Your suggestions for a replacement suspension fork

I just finished installing a Leeds 500 Watt front hub motor kit on my wife's Trek 7100. The motor ripped the dropouts off the stock aluminum RST forks in the first few feet of my test ride even though I used the torque arm that came with the kit.

I obviously need a heavy duty steel fork to handle the motor's power and am wondering if you have any suggestions. I have never replaced forks before, do I need to know anything other than bike model/year, tire size, and travel to make sure the new forks fit properly?


Thanks.

Doesnt' take a steel fork to do it (I've used alloy forks with 2kW+ and a really heavy bike); just requires correct mounting of all teh axle hardware, including the torque arm--there's a number of ways to put stuff on but they won't all keep teh axle from spinning.

But it is easy to break them when it's not installed right.

I recommend before you continue that you look at this thread,
https://endless-sphere.com/forums/viewtopic.php?f=2&t=26444
where there are posts showing and describing various issues mounting different types of torque arms / axle hardware.

There are many other similar ones if it's not enough:
https://endless-sphere.com/forums/search.php?keywords=torque+arm*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search


As for the fork, you could replace it with the same model and it'd be fine, once the hardware is mounted correctly and tightly.

If you want a different one, you need one with the same height, rake/dropout offset, etc, so it doesn't change your riding geometry. Also needs the same steerer type and size (and has to have a steerer at least as long as your old one; longer is ok as you can cut it).

Knowing what year/etc the bike is might help a bike shop find the right one for you, but they could also get that information from the original fork.



FWIW, none of the steel-lowers suspension forks I've ever worked with were really useful as suspension; they did make bad pogo sticks and were ok at making the frontend heavier. The steel-lowers RST Omni on my old DayGlo Avenger bike were easily bent/stripped out when I didn't have proper torque-control hardware; so they're not really any better than the alloy is without that.

The ramifications of a fork failure could be severe, and I would consider only a steel fork for my wife. As stated above, there aren't any decent suspension forks with steel front lowers. This limits your choice to a suspension-corrected rigid steel fork (apparently with "V" brake `posts). You might need to have one custom made.

Thank you for the responses. This has been a learning process and I appreciate the information.