Rambo hunting e bike as a road bike?

[BrianK]

I recently found a steeply discounted leftover 2018 Rambo R750CG3 at at local archery shop. Rambo e bikes are geared down for riding off road on trails, hills and even mountains while hunting. As such they are geared LOW and slow, and seemingly not very appropriate for road.

This model has a 750w Bafang BBS02 mid drive, a 48v 10.4 ah battery and a Sturmy Archer 3 speed fat bike rear hub, and 26x4” fat bike tires. Coming from a full size motorcycle I don’t mind the size of the tires or the extra heft of the bike overall, and frankly I like that it doesn’t have an external derailleur.

The cadence PAS is adequate for my needs, but due to the ultra low gearing I couldn’t keep up with the RPMs of the pedals at what seemed like a low road speed. I contacted Rambo and they recommended a 46T front sprocket instead of the stock 32T sprocket for road riding, which they had in stock, as the simplest solution. I just ordered one, which should be here when I pick up the bike next week.

With this minor modification it seems the Rambo 750 should make for a decent road bike, and at the steeply discounted price at which I’m getting it, it seems a steal for a 750w mid drive Bafang bike overall. I might need more road oriented 26x4 tires.

Anything else I need to do to one of these fat tire hunting bikes to make it more road friendly?

Is there any reason these bikes aren’t more popular or talked about here on EBR? Anything wrong with them?

 

[BrianK]

Is there any reason these bikes aren’t more popular or talked about here on EBR? Anything wrong with them?

After more research, I get the impression the Rambo is just another fat tire e bike, but geared way down for hunting.

As such, changing the gearing by increasing front sprocket size should in theory make it an acceptable fat bike for roads and rails to trails. Am I missing anything?

 

[DaleF]

I recently found a steeply discounted leftover 2018 Rambo R750CG3 at at local archery shop. Rambo e bikes are geared down for riding off road on trails, hills and even mountains while hunting. As such they are geared LOW and slow, and seemingly not very appropriate for road.

This model has a 750w Bafang BBS02 mid drive, a 48v 10.4 ah battery and a Sturmy Archer 3 speed fat bike rear hub, and 26x4” fat bike tires. Coming from a full size motorcycle I don’t mind the size of the tires or the extra heft of the bike overall, and frankly I like that it doesn’t have an external derailleur.

The cadence PAS is adequate for my needs, but due to the ultra low gearing I couldn’t keep up with the RPMs of the pedals at what seemed like a low road speed. I contacted Rambo and they recommended a 46T front sprocket instead of the stock 32T sprocket for road riding, which they had in stock, as the simplest solution. I just ordered one, which should be here when I pick up the bike next week.

With this minor modification it seems the Rambo 750 should make for a decent road bike, and at the steeply discounted price at which I’m getting it, it seems a steal for a 750w mid drive Bafang bike overall. I might need more road oriented 26x4 tires.

Anything else I need to do to one of these fat tire hunting bikes to make it more road friendly?

Is there any reason these bikes aren’t more popular or talked about here on EBR? Anything wrong with them?

Hello BrianK. I have the same bike (less the camo) as you and I also bought it under similar circumstances. It was sitting for a year or more in a sporting goods store and I really like it for all the same reasons as you. I have made several changes to make it more comfortable for street cruising-seat, handlebars etc. and was wondering whether you had made the swap to the larger front sprocket that you had ordered. If so I would be interested to know if you are happy with it and why etc.etc.
Looking forward to swapping information with you.

 

[BrianK]

Hello BrianK. I have the same bike (less the camo) as you and I also bought it under similar circumstances. It was sitting for a year or more in a sporting goods store and I really like it for all the same reasons as you. I have made several changes to make it more comfortable for street cruising-seat, handlebars etc. and was wondering whether you had made the swap to the larger front sprocket that you had ordered. If so I would be interested to know if you are happy with it and why etc.etc.
Looking forward to swapping information with you.

Hi Dale,
Yes, I ordered and installed a 46tooth front sprocket from Rambo, but I’ve since discovered I could have ordered it direct from the Bafang site for less money. I did have to install a longer chain. Since it’s still relatively low gearing, I haven’t used the first or second gears of the Sturmy Archer IHG whatsoever.

Also I could have gotten a 48t or 52t direct from Bafang. After putting on about 20 miles now I think I would have chosen the 52t front sprocket. I’m either going to do that, or put a smaller tooth count rear cog on it, probably 14t. It comes with a 24t rear cog if I remember correctly.

As it is right now, I can ride it on PAS1 and contribute a lot of my own pedaling effort, but the bike is awfully slow that way. If I can change the gearing so I can pedal at a moderate pace and keep up with PAS2 I’ll be happy riding the winding hilly back country roads around here.

