GoldenMotor.com Forum

General Category => General Discussions => Topic started by: pieroh on May 09, 2009, 10:38:43 AM

Title: Which kind of fork to use with a front motor?
Post by: pieroh on May 09, 2009, 10:38:43 AM

Hi,
will a suspension fork be able to withstand the torque of a front motor (I have a kit with the 36V-250W mini motor)
What do you recommend by experience a rigid or a suspension fork?
Regards
Peter

Title: Re: Which kind of fork to use with a front motor?
Post by: shakkan on May 09, 2009, 10:04:05 PM

Hi Peter- ive used bikes with both types and never had a problem as yet- My forks are steel but the bike is ali.
You will find threads on the forum about other peoples forks breaking mounting lugs. They also have added torque bars.Ive done just over 1000miles and my forks still  have no slack in the sliding forks
my next bike will have duel suspension

Title: Re: Which kind of fork to use with a front motor?
Post by: Sideshow Bob on May 10, 2009, 09:54:22 PM

I have my kit (purchased from someone else sadly) installed on a Mongoose bike with dual suspension.
It is front wheel drive and I have had no trouble at all.  The front forks and suspension are very heavy duty.
I have ridden this setup for 3 summers.

Title: Re: Which kind of fork to use with a front motor?
Post by: Philip Lynott on May 11, 2009, 09:35:31 AM

If you want to use a front hub motor you should make sure it will fit your front forks correctly. I have used two bikes and the first one's forks were not wide enough, this meant that the suspention became stuck and offered no shock reduction.

The bike I am using now has wider forks (I think this is due to the fact that it has disc brakes) and the suspention works properly.

I have approx. 1000km done between both bicycles,

P.S. in my opinion you SLA batteries should be avoided - while they are initialy cheap and will do the job, you'll soon wish you paid a little bit extra and invested in a lifepo4 battery 

Title: Re: Which kind of fork to use with a front motor?
Post by: ravenracing on May 11, 2009, 03:52:25 PM

i am running a 1000w 48v front wheel motor and the torque has broken the lugs off my forks any idea of which forks I can use

Title: Re: Which kind of fork to use with a front motor?
Post by: e-lmer on May 13, 2009, 04:26:13 AM

There are two things you can do to improve the reliability of
the forks.

First, under no circumstances should you use an aluminum fork.
I recommend any titanium alloy fork that has a flattened slot at the
tip.  If possible avoid the kind that are set up for quick release because
they do not have a flat surface to clamp onto.

Second, get an arm to translate the torque up the fork.
I have designed my own, but I have seen them on ebay.
Look for item 310141583549.

Personally, I think that is too much to ask for it.  You could get
a local machine shop to make one that fits perfectly for half that.

Title: Re: Which kind of fork to use with a front motor?
Post by: pieroh on May 14, 2009, 09:41:47 PM

Quote from: e-lmer on May 13, 2009, 04:26:13 AM

Second, get an arm to translate the torque up the fork.
I have designed my own, but I have seen them on ebay.
Look for item 310141583549.

Personally, I think that is too much to ask for it.  You could get
a local machine shop to make one that fits perfectly for half that.

Thanks a lot for your reply!!
To add a  torque arm is a very good idea! Most of the complete ebikes one can buy have something like this.