Classic & Vintage - Drilling for rear fender

I just picked up some Giles Berthoud fenders earlier this week. I have them installed on my '73 Italvega Nouvo Record which is set up as a fixed conversion and is also my daily commuter. I am pretty sure these fenders will stay with this frame. So, my question is whether or not it is a bad idea to drill and tap a hole in the <edit>chainstay bridge</edit> behind the bottom bracket to attach the rear fender more securely than it is. Currently I am using zip ties for lack of anything better. Normally I would be against permanently altering a frame, but I don't believe this to be a huge collector's item. Also this procedure would not limit any future functionality of the frame.

Has anyone here done this?

http://i130.photobucket.com/albums/p271/jjvw1jjvw1/Italvegawfenders.jpg

I put a bracket that screws to the fender then clamps on to the bridge behind the bb shell on the chainstays. It works well with my Honjo's. I got it at the bike stand in Scotch palins N.J. I wouldn't drill the bridge.

I had a similar bracket on my SKS/Esge fenders that were on this frame previously. It kept popping loose. I know I can fabricate a better one myself though.

Jan Heine has an article on installing metal fenders in the current issue of Bicycle Quarterly.

You say "seat stay bridge behind the bottom bracket", but do you mean the chainstay bridge?

If there is no hole in the bridge, then yes, you'll have to drill one. With the fender positioned in place, mark two horizontal lines on the fender - one at the top of the bridge and the other at the bottom of the bridge - with a magic marker. Remove the fender and drill a hole centered between the two lines and halfway from one edge of the fender to the other. Drilling on a convex surface is tricky, so use a center punch and start with a smaller twist drill to provide a pilot hole. When attaching the fender, use a leather washer between the bridge and the fender, and a steel washer on the inside of the fender.

Yes, the chainstay bridge.

The procedure described is pretty much what I had in mind.

I use p-clamps rather than drilling out the bridge. My new favorites are nylon p-clamps sold in the electrical section of the hardware store. Pic below of the one on my Raleigh International (along with a piece of cork as a spacer).

Neal

I use p-clamps rather than drilling out the bridge. My new favorites are nylon p-clamps sold in the electrical section of the hardware store. Pic below of the one on my Raleigh International (along with a piece of cork as a spacer).

Neal
Yes.

drilling would be fine..
one thing though, it might be too thin to tap for a machine screw..
usualy when builders do this i think they use a threaded boss

you'd probably just through bolt it

If you decide to drill, the hole needn't be very large. A 3 mm or #4 bolt should be plenty strong enough.

My '83 Trek 400 has a factory provided hole in the chainstay bridge but, if it didn't, I'd have used zip ties or a P-clamp rather than going to the trouble of drilling it.

If you feel uncomfortable drilling the bridge, use a padded corrosion resistant steel Adel clamp instead of a plastic clamp. It'll be much sturdier and won't fall apart after a couple of years' exposure to UV. The Adel clamps are only a couple of dollars and are used mostly in airplanes for securing wiring bundles. Get one that's the appropriate diameter for the bridge.

As mentioned , it is usually a threaded boss, I don't think that the bridghe wall would be thick enough to provide more than a thread or two. And then how are you going to get your drill and tap in that narrow space? I would go for a clamp as suggested.

Your ride looks really nice! Where did you get the fenders?

vjp

I think it is a cleaner installation to drill... P clamps may work fine, but I tend to only use them to fasten to the stays etc.

Of course, I rarely do things the best way, so take this opinion witgh a grain of salt. :)

I got the fenders at Yellow Jersey in Madison, WI during a work related trip. Andy, the owner, said he only orders 5 sets a year, but usually only recieves two. I've looked all around Chicago for Berthoud or similar fenders and haven't had any luck yet. So far they are great -- much quieter than the SKS/Esges I had on before.

I am leaning towards making my own P-clamp since there probably isn't enough thickness for very many threads and I do not want to put a bolt through the entire bridge. Whatever I do, it will be a clean and uncluttered installation but not necessarily the easiest (a la Little Darwin).