I added a good quality comfort seat and I ordered a Satori Animaris suspension post for it. I also added 3/4” spacers between the cranks and the pedals and for some reason my lower back isn’t bothering me after riding (old herniated disk) like it was before.

I also ordered an adjustable 90mm stem riser so I could elevate and pull back the handlebars a bit. I think that will also help my back. If it’s not enough, I’ll swap out a more upwards and rear wards swept handlebar.

Since my riding is almost all paved back country roads and occasional gravel rails to trails, I pumped up the Kenda Juggernauts to 25psi. This made a world of difference! It’s like riding a different bike. I think when I picked it up they only had 6-8 pounds in the tires.

I tried to unlock the PAS and the top speed. I used the passcode 0512 and it entered into the advanced settings. However, when I went back to the main screen, none of the changes I made worked, so I’m assuming Rambo has the top speed and PAS setting locked in the firmware.

Does anyone know how to bypass this?

 

[DaleF]

Hi Dale,
Yes, I ordered and installed a 46tooth front sprocket from Rambo, but I’ve since discovered I could have ordered it direct from the Bafang site for less money. I did have to install a longer chain. Since it’s still relatively low gearing, I haven’t used the first or second gears of the Sturmy Archer IHG whatsoever.

Also I could have gotten a 48t or 52t direct from Bafang. After putting on about 20 miles now I think I would have chosen the 52t front sprocket. I’m either going to do that, or put a smaller tooth count rear cog on it, probably 14t. It comes with a 24t rear cog if I remember correctly.

As it is right now, I can ride it on PAS1 and contribute a lot of my own pedaling effort, but the bike is awfully slow that way. If I can change the gearing so I can pedal at a moderate pace and keep up with PAS2 I’ll be happy riding the winding hilly back country roads around here.

I added a good quality comfort seat and I ordered a Satori Animaris suspension post for it. I also added 3/4” spacers between the cranks and the pedals and for some reason my lower back isn’t bothering me after riding (old herniated disk) like it was before.

I also ordered an adjustable 90mm stem riser so I could elevate and pull back the handlebars a bit. I think that will also help my back. If it’s not enough, I’ll swap out a more upwards and rear wards swept handlebar.

Since my riding is almost all paved back country roads and occasional gravel rails to trails, I pumped up the Kenda Juggernauts to 25psi. This made a world of difference! It’s like riding a different bike. I think when I picked it up they only had 6-8 pounds in the tires.

I tried to unlock the PAS and the top speed. I used the passcode 0512 and it entered into the advanced settings. However, when I went back to the main screen, none of the changes I made worked, so I’m assuming Rambo has the top speed and PAS setting locked in the firmware.

Does anyone know how to bypass this?

I too changed the stem riser plus added moderately swept back and upward handlebars. This and a good seat helped my old back immensely-also added the spring assist fork which smoothes out the bumps somewhat. I wanted fenders but Rambo doesn’t offer full fenders, so I ordered a set from Rad which required only a minor modification to the rear for an otherwise perfect fit. I am running only 10psi in the tires. Does the extra pressure make it ride rough? I prefer not to do rough.
What is your top speed? Am I understanding that changing the sprocket didn’t change the top speed?

 

[BrianK]

I too changed the stem riser plus added moderately swept back and upward handlebars. This and a good seat helped my old back immensely-also added the spring assist fork which smoothes out the bumps somewhat. I wanted fenders but Rambo doesn’t offer full fenders, so I ordered a set from Rad which required only a minor modification to the rear for an otherwise perfect fit. I am running only 10psi in the tires. Does the extra pressure make it ride rough? I prefer not to do rough.
What is your top speed? Am I understanding that changing the sprocket didn’t change the top speed?

Actually since I’m riding on decent paved roads, the extra pressure felt better. I had noticed before that while pedaling hard at a higher cadence, the bike actually developed a bounce in tune with my cadence. Increased tire pressure solved that. Plus the steering and handling are more crisp.

Changing the sprocket did NOT change the top speed when running with only the motor. It only decreased my pedaling cadence.

The Rambo motor assist top speed is around 18mph, which seems to be set by Rambo. I used the Bafang passcode (0512 or 1919) and reset the top speed as well as changed PAS to 1-9, but when I exited the advanced parameters it was still set at Rambo’s setting. No luck after multiple tries. The most I’ve gotten it up to going down hill was about 22mph, but I’m still getting used to the bike and riding conservatively. Plus until I further adjust the sizes of the front sprocket or rear cog I just can’t keep up with the PAS above level 3.

