New fork or not?

[bluesoleli]

Hi Everyone,

I know this has been widely discussed but would like some more insight as my situation is a bit different. So basically I just got a used Giant Sedona CX with alloy SR Suntour XCT V2 forks with (I think) 63mm travel. I then bought a cheap CNEbike kit from a bicycle store that was closed for most part of the week and only opens once or twice a week (reflects how well they're doing lol), the person running the store was like whatever with the kits he sold, he didn't know anything about them and didn't do installs either. They basically colected dust on the shelves (my clothes were covered in dust after handling the boxes). Anyway for under $500 I got a 36V battery and a 200W front hub kit. The kit came with NO torque arms so I went and got an eZee torque arm for $18 at Glow Worm bicycles in Sydney. I installed that earlier today before actually riding the bike.

Now what I wanted to know is this, I spoke to a local e-bike store when I was looking for other odd bits and was told the alloy forks are pretty dodgy even with torque arms so it would be best to buy a Kona suspension corrected fork made of chromoly steel for $160 (ouch!) and pay another $70 for install (another ouch!) as even with a torque arm it might fail elsewhere?

So just need some advice, should I buy the Kona steel fork? I know its a bit of an ouch for me, but will I kill myself using Suntour forks in the long run?

*checks my eZee bike*... um, I think it has alluminium front forks with a stronger motor?

Thanks!

 

[dogman dan]

You can use the alloy fork, but you will have to install the motor expertly. If you have tightened a nut on it already, it may be too late, you may have cracked the dropouts.

What you must have, is two torque arms, and two C washers. Look in the reviews section for my threads on how the install must be done.

The short version is, you have to have the inner washer that fills the small cup built into the fork dropout. If you cover that hole with the typical oversize washer, tightening the nut starts cracking the fork. A micro crack on that alloy fork WILL fail later. If you are lucky, you only break both collarbones. if not lucky, you bash out your teeth too.

If the suspension travel is that short, I think you can just use a common fork. When you get on the bike, that suspension fork nearly bottoms out anyway. So find a cheaper fork that fits, possibly off a cheap used bike.

 

[bluesoleli]

Oh, I definitely didn't use the washers that came with the kit. They weren't oversized as they actually fit into that cup thing on the fork, but they were uneven (face surface wise). I went and bought these instead (in 10mm size). http://glowwormbicycles.com.au/store/e-bike-parts-and-accessories/freewheels/axle-washer-hubmotors

I'll try to upload some pics when I can figure out how to do so.

 

[dogman dan]

That is a different washer than the one Justin at Grin Cycles invented to solve the problem, but it's very similar, and if your cups are big enough, it will do the same job just fine. Or, they can be ground down a bit to fit.

Good luck, if you get er done right, you should have no problems. I rode at least 8,000 miles with a front hub and alloy forks.

One thing though, some forks would not move if the power was on, so I had to roll off the throttle for a pothole, or speed bump.

 

[d8veh]

The main thing is that the first washer must not overlap the edges of the dimple (layers lips). You don't need steel forks for a 200w motor.