Thu May 29, 2014 12:49 pm
Let's go 4-wheelin' (S&G 6731)
I haven't seen much discussion of 4-wheel locks in this forum so I thought you might find a 4-wheel post interesting.
Design: The 4-wheelers I have been working with are both S&G 6731's. This is simply their 6730 with an additional wheel stuffed in there. I think that there is something "cooler" about a 4-wheel lock that goes beyond just being "different" from what I am used to. I am not an expert in lock history, but it seems that the 4 and even 5-wheel locks harken back to safes 100+ years ago. The difference between the 4-wheel and 3-wheel is immediately noticeable by the increased thickness of the lock body. The back is significantly thicker and adds the volume required to make room for the additional wheel.
Security: Because of the increased number of spins (and it can get a little confusing!), I initially questioned the value of a 4-wheel Group 2 versus a 3-wheel 2M or Group 1 in today's market. Why sell a 4-wheel Group 2 when a 3-wheel 2M or Group 1 is much harder to manipulate open? I assume it is because of the threat of the autodialer. While a 3-wheel lock theoretically has 1 million possibilities, a 4-wheel theoretically has 100 MILLION possibilities! So besides the cool factor of the 4-wheel, it clearly offers significantly greater resistance to the autodialer.
Dialing Sequence: The 6731 dialing sequence is 5R, 4L, 3R, 2L, right to drop in. After the first wheel is set, you can basically think of it like a regular 3-wheel lock. The 4-wheel is GREAT for training you to park wheels and keep track of things in your head. For me, this is the most enjoyable aspect. It gets particularly tricky when you start parking multiple wheels in one direction. Imagine the following sequence: R11- L35 - L22 - L46. Lot's of extra dialing!
Strategy: I have found that my 4-wheel locks are more consistent about giving up more than one gate on a single AWx spin. Whereas I have very few 3-wheel locks that will read two gates on one graph, the 4-wheels consistently read two, even after many combo trials. As you will see momentarily, this one actually read all 4-wheels in two graphs! No brute force necessary! That's never happened before, and it made it an even cooler open that I am excited to share! On that point, if ever there was a time when it is better NOT to brute force the first wheel, this is it! Thank your lucky stars if you can find W1 in your graphing, because brute forcing wheel one = wrist pain. One other point on finding the correct wheel for each gate: Hi/Low testing has worked MUCH more consistently for me on the 4-wheel locks than the 3-wheelers. I have a few theories on why, but they are just theories. The good news is this seems to be a pretty consistent rule on the 4-wheel. This one was opened without any complex wheel isolation work.
Search 1: AWL
Purpose: Find initial gate indication(s)
I chose an AWL approach for this lock. I had just mounted it and this was my first attempt at manipulating this particular S&G 6731. I was excited to see if it behaved like the other S&G 6731 in my collection.
I was very pleased by this first graph. It was very clear that I had a gate at L46 and L22. The other drop-offs seemed like they might indicate a gate, but for now, I was happy to do a Hi/Low for these first two indications and hopefully move forward with two confirmed gates.
4-wheel Hi/Lows are fun. Like I said, you get good at keeping track of the number of spins you've completed and where the gates are parked.
Unmistakable, text book indication for W4 at L46. LOVE doing Hi/Lows on the 4-wheel! Now for L22...
Again, a clean result for W3 at L22. I converted this to R20.5 as it will be dialed right when testing combos.
Search 2: W1 & W2 LA, W3 R20.5, W4 L46
Purpose: Find a gate on W1, W2, or both
There is a debate on whether it is better to move one wheel or two wheels when starting the second graph. For example, on a 3-wheel lock, if you have a known gate at W3=L50, some folks would go W1 & W2 RA, W3 L50, others would park W1 at L50 and search W2 by itself. On the one hand, parking W1 removes the additional variable that it adds to your readings, and ensures that any gate you find will belong to W2. On the other hand, it is possible that W1 should read next, or creates a large shadow at L50 that hides W2 anyway. Not sure if one is truly better than the other, but I typically start out moving two wheels together. If I don't find anything, I park W1 at the lowest point I found during that search, and search W2 again. Seems to work for me. In this case, I moved W1 and W2 together and it paid off bigtime!
The only problem with this graph is that it appeared to have four gates instead of two! I was pretty puzzled by this and was starting to question my sanity. It was about 1AM at this point so I truly think I was seeing gates that weren't there. I dunno. The good news is that the real gates were the most prominent. I started out by testing L11.
This test suggested that L11 was on W1, but the other Hi/Lows were so dramatic that I decided it would be better to focus on the L35 indication. I wasted some time testing some trial combos using L25 and L62, but wasn't getting anywhere. I decided to test L35 next.
BOOM! I didn't even do the Hi test because I knew I had my gate.
Normally, I would start bruteforcing if I had no other indications, but the ghost gates on my second graph were beckoning too me. "Trevor," they said in a strange, high-pitched voice that was coming from my cat, "do some trial combinations...you might not need to brute force us..." I nodded skeptically at that cat and began with L11 (R8) on W1.
Really pleased with this one. I've never had all the gates come out in the graph. As you've noticed, I've started using a manifying glass with a magnetic base and an LED light. It works wonders and I think it allows me to pick up a lot more. Mine has a magnetic base so it can stick to a safe, but it comes with the little metal clamp base which works perfectly on my lock stands.
Hope you enjoyed this one, because I sure did! Take care, fellas.