 

[BrianK]

The archery shop had a pair of what I assumed were Rambo fenders and put them on for me. Maybe they’re no longer selling these.

 

[DaleF]

The archery shop had a pair of what I assumed were Rambo fenders and put them on for me. Maybe they’re no longer selling these. View attachment 59751

The archery shop had a pair of what I assumed were Rambo fenders and put them on for me. Maybe they’re no longer selling these. View attachment 59751

Ok I understand- your top speeds are comparable to mine. I haven’t attempted to change any of the factory settings.
They do list the fenders like yours “for backorder”. I preferred full fenders anyway so I took a chance on the ones go the Rad Rover 5 and am pleased with them.

 

[BrianK]

I too changed the stem riser

Mine came today. I put them on and went out for a short jaunt. They definitely made a big improvement for my lower back.

added moderately swept back and upward handlebars

Do you have a link for the ones you used? How difficult was it to switch everything over?

 

[DaleF]

Mine came today. I put them on and went out for a short jaunt. They definitely made a big improvement for my lower back.

Do you have a link for the ones you used? How difficult was it to switch everything over?

It wasn’t difficult at all-I took pictures for reference-loosened everything, removed the bars, slid everything off and reversed the procedure.
I bought on eBay and I don’t know how to get the information transferred so here’s a screenshot with the pertinent information. This was the closest thing that I could find to what I thought I wanted.

 

[BrianK]

It wasn’t difficult at all-I took pictures for reference-loosened everything, removed the bars, slid everything off and reversed the procedure.
I bought on eBay and I don’t know how to get the information transferred so here’s a screenshot with the pertinent information. This was the closest thing that I could find to what I thought I wanted.

Great, thank you!

 

[BrianK]

By the way, I pumped up the Kenda Juggernauts to the Max 30psi for riding on the road, which has continued to make a big improvement. My course includes an uphill rutted two mile gravel shortcut, but I had no problems with it at that psi.

I’m expecting a Satori Animaris suspension seat post in the mail any day and that should improve what bumps I have encountered, especially two railroad crossings.

 

[DaleF]

By the way, I pumped up the Kenda Juggernauts to the Max 30psi for riding on the road, which has continued to make a big improvement. My course includes an uphill rutted two mile gravel shortcut, but I had no problems with it at that psi.

I’m expecting a Satori Animaris suspension seat post in the mail any day and that should improve what bumps I have encountered, especially two railroad crossings.

I believe you would also like the spring assist fork. It is also on back order on the Rambo site but I found one on eBay.
I am urban so my “course “ is a bike/hiking trail which is probably about 4 miles total. I am not able to ride as hard as you obviously do, but can get into a rhythm (3rd gear-pas 1&2) which works legs and cardio. The trail is about 3/4 mile via city street which I traverse “flat out”.

 

[newheights]

Are you still liking this bike? It's being sold by Costco for $2k with front/rear racks and fenders and a waterproof panier bag. Reviews there are negative, but on paper looks good.

Also, have you found a way to upgrade the battery to larger AH? (Like an aftermarket one that fits the connectors or something) Or, is there a way to buy a second battery other than through Rambo (they want $600 for the 10.4 AH battery, and it's ok backorder)

Thanks!

 

[BrianK]

Are you still liking this bike? It's being sold by Costco for $2k with front/rear racks and fenders and a waterproof panier bag. Reviews there are negative, but on paper looks good.

Also, have you found a way to upgrade the battery to larger AH? (Like an aftermarket one that fits the connectors or something) Or, is there a way to buy a second battery other than through Rambo (they want $600 for the 10.4 AH battery, and it's ok backorder)

Thanks!

It’s working well for me, but only after a number of upgrades.

One of the common complaints over at the Costco site was its slow speed. Well, it’s made for riding off road, hauling hunting gear and game, so it’s geared really low. At road speeds my legs simply couldn’t keep up with how fast the pedals were turning.

I upgraded the front sprocket from the stock 34t to 46t. That still wasn’t enough for road oriented riding so I upgraded again to a 52t front sprocket and now that works fine. You have to have a pedal tool to replace the front sprocket as well as extra chain and a chain break tool to create a longer chain to fit the larger front gear.

The brakes are cheap manual disks. Learn how to adjust them and that takes care of the squeaky brakes complaint. Or upgrade it to better disk brakes.

The stock seat is uncomfortable. I replaced it with a comfort seat as well as a suspension seat post.

I added an adjustable handlebar riser and swept back cruiser style handlebars. That made it far more comfortable with my lower back since I am now not as crouched over.

