Norco A-line CNC'd Replacment Dropouts

Well it seems there is a small demand for a run of Norco A-line dropout replacements. If you don’t already know Oatnet had contracted me in December to make a set for his Aline and was amazing about getting the word out (lots of great photos too): http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=34230&start=49

Since then I have got several emails from folks, so I am going to do a new design. I wanted to put up this thread to see what you all wanted from these.

What I want to keep:

- I would like to continue to use the 7000 series aluminum as the material. It has a PSI strength of almost 80,000 yet weighs almost ¼ of steel. Unless I use something like Domex most mild steels are similar in strength unless we harden. The original dropouts were 6061 which is about half as strong as the 7000 series.
- 135mm Axle spacing
- 1.5in Extension toward the rear for wheelie reduction
- Improve derailleur mount design
- Priced around $200 possibly lower

Requested changes:
- It seems most people would like a packman styled design with a tensioning bolt. I’ll have to do more research into the stresses at work here and see how well this will work as opposed to the fully enclosed design. With the milled in 135mm spacer you have almost a 3/4in of metal on each side of the axle. I am still not super fond of this idea since no matter what the enclosed design is insanely strong.
- Ensure axle is sitting on the flats and not the rounded section when installed

Here are some photos of the originals:

Gorgeous work! Looks to me like with that much meat on it, you don't need steel.

For those that insist they want a pinch droput, just make dropouts normal open ones, but generously deep. With a nice big flat area, they can bolt on whatever steel device they prefer to do the pinching.

Many Freeride and DH racing bikes have bolt on dropouts now. They are good choices to build a powerful Ebike with, for strong dropouts can be made to replace the originals, thus making a neat build without the need for additional torque arms or plates.

Even with the best fit, with a powerful setup and regen, the steel axle will shear its way through the alu until it spins into it.
Make them with hard steel, and make them adjustable. A diagonal pinch dropout is best IMO, for it could fit or easily be modded to fit any motor and setup, and eliminates the need for the axle nuts. If it is vertically and horizontally adjustable, one could set appropriate geometry with various wheel size and riding style.

Maybe you will find it complicated, and likely to make it more expansive, but it is the best fit-all system IMO. Else, you would have to make a variety of lenght and height and axle hole size to suit specific needs.

+1 on MR's comments, the enclosed dropouts are great in terms of safety, ie they pretty much cannot fail... but the issue I found when I made mine is that the axles (in my case, a HT35) aren't perfectly made... the '10mm' flats vary by about .1-.2mm along the length of the axle. that means that you have to either file down the high parts of the axle or file out the dropouts, and it leaves a small amount of play between the axle and the dropout. Having it CNC'd might help alleviate this problem a bit, given mine were made with a mill... but this problem could be eliminated entirely by using pinching drop-outs. It also means you can take the wheel off easier, witch is a pita with enclosed axles, since you also have to take off the brakes, and the derailleur along with the 6 bolts.

otherwise they look bloody amazing mate. any chance you'll get some with a bit less than 1.5inch extension? I find 2cm (about .8") longer and 1.5cm lower than the standard axle to be about perfect for me...


Just another idea, with my own dropouts I used two plates that I bolted together... each 10mm thick. It might be an Idea to use 2 plates in this case, one normal Ushape dropout for the outer plate, that attaches the bike to the wheel... and a second, inner plate that bolts to your custom dropouts, like a bolt on torque plate. that would allow you to have a bullet proof dropout/torque arm combo, with an enclosed torque plate that bolts directly to the dropotus... when you remove the wheel, you only need to unscrew 1 bolt on each side, to detach the torque plate from the dropouts, then the wheel can be removed (with the torque plates still attached to the axles...)
<< Hope that makes enough sense that you can picture what Im saying.... :?


edit
is it just me or are the mounts for the disk brake calliper in an unusual position compared to stock?

they look awesome! could they be 2 inches longer instead of 1.5?

A great product at a great price. I am really pleased with my first set, I am going to be back for two more when I get the motors in!

-JD

Looking good!

I bought one of those ebay A-Line frames, a medium. It just arrived, and I can't wait to see what comes of these replacement dropouts.

