Updating my front forks to suspension forks...

[TimJohn]

Hey,

I was wondering has anyone updated their 20" Tern to front suspension forks. If you have could you please point me to a reliable brand?

 

[tomjasz]

Just make sure your choice doesn’t mess up your geometry and steering. Good forks are expensive. If you don’t have disc brakes do buy a fork that is disc ready. Someday you my want, for many reasons, replace a wheel and buy a disc brake ready wheel.

 

[TimJohn]

I have a disc brake already with the TERN...you are correct about the geometry and that's why I ask if someone had experience with this conversion.

 

[tomjasz]

I found a number of options by searching, Tern suspension fork. Including YouTube posts.

Suspension forks for folding bikes in the USA

Suspension fork option for 20" wheel folding bicycles. We discuss the only available options in the USA.

www.downtube.com

 

[TimJohn]

I looked at the Suntour site and emailed them. Asking if they have a product that is compatible with my Tern. The problem I see is there are no mounting points for my fenders and for my GRIN torque arm. I have a front HUB motor. In fact I don't see any products from any manufacturer to date that has all these requirements. I will contact down tube as well.

 

[tomjasz]

I looked at the Suntour site and emailed them. Asking if they have a product that is compatible with my Tern. The problem I see is there are no mounting points for my fenders and for my GRIN torque arm. I have a front HUB motor. In fact I don't see any products from any manufacturer to date that has all these requirements. I will contact down tube as well.

Wait, you are considering a front hub motor on a suspension fork? BIG mistake!

 

[TimJohn]

OK maybe a little explanation...I already have a front motor hub. Now I was thinking about a front suspension. So what are the problems here. I can think of one. The twisting effect (torque) will effect the handling. Others??

 

[TimJohn]

Maybe I should rethink this then...

 

[harryS]

Some people say that the weight of a motor on suspension forks causes them not to work too well, and that in itself puts stress on the forks. And most people say motors and suspension forks are not a good mix.

I've put suspension forks on two bikes that had regular forks. It raises the front of the bike 2 -3 inches. Probably won't affect your Term, but when I stop my Trek 800, there's little space between me and the top tube when I put my feet on the ground.

 

[tomjasz]

OK maybe a little explanation...I already have a front motor hub. Now I was thinking about a front suspension. So what are the problems here. I can think of one. The twisting effect (torque) will effect the handling. Others??

Exactly as you pointed out, attachment point. You’re missing attachment points for torque arms. The ONLY moderately safe install is to use two torque arms. I’ve done an install on a suspension fork, but was able to use two TA’s. My buddy puts on about 1000 miles a season and this is season 3. If you can’t add two torque arms please don’t.

I’d limit the motor to 500W and never with a high torque gear drive.

 

[TimJohn]

That makes a lot of sense. Maybe that's why there are no mounting points on these suspension forks...because not a good to place a motor there. Anyway I only have a 250 W motor that weighs in about 2.5 kg and this probably being unsprung weight would effect the effectiveness of the shocks. OK I decided...its a no go!

 

[tomjasz]

That makes a lot of sense. Maybe that's why there are no mounting points on these suspension forks...because not a good to place a motor there. Anyway I only have a 250 W motor that weighs in about 2.5 kg and this probably being unsprung weight would effect the effectiveness of the shocks. OK I decided...its a no go!

250w is pretty mild. You could get away with a single torque arm. I used a Grin V4 TA for my buddies front drive.

 

[TimJohn]

OK that's a possibility. I still haven't heard back from the suppliers so its back on the table then....