I swapped out the tires with road oriented Origin8 Supercells. Huge difference with vastly decreased road noise, better steering and far less rolling resistance. They recommend 20 pounds max but I run them at 22 pounds and it’s definitely improved the battery life.

The battery itself has been fine. I’ve ridden on the lowest assistance ten miles a day for several days in a row for a total of 30 miles on one charge and still had two bars left. If I were to upgrade I’d upgrade the battery mount/carriage too. It’s too hard to find replacement batteries for that old style mount and the newer style are easy to find.

I also had the controller flashed and Luna’s power and speed settings installed since I couldn’t override Rambo’s factory preset speed limitations.

One complaint there was a constant clicking sound. All Internal Gear Hubs click when you ride them.

Since I only paid $1200 for it last summer, I had no qualms about the cost of all these upgrades.

At $2000?

I’d be tempted to just look around and see if there’s anything else out there in that price range built for road or rail trail riding with the types of upgrades I mentioned.

But yes, I do like this e bike since I customized it for my liking.

 

[BrianK]

Or, is there a way to buy a second battery other than through Rambo (they want $600 for the 10.4 AH battery, and it's ok backorder)

This is a direct replacement. Look for batteries with the S039 type mounting plate.

https://www.amazon.com/Battery-12-5AH-Electric-Lithium-Waterproof/dp/B086DP4G53/ref=mp_s_a_1_1_sspa?dchild=1&keywords=electric%2Bbike%2Bbattery%2B48V%2B10AH&qid=1617669395&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTTRRNTNWOVFNQ0FQJmVuY3J5cHRlZElkPUEwNzYzNjczM0FRREs5SEo5U0NQSCZlbmNyeXB0ZWRBZElkPUEwODY5MDk4MkpaMEJYVVg0V0ExSCZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

It’s not difficult to swap out the battery mounting bracket. These are all options if you’re willing to swap the bracket:

E-Bike Battery | Electric Bicycle Batteries

Ensure that your e-bike won’t let you down on a long trip. Find the e-bike battery you need to keep going. Shop our electric bicycle batteries today!

www.bafangusadirect.com

Amazon.com : 48v e bike battery

Or buy the Bafang parallel cable and add a 48v battery to the existing battery. Ah is additive this way:

Parallel Battery Connector Cable– Ebike Essentials

Parallel Battery Connector Cable allows you to connect two of the same voltage batteries to increase your total Amp hours and range. (Example: If you have two 48V 17.5Ah batteries, this connector will allow you to install and use both batteries on your bike with your motor kit for a total of...

www.bafangusadirect.com

A more advanced option for running two batteries:

Dual Battery Converter - instantly double your riding range!

Have you ever wondered about what to do with all your old ebike battery packs ? Watt Wagons is introducing an incredibly easy way to use your old battery packs and double your riding range. This converter will only work with two packs of the same voltage (e.g. 2x48v, or 2x52v).

wattwagons.com

 

[newheights]

Awesome, thanks!

How did you flash the luna settings?

 

[BrianK]

Awesome, thanks!

How did you flash the luna settings?

A local Bafang builder had the Luna hardware to reprogram the controller and did it for me. Luna used to sell an electronic control box specifically for that purpose.

 

[BrianK]

By August of last summer, my “best” ride was 20.5 miles on a rail trail not far from Harrisburg PA.

I developed multiple serious health problems that included acute severe congestive heart failure due to left bundle branch block from an old heart attack and ended up with a biventricular pacemaker defibrillator in December, then Covid in April.

So I hadn’t ridden since August and got the bike back out a couple weeks ago.

So far I’m up to 11.5 on local hilly back roads. I hope to repeat the 20 mile ride by August.

Eventually my goal is to complete the Camino de Santiago pilgrimage in Spain. You can complete it by e bike (no throttle permitted) and get the official certificate of accomplishment for the pilgrimage. The tour companies will rent you one there, bring it to you at the beginning of your trip then pick it up when you’re done.

 

[mjeds]

Yeah I think you need road tires.

Chaoyang SandStorm

Origin8 Supercell

These tires are great, I swapped them on all 4 of my fat tire bikes as all we do is street/bike path riding.

I will note however that the prices swing wildly on these. I bought 4-sets (8 tires) at $44 for each tire back in Feb. went to get another set a few weeks ago for my tandem, not that the original tires are nearly done and lowest I could find them was $98 EACH.

FWIW. with these Origin8 tires I have over 4,000 miles on one set of them on one bike and they still look great, not a whole lot of wear. the original knobby Kenda tires that came with the bike didn't even last 2,000 miles.

the Kenda Juggernaut tires on my tandem have 1,900 miles on them and are nearly smooth, though to be fair they are taking double the weight since it is a 2-up bike.