S&G 6731 4-Wheel Group 2
Design: The 4-wheelers I have been working with are both S&G 6731's. This is simply their 6730 with an additional wheel stuffed in there. I think that there is something "cooler" about a 4-wheel lock that goes beyond just being "different" from what I am used to. I am not an expert in lock history, but it seems that the 4 and even 5-wheel locks harken back to safes 100+ years ago. The difference between the 4-wheel and 3-wheel is immediately noticeable by the increased thickness of the lock body. The back is significantly thicker and adds the volume required to make room for the additional wheel.
A 3-wheel 6730 (left) vs. 4-wheel 6731 (right)
Thick stack! (left). The 4-wheel's thicker back makes room for the extra wheel (right)
Security: Because of the increased number of spins (and it can get a little confusing!), I initially questioned the value of a 4-wheel Group 2 versus a 3-wheel 2M or Group 1 in today's market. Why sell a 4-wheel Group 2 when a 3-wheel 2M or Group 1 is much harder to manipulate open? I assume it is because of the threat of the autodialer. While a 3-wheel lock theoretically has 1 million possibilities, a 4-wheel theoretically has 100 MILLION possibilities! So besides the cool factor of the 4-wheel, it clearly offers significantly greater resistance to the autodialer.
Dialing Sequence: The 6731 dialing sequence is 5R, 4L, 3R, 2L, right to drop in. After the first wheel is set, you can basically think of it like a regular 3-wheel lock. The 4-wheel is GREAT for training you to park wheels and keep track of things in your head. For me, this is the most enjoyable aspect. It gets particularly tricky when you start parking multiple wheels in one direction. Imagine the following sequence: R11- L35 - L22 - L46. Lot's of extra dialing!
Strategy: I have found that my 4-wheel locks are more consistent about giving up more than one gate on a single AWx spin. Whereas I have very few 3-wheel locks that will read two gates on one graph, the 4-wheels consistently read two, even after many combo trials. As you will see momentarily, this one actually read all 4-wheels in two graphs! No brute force necessary! That's never happened before, and it made it an even cooler open that I am excited to share! On that point, if ever there was a time when it is better NOT to brute force the first wheel, this is it! Thank your lucky stars if you can find W1 in your graphing, because brute forcing wheel one = wrist pain. One other point on finding the correct wheel for each gate: Hi/Low testing has worked MUCH more consistently for me on the 4-wheel locks than the 3-wheelers. I have a few theories on why, but they are just theories. The good news is this seems to be a pretty consistent rule on the 4-wheel. This one was opened without any complex wheel isolation work.
Note: Everyone knows I hate graphing, but recently I've run accross locks that I simply cannot keep track of in my head. That got me looking for a better way to graph. Anyway, I've started using Excel and letting it do the work for me. It also makes it much easier to make changes, fix things, etc. Hope you guys don't mind the graph screenshots! I also don't have Oldfast's crazy neat handwriting! 
Search 1: AWL
Purpose: Find initial gate indication(s)
I chose an AWL approach for this lock. I had just mounted it and this was my first attempt at manipulating this particular S&G 6731. I was excited to see if it behaved like the other S&G 6731 in my collection.
I was very pleased by this first graph. It was very clear that I had a gate at L46 and L22. The other drop-offs seemed like they might indicate a gate, but for now, I was happy to do a Hi/Low for these first two indications and hopefully move forward with two confirmed gates.
4-wheel Hi/Lows are fun. Like I said, you get good at keeping track of the number of spins you've completed and where the gates are parked.
Unmistakable, text book indication for W4 at L46. LOVE doing Hi/Lows on the 4-wheel! Now for L22...
Again, a clean result for W3 at L22. I converted this to R20.5 as it will be dialed right when testing combos.
So Far: Rx - Lx - R20.5 - L46
Search 2: W1 & W2 LA, W3 R20.5, W4 L46
Purpose: Find a gate on W1, W2, or both
There is a debate on whether it is better to move one wheel or two wheels when starting the second graph. For example, on a 3-wheel lock, if you have a known gate at W3=L50, some folks would go W1 & W2 RA, W3 L50, others would park W1 at L50 and search W2 by itself. On the one hand, parking W1 removes the additional variable that it adds to your readings, and ensures that any gate you find will belong to W2. On the other hand, it is possible that W1 should read next, or creates a large shadow at L50 that hides W2 anyway. Not sure if one is truly better than the other, but I typically start out moving two wheels together. If I don't find anything, I park W1 at the lowest point I found during that search, and search W2 again. Seems to work for me. In this case, I moved W1 and W2 together and it paid off bigtime!
The only problem with this graph is that it appeared to have four gates instead of two! I was pretty puzzled by this and was starting to question my sanity. It was about 1AM at this point so I truly think I was seeing gates that weren't there. I dunno. The good news is that the real gates were the most prominent. I started out by testing L11.
This test suggested that L11 was on W1, but the other Hi/Lows were so dramatic that I decided it would be better to focus on the L35 indication. I wasted some time testing some trial combos using L25 and L62, but wasn't getting anywhere. I decided to test L35 next.
BOOM! I didn't even do the Hi test because I knew I had my gate.
Almost there: Rx - L35 - R20.5 - L46
Normally, I would start bruteforcing if I had no other indications, but the ghost gates on my second graph were beckoning too me. "Trevor," they said in a strange, high-pitched voice that was coming from my cat, "do some trial combinations...you might not need to brute force us..." I nodded skeptically at that cat and began with L11 (R8) on W1.
OPEN: R8 - L35 - R20.5 - L46
Really pleased with this one. I've never had all the gates come out in the graph. As you've noticed, I've started using a manifying glass with a magnetic base and an LED light. It works wonders and I think it allows me to pick up a lot more. Mine has a magnetic base so it can stick to a safe, but it comes with the little metal clamp base which works perfectly on my lock stands.
Hope you enjoyed this one, because I sure did! Take care, fellas.
