ebikes - conversion kit vs dedicated model
October 20, 2023 11:09 PM Subscribe
I'm considering getting an ebike (mid-drive with torque sensing) and am debating two possible paths: either converting my existing commuter bike, which I have known and loved dearly, using a kit (TSDZ2), or selling my bike and purchasing a new, dedicated ebike from a reputable brand.
The bike in question is a Surly Midnight Special frame I've fitted with flat bars and an Apex groupset, plus racks and fenders exactly the way I want it. I really like it and have commuted for a few years on it, but I've recently moved to a much hillier neighbourhood with a longer commute that's just not realistic for me to do regularly on an acoustic bike. (I also have a semi-fancy full carbon gravel bike for when I'm feeling Sporty, so a straightforward N+1 would be hard to justify in this case...)
My LBS, which is great, has already given me a quote for the TSDZ2 kit+labour cost for the conversion; if I have them do it, they will also be able to provide support and maintenance on an ongoing basis. I can also find ebikes from mainstream bike manufacturers (example) which seem to fit my needs. The net cost of going either route would probably end up roughly the same. (I do hate selling things on Marketplace/craigslist though, so that's a point in favor for the conversion route.) Mostly I just want to make sure I end up with a safe, reliable ebike that I enjoy riding and that gets me where I need to go in style. Bike enthusiasts of Metafilter, what would you do?
The bike in question is a Surly Midnight Special frame I've fitted with flat bars and an Apex groupset, plus racks and fenders exactly the way I want it. I really like it and have commuted for a few years on it, but I've recently moved to a much hillier neighbourhood with a longer commute that's just not realistic for me to do regularly on an acoustic bike. (I also have a semi-fancy full carbon gravel bike for when I'm feeling Sporty, so a straightforward N+1 would be hard to justify in this case...)
My LBS, which is great, has already given me a quote for the TSDZ2 kit+labour cost for the conversion; if I have them do it, they will also be able to provide support and maintenance on an ongoing basis. I can also find ebikes from mainstream bike manufacturers (example) which seem to fit my needs. The net cost of going either route would probably end up roughly the same. (I do hate selling things on Marketplace/craigslist though, so that's a point in favor for the conversion route.) Mostly I just want to make sure I end up with a safe, reliable ebike that I enjoy riding and that gets me where I need to go in style. Bike enthusiasts of Metafilter, what would you do?
One thing to keep in mind is that it looks like the max torque of the two options is quite different (google seems to be saying 80 or 90nm depending on model for the TSDZ2 vs 40nm for that Marin Sausalito E1). e-bike motor specs are often creative enough that it's hard to compare directly, but if one of your criteria is ability to handle steeper hills, I think it would help to take some test rides (ideally on the actual hills you'll need to traverse for your commute) with different motors and compare how they feel. I live in a famously hilly city and want to be able to comfortably get up a 12% grade with loaded panniers, so the extra torque matters a lot to me, but 40nm is generally considered on the low side if you're dealing with steep hills (they make a lot more sense for people in largely-flat European countries looking for a bit of a boost). It may be fine for you if you're looking for more of a workout and/or your hills aren't as steep, but the only real way to tell is to ride a bunch of e-bikes and see how they feel to you. I'd also want to get a feel for how the torque sensors and power curves behave on the various motors, as they all have different feels, and some may match better with your preferences.
I'd definitely be considering the conversion in your situation if the LBS thinks your bike and components are up to the increased load of an e-bike. You have a great LBS who will maintain it, and the cost of getting a new e-bike would also have to include accessories to kit it out to be useful for commuting, which can add up to a lot (that Marin is nice but doesn't have any racks, fenders, lights—many e-bikes have them built-in and powered off the battery which means they're always charged and there for you), while your Surly is already outfitted the way you like it.
posted by zachlipton at 12:01 AM on October 21, 2023 [1 favorite]
I'd definitely be considering the conversion in your situation if the LBS thinks your bike and components are up to the increased load of an e-bike. You have a great LBS who will maintain it, and the cost of getting a new e-bike would also have to include accessories to kit it out to be useful for commuting, which can add up to a lot (that Marin is nice but doesn't have any racks, fenders, lights—many e-bikes have them built-in and powered off the battery which means they're always charged and there for you), while your Surly is already outfitted the way you like it.
posted by zachlipton at 12:01 AM on October 21, 2023 [1 favorite]
I don't know exactly how much of this can be generalized to include your precise conversion question, but Why You Definitely Shouldn’t Electrify Your Acoustic Tern Bike sounds pretty convincing to me.
posted by pracowity at 12:36 AM on October 21, 2023 [1 favorite]
posted by pracowity at 12:36 AM on October 21, 2023 [1 favorite]
Tern aren't exactly an unbiased group here, I would consider some of what's in that piece but none of it is dealbreaker material. There are plenty of converted bikes around and plenty of happy riders of them.
