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Discussion Starter #1
Over the years I have collected many nrs parts and pieces, a lot of which don't match the boats I have at this time. I would like input on how to shorten cross bars that may have been maybe 72" and convert to say a 66". Now the cuts are straightforward but without machine shop tools how do you set up to take on this project. Is a drill press the only way to acomplish this, it seems like to find the center would be difficult to match the outher side that still have the low pro intact and then to drill completely thru the pipe withough being off on the outher side. Then to tackle a seat bar which would require to split the difference from each side and then I don't even know. Am I overthinking this,is there some tricks maybe setting up a jig is required? Any tricks of the trade would be greatly appreciated. The Montana winter is starting to set in and I am getting a little stir crazy and could use a good project.
 

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It's not that hard. Do your work on a flat bench. Set your bolted lo pro to one of your scrap pieces of pipe (just as it sits on the frame). Measure the hole on the lo pro you will use on the cut side and with a t-square mark where to drill. Now set the loose lo pro back in and set on another piece of scrap pipe ( as it would be set on your frame). Drill through your pipe. The lo pro will guide the bit so you will have a straight enough hole through your pipe. Aluminum is very easy to work with. Just take your time. I have a drill press with a big table and fence but never used anything other than a hand held drill. The best way I found to cut the pipe is with the pipe cutters that you spin around the pipe and tighten a little every couple of turns. You get a square cut that way. I hope you understand what I am saying here and find it helpful.


Jim
 

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I really like the NRS frame system and I have done a lot of custom NRS stuff. It can be even easier than that if you want. First you need to realize that NRS doesn't use a jig (with the older lo-pros at least) They are just hand drilled with the lo-pro in the pipe end. What that means is that they may not be centered and no two are the same.

They may not be centered but all of them that I have seen are drilled exactly 1.5" inches from the end. So.. Just put the low-pro in the pipe and drill a new hole through both sides @ 1" from the end. This is still just as strong and I have built 4 cat frames that way.
 

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Can't help you with the drilling part, but I took my NRS side rails that I wanted shortened to Home Depot. They cut them and finished the ends (reamed them????) all for free. Turned out perfect and the rubber end caps fit back on snug.
 

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Your not overthinking it. If there is any fixed part on the bars, then that fixed part must be centered. Don't measure from the part, just measure the difference. If you have 72" bars and you need 66" bars, Just cut three inches from both ends. Also I should have mentioned above that you do not need a drill press. Just use a hand drill and drill as close to center as you can. There is nothing wrong with that. It is not critical that the bolts are perfectly centered (as long as it's close). Just make sure that they are horizontal as the frame sits on the tubes.
 

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Discussion Starter #6
Thanks for the info it would be nice to take enough measurements to use the original holes in the lopros
 

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Sembob mentions using pipe cutters to get perfect cuts of NRS tubes.

A big ten four from me for using a pipe cutter.

I did some NRS frame mods and my first cut was with a hack saw. I found out that what worked for me on a 2 by 4 was not acceptable on a raft frame tube.

Went to the local hardware store and spent the money for a pipe cutter. I even got the cheap version. The pipe cutter worked perfectly for me.

Highly recommend using a pipe cutter on NRS frame tubes.
 

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Pipe cutter makes a very clean and perfectly round cut every time. It even bevels the outside edge.

Sent from my SM-N900V using Mountain Buzz mobile app
 

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Yep. If you have a chop saw for cutting metal that is the way to go. I don't so the pipe cutter was my best option.


Jim
 

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Yes, I agree. Cut the tubing with what you have. I've cut lots if copper tubing and many steerer tubes on MTB forks with a tube cutter as well as MTB seat posts. Since I happen to have the the blades and saw handy, I like to cut the tubing that way. If I need to, I can hit the inside with a rat tail file, but if it going to be used with a speedrail fitting, you're good to go.
 

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You can use a regular wood blade in your standard chop saw and it works just fine. Protect you eyes and ears and be prepared for the mess. Your wife will love the Al chips you track in on her nice wood floors.

The triple chip blade are great in the production setting but not needed for a few cuts.
 

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Discussion Starter #16
Yes, it seems that there are many ways to cut the pipe with the pipe cutter being the cleanest leaving a beveled edge. As far as drilling the holes that will match the existing holes in the lopros is we're it could all go very badly. Any more pro tips out there?
 

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You need a tool called a pipe notcher to do it right. Like this one
Sync180 JR Tube Notcher

Then you attach a drill chuck to it. This allows you to center the hole and drill it straight.

Alternatively you can use a punch to create a dimple for the drill bit. Drill the first hole then insert the fitting and use the fitting guide the bit and proceed to drill the second hole.

Better yet use speed rail and save your self a headache and some weight.

If you were in the medford, or area I's help you out.

Good luck.
 

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Here's an idea for lining up shortened pipe to the old bolt hole of a lopro. You'll want a sleeve of some type that fits over the NRS pipe snugly, but will still slide. You could use a piece of metal or PVC pipe for this, or even the cardboard tube from a paper towel roll, but metal is probably the best. You can use this sleeve for your jig. If there is too much play in the sleeve and the NRS pipe you can put something like blue painters tape on the area of the pipe you are working with until it snugs it up.

The idea is that you can drill one hole in your sleeve to match just one side of the bolt hole. Then use the hole through the lowpro to drill out the other side of the pipe.

It looks like this. Obviously you only need to do this to one side of each crossbar because one end already has a lopro that fits it. Attach one end of the crossbar to one side rail. Attach the other lopro that you're trying to match to the other side rail by the U bolt. That way you can put it all out on your garage floor and it will all lay flat and line up. Cut the crossbar to the desired length. You'll end up with a scrap piece of NRS pipe with the hole pattern that matches. Now take the sleeve and drill just one hole 1 1/2" from the end. Slip it over the scrap pipe, and rotate it until it matches a scrap pipe hole and a lowpro hole. Tape the pipe if it isn't a snug fit. Now make markings on the sleeve and the lopro so you can line the sleeve back up. Disassemble everything. Put the sleeve over the end of the cross rail you want to match and put the lopro in the end of the cross rail. Line up the mark on the sleeve and the lopro. This should give you a jig hole to drill out one hole of the crossbar with a hand drill that aligns with the lopro hole. Once you're through one side pull the sleeve back or remove it, then drill through the lopro and drill out the other side of the crossrail. This should give you pretty close results. Even anything slightly off will be taken up if you loosen and retighten the u bolt.

The seat bar is even easier. You said you have a mix of NRS fittings including the new forged shiny ones. Use 2 of these for your seat bar. Those don't use a through bolt but instead use a smaller self tapping set screw that only goes through one wall of the cross bar. Cut both ends of the seat crossbar to where you need and use the new lopros on these and drill into the lopro on the opposite side of the old screw hole.

If you have any other of the new lopros you can do the same for your crossbars and don't need to use the sleeve jig. Heck if you have enough new forged lopros and don't mind a mismatched frame use the forged ones anywhere you had to cut the NRS pipe and your done in about 10 seconds.
 

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Yes, it seems that there are many ways to cut the pipe with the pipe cutter being the cleanest leaving a beveled edge. As far as drilling the holes that will match the existing holes in the lopros is we're it could all go very badly. Any more pro tips out there?

Seriously?


Jim
 
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