Will it fit your bike? The lowdown on ebike conversion kits.
Will It fit? An In depth overview of ebike conversion kits
Its important to understand potential compatibility and fitment issues that could arise from various bike frames and motor conversion kits. The good news is that most bicycles have fairly standard sizes of 100mm front forks or 135mm rear dropouts .
Get to know your bike - Dropout Sizes
A lot of modern and higher end bikes now days use thru-axle dropouts instead of slotted dropouts (pictured below). Thru-axle is as it implies; the axle fits through a hole in the frame and is generally not a good candidate for an ebike conversion kit. While both are proven methods, the thru-axle design provides slightly better rigidity and security, but has created a great complexity in fitting ebike motor hubs. Generally slotted frames provide an easier hub motor compatible as most are made for 100mm forks.
Bikes, bikes and more bikes...
Lets take a look at some common bikes!
Take a look below at some common bikes and some standard sizes. Lets see if an ebike kit will fit!
Most mountain bikes were made with the same slotted dropout width. The front fork dropouts were routinely spaced 100mm apart with a rear frame dropout spaced at 135mm. This generally lead to enough room for the 7, 8, 9 and 10 speed gear clusters we commonly see. The width of this dropout slot was ~9.7-10mm, so that the standard 3/8″ bicycle axle would slide in with ease.
These types of bikes have become the standard most ebike hub motors are designed to fit. If you have a classic bike or mountain bike you can feel confident most conversion kits will fit your needs. In some minor cases you may need to adjust or file open the dropout slot in order for the axle to slide in, and in other cases you may need so spread the rear frame a little to span to 138mm. This is generally within the structural integrity for most dropouts and you’ll have very few fitment issues with hub motors on the market..
Tandem Bikes - Double the fun
It’s common for tandem bikes to have a wider dropout in the back. This is generally due to it needing a stronger rear wheel due to the extra weight of multiple riders. Most rear hub motors are found in sizes around 135mm but occasionally you can find some 138mm-142mm. Sometimes you can make certain sizes work by installing a few washers on the axle to space it out and a corresponding spacer on the disk rotor as well.
The front forks on tandem bikes generally use the standard 100mm spacing For this reason front hub solutions may be the easiest option. Due to the extra weight of tandem riders a dual front and rear ebike kit would be a great solution.
Folding Bike - Space Saver
Because folding bikes by nature are space savers, they often use
narrower hubs and smaller dropouts. It’s not uncommon for front fork of a folding bike to be as small as 75mm apart instead of the standard
100mm. Make sure when using an ebike conversion kit that the kit will work for your application.
If your folding bike has a set of derailleur gears, your most likely in luck with having a standard 135 rear dropout. If this is the case, any standard rear hub ebike motor will work. If your folding bike model comes with a single speed gears you most likely can not fit most rear motor hub kits on the market as the dropout can be as narrow as 120mm.
Derailleur Gears: If your chain moves between different cogs on the rear wheel, then you have a derailleur gear system. This gearing system consisting of multiple components including a chain, multiple sprockets of different sizes, and a mechanism to move the chain from cog to cog.
IGH - Internal Gear Hub Bike
Bikes with an internal gear hub usually have slotted, horizontal dropout slots to allow the rear wheel to adjust for chain tension. If you are electrifying a IGH bike we generally recommend using a front hub motor.
Most road bikes have a 100mm front fork spacing but have a slightly narrower 130mm rear vs the standard 135mm. They will fit standard front gun ebike kits while rear hub motors options may requires some frame spreading. Our ebike conversion kits are great mated with a road bike as they are small, lightweight and keep handling and braking at top performance.
One thing to note during installation is it can be a bit tricky to mount a thumb throttle on a drop-bar with bar-end shifters installed. We generally recommend a handlebob post to provide a mount for a thumb throttle.
Trikes - Three wheel bikes
Trikes are a great option for a front wheel ebike conversion kit. The front hub generally fit well on trikes and have no issues as they usually come with a standard 100mm front fork. They commonly have a basket or space in the back and are a great candidate for rear mounted battery systems such as our Voyager or Discovery series. We do find with the extra wheels, friction points and general higher usage of users a larger battery is recommended.