Rebel Scum : DIY 3000W Ascent Full Suspension Sniper 10 speed ~$3520 46lbs w/ out battery

I had been itching to do a full suspension electric fat bike back when I first started this blog several years ago. The bike I had my sights set on was the $1500 Bikes Direct Quigley which promised a full suspension frame, X9 derailer, X7 everything else and a Bluto front fork. I knew there was no way I could build a bike myself for less than that so I anxiously awaited the coming of the Quigley. About a week after it was released it was suddenly marked as ‘sold out’. Apparently what actually happened was that Bikes Direct suffered a rash of frame failures and was forced to stop selling the bike. For people who had already taken delivery of the Quigley, they were shipped replacement Boris frames and promised a new Sniper frame when it was released. Some people opted for a full refund, but many took the frame swap deal with a partial refund and all was right in the world again.

My 2nd favorite line from "The Return of the Jedi" right after "It's a Trap"

“You Rebel Scum” is my 2nd favorite line from The Return of the Jedi” right after “It’s a Trap”. I have the entire movie memorized. A waste of good brain cells.

Several months later the Sniper was released with a reinforced heat-treated rear triangle it seems that the problem with frame failures was finally fixed.  I can’t seem to find a single person whining on the world wide web about their Sniper frame breaking which is great news because that means I can be first at something. My Sniper arrived with a bunch of issues including 4 paint chips on the frame, a missing lower headset bearing, and a very leaky rear shock right out of the box. After buying 15 Bikesdirect/BikeIsland bikes without a single issue I was incredibly disappointed. To say it took me a long time to finally get this build right would be a massive understatement. I have never spent this much time on any build I’ve ever done.


The Ascent does fine on the roads as a high speed ebike, but make no mistake its natural habitat is in the woods.

I swap around drive units on my bikes like I change my underwear (meaning I do it religiously at least once a month) and Rebel Scum was no different. Originally I started off with a BBS02 drive unit, then I upgraded to a BBSHD unit. The problem I kept having is that the pivot was so high and the shock was so leaky and squishy that I kept smashing the drive unit on every single log I rode over. I also felt like I really needed more power on this build than either of these drive units could provide. I had tried using the Cyclone 3000W drive unit on trails with my Dark Side build but I found the mounting bracket was too sketchy and the drive unit was just too heavy to enjoy myself fully. I read about the Tangent Ascent drive from a devoted blog reader which promised a full 3000W in an ultra lightweight 7.5lb package and I knew that I had to give it a try. Ron did an article about the Ascent here a month ago on our evil-twin stepsister site which is a good read, but left me hungry for more.

The Tangent Ascent drive is made entirely in the US and is like nothing else that you will find.

The Tangent Ascent drive is made entirely in the US and is like nothing else that you will find on the market.

I contacted Dave at Tangent and told him to sign me up and several weeks later a 100mm drive unit showed up complete with everything I needed to get riding. I was really impressed with the quality of construction and the engineering that was put into the Ascent drive system. The unit is available now for 68, 73, 85 and 100mm bikes right here for around $1900 – $2020 depending on your BB size. It was remarkably easy to install the 7.5lb drive unit and it took about as long as it takes to install a BBS02 or BBSHD once you get the existing BB out. In order to install the ISIS BB you will need a threaded BB or it just won’t work. You will need a special ISIS BB tool which I didn’t have, but my local bike shop did have one and they were happy to let me use it for free.  If you need to get one then just buy the Park tool BBT-18 which runs about $14 or so on ebay. For DIY builders you can also just buy the barebones housing for $750 and add your own Astro motor and controller right here. The housing will support the more powerful Astro 3220 which runs about $695 before options from Astroflight here. Be aware that the 3220 is much longer than the 3210 so it may intrude on the crankarms for a narrower BB bike. There are also plenty more Castle Creations controllers to choose from which go all the way up to 160Amps in an incredibly small package here. If you use a different controller than the HV80 be aware that the mounting holes will not line up and you’ll probably have to drill new ones. I would not waste your time putting this drive on anything but a full suspension bike, you’re just going to have to trust me on this one. One of the greatest pleasures with this drive is to be able to ramp up the power and hit jumps which can be incredibly sketchy on a front suspension or no suspension ebike.

I wasn't crazy about the Cycle Analyst. Feels like something that should have been mounted in Doc's Delorian from "Back to the Future".

I wasn’t crazy about the Cycle Analyst. Feels like something that should have been mounted in Doc’s DeLorean from “Back to the Future”. It’s a necessary evil to tame the massive power of the Astro motor.