One of the things in the Surly's favour is that it's a steel frame which treated sensibly will never wear out, this is probably not going to be the case with an ebike. You've got a bike you really like now and you can always bring it back to its analogue state if your circumstances change again. Even as an ebike it's probably going to be more repairable and upgradeable than a off the shelf ebike due to the number of custom parts the latter use.
posted by deadwax at 2:53 AM on October 21, 2023 [1 favorite]
One of the things in the Surly's favour is that it's a steel frame which treated sensibly will never wear out, this is probably not going to be the case with an ebike. You've got a bike you really like now and you can always bring it back to its analogue state if your circumstances change again. Even as an ebike it's probably going to be more repairable and upgradeable than a off the shelf ebike due to the number of custom parts the latter use.
posted by deadwax at 2:53 AM on October 21, 2023 [1 favorite]
I’d be thinking about any additional costs of having to replace parts such as tires, wheels, brakes, and drivetrain. Basically anything moving will be subjected to more force and wear. My personal rec is to not do it unless you have hydraulic disc brakes on the bike, for maximum stopping power.
posted by computech_apolloniajames at 5:04 AM on October 21, 2023 [1 favorite]
posted by computech_apolloniajames at 5:04 AM on October 21, 2023 [1 favorite]
I'm another person with a converted Surly mid-drive bike, in this case it's a 1×1 with a 250W* Bafang kit and Shimano hub gear that I've had for 6 years. It works great for me. It's my city/do everything bike, and the mid-drive motor does hang low, but this really is only a problem when I take it on farm tracks, not on tarmac roads. The torque is fantastic: I bought it when my ride home had about 200 metres of climb over 2km, and it was not a problem at all doing that.
So yes, it's a big recommend from me. I have it on (cable) rim brakes at the moment, and that's not a problem, but if/when I am well enough to start riding again (I've had 2 years of chronic fatigue), discs will be one of the early upgrades I put on it, but more because of rim wear (and not having metal dust everywhere) than lack of braking power. Even with a hill where I could freewheel to 35mph on my regular journeys, they were adequate: the overall bike is not heavy.
*maximum legal UK amount without registration and insurance
posted by ambrosen at 6:18 AM on October 21, 2023
So yes, it's a big recommend from me. I have it on (cable) rim brakes at the moment, and that's not a problem, but if/when I am well enough to start riding again (I've had 2 years of chronic fatigue), discs will be one of the early upgrades I put on it, but more because of rim wear (and not having metal dust everywhere) than lack of braking power. Even with a hill where I could freewheel to 35mph on my regular journeys, they were adequate: the overall bike is not heavy.
*maximum legal UK amount without registration and insurance
posted by ambrosen at 6:18 AM on October 21, 2023
With electric assist, the bike is much more powerful and heavier. You will absolutely need disc brakes, ideally hydraulic.
posted by bug138 at 7:53 AM on October 21, 2023 [3 favorites]
posted by bug138 at 7:53 AM on October 21, 2023 [3 favorites]
It's not mid-drive, but I had my LeBS (local ebike shop) -- who actually specializes in conversions -- convert my Surly Long Haul trucker with the Grin Tech GMAC system.
It's been the best choice I ever made. I got to keep everything I loved about my bike, including its generous gearing in case I want to ride it with little or no assist, and add torque-sensing assist (with a continuously variable adjustment dial!) and a throttle. My favorite thing about the throttle is extra boost on very steep hills, but my second favorite thing, honestly, is using it for easy starts from stops in traffic! It's a definite knee-saver.
I did end up getting another LBS to swap in a Disc Trucker front fork for better braking power (initially because I was doing some towing, but with wet steep hills and now-somewhat-heavier bike I think this was a great decision even without considering the towing). Combining my disc brakes in front, regenerative braking in the hub motor, and regular rim brakes on the back, I feel like I have better braking than ever post-conversion.
