ISO: 57cm Rambler

[Alberto Robador]

Looking for a 57cm Rambler. I missed my chance years ago when I had the opportunity to buy one. I regret it to this day...anyone holding and willing to let go?

[Michael Mann]

A word of caution to anyone searching for a used OAC Rambler from a former Rambler owner. I would strongly caution against buying a Rambler without being able to closely inspect the frame for damage, especially if you know or suspect it came out of the large batch made by Zen Fabrications (Which includes almost all Ramblers.)

I got in on a Zen Rambler frameset from Zen Fab early before they were released. A sunflower yellow in size 54 (I think?) I met with Rob when he was visiting Portland, had great correspondence with him throughout the process, and the whole experience was positive and I lovingly curated the build and happily rode it for thousands of miles commuting, long day rides, and lots of multi-day tours. Handling was fantastic and I enjoyed the bike a lot. 

However, after about 3 years I noticed what I thought was a crack in the powdercoat near the bottom bracket that turned out (as I feared) to be a crack in the frame, starting at the bottom bracket but spreading up the downtube. I consulted with Bob Kamzelski of Bantam Bikes (who was intimately familiar with Ramblers since he'd made one of the post-Zen small batches of Ramblers) and he confirmed the frame crack diagnosis. But I continued to ride the bike for over a year, including a few thousand more miles of commuting and two weeks of bike touring because steel, keeping an eye on the very slowly growing crack. Unrelated to all this I had a hard crash with the bike that didn't leave me injured but buckled the toptube and downtube and that ended it.

I personally know of at least two other Zen Fab Ramblers that have suffered similar cracks in the frame, and while I don't believe Rob has publicly acknowledged it, I've had framebuilder confirmation that the cracks are a likely result of faulty design. On the Zen Fab frames, the internal wire routing for the rear light goes through the bottom bracket shell. In order to accomplish this without interfering with the bottom bracket, there's a slot in the top of the bottom bracket between the downtube and seattube. Where on a normal bike each of those tubes would be welded to the BB in a full circle, on the Zen Fab bikes the circle isn't complete. Another way to imagine the forces at play is if you took a toilet paper rube and grasped both ends and bent them down (simulating pedal forces on a bottom bracket.) Now imaging what would happen if you did the same thing with a tube that had a slot cut into the middle of the top.

I've hesitated to say anything about this, hoping someone else would. And it's probably true that most Ramblers, including the Zen Fab frames, are fine and will be fine forever. But Mine wasn't, and there was no way to tell until it happened. And for the record I weight 145 clothed and wet, and only occasionally rode my Rambler on pretty smooth gravel, so it wasn't weight or aggro riding that caused the frame to fail.

I'd also encourage other Rambler owners to regularly inspect their frames, especially around the bottom bracket welds. And if you have had a similar experience please share so that if it's happened to others, there's a record of it.

Mike M

[Jason Ferrier]

Hey Michael,

Sorry to hear about your Rambler failing, but glad you’re alright. I retired mine after finding a crack years after crashing it… read on for more. We met back in those early days in PDX when I accompanied Rob on that road trip.

I also have a Zen built 57cm Ramber which I crashed many years ago when hitting a buried tree stump in sand. Blame me on that one for riding it on a cyclocross course more like a mountain bike.

I noticed the downtube had a slight bump at the head tube but I continued to ride it for another few years.. because steel. It finally starting cracking  about 2 years later near the head tube and I retired it before it separated while riding. I never noticed any issues at the BB.

Could you post some photos of where your frame cracked? I have seen the inside of the where you are talking but am having a hard time imagining where your crack was. The welds on my frame looked solid inside and out, so I’m not sure if mine would have suffered the same fate.

I cut out the downtube and filed down what was left at the BB and head tube, have a replacement downtube to go in, but then COVID happened and my friend locked down, so I haven’t picked the project back up.

As I currently have a “road plus” mid-trail bike now that I am not in love with since it feels dead and “doesn’t plane”. I’m hoping to pick up the project this winter and be back on my fixed rambler soon.

Jason

https://www.flickr.com/photos/jferrier/albums/72157632663322272/

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[Michael Mann]

Per request, I'm including a couple a photo of the crack in my Rambler frame at the bottom bracket/seattube area, as well as a photo of the inside of the bottom bracket showing the cutout slot that I and others believe compromises the lateral strength of the BB shell.

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Michael Mann

[Jason Ferrier]

Thanks for following up with the photos. Can you see from the inside of the BB shell if it looks like the welds penetrated or overheated the shell and/or the seat tube and/or the down tube where they all intersect there?

My frame is about 30 miles from me at said friend's house, but when I'm there in the next week, I'll inspect to see if I have any similar cracking, but last I remember the only issues were where I compressed the downtube near the head tube.

