Hello from Western WI

Knife2Sharp

New Member
Region
USA
I was an avid BMX/freestyler back in the 80s and got my first MTB in the late 90s. After doing two MS150 events in back-to-back years, I got out cycling because my hands became numb for days afterwards. I had also moved from the Twin Cities to WI, and just got out of riding, even short excursions. My friend and I lease some hunting land, as well as hunting some public and other small private parcels, so we have a lot of trail cams out. Some of our more recent properties are quite a hike, 1/2 - 1 mile one way, and I realized an e-bike would be a great tool.

This spring I bought a Rambo Bushwacker and started having problems with the SA 5-speed IGH skipping, primarily 3rd gear, from day one, while I was just pedaling it to break in the brake pads. Although, each gear does make a 'clunk' sound, about every 100-200 yards, no matter if I'm off-road or on pavement, 3rd gear skips to the point where I notice a brief slow-down. I now just use 1st gear for all off-road use, which is all I do. I've gone through quite a journey to try and get it addressed, which is still on-going.

Prior to getting the Bushwacker, I was interested in their Krusader, the AWD model. After doing some research and some comments I came across on the internet, primarily Bakcou's video about AWD bikes, I decided on the mid-drive model without a derailleur. But, after riding one, and coming to the conclusion, I just want an e-bike for relatively short distance off-road excursion, I bought one. So far, it's been solid, and I really like the traction I get from both tires. The PAS isn't the same as my mid-drive, but I don't deal with many hills, just slight grades.

I'm debating whether or not to keep the Bushwacker as a backup, for more of a road/trail bike, or sell it, to recoup some money; however, I don't have a clue what the value of my bike would be, with the faulty but functioning IGH. I brought it Erik's and they stopped dealing with Rambo, whom I've sent a lengthy message to their CS, and pretty much received nothing, accept they'll work with any bike shop. Nobody other than Rambo uses these hubs, and the axels are so large, 240mm, that there's no alternative IGH, other than possibly an Rohloff. A bike shop in Canada has one on Ebay for $800, but not sure if that's what it's worth or it's inflated due to nobody else having them. I'd even consider just 'bricking' the hub, to lock it in 3rd gear, if that's even feasible, or getting a tire/rim with a rear sprocket of comparable size to 3rd gear. But again, I don't know who I can talk to about alternate solutions or even do the work.

This is me, those are my bikes and that's my story :)
 

PedalUma

Well-Known Member
Region
USA
Welcome! Here is the Service Manual. The lines should align in gear two. Cables stretch or the ends are often not fully seated on new bikes. It is likely a matter of using the barrel adjuster, twisting it out about two turns. IGHs can be serviced, I did one over the weekend, but that is probably not required unless you or someone else tried to down-shift uphill while under power. Crunch. Bafangs have some lag so shift timing can be difficult even with the gear sensor. https://www.sturmey-archer.com/files/catalog/files/85/MANUAL - 5 SPEED ROTARY HUBS.pdf
Post some photos, please.
 

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Knife2Sharp

New Member
Region
USA
Hi PedalUma, I did find the instructions not long after getting the bike on how to adjust it with the barrel adjuster and I always keep an eye on it. It was off by about 1/16" out-of-box. I had also reached out to JohnnyNerdOut, who has one of these hubs (RSX-RK5), and he said 3rd gear is the weakest and 1st and 5th are the strongest, and there should be a rebuild kit for them. But I'm not finding anyone around me who services them. Maybe the occasional clunk is somewhat common in any gear, but even the tech at Erik's noticed 3rd gear was slipping when he put it on a stand and back pedaled it.

Edit/update: I got a hold of the lead guy and Rambo and they're ordering me a new wheel/hub.
 
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PedalUma

Well-Known Member
Region
USA
Hi PedalUma, I did find the instructions not long after getting the bike on how to adjust it with the barrel adjuster and I always keep an eye on it. It was off by about 1/16" out-of-box. I had also reached out to JohnnyNerdOut, who has one of these hubs (RSX-RK5), and he said 3rd gear is the weakest and 1st and 5th are the strongest, and there should be a rebuild kit for them. But I'm not finding anyone around me who services them. Maybe the occasional clunk is somewhat common in any gear, but even the tech at Erik's noticed 3rd gear was slipping when he put it on a stand and back pedaled it.

Edit/update: I got a hold of the lead guy and Rambo and they're ordering me a new wheel/hub.
Great.
Someone mechanically inclined would just replace the core and not the entire wheel. This also is easier than lacing in a new hub. That is a Nexus 8 core next to the Mobil 1 in the photo. If you are paying and not Rambo, this would probably be better for you. Also less shipping. Your local bike shop can do the labor on the core swap if it is not your thing.
 
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Knife2Sharp

New Member
Region
USA
FYI, Rambo is replacing under warranty. BTW, isn't the RX-RK5 and Nexus, much shorter hubs? Meaning, the internal spacing for the frame is much smaller than 193-197mm on these Rambos, and the axels are also short? The RSX-RK5 has a 240mm length axel. The only other one I know of that could fit, would be the Rohloff XXL. I think that's why Rambo replaces the whole wheel/hub, as it's easier for the customer to replace, since these hubs or internal components aren't available to repair shops, nor even Rambo, but they don't service them anyways. I also came across a video on YouTube of a guy dipping his SA internal mechanism in a pitcher of ATF for a minute, then removing it and let it drain for a bit before putting it back in the housing.
 
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PedalUma

Well-Known Member
Region
USA
That is good that you are getting the new wheel under warranty. I did not check the spacing when giving an illustration of the overview concept. I like dipping them in Mobile 1. The one from this weekend is old, from a cargo bike from the Netherlands and it lives on a big hill. So, I let it soak for three-hours in a warm ultrasonic bath of synthetic oil before packing it in grease.