Since I have some of your attention I'll ask another question. Those of you with steel fenders, are they attached at the brake bridge? How did you do it? I was thinking of getting a second "silent block bolt (http://www.peterwhitecycles.com/berthoudparts.asp)" to attach the rear fender to the brake bridge.

http://www.peterwhitecycles.com/images/products/Accessories/bert21P14.jpg

Your ride looks really nice! Where did you get the fenders?

I just bought a pair of Berthoud 700c stainless steel fenders from Il Vecchio (http://www.ilvecchio.com/) for $65.00 plus shipping.

^^Including your shipping, that's about what I paid.

Those of you with steel fenders, are they attached at the brake bridge? How did you do it?
Fenders attach to the brake bridge using a "fender bridge clip" that is essentially an "L" bracket with one side of the L riveted to the fender and the other side having a hole that the brake mounting bolt goes through. I'll see if I can find a picture.

EDIT: Look HERE (http://davesbikes.com/fenders.htm) and scroll down the page to Wald #827 and Wald #847.

Mine does not have an L-bracket. The only place the rear can attach out of the box is at both ends. Nothing else is drilled. The front hangs off of the above mentioned block bolt and a set of stays.

Mine don't have an L-bracket. The only place the rear can attach out of the box is at both ends. Nothing else is drilled. The front hangs off of the above mentioned block bolt and a set of stays.
Well, they deliver them without a lot of pre-drilled holes so you can "match drill" them for the position of the bridges on your particular bike.

So even hough Berthoud does not supply a rear bridge support, I should go ahead and devise one myself.

I just bought a pair of Berthoud 700c stainless steel fenders from Il Vecchio (http://www.ilvecchio.com/) for $65.00 plus shipping.

I was in Seattle yesterday for a meeting, I went early so that I could drop by Il Vecchio first. They open at 11:00 am but by 11:30 George was still not there and I had to get to my meeting. Kind of pissed me off but I grabbed 5 minutes at Elliot Bay and that gave me my vintage fix, along with Brett Hortons new book "The Golden Age of Racing" which I picked up.

vjp

So even hough Berthoud does not supply a rear bridge support, I should go ahead and devise one myself.
That's what I'm going to do.

Here's a catalog photo showing the rear brake bridge fender clip on a Schwinn World Tourist.

I was in Seattle yesterday for a meeting, I went early so that I could drop by Il Vecchio first. They open at 11:00 am but by 11:30 George was still not there and I had to get to my meeting. Kind of pissed me off but I grabbed 5 minutes at Elliot Bay and that gave me my vintage fix, along with Brett Hortons new book "The Golden Age of Racing" which I picked up.

vjp
I picked up a copy of "Cycling's Golden Age" at the San Francisco Velo Swap and had it autographed by both Brett Horton and Owen Mulholland. Another great book is Jan Heine's "The Golden Age of Handbuilt Bicycles".

The authors all like "golden age"... :D

I picked up a copy of "Cycling's Golden Age" at the San Francisco Velo Swap and had it autographed by both Brett Horton and Owen Mulholland. Another great book is Jan Heine's "The Golden Age of Handbuilt Bicycles".

The authors all like "golden age"... :D

Right, "Cycling's Golden Age", I told you I was rushing! I also have Mr. Heine's book, it is really interesting, not much "new" in our little world when you look back.

vjp

I tend to stick to a very simple principle : never drill if there's any possibility to use ties or clamps.

Most touring bikes come from the factory with pre-drilled holes in the chainstay bridge and brake bridge to accommodate mounting fenders. They also usually have eyelets on the dropouts for accommodating the fender stays. These bikes are "fender friendly". Most racing bikes have no factory provisions for mounting fenders.

The OP's question was essentially "what modifications does one make to a bike that didn't come from the factory already set up for fender installation?" There are several ways to set up a non fender-friendly bike for fender installation. One is to emulate the way fender-friendly bikes come from the factory by drilling the necessary holes and brazing on eyelets. The other way is to make the fender installation as non invasive as possible to the bike so that the fenders can be removed without any evidence they were ever there.

The OP stated in his first post that he was "pretty sure these fenders will stay with this frame". To me, that meant he wanted a clean, sturdy installation that would more or less emulate the way bikes with fenders come from the factory. He also said he wasn't too concerned about drilling the frame.