Jason

[Robert Perks]

In theory all of the Ramblers were built with similar mitering, assembly and welding.  This area of the design got a significant amount of attention to be able to get a lighting wire through to the back of the bike with tig welded construction.  In execution I am not sure Zen was able to handle the detailing required to make it bomb proof.  I had considered gussets similar to older bontrager cross frames that exhibited similar failures when made super light.  I had specified careful attention to the butts, and welding at the corner where the seat tube hit the slot in the BB.  In hindsight Zen did not have the quality control to handle this.  The miter needs to be tight and the TIG weld for the seat tube/BB junction needed to terminate perfectly.  In their production setting with aluminum MTB focus it was not something they valued as highly as me. 20/20 hindsight gussets would have been mtb strong.

I made the call to roll with it as they were still strong and the risk of catastrophic failure extremely low.  Prior to production I also had samples tested to failure, and this was not the weak point. Zen's quality control was extremely disappointing, the amount of unusable frames and hand work that I needed to correct was astonishing.  This was really hard (time and money) and in the end I was and am fully confident that the frames that made it to the road were safe.  That said, I know Zen ended up selling at least ten that I rejected as beyond accepting and more than a few were sold via Velo Cult as both businesses were desperate and sunsetting.  Those frames have no OAC or Rambler decals, and possibly no serial numbers.  We did have a few where serial numbers were nearly invisible due to powder coating, but would have the decals I applied.

I'm not making excuses, it is what it is, and I only know of two failures in this area of about 100 Ramblers rolling.  Mike's is one of them.  Inspection of used bikes is critical at this area as well as the cluster at the seatpost.  Tig welded frames made of standard diameter tubing were prone to similar cracks.  Keith Bontrager had actually written papers on the engineering as did ibis at one point you could find them on the web. The industry wide fix was oversized tubing and the way the welds overlap at the cluster.

Bottom line is always inspecting the bike, for self use or sale, if you are riding lightweight TIG welded frames.  If you find a Rambler it is likely fine, but as with all bikes can fail.  If you have the cash flow, get similar design made by Bantam.  Bob's were the absolute best ones ever made and his attention to detailing minimizes the possibilities of failure while delivering on the feel of a bike made with standard diameter tubing.

Best Regards and good luck with the hunt

Rob

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[Michael Mann]

A couple of additional points for the sake of clarity. 

I'm not an engineer or framebuilder, but regarding Jason's question, no, I don't see any evidence inside the bottom bracket shell of overheating or bad welds. But I may not know what to look for in that regard. 

I have no hard feelings about my experience, and Rob has been a clear communicator and a stand-up guy from day one when we first started corresponding, before the Zen frames had even been welded. For his sake I wish the whole quality control thing with Zen had not happened; it obviously costs him a lot, personally and financially, which I'm sure helped kill the future production of Ramblers. One of the things I always appreciated about Rob and OAC was his desire for a U.S. manufactured bike with as many U.S parts as possible (like Paul centerpulls). His options were obviously limited, and with the recent demise of Waterford, I think small-batch production of bike frames in the U.S. would now be impossible. Which is sad. There are several reasons why Black Mountain Cycles, Crust, Rivendell, etc are made in Taiwan. The country is set up for it, facility-wise, there's a solid pool of really talented welders, and labor costs are lower than in the US. Even if customers were willing to pay more for the cost of a US made frame, it's not clear there's even a workforce here that can come close to matching what's made in Taiwan, quality-wise. Zen Fab is exhibit #1 on that front.

Also, the photo of my cracked frame is what it looks like now. Keep in mind that I continued to ride the bike, daily, for over a year after first discovering the crack. That year I had a new job with a longer commute (32 miles round-trip, 5 days a week, for over 9 months.) I was also doing longer weekend rides pretty regularly, AND did my longest bike tour that summer (13 days and nearly 900 miles). Conservatively, my Rambler had 8K-9K miles AFTER I discovered the crack. It grew a little, but if I hadn't destroyed the frame in a crash, I have no doubt it had a few thousand more miles in it. Steel is awesome that way.

Did I get my money's worth out of it? That's a tricky question. When I bought my Rambler I assumed I'd ride it until I was unable to ride anymore, and maybe pass it on to one of my children. But if you count how little I paid for each mile and each smile I got out of my Rambler, it was a bargain. And its demise led directly to the Bantam that replaced it. 

One of the things I found limiting about the Rambler was that the Paul Centerpulls kept me from running tires wider than 38mm (650b) and even then I had to deflate them to remove the wheels. THe brakes performed great, but I've found 650b x 42 to be my sweet spot for touring. My Bantam has disc brakes, and for my purposes it's a real improvement. 

Mike M