Surly Ice Cream Truck ~132mm bottom brackets and 190mm rear dropouts, choices?

[Blacksword]

I bought an older model Surly Ice Cream Truck frame off ebay and am building it up.

I am looking for a solid motor choice, speed isn't necessarily a need but I would like hill climbing ability and something to haul some weight bikepacking.

The bottom bracket on this bike is ~132mm wide with a 40mm internal diameter. The dropout specs are 197 rear. Front is a 150 thru axle.

Outside of trying to get a custom 190mm axle hub motor some place (do they even make these?), I am looking for some ideas on whether I could still get a mid to fit this or what wheel options may be available, any help would be much appreciated.

 

[MadRhino]

Motorcycle hub motors are common in 200mm width. They are easy to fit on your dropout width. Custom dropouts or torque plates are easy to make, to fit any motor.

Your BB is weird if it is really 40mm. You’d likely have to make a fit by yourself. Is it threaded? If so, I have never seen one.

41mm press fit is Shimano, that is available in 132mm width. That is the closest that I know of, and yours is probably this one.

41.2 press fit is known as ‘mid press fit’, BMX standard.

42mm press fit is the BB30, pretty common standard.

 

[Blacksword]

Thanks MadRhino - its a pf41 on the spec sheet, my caliper must be off.

Looks like one of the larger hubs might work, what models can I still reasonable run at 52volts on a bike like this or do I need to go to 72v+ to even power these beasts? I am after hill climbing ability so I guess powering them appropriately is a good thing.

What models and suppliers are good for these bigger motors? TY VERY MUCH

 

[999zip999]

You have some pictures ?

 

[Blacksword]

Here is the frame spec:

https://surlybikes.com/bikes/legacy/ice_cream_truck_2016#spec-geo

The rear dropouts are 190mm I am going to look for a powerful hub motor 3k 72v+ that will fit that bracket. If anyone can recommend a specific rear hub motor and supplier I'd appreciate it, thank you.

 

[MadRhino]

Since you will need to make custom dropouts, or torque plates at least, It is not much more work to make them to match any motor. Commercially available torque arms are not strong enough to be safe with higher power than the usual ebike kit.

I would rather build higher voltage to power a slow winding motor, than low voltage with a fast motor. That is because the Amps required to make powerful wattage, are lower at higher voltage.

To recommend a motor and what else you need to build, we first need to know your target performance, terrain, range.

 

[Blacksword]

This bike will be for bikepacking maybe 40 miles a day on road and offroad, some mountain paths - so I expect long hills under load.

Speed is not necessary but a bonus.

 

[MadRhino]

I would go for the QS205h50. It is available for ebike or motorcycle. The ebike version is 150mm width that you’d have to fit with torque plates. The motorcycle version is 200mm and your dropout width can easily be spread to fit, but you will need torque plates anyway and the brake mount will be for a motorcycle rotor, so you will have to make an adapter.

It is available in a large variety of windings. Order a low Kv if you don’t need speed.

 

[999zip999]

A muxus 3,000 5t v3 @ 72v is 150 mm so spacers investigate. Qs has a lot of choices there. But a big hub motor @ 72v as you need the power and not over demand the motor. just because your Corvette does 200 miles an hour you're not going to drive your Corvette at 200 miles an hour. A great battery so it will last and you don't waste money.

 

[Blacksword]

I like the idea of the MXUS 3000w, it looks like it may fit a fat bike a little better.

Are there any suppliers who would pre-lace these into an 80mm rim?

 

[Balmorhea]

I like the idea of the MXUS 3000w, it looks like it may fit a fat bike a little better.

Are there any suppliers who would pre-lace these into an 80mm rim?

With few exceptions, wheels built up for you by motor suppliers are poorly assembled from poor quality components, and usually built with spokes that are much too thick for the rim. Better to have your wheel built by an experienced bicycle service professional.

 

[MadRhino]

I like the idea of the MXUS 3000w, it looks like it may fit a fat bike a little better.

Are there any suppliers who would pre-lace these into an 80mm rim?

What would make a motor fit a fat bike better?

I have never seen a good lacing job from Chinese sellers or manufacturers, with those big hubs especially.

 

[Blacksword]

Fair enough. I called around a bunch of local shops I mentioned lacing and they cringe, I guess its a rare skill around here. I can go find an online service, Id give it a shot but a bit further in scope that I want to go this go around.

 

[amberwolf]

I like the idea of the MXUS 3000w, it looks like it may fit a fat bike a little better.

I have a couple versions of that motor, and a QS205. The QS is MUCH better built. You can find pics of the insides of each in my SB Cruiser thread. If I were to buy new motors for the SB Cruiser heavy cargo trike, that's what I would get, though I would ask for a custom tube-style hollow axle at least 25mm in diameter (wider if possible), rather than the flat-style solid axles, so wiring goes inside the axle, and custom dropouts would clamp the tube, to prevent the problems with broken axles all hub motors can get with high torque and various kinds of loading on them.

Oh, FWIW, if you read around the main MXUS 3k 3000w motor thread, you'll find that it's only really a 3kw motor when it's in a 20" wheel. Probably would want to derate to 2kw or less in a big fatbike wheel.

The QS205 doesn't appear to have that limitation.


BTW, lacing up wheels and tensioning / truing them isn't that big a deal, though it can be time-consuming to learn at first; there's plenty of videos to show you how, even with just homemade tools (other than the spoke wrench), and sites like Sheldon Brown's with lots of info on how and why things work the way they do, including wheel stuff. Plenty here on the forum, too.

Start with a junk wheel, and take pics of it then take it apart, then put it back together, and you'll become familiar with the idea and learn what *not* to do, and how to do the things you need to know.