The regen on the GMAC is awesome. I even have backpedal regen set up (and well as the classic regen using controls on the handlebars - mine is triggered by pressing the throttle when the rear brake lever is at least slightly pressed) so I can brake while riding no hands. Gives me so much happiness when cruising around on a nice fall day!
So, data point of one: going with a local ebike shop who specializes in conversions worked out fabulously for me. I also really appreciate having a local shop to turn to for their expertise in any maintenance or troubleshooting that comes up with my system.
posted by cnidaria at 7:57 AM on October 21, 2023 [2 favorites]
It's been the best choice I ever made. I got to keep everything I loved about my bike, including its generous gearing in case I want to ride it with little or no assist, and add torque-sensing assist (with a continuously variable adjustment dial!) and a throttle. My favorite thing about the throttle is extra boost on very steep hills, but my second favorite thing, honestly, is using it for easy starts from stops in traffic! It's a definite knee-saver.
I did end up getting another LBS to swap in a Disc Trucker front fork for better braking power (initially because I was doing some towing, but with wet steep hills and now-somewhat-heavier bike I think this was a great decision even without considering the towing). Combining my disc brakes in front, regenerative braking in the hub motor, and regular rim brakes on the back, I feel like I have better braking than ever post-conversion.
The regen on the GMAC is awesome. I even have backpedal regen set up (and well as the classic regen using controls on the handlebars - mine is triggered by pressing the throttle when the rear brake lever is at least slightly pressed) so I can brake while riding no hands. Gives me so much happiness when cruising around on a nice fall day!
So, data point of one: going with a local ebike shop who specializes in conversions worked out fabulously for me. I also really appreciate having a local shop to turn to for their expertise in any maintenance or troubleshooting that comes up with my system.
posted by cnidaria at 7:57 AM on October 21, 2023 [2 favorites]
Oh, and I have the torque to tackle Seattle's Queen Anne Hill, among other things, so I'm pleased with the bike's performance.
posted by cnidaria at 7:59 AM on October 21, 2023 [1 favorite]
posted by cnidaria at 7:59 AM on October 21, 2023 [1 favorite]
I have a friend who was in exactly your position and ended up switching his own bike using a Swytch Bike. He loves it and did it himself.
posted by dobbs at 8:33 AM on October 21, 2023
posted by dobbs at 8:33 AM on October 21, 2023
Response by poster: The Swytch kit is a hub motor, which isn't quite what I'm after.
I fell down an internet research hole this morning and am now also considering the CYC Photon as pricier but more low-profile option (I'm a bit concerned about the low-hanging motor that ambrosen alluded to; the MS has much lower bottom bracket than the 1x1). Good call on the increased wear in components, I'll have to factor that (plus maybe upgrading my brakes from mechanical to hydraulic disc?) in to my budget.
posted by btfreek at 12:44 PM on October 21, 2023
I fell down an internet research hole this morning and am now also considering the CYC Photon as pricier but more low-profile option (I'm a bit concerned about the low-hanging motor that ambrosen alluded to; the MS has much lower bottom bracket than the 1x1). Good call on the increased wear in components, I'll have to factor that (plus maybe upgrading my brakes from mechanical to hydraulic disc?) in to my budget.
posted by btfreek at 12:44 PM on October 21, 2023
I went the conversion route recently and have no regrets. I live in Seattle and this thing can tackle any hill we have. I love supporting my local bike shop, and they are experts at installing and maintaining the Bafang BBS02 mid drive system, so that's what I went with. Having the hydraulic disc brakes was a must for me, so I purchased a new Kona Dew Plus which has a 10-speed cassette, quality components and nice wide, supple tires for comfort. The conversion kit added about 13lbs to the bike. The battery sits on the rear rack, and I appreciate how the bike looks like a regular bike with a cargo setup. (Rather than an eBike with a bulging downtube) The front and rear lights are connected to the bike battery. The bike is comfortable to ride on flats and downhills with no motor, and the motor gives a nice boost when I need it. It makes me feel more secure that if the battery ever dies, the bike is still decently rideable. Another thing I like is that if I remove the battery, the bike is just under the 40 lb limit for my Kuat hitch mount bike and the bike is easy to lift onto it.
