieces of plywood cut to the radius of the 20" fenders and beveled across the edges for the fender curvature. They would be relatively light, rustproof, and rot proof (because of the epoxy saturation).

The Wald lightweight 20" might work, and give you the metal fender look similar to the Honjos you mentioned. When I build my Friday (I used to build there) they are what I used.

http://farm3.staticflickr.com/2388/1...277d230ea9.jpg

You can buy aluminum in a 3" wide by .125" thickness , and get creative/

BF has vendors for exotic hardwood ones, too

something like this could work

http://www.pvcworkshop.com/bendpipe.htm

Looks like I might have a couple of options, found some made by an Italian company that I need to check on might not be made anymore. Also spoke with a local artist friend of mine and he is willing to take a set of chrome ones and work something out of them for me.

Eighth inch thick? He needs fenders, not armor. ;)

I think the Honjos are made out of 1/32" thick aluminum, they crumple like aluminum foil. Who knew there were weight weenies that run fenders?

I made some flat one's that work just fine they start about page 8 on my flickr page.


http://www.flickr.com/photos/timdude/page8/

Cold molding never occurred to me. Good thought.

Nice Job Tim.

Seems simple enough to just slice some thin veneer, then bend it around a curved form and wet with some ammonia solution in very hot water, let dry thoroughly and then use epoxy or gorilla glue or some other waterproof glue to hold the laminate.

Put the hot water/ammonia solution on the outside of the arc to make the wood curve properly.

Have turned 2 rear blumel sovereign/esge chromoplasts into a pair with a longer
front coverage mudguard then some DIY LDPE mudflaps..
and bike friday 20" ones with PB 20" parts.

The reason fenders are compound curved is that they are stiffer that way, in materials that do not easily yield stiffness, like sheet metal. Wood is a naturally stiff material, for it's weight, so it isn't necessary to make them compound curved. I have made compound curved wood fenders, and it was that experience that convinced me that the next set I would make would be flat. After thousands of miles riding them, the dirt line was very narrow, right down the middle. I never got wet riding them from water that was just barely keeping in the fenders and would have been all over me had they not been CC. The CC ones do haev more wind drag. So I think narrow and flat is the way to go, for me.

Making CC fenders is not difficult, but if you want to drill a hole you need a drill. There is a tool for everything, and this is no exception. Carbon fiber or heat formed plastic are probably the easiest materials to work if you don't have any skills or tools. Concealex is a moldable plastic that has a carbon fiber like finish.

MassiveD,

Very interesting and thoughtful post.

I think (guess) that compound curved fenders would be not really much different, wind drag wise.

I like your reasoning re the narrow fenders. This would be assuming they are installed perfectly on centre.

That must have been a chore to make compound curve wooden fenders!

My concerns re justification for fenders are;

1. Skunk line up the back with a wet spot around the seat in rain or slush
2. Snow/slush on the front shifters
3. mess on frame with snow
4. Chain carrying stuff from the crank, transferring to the chain and then ending up on the rear cassette gears causing chain slip/gear slip.

Anything to add to that?

Just out of curiosity, how did you make the compound curved fenders? Any pictures anywhere?

"I think (guess) that compound curved fenders would be not really much different, wind drag wise."

If there was a good reason to have them curved, then I doubt it would be a deal breaker since people use them all the time. On the other hand, when people say they prefer the way something looks, they are often just saying that it is normal to them, and also that they see a form function thing. So if you can counter by saying the preferred version isn't that functional, it starts the process of letting go of the form.

On my front fender the part ahead of the fork is almost horizontal, and probably does not create much more drag whatever the form, though smaller is better. The part that curves back from the fork is mostly a cup facing forward. I don't see the advantage to that aerodynamically. None the less I figured that if it catches air, it must be catching water also. But studying it over a very wet tour suggested it was wider than necessary, and was doing a good job while flatter than most fenders.


"That must have been a chore to make compound curve wooden fenders!"

The ones I made were easy I hand planed out a gutter, and curved the outer surface, then I steam bent them. It went pretty quick. I ended up with semi curved in section fenders. They look good, one looks at them and does not feel they are flat or someone cheaped out on the construction, but they are not really contoured in section. If one wanted super contoured ones it would be more trouble. I would probably make them out of strips. I am pretty used to that method, so it goes quickly for me.

"My concerns re justification for fenders are;

1. Skunk line up the back with a wet spot around the seat in rain or slush
2. Snow/slush on the front shifters
3. mess on frame with snow
4. Chain carrying stuff from the crank, transferring to the chain and then ending up on the rear cassette gears causing chain slip/gear slip.

Anything to add to that?"

I got into bikes with the '10 speed" craze in the 70s. Racing bikes were all the rage (for people other than racers). Next up were MTBs. Seems like a lifetime of bikes without fenders. But if one rides a bike in the rain, one really does not need a justification. I made my fenders for touring where I have spent weeks at a time cycling in the rain, or after the rain. At least while cycling in the rain one has rain gear on.

Thanks for all the replies guys. I've decided to go with the below, with a twist.

I'm going to buy a set of these and hand them off to my metal artist friend. He is going to do the dimple hammer work like the Honjo's on them. Yes this will destroy the chrome, he is then going to remove any remaining chrome and apply a "black chrome" finish, similar to this auto wheel.

http://www.challengeralloys.com/gall...chrome_big.jpg

I'll post them over when they are done. Should be mid February before I receive the new bike.

MassiveD,
I would love to see some pics if possible.

As I think about it I can envision ways to make them curved and cupped by putting a strip on either side which would help hold the curve.

once glue and carving is involved, it's trivial to exactly copy just about any smooth fender. I have some heating blankets for bending guitar sides, unfortunately a rear fender is about 30% longer than they are.

I was thinking that the way to do it is to cut out the flat centre strip, then cut some small strips on the tablesaw that are angled so as to fit on either side of the main strip on the outside edge. Simply glue them on.

To bend the main centre strip just wet it with a hot water/ammonia blend or make a long tube that you flow steam into like when making snowshoes.

Then you simply cut a jig with the desired curve. Then you drill holes in the jig about an inch in from the edge which you can put your spring clamps into.

Then you clamp the wetted centre strip in place and leave it till it dries.

Then you leave it in the jig and use something like clothespins to clamp the outer edge which gives you the compound curved look. A bit of finish sanding would be all that is needed.

The compound curve would simply look great, maintain a stiffer fender and best of all, stay out of the way of your legs, as you hoist them over the back of the bike. This is especially true when wearing winter pants, as they catch on the fender.

How about fiberglass?

Make a mold by doing a layup over a thickwall rubber tube or even an existing metal fender.
Then layup fenders, remove, trim and paint.

Then get crazy and try some in carbon.

carbon would be fun. I always wondered why the Berthoud carbon are essentially flat. Seems like it would be easy to lay up a nice contour with carbon.