I got the Ascent with the extra long extended bracket so that I wouldn’t have to worry about hitting it on logs or going over log piles. Even with the very loose shock I never hit the drive unit on anything for the full week that I tested it. The drive unit I got was a 40:1 reduction which produced an insane amount of torque at very low pedaling cadences. I got in the habit of going off jumps while going up 25-degree grades at over 20mph which gives you some idea of the insane power of this kit. The biggest problem that most people have had custom developing custom Mid Drives around the Astro drive unit is things like jackshafts breaking. The 3210 Astro produces an insane amount of torque (200 ft/lbs) for a little tiny motor and it is designed to be installed on large RC airplanes, not to mid drive bicycles. The air never offers resistance the way a fully loaded ebike with your fat ass in too high of a gear does. I rode the Ascent in a variety of conditions for about 50 miles before the drive unit failed on me most likely due to a bad reduction gear bearing. The kit still ran but was clearly having serious power problems, and I noticed when I rolled the bike backwards without any power there was much more resistance than there should have been.

I used a 34T Race Face chainring which gave me zero chainline issues even under full power.

I used a 34T N\W Race Face chainring which gave me zero chain line issues even under full power and it matched the “Don’t shoot me, I’m with the Rebellion” Orange powder coat.

I contacted David about the drive unit failure and he was incredibly helpful and cooperative. One of the awesome parts of this design is that the bearings can be swapped out in less than 5 minutes and the entire drive unit can be taken apart with screwdriver very easily. I shipped the drive unit back and he suggested that I try the 20:1 reduction ratio instead so I’m going to get the drive back in a week or so with a different drive ratio. The 20:1 spins much faster but allows you to get much more access to the power of the Astro motor which really likes to spin fast. The only problem with the 20:1 ratio is that most of the time you are running the drive unit faster than you would want to pedal to keep up with. Since the unit was so powerful and was throttle only I felt like I wasn’t really pedaling at all anyway on most of my rides. Your pedal input feels positively pointless when you have 4hp at the twist of your wrist. The only exercise I got while driving this unit was trying to keep myself upright and not wrapped around a tree while going much faster than I really should have on the trails. Did I mention that it’s insanely fast?


You will want a steel cassette and freehub body and a decent quality derailleur for your Ascent build. I’ve standardized on X7 or higher components.

The only two serious downsides I found with the Ascent drive system were the noise that the drive unit made and the fact that you have to add 1ml of grease to it every 100 miles. The drive unit does not make that much noise at lower RPM ranges, but when it is wound out, it sounds like a swarm of angry bees. Ironically when you’re riding the ebike it sounds a lot louder than it does to everyone else around you. When I would loan it to my friends I felt like I could barely hear the motor whine and it wasn’t that annoying. When I was riding the bike I yearned to have death metal blaring in my ears to drown out the sound of the motor. Greasing the motor was a simple task that took less than 2 minutes. For a bike enthusiast like me, it is no big deal as I am used to lubing my chain after every use anyway. For your average Joe it might be a bit of a stretch to remember to do the maintenance. Luckily the Cycle Analyst has a trip meter you can use to keep track of your maintenance schedule as long as you remember to look at your CA every hundred miles or so. I did the best job I could ignoring the fugly CA entirely.

The first rear tire I tested with this build was the Kenda Juggernaut Pro 4.0 tire which turned out to be a real loser as it only lasted about a mile before the sidewall ripped apart. I ended up settling on the Kenda Juggernaut 4.5 which is a much heavier and more robust tire which I am happy to say worked quite well with this setup with plenty of clearance on the rear chainstays. Although it was tested with ultralight Qtubes on it, I will set it up Ghetto tubeless in the not to distant future. I ran the front with a Bulldozer 4.7 tire that I stole off my Dark Matter build as I am running short on decent fat bike tires, but have a HUGE pile of crappy ones.

The Castle Creations HV 80 controller shown here next to a 65Amp 18Fet Lyen Controller.

The Castle Creations HV 80 controller shown here next to a 65Amp 18Fet Lyen Controller. Compensating?

I used a backpack battery exclusively with this build, but construction is almost finished on a 52v 25Ah GA custom pack designed to fit in the top part of the triangle of the Sniper and put out 50Amps Cont. I highly recommend that with the Ascent drive system that you only use it with a battery that can put out 50 Amps continuous and runs at 52v. The power capability is there, so why not use it? The Castle Creations controller cannot take any battery over 52v, so don’t waste your time. I’ve had issues lately with batteries getting thrashed when I mounted them on the frame, so if you do it make sure you have a lot of padding around the battery, or better yet just keep it safe in your backpack.

I’ll be writing a longer separate article on the Ascent mid drive in about 2 weeks when I get the drive unit back with the 20:1 reduction ratio. I’m going to save more of my critiquing of the drive unit for that article. Suffice to say I have not ridden any drive unit that outperformed the Ascent from a weight\performance standpoint. Although the Ascent is expensive at around $2020 for the tested 100mm version, everything about this drive unit screams quality and the support from Tangent on it has been very excellent. I fully expect the Ascent will give me years of trail & snow shredding performance. After a week on the Ascent, it sure is hard to go back to the old 25 & 30 amp mid-drives. They all feel grossly and unforgivably underpowered.