So, the choice to me is really to do it like a factory would or have it look like a kludge with tie-wraps and plastic clamps.

The P15-9 I'm putting my Berthoud fenders on came from the factory already set up for fenders, so I don't have to decide, but if I were mounting those same fenders on a bike without drilled bridges and dropout eyelets, and I intended for the installation to be permanent, I wouldn't hesitate to drill and get eyelets brazed to the dropouts. These fenders are much too classy to look like they are installed by Rube Goldberg.

...To me, that meant he wanted a clean, sturdy installation that would more or less emulate the way bikes with fenders come from the factory.

...So, the choice for me is really to do it like a factory would or have it look like a kludge with tie-wraps and plastic clamps.

...These fenders are much to classy to look like they are installed by Rube Goldberg.

Scooper, you nailed it! If I can't fabricate a simple and elegant p-clamp or strap, then that bridge is likely to get drilled.

Scooper, you nailed it! If I can't fabricate a simple and elegant p-clamp or strap, then that bridge is likely to get drilled.

One or two small black tie-wraps run through small holes in the front edge of the rear fender should be at least as "elegant" and a nut and bolt.

A tie wrap doesn't look it is meant to be there, especially on an all steel bicycle. I'm being picky about it, I know. :)

I'm being picky about it, I know. :)
Not to me; I think you just want it to be "right". If you didn't, you wouldn't have started the thread.

Scooper, you nailed it! If I can't fabricate a simple and elegant p-clamp or strap, then that bridge is likely to get drilled.
Have you been reading the other posts?
You can easily.

As I stated in a previous post, I am concerned about the wall thickness and there not being much room for threads. Is this an unnecessary concern? I do not want to drill all the way through to the other side of the bridge.

As I stated in a previous post, I am concerned about the wall thickness and there not being much room for threads. Is this an unnecessary concern? I do not want to drill all the way through to the other side of the bridge.
I think you have reason for concern since there's really no way to tell the wall thickness of the tubing used for the bridge without drilling. If you don't want to through-bolt, then use a clamp.

i'm pretty sure you're not going to be able to tap a chainstay bridge for a metric thread machine screw..
it is standard to just through-bolt it..

as an alternative, i suppose you could try to use a sheet metal screw but i'm not sure how it would work with the slight curve of the bridge tubing


As I stated in a previous post, I am concerned about the wall thickness and there not being much room for threads. Is this an unnecessary concern? I do not want to drill all the way through to the other side of the bridge.

My rear eyelets came threaded at 10-32. I bought a matching tap for the front which had not yet been threaded. Assuming I do drill the bridge, I had planned on using the same size for the sake of consistency.

My rear eyelets came threaded at 10-32. I bought a matching tap for the front which had not yet been threaded. Assuming I do drill the bridge, I had planned on using the same size for the sake of consistency.
#10 is pretty big. Attached is the chainstay bridge on my P15-9, and the bolt is 8-32. This is what I'll use to fasten the fender to the bridge, with a leather washer between the fender and the bridge, and a steel washer and star lock washer inside the fender. The head of the screw will come from the front, and the nut will be inside the fender.

#8 it might be then. Thanks.

Did you happen to notice how thick the tubing was on your Paramount's bridge?

#8 it might be then. Thanks.

Did you happen to notice how thick the tubing was on your Paramount's bridge?

It's Reynolds 531 and the wall thickness is 1.0 mm

It's Reynolds 531 and the wall thickness is 1.0 mm

Mine is a mysterious Columbus pre-SL.

I fashioned a p-clamp out of a sheet of scrap 16 gauge stainless steel.

http://i130.photobucket.com/albums/p271/jjvw1jjvw1/P-Clamp.jpg

It isn't drilled yet. I won't do that until I get these SS nuts and bolts to match the rest of my mounting hardware. :)

http://www.peterwhitecycles.com/images/products/Accessories/bert21P11.jpg

Well, I finally got my Berthoud stainless fenders installed using stainless hardware.

http://i32.photobucket.com/albums/d7/k4drd/Bicycles/P15-9fenders.jpg

Very nice. I like how tight they are to the wheels. Time hasn't allowed me to finish perfecting mine yet. The rear is still held on by zipties. Hopefully next weekend.

