Small machine work job- thoughts?

[AngryScientist]

I absolutely love my Ritchey breakaway bike. It’s my main gravel bike and I travel with it often. It fits perfectly and i like everything about it.

The bottom flange though; worries me. I’m often far from home, far from help and out of cell coverage while riding it. The flange is now totally rusted, especially the bolt. It’s in a bad place and sees a lot of road debris, mud and wet. Poor conditions for a steel fastener.

Yes, I know I can just carry a spare with me.

My mind has turned to having someone fab a totally and completely overbuilt flange thingy out of stainless that will last a couple lifetimes.

Anyone know who might take on such a project?

[echelon_john]

3 come to mind:

1. Paragon Machine Works because they could sell ‘em if it’s an item with a market

2. Frank the Welder because he can make anything

3. Dunno if Don at Anvil would take it on but could be worth a ping

Or just look for a local small machine shop? I don’t think it’s terribly specialized to make.

[unterhausen]

If a machine shop did this and charged for design, they really should charge you enough that it would be cheaper to have the fittings replaced with an S&S. And I am not convinced you want to have a set machined. It's a part that is subject to fatigue failure, so unless you have experience designing for fatigue, you will probably be worse off than using the ritchey part. I suggest buying spares and swapping them out more frequently.

I am not sure it's a standard flange, but the thing you want is very similar to a "sanitary flange clamp" I have always assumed that Ritchey was reselling someone's sanitary flange fittings, could be wrong.

I forgot what search term I used at mcmaster. They call it a "quick clamp," but you have to sort through the fittings.

There are high pressure bolted sanitary flange clamps available. Really comes down to the shape of the flanges on the ritchey. I was considering making a bike with a sanitary flange, but S&S agreed to sell me a set of their parts for personal use and I gave up on the idea.

Eta: saying it's a "small job" immediately raises red flags at any machine shop (see also, "should be easy for you"). They want a fully dimensioned and toleranced drawing, then they will tell you if it's a small job or not.

[sokyroadie]

Originally Posted by unterhausen

If a machine shop did this and charged for design, they really should charge you enough that it would be cheaper to have the fittings replaced with an S&S. And I am not convinced you want to have a set machined. It's a part that is subject to fatigue failure, so unless you have experience designing for fatigue, you will probably be worse off than using the ritchey part. I suggest buying spares and swapping them out more frequently.

I am not sure it's a standard flange, but the thing you want is very similar to a "sanitary flange clamp" I have always assumed that Ritchey was reselling someone's sanitary flange fittings, could be wrong.

I forgot what search term I used at mcmaster. They call it a "quick clamp," but you have to sort through the fittings.

There are high pressure bolted sanitary flange clamps available. Really comes down to the shape of the flanges on the ritchey. I was considering making a bike with a sanitary flange, but S&S agreed to sell me a set of their parts for personal use and I gave up on the idea.

Eta: saying it's a "small job" immediately raises red flags at any machine shop (see also, "should be easy for you"). They want a fully dimensioned and toleranced drawing, then they will tell you if it's a small job or not.

+100
If I had a dollar every time someone say's it is a small job and then I tell them the price and they are dumbfounded/pissed, I would be rich.

Managed a Fab/Machine/Rigging shop for years.

Tri-clover is the sanitary fitting/clamp.

[likebikes]

sounds like a solution in search of a problem to me.

[Mzilliox]

I totally agree with you and wish Ritchey would make something superior for their bikes. its a true failing on their part to allow these things to wear so fast. id get another breakaway, but the flanges worry me too, so next travel bike has to be s&s

[rrudoff]

I have stuff made like this custom all the time for machines and optics I design. It will be much cheaper to just buy several Ritchey clamps. Assuming you could design yourself, a one off would be about $ 300 to $ 500 in stainless. If you made 20 of them, price would be a lot less, maybe $ 100 each, but this would be a substantial investment. If you pay someone to also do the design, add another $ 300 to 500 for their time.

The fittings used for Sanitary (tri-clover) and Vacuum/Low Pressure (KF) are much bulkier than this fitting. They are usually made of castings, though machined ones do exist and would not really be suitable for joining a downtube.

You could possibly have an existing hinged or two bolt split shaft collar modified with the needed groove if you could find one in the correct ID, this might be more like a $ 150 job in a one off, but as one of the other posters pointed out fatigue is not really considered and the Ritchey part has a lot of material removed to save weight relative to standard shaft collars.

[donevwil]

Same issue a buddy faced leading him to go the S&S route.

Grooved split flange couplers are a common, standard item, granted not necessarily the most precise components unless you find one used for cleanroom or high pressure gas. Finding one in the required size (and without the compliant ring inside) may be the issue.

I suggest contacting Ritchey, they have sent me detail drawings of every part I've asked for. If you have the critical flange dimensions you "may" find a standard coupler that will work.

[AngryScientist]

thanks guys. and good points raised.

i'm going to email Ritchey and see what they have to say.

i would think they would be keen to have a good stainless part made that is a little beefed up. specifically since they are making and marketing gravel and offroad bikes with this coupler system, it would seem they would want a robust part at the bottom of the bike.

stay tuned for more.

[AngryScientist]

wishing for something a bit beefier/corrosion resistant.

at a minimum i guess i could go to a stainless bolt.

[unterhausen]

I was thinking that if it was mostly the rusty bolt you were worried about that a high quality stainless bolt would be a good start. And maybe some rust prevention steps on the clamp. I suppose there isn't much you can do about the pivot except for waxing it. There are many rust-preventative waxes out there. I know some people that mix carnuba wax with beeswax or paraffin to rustproof tools. Or you can get some Alfie Shine

[Mikej]

Stainless may have too low of a carbon content to be properly hardened. This is why the rusty old bolt is what they use - grade 5 or 8 carbon steel. SS may also gall.

[rrudoff]

I am assuming a Metric Socket Head, so it is DIN 12.9, equivalent to Grade 8, with a Yield around 170Ksi, versus 18-8 SS, which is around 70Ksi. Would not be a good idea to substitute as it is a single point of failure. There are a wide range of Zinc coated metric Socket heads DIN12.9 available from Mcmaster which will hold up much better and also be less likely to gall due to the coating. They are quite cheap on McMaster. The Zinc Flake and Zinc Aluminum coatings are designed to withstand salt spray specifically.

There are high strength SS alloys with yields near 170KSi such as 17-4PH, Bumax and A286, but they are not readily available in Metric threads in the US. If the screw is an M5, a 10-32 can substitute, but otherwise your out of luck.

[weisan]

Angry pal, my breakaway frame is 10 years old and showed no sign of rust or any indication of impending failure.

To see the kind of failure you are talking about, it has to be

A) long, sustained period of neglect

Or

B) bike is used as a submarine for underwater exploration.

Knowing that little bit about you, I don't see either one of the two happening any time soon....eh...A) for sure....B) maybe.