Road Fan

I'm installing a Honjo front fender which is not drilled and is not dimpled. Drilling of course is needed to add either a daruma bolt to attach it to a caliper brake pivot bolt, or a vertical bolt to thread it into the fork crown. My fork uses cantis, so no daruma is used.

Heine and others recommend adding a dimple to the fender at the bolt location to enable the fender to clear the fork. This reduces stresses in the fender ('tis said) and let's you get a good fender line. What it amounts to is cold-setting the fender.

I'm looking for, what's the best way to do this? Heine (BQ, V9#2) recommends making a set of forms out of a 2 x 4 and a dowel and gently hammering the dowel into place to distort the fender. I think the forms are kind hard to make, so I'm looking for a simpler technique. Elsewhere (sorry, can't find the source) it's suggested to bolt it onto the fork with a large steel washer between the fork and fender, and bend the fender forward to set the aluminum.

I'm concerned about getting this done without building a set of forms that have to be curved with some intricacy.

What have you guys used? What works best, looks neatest, needs simplest tooling ... ?

AZORCH

Calling Southpaw Boston - As I recall, he figured out a quite elegant solution to dimpling the fenders using a dowel.

Road Fan

Ok, I looked over some of the Southpawboston threads. He's got some great methods and tools for chainstay clearancing, but I didn't see a good discussion on the fork crown area.

Puget Pounder

Same concept, right?

I didn't have a form, but I had a dowel. I just took the dowel, placed it on a fender, and tapped it with a hammer against a flat surface. Worked like a charm.

ColonelJLloyd 

+1

southpawboston

Hey, I missed this thread. Glad I found it.

I assume that Road Fan is inquiring about the part of the fender where the daruma bolt actually goes through?

This is exactly what I do! but I use a long threaded rod as a lever.

Get some 6mm threaded rod stock, two steel fender washers (that's what they're called! Get a couple roughly the size of the daruma washer or slightly larger; find them at your hardware store) and two 6mm nuts.

After drilling the fender for the daruma bolt, feed the threaded rod through the hole in the fender. Attach a fender washer and nut on each end of the rod to sandwich the fender between the two washers, leaving most of the rod sticking above the fender. Tighten the nuts all the way to pinch the fender flat and tight between the washers. Now get another person to help you. One person holds the fender steady with both hands, and the other person torques the rod like a lever. The lever action should be toward the FRONT of the fender, which will cause a perfectly round indentation in the fender, with the front end of the indent sunken deeper into the fender. This angle should match the angle at which the daruma bolt seats the fender.

Like this:

JohnDThompson 

I wonder if you could make your own daruma using a star nut and a bolt?

southpawboston

Indeed, and I think others have done this, in cases where there's no drilled brake hole in the crown.

LaissezPasser

Just so I'm clear, is it really okay to flatten the aluminum like a pancake with the washers/nuts/rod stock rig, like this? This is the first time I've done this. I'm working with 35mm VO fenders, which I imagine have a more acute curve to be flattened than, say, wider 45mm fenders. Mind taking a look at these pictures, particularly at the size of the gap between washer and the fender's concave side, before I go ahead with tightening the nuts and flattening the flattening it?

southpawboston

Like you say, the arc radius of your fender is narrower than the fenders I've performed this trick on, but you will probably okay. What may happen is that you will get some minor deformation beyond the flattened area, for example the overall arc radius may increase around the vicinity of the flattened area. But that is something that you can also reshape by hand if it happens. Here's a recent 50mm Honjo hammered fender that I flattened for the daruma bolt, it's perfectly flat and angled forward to result in the desired fender line (I do the forward angling step not with the threaded rod but with the fender bolted tightly to the daruma bolt, by simply forcing the fender to the correct angle), yet there was no other deformation beyond the washer:



In the end, this leads to a much more reliable fender with minimal risk of eventual cracking because it is stress relieved. Notice in this next pic, the fender is attached to the fork at only one point-- the daruma bolt. The stays are just suspended in air, they are not actually bolted to the dropout eyelets (although you can't tell this from the pic!). The fender is completely stress relieved and 100% aligned.

LaissezPasser

Thanks so much! It sounds like I just need your courage to flatten whatever's in my way and bend these fenders to my will.