A lot of good advice.....I personally would never, never ever, ever, ever, never ever, drill a hole in any of my keeper frames, but thats just me :D ;)

Since I have some of your attention I'll ask another question. Those of you with steel fenders, are they attached at the brake bridge? How did you do it? I was thinking of getting a second "silent block bolt (http://www.peterwhitecycles.com/berthoudparts.asp)" to attach the rear fender to the brake bridge.

I don't have a rear brake (coaster) and I am thinking of this, since using one silent block bolt attached to a brake bolt requires a) only one hole in the fender, b) has a rubber damping mechanism and c) is length adjustable

i ordered the brake bridge mount (L-bracket) from berthoud with my fenders but haven't mounted it yet. i think this works well if your wheels fit your frame nicely. i have 700c wheels on a 27" frame, so i have to drop the fender from the brake bridge a bit more than normal. i currently have a sliding bridge which rattles like crazy and needs to go...soon

regarding p-clamps - i think they are more elegant than ties, but still not great. i used a p-clamp on my winter build (Raleigh SuperCourse) and the fender sits about 6mm higher than it usually would. my first ride in the rain proved that this doesn't give enough protection against dirt and grime. my BB and chainstays were pretty dirty.

i am still thinking about drilling - or turning the p-clamp upside down. i haven't decided yet

Some fenders mount to the chain stay brace with an upside down P type clamp the the clamp does not actually clamp to anything. Rather, the open end, or should I say have end, simple slides down over the brace. The 1/2 P-Clamp is bolted to the fender and sits on the brace. This is an incredibly easy bracket to make and you will not have to damage/alter your frame set in any way to accomplish this simple installation.

My description might be poor and I will elaborate(with a pic if I can find time to search through The Old Shed) if need be.

Hope this is a help and you might even consider gluing a piece of inner tube rubber to the part of the bracket that slides over the brace just to protect paint.

your description sounds like the solution i currently use. a picture would help understand your description better.

cheers, dan

This shows how Berthoud fenders are intended to be attached. It's a traditional French mounting method, but few bikes have the proper fitting at the brake bridge.

http://www.wallbike.com/berthoud/ssfenders.html

Drilling the chainstay bridge invites rust in a very suseptible area. I'd prime and paint the edges of the holes with a small brush. I like the P clip idea better.

how are you going to get your drill and tap in that narrow space?
A Dremel would work.

Drilling the chainstay bridge invites rust in a very suseptible area. I'd prime and paint the edges of the holes with a small brush. I like the P clip idea better.

true but i just saw that hufnagle did it:

http://farm4.static.flickr.com/3526/3724281761_a0d8f5df13.jpg

A lot of good advice.....I personally would never, never ever, ever, ever, never ever, drill a hole in any of my keeper frames, but thats just me :D ;)

Second that. A metal p-clamp (get it in the electrical section of your hardware store) is decent looking and hardly noticeable. Seems like a pretty minor thing to be drilling into a frame over. Like hacksawing the hanger off of a SS conversion. Yeah, I suppose it does look slightly better without it there, but pretty drastic solution.

I didn't vote, because it's not my frame. You don't need my permission to drill your frame. Not that I mind if you do. If it were mine, I might drill it. But I'd try something else first.

Old Raleigh fenders have an interesting clip at the front of the rear fender, it's kinda a S shape, or maybe more like a 2 shape-- the round part goes around the bridge, the flat part clamps to the fender itself. I don't know where you'd find one, though. Therefore I'd try #4 in this photo (http://www.yellowjersey.org/hardware.html) first:

http://www.yellowjersey.org/hardware.jpg



Thinking about drilling.... You can find very long drill bits, but probably not cheap. I got a set of 6" bits at a tag sale last summer, but I think they're for wood. A dremel-like flex-shaft tool would be a good way to drill the hole. I'd definitely try to run a metric tap through the hole, but the difficult part would be finding an extender for the tap.