Any update?

way cool, instead of going back to steel, why not use steel shims inside the current milled opening.

in fact since the rig could be fastened to the frame first, you could force the shims into the opening on each flat after the dropouts were bolted on and that would allow you to insert different shims on either side to totally eliminate any slop, and have a steel wear face against the aluminum. easy to check if it is wearing down, and add more shim to get it tight again.

but you guys will have a better idea.

I have a few thoughts:
1) If there is enough demand... say, 10 pairs of dropouts, consider looking at emachineshop.com to do the actual CNCing. For one-off jobs, doing the CNC yourself is best. But with a refined design and at least a small volume for the order, their price per copy drops pretty quickly. They also do post processing for a fee, e.g. anodizing. All that said, I have not had the balls to "press print" on any of my designs so I don't have actual experience with the company.

2) I like Dnmun's idea, it increases flexibility. But it also increases parts count, and in the end might not be worth the hassle.

3) I'm shopping for replacement dropouts to extend the rear a bit like most everybody else. But I plan to bolt a NuVinci (N360) into the dropouts not a hubbie. This might mean different thru bolt diameter and length. If so, #1, above, is less appealing (same basic aline dropout shape but different bolt holes?) and makes #2 slightly more appealing (one basic aline replacement drop, but steel shims at the bolt that come in different sizes.

Magudaman! Have ye abandoned yon E-Liners to their bolt on fate? Have ye left us, tired and parched, in the valley of desire. Money in hand, we prostrate ourselves before you, Please! we say... Drop-outs! My children, they need drop-outs!

I keep thinking about the modular Sliding Dropout concept. It promotes versatility. Look at this one for example:

View attachment 1



A custom A-Line dropout along the same line could be a big win. Maybe make the custom piece that interfaces with the bike mate with the dropout/brake attachment pieces that can be bought off the shelf - there already appears to be a standard. Each customer (there are like 5-6 of us interested in A-Line drop replacements, right?) can use the slider to dial in custom extension...

Or, maybe make both pieces - so the mating surface where the parts slide can be beefed up. This second approach is great if one wants to tap into a market beyond the A-Line... There might be enough of a demand here for a simple weld-on dropout system (top piece of each half) that accommodates different, or even further customized dropout pieces (the bottom piece of each half).

Nice. I was wondering if anyone had done aluminum drop outs. Thanks for the inspiration! I can certainly mill 7x aluminum on my mini mill.

dnmun said:

way cool, instead of going back to steel, why not use steel shims inside the current milled opening.

in fact since the rig could be fastened to the frame first, you could force the shims into the opening on each flat after the dropouts were bolted on and that would allow you to insert different shims on either side to totally eliminate any slop, and have a steel wear face against the aluminum. easy to check if it is wearing down, and add more shim to get it tight again.

but you guys will have a better idea.

Click to expand...

Well it seems that is what everyone is wanting. So I may create an insert in the aluminum were we can fasten on a piece of steel. It would be really cool if the insert was able to be the full thickness of the original design, but be small and gathering its full strength from the surrounding metal.

Andje said:

Magudaman! Have ye abandoned yon E-Liners to their bolt on fate? Have ye left us, tired and parched, in the valley of desire. Money in hand, we prostrate ourselves before you, Please! we say... Drop-outs! My children, they need drop-outs!

Click to expand...

:lol: You cracked me up. Sorry I have not been doing regular updates, I have been pretty pegged with projects for fun and work. This project is also a sort of daunting task. One thing that is hold me up is that the dropouts I had created were just a little too tight in a couple areas and required some filing. But figuring out exactly what needed reduced is tough without actually seeing the fit on the frame. It seems I'll have to dump another one out of aluminum then try to find a frame to test it out one to really dial in the fit. But again that takes a lot time and then material costs too. I would say end of march I would have something dialed in.

MattyCiii said:

I keep thinking about the modular Sliding Dropout concept. It promotes versatility. Look at this one for example:

A custom A-Line dropout along the same line could be a big win. Maybe make the custom piece that interfaces with the bike mate with the dropout/brake attachment pieces that can be bought off the shelf - there already appears to be a standard. Each customer (there are like 5-6 of us interested in A-Line drop replacements, right?) can use the slider to dial in custom extension...

