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How Heavy's Your Knob?

A bloody cheap upgrade

by Julian Edgar

Click on pics to view larger images


This article was first published in 2007.

Ever thought of what’s on the end of your car’s gear lever? Yep, duh, a gear knob. But here’s a different question: ever considered how the mass of that gear knob affects your gear-change? Nope? Well, here’s why you should care.

Click for larger image

The gear knob is mounted on the end of a lever, with the pivot point way down near the bottom. That means that compared to the other end of the lever, the gear knob moves both far and relatively fast when you change gear.

And it’s the ‘fast’ bit which is the key. The heavier that the gear knob is, the more kinetic energy it has once it’s moving. And the higher the kinetic energy, the easier it is to overcome notchy gears. In other words, the fast-moving gear knob actually helps you change gear! Of course, the downside is that the heavier the gear knob, the more force that needs to be applied to get it moving. But in the overall scheme of things, that greater force is no big deal. In fact, a heavy gear knob is likely to feel chunkier and more robust and also slide home easier.

A better gear change just by changing the gear knob? Sounds like garbage doesn’t it? But it ain’t.

The Background

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This story came about because I was wandering a wrecking yard, looking for a suitable gear knob with which to upgrade the standard knob in my Honda Insight. I wasn’t particularly after a huge upgrade in appearance; nope, what I wanted was an improvement in size. The Honda’s standard gear knob is simply a bit small for my hand.

The first gear knob I found that had (a) the right shift pattern marked on it, (b) the right thread and (c) the right height, was from a big Hyundai people mover. That probably would have been sufficient, but I kept on browsing anyway. And that’s when I made a startling discovery – some factory gear knobs are very heavy! A Suzuki Swift (current model) knob is f-a-r heavier than the Hyundai knob; a Suzuki Liana knob heavier again. And it wasn’t just chance: the heavy gear knobs were clearly designed to be heavy. In fact, some felt like solid steel encased in grained plastic...

So I bought four different factory knobs at AUD$10 each.

Weighing Them...

Back home I weighed each knob.

Gear Knob

Mass

(grams)

Honda

300

Unknown

310

Hyundai

325

Suzuki Swift

470

Suzuki Liana?

580

Sorry about the ‘unknown’ and question mark but I collected, put back and swapped so many gear knobs it became rather confusing which cars they were from!

Think about the mass of the heaviest knob – that’s over half a kilogram swinging on the end of the gear lever!

Installation

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It obviously makes things easier if you select gear knobs with the same thread as standard. Note that in some cases, a plastic collar is inserted into the gear knob and it’s this collar that screws onto the shaft. (Without the collar, the hole in the gear knob is way too big.)

Only one of the knobs needed an adaptor (the lighter of the two Suzuki knobs – maybe I forget to get the insert) and so I simply removed the standard knob and replaced it with the heaviest.

An immediate 93 per cent increase in mass...

Fifteen seconds later, the test drive could be begin – a modification doesn’t get much simpler than that!

The Results

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The change in shift feel was immediately noticeable. It wasn’t as great as swapping from a poor gearbox oil to a really good one (although the difference that makes varies from gearbox to gearbox) but the heavier knob gave a clear improvement. Notchiness in the gearbox was reduced and the gearbox had a slightly beefier feel. Together with the larger gear knob that better matches my hand, the overall effect was clearly better.

Yep, the mod worked...

Click for larger image

We’d suggest the first step is to unscrew your gear knob and weigh it. If it’s light, take it along to a wrecking yard and find one that’s swappable but weighs a heap more. And of course, the lighter the gearbox, the more we’d expect the improvement to be – there’s no point adding a few hundred grams to the knob on a Kenwood truck and expecting the shift to suddenly be sweet...

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