Ride On.

Every piece of this drive unit is custom fabricated with care. A real work of art.

Every piece of this drive unit is custom fabricated with care. A real work of art.


41 thoughts on “Rebel Scum : DIY 3000W Ascent Full Suspension Sniper 10 speed ~$3520 46lbs w/ out battery

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  2. Karl, any comments on the handling of the Sniper? Luna tried one and wrote a pretty negative review over the issue of swingarm flex under power. I have a Sniper with a BBSHD and while I can feel the wiggle when the power hits it is not an issue for me. I mostly ride on PAS so that keeps the power delivery steady and prevents upset most of the time, but even under throttle, it will just wiggle and take a set then settle down.

    What is your take?


  3. I tried an earlier version of the Tangent motor last year using an Astro 3210 paired with a c-phase runner (Grin controller also earlier tester version)
    The camera was kinda pointing down so you can’t reeeally tell the insane acceleration and speed… it pulls reeeeeeeally nice… then you stop and look that little motor and you just can’t believe “size vs power” it is hard to believe… haha
    Yes, David is super nice and VERY helpful =]


  4. I am still confused as to whether this Sniper is a good full suspension bike. I see lots of problems, but will it be great for use with BBSHD? Or would another full suspension brand be better? I’ve seen some Turner full suspensions for sale on local CraigsList and also seen reviews on them. They are obviously high end. But I am kind of afraid to buy a used bike, only to find out the frame has a hidden crack somewhere. . . . .


    • I would not call it a good full suspension bike. It works ok with the right shock and the right shock pressure. The Monarch 2.1 is not the right shock. If you ride it too soft then it is not fun.

      There has to be a better option out there. Just wait. In a year or two there will be.


      • Say, Karl, what do you think is a good full suspension bike for the BBSHD? How about used Turners or Salzas? Pricey, I know, but used they’re not bad and some models do support 5″ tires. What say you?


  5. I have not tried them. I’m not really crazy about Full Susp on a fatbike. Honestly I don’t think you need it. Riding with a Bluto and a thudbuster you can still hit pretty big jumps and be fine. I think the FS is an overkill.


    • Have you tested other seat suspensions like the BodyFloat? They’re $225 for the aluminum ones, versus $130 for the Thudbusters. Some reviews are saying BodyFloat is the best, but they’re obviously extra bucks. What say you?


  6. Good point about big jumps, but what about just cruising? I won’t be jumping but more cruising on lava rock trails in Hawaii.The trails are in very good condition, more like walking trails, so I think fat tires will be more stable when encountering loose rocks. Your suggestion about seat and front forks might be good enough when combined with the fat tire softness.


  7. Now there’s exactly 2 of us with Tangent Fatties. The 20:1 drive will cut your torque in half, and I’m shying away from it at the moment. Something about running the 70:1 to the crank, and having a 34T ring driving a 42T granny. I’m 220 lbs and haven’t found a single hill I can’t climb without pedaling. A lot of times I shoot off the top lip of the hill in a wheelie. The wolf tooth 42T has 150 miles on it with no issues.

    Here’s a couple pointers. 34X11-42 will let you climb anything, and also hit 35 mph. A double throw shifter like an XT 10 speed is essential. You can double shift all the gears and treat it like a 5 spd. The most annoying thing that happens is when the chain gets stuck between the two rings. A clutched derailleur cuts way down on this but it can still happen if you hit drops. Giant brakes make a huge difference in confidence on the trails.

    Wish I had some suspension, I’m thinking the next ride is gonna be a YT Capra and a 3215 or 3220


    • Doesn’t it seem like the best way to avoid gear problems is to just have an internal gear hub installed? For a $200-300 one could yank the derailleur and put in the IGH. Then sell the derailleur on eBay if it is new enough. Net cost, maybe $200. Plus you have the ability to b shift while stopped. Is this a good idea?


  8. Nice to see an American made motor that blows the comp. out of the water. The extra lubrication step is hardly an issue if your comparing maintenance on an combustion system, but still might deter some. Thanks for the review(s). Maybe I can finally convince someone to get into e-singletrack with me.


      • What is this thing, of which you speak? I found the link, but I’m unsure what you’re getting and what you’re gonna do wit it. What is the 20:1 part of it? The Ascent site does not make that clear. Is this the $2,000 one? Here is the link to the site:


      • A 3210 puts out about 200lb ft of torque at 3000 watts with 40:1 reduction gears installed and has a 140 pedal cadence. A 20:1 cuts the torque in half but doubles the cadence, so you can ride each gear longer. A 3220 is a 6000w mid drive that has twice the power of the 3210. There’s so much torque it’s questionable whether normal bike components can hold up to it, but if you cut the torque in half with the 20:1 and double the cadence, now you have insane power, and top speeds that reach 60 mph. It’s a mini motocross bike.

        Liked by 1 person

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