Or, maybe make both pieces - so the mating surface where the parts slide can be beefed up. This second approach is great if one wants to tap into a market beyond the A-Line... There might be enough of a demand here for a simple weld-on dropout system (top piece of each half) that accommodates different, or even further customized dropout pieces (the bottom piece of each half).

Click to expand...

I'm not sure that I exactly like the strength in that particular design. It seems like everything ends up riding on your fasteners which is a bit scary. I think I am going to just shoot for 1.5in to 2in extension.

willo said:

Nice. I was wondering if anyone had done aluminum drop outs. Thanks for the inspiration! I can certainly mill 7x aluminum on my mini mill.

Click to expand...

The ones I made for Oatnet in the very first post are aluminum.

magudaman said:

figuring out exactly what needed reduced is tough without actually seeing the fit on the frame. It seems I'll have to dump another one out of aluminum then try to find a frame to test it out one to really dial in the fit. But again that takes a lot time and then material costs too.

Click to expand...

Perhaps I can help here. I have a Makerbot 3D printer, and of course an A-Line. I can print up a copy of the frame mounts. Clearly there's a limit to the precision you can when creating a design from the stock dropouts and a pair of calipers. Closing the remaining gap involves a little trial and error.

The same is true for 3D prining, moreso I'm sure. What I can do is design/print a copy of the frame mounts that are "close enough", then use knife,file,sandpaper/dremel to get it to a 100% match. I'll use my stock dropouts to ensure I'm getting the same close tolerance fit one gets between the stock dropouts and stock frame.

Let me know if you want me to do this. No charge of course, it's just 3D printed plastic. I'd be happy to do this to help keep the process moving & make it cheaper and easier for you to produce these awseome replacements.

I could ship my 2nd frame up to you... Maybe I should have done that in the first place. I didn't find the filing I did to be an issue, just tweaks.

-JD

Not the whole frame... Just the top half of the rear triangle!

Alternative 3: I have some mold-making materials, I could make a mold of the frame interface, then male a cast of it in polyester plastic & foam. That would take several days to work up, but not difficult to do. The advantage of a 3D printed model or a cast is of course I wouldn't ever need/want it back. Conversely, sometimes there ain't nothing but the real thing...

Man, those dropouts make me want to go buy an A-line. :lol:

etard said:

Man, those dropouts make me want to go buy an A-line. :lol:

Click to expand...

S#it, I fell for that! Stop yourself now, it'll be the beginning of a long downward slide into maxxed credit card!

Do you still offer your services to fabricate those drop-out ?

200$ for a set in 7075 would be awesome.

I have IGS files of a set that was tested and optimized to fit without the need of grinding any material.

you can see the rendered image result from this thread : http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=37182&sid=5c9a2274a9b775e3b53cc5b878df085b

*Bump*

Magudaman, can you please update whether this is still in the works? Life throws us all curve balls so if your ability to provide this service has changed that's understandable, but I'd certainly want to get started on Plan B if that's the case. Also, if it is still in play, can you provide a notional timeline?

Thanks!

Bump again... that means no more replacement dropouts magudaman?

gensem said:

Bump again... that means no more replacement dropouts magudaman?

Click to expand...

You've probably seen all these builds, but in case you have not:

I have a spare set of custom dropouts for the 2009 A-Line. They might be adaptable to meet your needs, check out my A-Line thread here: http://endless-sphere.com/forums/viewtopic.php?f=6&t=37207.

Adam333 custom-modified his original dropouts (http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=37182&hilit=adam333&start=15#p556265), and Fractal had some machined by a local machinist - I'll bet he'd at least share the CAD files if you like his design (http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=31850&hilit=fractal+norco&start=120#p553026).

Then you have the DIY stylings of Sn0wchyld (http://endless-sphere.com/forums/viewtopic.php?f=3&t=29373&start=30#p445599), hand-built, solid, functional.

Back to what I have, they're designed to adapt the A-Line to a 135mm width, standard diameter (10mm?) axel of a NuVinci N360, but can accomodate a 135mm hub with derailler. Let me know if you're interested in them at all/have any questions.

Best of luck!
Matt

Thanks for the help MattyCiii. I did saw all those threads but its still nice to have all the links together.
Anyway I ll have to delay my frame order for some months, but I let you know if the dropouts will be needed.