So far the only drawbacks for this system are:
• The Bafang LCD screen battery life display doesn't seem super granular and I don't know if I can trust how much power I have left
• There sometimes is a bit of delay in the crank action as the drivetrain catches up with the pedaling
• There is no visual indicator for what cassette gear I'm in (which is pretty important to know)
posted by oxisos at 3:13 PM on October 21, 2023 [1 favorite]
So far the only drawbacks for this system are:
• The Bafang LCD screen battery life display doesn't seem super granular and I don't know if I can trust how much power I have left
• There sometimes is a bit of delay in the crank action as the drivetrain catches up with the pedaling
• There is no visual indicator for what cassette gear I'm in (which is pretty important to know)
posted by oxisos at 3:13 PM on October 21, 2023 [1 favorite]
I think this is a great N+1 scenario, especially if you have room for bike storage and can afford the new bike without selling. Gravel bike and city bike and city ebike is actually pretty much what I have. A friend of mine did a conversion kit and still ended up buying a separate ebike.
posted by bluedaisy at 10:17 PM on October 21, 2023
posted by bluedaisy at 10:17 PM on October 21, 2023
Ars Technica just posted a detailed long term review of Swytch conversion kits on Friday, and as always there is much wisdom in their comment section.
posted by fairmettle at 6:13 AM on October 22, 2023
posted by fairmettle at 6:13 AM on October 22, 2023
I purchased an expensive carbon framed folding e-bike last spring and I'm underwhelmed by the component quality and ride experience per dollar spent. If I had space for a non-foldable, I'd much rather start with a good bike and add onto it. A big reason is to have some truly useful hill-climbing gears available for when your battery runs out. If throttles are legal in your locality, get one.
posted by brachiopod at 10:16 AM on October 22, 2023
posted by brachiopod at 10:16 AM on October 22, 2023
I pained over these options, both for myself and a couple family members and after a TON of research, crunching the numbers, riding many bikes, etc i came to the conclusion that nothing came even close to buying an already complete bike(converted or factory ebike) used on fb market/offerup/craigslist/etc.
And bear in mind, i'm an experienced bike mechanic who ran the student bike shop in school years ago, and has built up and torn down innumerable bikes. I used to build bikes and sell them.
The retail price of the kits or a complete bike is just too high compared to the used market prices. Like, we ended up getting a $1800 bike for $300 with all the stuff that came in the box, and a bunch of accessories. I saw lots of too good to pass up deals in the $600-1000 range, yes even for mid drives, yes even nice ones in amazing shape. It just didn't make sense to build or buy my dream bike, or theirs. Too many people buy these and don't ride them, or hate them, or get a minor injury and let them sit etc.
My sister has been enjoying the hell out of her comparatively super cheap bike after i did a tuneup, and maybe $120 of repairs/maintenance items. It had 50 miles on it. And that wasn't really some unicorn, i saw a BUNCH like this. I'm about to buy my mom one now.
If you're averse to going the completely secondary market route, i would strongly encourage shopping around at used bike stores, even in nearby cities. The new/used price difference on these things... they might as well be 10 year old luxury cars.
posted by emptythought at 8:23 PM on October 27, 2023 [1 favorite]
And bear in mind, i'm an experienced bike mechanic who ran the student bike shop in school years ago, and has built up and torn down innumerable bikes. I used to build bikes and sell them.
The retail price of the kits or a complete bike is just too high compared to the used market prices. Like, we ended up getting a $1800 bike for $300 with all the stuff that came in the box, and a bunch of accessories. I saw lots of too good to pass up deals in the $600-1000 range, yes even for mid drives, yes even nice ones in amazing shape. It just didn't make sense to build or buy my dream bike, or theirs. Too many people buy these and don't ride them, or hate them, or get a minor injury and let them sit etc.
My sister has been enjoying the hell out of her comparatively super cheap bike after i did a tuneup, and maybe $120 of repairs/maintenance items. It had 50 miles on it. And that wasn't really some unicorn, i saw a BUNCH like this. I'm about to buy my mom one now.
If you're averse to going the completely secondary market route, i would strongly encourage shopping around at used bike stores, even in nearby cities. The new/used price difference on these things... they might as well be 10 year old luxury cars.
posted by emptythought at 8:23 PM on October 27, 2023 [1 favorite]
This thread is closed to new comments.
Have been riding mine for about a year now, and the one big issue I've had is drivetrain related. I originally had the Straggler set up with a SRAM 1X drivetrain, and the Bafang just chewed that rear cassette up. Too much torque for those precise little teeth. I've converted to a single speed drivetrain, which kind of defeats the purpose of a mid-drive system, but it's been solid ever since.
posted by flod at 11:59 PM on October 20, 2023 [2 favorites]