What makes a motorcycle a bobber? Features Checklist
April 17, 2020
After having seen in the article bobber: the motorcycle that looks like you how a bobber is defined, we will focus on the elements that differentiate a bobber from a classic motorcycle.
The rigid frame
The rigid frame , called hardtail on the other side of the Atlantic, is a differentiating element of a bobber compared to a traditional motorcycle. A rigid frame is, in fact, a frame made in one piece. There is no removable part called a swing arm to hold the rear wheel.
This type of frame is often found on bicycles.
This is the type of frame that was present on motorcycles in the 1930s before the development of rear wheel suspensions and later swingarms. Below is a Triumph 6/1 produced from 1933 to 1935 (source: Wikipedia).
The frame does not include any rear suspension, the "damping" is provided by the saddle (via the springs) and the rims/tyres assembly.
Here is a comparison between a VF750FD suspended frame (left) and a rigid Harley 125 frame (right). The different elements between these 2 frames are noted in red.
It has a rigid frame found on bobbers and choppers : the Gooseneck frame.
Gooseneck is an English word meaning gooseneck. The particularity of this framework lies on the part. It is a rigid offset frame.
For a little more comfort and "less" traditional, there are many customs which reproduce the line of a rigid frame but which have a rear shock absorber. This type of frame is called among our English-speaking friends " softail ".
Here is a Softail frame from Craft Tech, we find the line of a rigid frame but with additional comfort.
The swingarm follows the frame line and the shock is usually placed so that it is less visible.
A successful example of this type of frame is that of the BMW R18 where the line is respected and yet the motorcycle has a swing arm and a shock absorber (place concealed in the axis of the frame) for the comfort of the pilot.
The Zero Engineering Type 9 adopts a very particular system.
We can see better in this photo the " Mulit-Arm Suspension " it is an innovative damping system developed by the ZeroEngineering team with several arms and several pivot points. This product is offered only on the Type 9 to move more easily and react more effectively to the road.
But this is a lure for rigid purists.
Big tires ! Here is another characteristic of bobbers.
These oversized sidewall tires bring a look of adventurer, with similar dimensions at the front and rear are in the DNA of the bobbers.
Here on a collaboration between Rough Crafts and Zero Engineering.
These "square" tires are not recommended for the less experienced because they provide a very different ride than traditional tires.
They have a significant absorption capacity when riding rigid.
They influence driving and it is better to use the rear brake with them.
Several brands and models are popular.
In the first place we find the famous Firestone Deluxe and these copies.
The Avon tires are renowned and bring a little more serenity than the Deluxe.
The predominant size in the world of bobbers is 5.00x16 front and back.
Nothing original here, spoke rims are appreciated for most preparations. Note that on a bobber , the rims are preferably the same size at the front and at the rear.
And of course, in 16 inches, it provides an unstoppable look of “creeping” mechanics.
The Peanut Reservoir
The aluminum tank , preferably aluminum, brings an old school touch to the bobber . They are often small, it reminds us of the fact that they are often bikes for short rides.
In the multitude of tank types (Fatside, King tank, Bobbed gas tank, Wassell Peanut Style, Narrow Alien Chopper, Frisco Mount Chopper Bobber, Mustang, Axed...) available for customization, the Wassell type model is a model appreciated.
Here is the tank provided by remmotorcycle.com:
It is found on a famous preparation of Zeus Custom (different and less known than Deus Custom) or on the Zero Engineering.
And yes this is part of the characteristics of the bobber . There is very little jail on it. The only mandatory part is the tank. So this one dresses up the bike a bit. Many bobbers do not have fenders.
Only the rear fender is "authorized", there is no fairing at the rear, not at the level of the air filter, of the shoe, nothing. Minimum.
The low handlebar
Unlike choppers which tend to have high handlebars or even very high for some, for the bobber , the handlebar is low.
It is more or less wide, with different shapes but only slightly exceeds the tank or the fork in height.
The handlebar is even very low and you have to go forward on the Zero bobber where it is welded to the Springer fork. A special driving position between the arms and the feet forward.
Going back to the model, the flat and curved handlebars are a very popular safe bet.
Here in demonstration:
You can also find more atypical models like this model which takes its inspiration from the motocross handlebars of the 70s:
A classic upturned handlebar can also be used to lower the riding position of the arms.
On the bobbers called "Japanese bobber" the handlebars are higher and quite tight like on the 103 at the time.
The saddle on springs
The spring saddle is one of the first elements that the preparer wants to install to start preparing for a bobber . This is another common element of choppers.
There is a very wide variety of solo saddles on the market with various shapes, colors and qualities.
Model proposed by remmotorcycle.com
Bobber saddles are often black , and sometimes brown . For the type, in the minimalist spirit of the bobber, simple models are the most effective.
Small fantasies may be present at the seams. The saddle can be without seams, with straight seams or with diamond seams.
The shape can also vary. There are flat models and others that follow the shape of the buttocks.
Given the absence of a rear shock absorber, we recommend choosing a quality model. Good foam, the width corresponding to the width of the driver's hindquarters and a metal base that is not too rigid.
Associated with the saddle for comfort, the springs are a very important element. They are to be selected according to the weight of the pilot and must not be too hard otherwise they bring no comfort.
With poor comfort, you can turn a pleasant Sunday outing into a real ordeal.
Here is an example of a comfortable set offered by Remmotorcycle. A set of saddle support, wide springs and hand-shaped saddle.
The famous spring fork is the ultimate element of the bobber. Coming from the standard Harley models of the 60s and 70s, this type of fork is impressive.
The Springer fork has two small shock absorbers at its top.
Custom-made Remmotorcycle Springer fork.
It has great rigidity and a filtration quality different from conventional forks. With this old school technology, it correctly absorbs small irregularities and does not return racquet shots on the trigger.
Nowadays, there are Springer forks that can receive disc brakes at the front to ensure the safety of the motorcycle.
It is with a Springer fork that we differentiate a classic bobber from an ultimate bobber.
However, the Springer fork is not the only solution to bobberize a motorcycle. Parallelogram forks with a monoshock are a type of fork that appeared before Springers.
This type of fork brings a very old side to the preparation. We find beautiful models on Terrots, Peugeots and other vintage motorcycles.
Image: Bobber Shadow 600 in the works
The last solution, more economical to embellish the fork is a solution very appreciated by the Japanese. It is often found on the preparations of Japanese bobbers .
This is to dress the fork with a small fairing, aluminum. This makes the front part more imposing, like a Springer.
Photo: BMW Motorrad R5 compressor concept.
This style moves away from traditional bobbers but is an integral part of the bobber style in Asia. This is one of the differentiating elements between the typical American bobber and the Japanese type.
These fork covers are present on many two-wheelers but the style adopted here is close to that of the Harley Panhead.
This approach was chosen by BMW for its R18.
Photo: these fork covers are available on order.
This keeps the comfort of a classic fork without compromising on the look.
We have seen that for each component of a motorcycle, the bobber has specific elements which make its personality and its originality in the mass of existing motorcycles. In short, the bobber is a stripped-down motorcycle with a rigid frame (or approaching it) of triangular shape, with large tires, a spring saddle and a fan on it!