Your photos and clarification of that step are especially helpful. I probably would have done the same, but I was wondering about it ; )

Here goes everything...

fietsbob

I'd carve a wooden form like the inside shape you want it to be ,

a polished face of a hammer wont make marks every time you hit it..

trouble with aluminum is It's hard to anneal , and that reduces the work hardening that is natural to a reshaping .

but it can be reshaped a small hammer blow at a time , till its shaped like the form you made underneath it.

this is a way to narrow the width to not wear the paint where the edges touch the Paint.

The Golden Boy 

Southpawboston has been really great with documenting how he's done this so well.

I can't seem to get it right for anything though...

markk900

I also had problems with clearance on either side with the ends of the crown "lug", which meant I couldn't get the fender high enough into the crown for a good line (VO fender, trek 600). Is it recommended to dimple the sides of the fender as well?

southpawboston

Yes, this has no ill effect on the strength of the fender. I've done this on bikes where there wasn't enough clearance between the fork blades. It usually doesn't affect the tire, either, because the part of the tire closest to the fender's rolled edge (the tread) is much narrower than the fattest part of the tire (the sidewall). In this pic I have a 52mm fender running through fork blades that are 46mm apart.

Road Fan

Wow, I had totally forgotten about this thread.

I'm not happy with the fenders on my 650b - if I find a deal on some 55 mm hoops I might try it again. I think I did the chainstay hole well and the fork crown, but after two tries I can't sort out the seatstay hole.

Anyway guys, thanks for the great dialog!

LaissezPasser

I flattened the fender with the nuts, no problem; almost no lateral deformation as I had feared. Here’s the problem: With the fender off of the bike, I’ve torqued the threaded rod forward (that is, such that the top of the rod, the long arm of the lever, tilts toward the FRONT of the fender, as southpawboston illustrates above). It produces an angled, flattened dent for sure, but to no effect: the front of the fender still rubs against the top of the wheel, while the back end of the fender hangs with its ass sitting 6cm off the wheel. I’ve also tried torquing the fender while it is bolted into the daruma, in an effort to produce a flattened, angled dent that brings the ass of the fender down and the front end up off the tire. That method, too, produces a very vsisble dent at an ever-increasing angle tangent to the arc of the fender, but the front of the fender still rubs on the tire, and the ass end still hangs in the air, way off the back of the tire. What am I doing wrong?

Velocivixen

When you install the metal fender stays around the back of the bottom part of the rear fender, and attatch the other end of the stays to the eyelet by the fork ends, wouldn't that act to pull the rear of the fender in toward the tire?

LaissezPasser

Yes, it would, but that's exactly what you're not supposed to do: Put the fender under tension. It will crack the aluminum eventually, as inevitably as the tide.
So. Solutions?

MercianGrace

Hi,

I just got a pair of Honjo fenders and I've been reading all I can about best installation practice. I'm particularly interested in the technique you describe for preparing the front fender before fitting the Daruma. Was it a success? Would you recommend it? My fenders are 35mm hammered.


Best wishes.

Road Fan

Well, after 6 ¾ years I have not done my fender as Anton (aka Somerville) did, except for using the same broad principle. I attached my Daruma to the drilling on my fender and threaded it into the fork crown bottom with a fender washer (or something) above it and tilted my fender up in the back and down in the front. I have no recollection how I formed it from there. I think I just did the pull and push, drilled it for the stay and attached it, installed the wheel, and set up the stay to make a decent rear gap, then bolted it all down. I think I re-installed at one point to get more front fender coverage and raise the mudflap off the ground somewhat. I didn't need any more fender side clearance. Not much riding on it since this re-fitting and a more difficult re-fitting in the rear.

I also haven't installed any more Al fenders. I have one project for it, to add 35 mm fenders to Mrs. Road Fan's Georgena Terry Classic, a steel road frame from 1997. Here the frame to wheel clearances are extremely tight, and I'm fitting the fenders split, using the River City Bikes split fender brackets. Several other projects have gotten in the way. One result is that my 1984 Trek 610, Mrs. Road Fan's Georgena Terry from 2013 and my build of my steel Meridian tandem have received SKS chromoplastic fenders. I think once I'm done with the Trek and decide what to do with the 1980 Woodrup build, I'll be done with Honjo, Velo Orange, or Grand Bois aluminum fenders. No offense, but I think they are more trouble than they are worth.