Is it possible to stiffen the front fork

Athena

New Member
The bike is an IZIP Mountain Trailz AL with a rather wobbly front wheel to my thinking. Maybe this is normal, but is there a way to stiffen the front wheel fork?
 
Did you check the bearings in the wheel and steerer? No way to stiffen a fork, but there are lots of options to replace it.
 
Wheel has been checked. Solid, not bends. Seems the wobble is coming from the triple tree. The wheel will readily swing backwards on a stand.
 
Wheel has been checked. Solid, not bends. Seems the wobble is coming from the triple tree. The wheel will readily swing backwards on a stand.
This is a triple tree. That bike has that design? What bends? The wheel? No wheel is fine if it bends.
 

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The wheel is solid, the tire is good, rims are good. It is not bending as such but sort of an annoying shimmy /wobble that you might feel in the steering wheel of an auto only not as rapid.
 
Sorry folks, @Athena & @rich c; the Izip Mtn. Trailz came with a non-adjustable suspension fork with some covering material at the top part of the fork just below the crown.

Izip-Mtn-TrailZ-ebike.jpeg


Try holding the stem and fork area at the crown and rock the fork back & forth. If there's movement, then either the headset is loose and needs adjustment or the 2 bearing sets (generally found in a retainer ring) are worn. Or possibly both. Heavy use without proper maintenance or adjustments of the headset can wear the bearings rapidly as can riding with big loads or over roads with lots of potholes.

If I remember correctly, this bike has a threaded headset, with an upper & lower set of bearings. The upper set of bearings will have 2 nuts present. The lower one is the race that the upper bearings run in, the upper is an adjustable lockring. If what you're experiencing is a little 'shimmy' that sounds more like an adjustment issue with the possibility of bearings starting to wear.

This is a simple adjustment that you can do yourself with a pair of thinner adjustable wrenches if you don't have a headset wrench.
  • With the handlebars still in place loosen the upper lockring nut so that it's easy to get the headset wrench or a thin adjustable wrench on the lower nut. You will want the headset to rotate freely without binding from being too tight or knocking from being too loose.
  • Once you have the lower nut where everything feels smooth, give it a final check by holding onto the forks near the crown (this is critical so that normal play with a suspension fork doesn't interefere) and rocking them back & forth and checking that they swivel smoothly without little hops, grinding or sticky points.
  • Finally, with your thin wrench or headset wrench on the lower nut, tighten the upper locknut while keeping the lower nut from moving.
  • Check your adjustment one more time to make sure you didn't accidentally over tighten the lower nut. It might take a couple of tries to get the headset exactly how you want but it's a fast process.
Here's a short video that makes the adjustment process easy to understand:


After getting the headset adjusted properly, if there's still some grinding it may be time to replace the bearings and install some fresh grease on the races. This might be something you'd want a bike shop to do.

If on the other hand, you can hold the fork crown still and get the arms of the fork to move back and forth, that's a very serious issue and you should stop riding the bike immediately until you can get it to a shop. That means there's cracks from metal fatigue starting to form which could result in a bad accident from a sudden failure of the fork.

Adjustments are not costly at a shop and if it's bearings, there's a little more cost but not excessive. Even a replacement suspension fork similar to this (Zoom brand) run about $50/$60 and a rigid fork might be as little as $30.

No matter what you diagnose, don't delay getting it fixed; even a loose headset can result in damage to the forks.
 
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The wheel will readily swing backwards on a stand.

I'm assuming the bike has a suspension fork. It could be one of two things. Either the steering bearings, a.k.a. the headset is loose, or there is play in the suspension itself. The steering bearing is an easy repair; usually it is just loosening the bolts on the side of the stem, gently tightening the top cap until the bearings are no longer loose and retightening the stem bolts. If there is play in the suspension itself, this is often not repairable on an inexpensive fork because replacement parts (bushings) are not available.
 
@Nova Haibike, this bike has a threaded headset. What you're talking about is a threadless headset. Think I've got myself a topic for another article :D Either one is easy to adjust unless the races or bearings are shot.
 
Looking it over it appears that it needs tightening at the two arrow points. All the hex bolts are tight, there is no play, but absolutely no resistance at the two arrows.
 

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Athena, have you loosened the lockring on top first, then adjust lower nut, then tighten lockring. That's the only way to be certain that both nuts are tensioned properly. Getting the proper adjustment on the top bolts should fix the lower bearing set. If it doesn't the bearings are worn or the races are too worn.
 
This bike doesn't have a lock ring. There are two style clamps with bolts attached to the stem tube, and a top bolt that feeds into the stem. These clamps may replace the lock nuts, there are none.
 
Have you thought about swapping the fork for a rigid one ? I did with my Mozo and it really helped with handling and braking.
 
I think I know the wobble you are talking of... I have a cheap non-adjustable shock on my bike and the wobble is in the shock itself... I thought my headset was loose.
Just squeeze the front brake and gently rock the bike back and forth, You will see the wiggle spots.
... Unless you replace shock with a higher end adjustable or solid fork set, You are kind of stuck with it.
 
I think I found the problem. The second battery makes the bike so heavy and off balance, and my weight is minimal, that the front wheel is actually not fully on the pavement. I pulled a battery and there was a considerable difference in the stability and the wobble disappeared.
 
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