The Jackshaft castle nut holds together the bolt that goes through the swingarm and jackshaft. It is that annoying piece on your e-moto that requires a completely different tool than anything else. OK, it might be annoying to remove or tighten, but it does a big job. It basically holds together the rear end of your Surron!
Why is it not a standard hex nut? Can you change it? Let’s look at what many riders do to simplify things while improving their Surron LBX to make it stronger.
What is the jackshaft castle nut?
The jackshaft castle nut is a ‘castle’ looking nut on the pivot point of your swing arm. It requires a special tool to remove. A quick search on Amazon will show the removal tool isn’t expensive. But, it’s another gadget you’ll need in your toolbox – and something else to carry to the track.
One alternative is to get yourself the GritShift Belt Change Multi Tool – something that is specific to the Surron and handy for lots of different things. It also doesn’t take up much room in your bag.
The jury is still out as to why the swingarm bolt requires a castle nut. Typically castle nuts have a locking device to ensure they don’t rattle loose. However, there is no such thing on the Surron. This is probably why many people upgrade their jackshaft castle nut to something more universal – that and how hard it can be to find a removal tool.
Why improve the Jackshaft castle nut?
In the scheme of modding, changing the castle nut to a normal hex nut seems pretty insignificant. Until that moment you realize you need to do a quick belt change, or the nut’s a bit loose and needs a tighten. Having something that is a universal size and can be changed with your limited toolkit trackside is very handy.
But, if you feel it’s a bit of a waste to change a simple nut over, then why not consider changing the whole bolt to something sturdy? Or, if you’re in the mood for modding, then you could consider changing the whole Jackshaft to something that will withstand any huge landings! But first, let’s look at the Jackshaft bolt.
Surron Jackshaft bolt
A commonly overlooked weak point on the Surron LBX is the jackshaft. If you’re riding hard and scrubbing those jumps, the force that goes through this single point on your e-moto could be way more than it was intended for, especially if you have modded your wheels or suspension to withstand bigger jumps than stock.
The jackshaft bolt has been known to bend and even break. It doesn’t take much to imagine what sort of damage this could cause – both to yourself and your e-moto. When adding big power and suspension upgrades, don’t forget to look at the jackshaft bolt.
Another reason why your jackshaft bolt could bend is if you have your chain tension too tight. Especially if you’re riding in soft sand, mud, etc which gets bound up in the sprockets, making the chain tension even tighter.
How to replace the jackshaft bolt
Replacing your Jackshaft bolt is a relatively simple process… when you know what you’re doing! Have a watch of this video where Bullet goes through the steps needed. The purpose of this video is how to change the belt, but removing the jackshaft bolt is a necessary part of this. You can also see what happens when the jackshaft bolt starts bending!
If you would rather read, here are the steps for the jackshaft replacement:
Tools needed: GritShift multi-tool or castle nut removal tool, Allen key, Philips head screwdriver.
- Remove the castle nut using the removal tool and the Allen key.
- Use the screwdriver to push the jackshaft bolt through the swingarm. Leave the screwdriver in place to keep the swingarm in alignment.
- Replace the jackshaft bolt by manipulating the rear tire to line up the swingarm and jackshaft. As you slide the jackshaft bolt through, remove the screwdriver.
- Tighten using the new hex nut/Allen key or as per any instructions that came with your jackshaft bolt.
Remember to always check if anything has rattled loose after the first ride, and every few rides. This should apply to any mod, big or small.
Do I need to replace the jackshaft?
Replacing the jackshaft is relatively simple. If you’ve already removed the bolt, you’re halfway there! However, do you *really* need to replace the jackshaft? It’s completely up to you and how you ride.
The bolt is important to replace, as it is a known weak point on the bike. Call it cheap insurance. The jackshaft itself isn’t so critical unless you’re landing big jumps often. Or casing them, more to the point!
What is important is looking after your jackshaft and the internal bearings. If you keep it running smoothly, you’ll be able to transfer more power to the rear wheel as friction will be less.
How to grease the jackshaft bearings
This video that Rusty put together on greasing your jackshaft bearings is a great one to watch:
If you’ve never replaced bearings in anything before, I would suggest you watch this first, re-watch parts you weren’t too clear on, then give it a go with the video on your phone and pause between steps. That way, you’ll be able to plan ahead and get yourself prepared with the correct tools.
Tip: Get yourself a good heat gun. By using heat, you can expand metals to make your life much easier! (Also, by contrast, the freezer is good if you need something to contract slightly)
If you’re looking at the video and thinking, I don’t have the time or patience, then there are Jackshafts you can get that are easier to maintain. Look for one with grease ports to allow easy bearing greasing.
Replacing the Surron jackshaft castle nut
Do you need to replace the Surron jackshaft castle nut? If you don’t mind carrying extra tools to the track, or out on rides, then there is no real reason to change the castle nut. The GritShift multi-tool makes that simple.
What would be more important to consider is if you need to change the jackshaft bolt to keep it from bending. That only really applies if you ride outside the stock Surron capabilities. Put it this way, if you’ve beefed up your suspension, and perhaps up-ed the power, I would highly recommend changing the bolt.
While you’re thinking about changing the jackshaft bolt to something stronger, seriously consider getting something with a hex nut to make your life simpler!
We’re here for you at GritShift to help you spend less time in the garage and more time on your e-moto. Grab the parts you need right now at www.gritshift.com
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