VoilamartQA How to choose a hub motor wheel ebike conversion kit for your bike - The size you should check befor purchasing

Hi, First of all, thanks for your interest in turning a pedal bike into ebike.
But I wanted to create an article series to illustrate how you should choose the right e-bike conversion kit for you and your bike.

This one I will talk about and explain some of the dimensions of the frame: Wheel Diameter, Dropouts, Axel Catcher size, and Tire Width fitment.
I will try to find some example pictures to illustrate this, and the only tool you will need when you face this problem is a ruler.
Of course, it needs to be long enough.

1, Dropout.

The dropout also means the places of a set of bike frame to catch and fix the bicycle wheel's axel, and there's two type: Front Dropout, and the Rear Dropout.

Actually I think it's for fits with the wheel hub, so both dropout should measure the inner side to the other inner side.

1.1, The Front Dropout should measure the axel hook's inner to inner, and you'll get a width between them. And for Voilamart normally front wheel conversion kits they would fit with 100mm Front Dropout (about 100~103mm or 3.94~4.00in width).

1.2, The Rear Dropout also a width between both inner sides, and for Voilamart rear wheel conversion kits they would usually fits with 135mm Rear Dropout (about 135~137mm or 5.315~5.39in width)

1.3, Also theres some wider dropout type for Fat Tire Bikes, Beach Cruisers, or Snow Bike. These would be different in the parameters, but you still can get them by a ruler, it's easy.

2, Wheel Diameter.

From the bike frame, you can get the wheel diameter by measuring the length between axel dropout hook and the bottom bracket(for rear wheel) or fork bottom(for front wheel), just like the picture above shows. In this way you'll get a "Half Diameter of Wheel", so you should know the diameter by "2 x Half Diameter".

But if you've got a whole bike, maybe it's easier. You can just find the tire info on the tire, they've been mark on the tire surface and shows as form like "wheel diameter X tire width".

3, Tire width.

Yes, the 3rd I'll mention is the tire width. It's measured in much the same way as the dropout, but the measure way will be closer to the bottom bracket and the fork bottom. You should figure out the Max Awailable Tire Width of your bike frame, and then choose the right tire.

If you install a over-wide tire on the wheel, you'll mostly find that the tire will get touch with the bike frame, and the wheel would been fixed, unspinable. 

4, The Dropout Space.

Let's look at the picture following:

The measure way is in the picture, and for Voilamart Hub Motor Wheel Ebike Conversion Kit, all the hub motor axel is oval in 10 x 9 mm Dia. 

Now, the 4 info of your bike / bike frame should confirm before purchasing ebike conversion kit and turns it into electric bike, are all above.

Before starting turn your bike into ebike, I think there's another info you should know: the dropout of the hub motor wheel is fixed and can only be changed in small amounts by spacers. The rear wheel can only be mounted at the rear of bike frame, and the front wheel can only be mounted on the front fork.

Purchasing the wrong item, would suffer the highest cost. You can return the item, but your time has flowed.

Let's check before purchasing and save your time.

In next, we'll talk about the Voltage of Ebike System, click to open it in a new window and don't miss it.