Fork top refers to the top of the chrome tube, not including the height of any fork cap or adjusting screws etc.
Top triple vertical offset refers to the “gullwing” design of top triple clamp where the clamps are lower than the stem top; we will find a photo to explain. Shorter forks are lighter, and you can get the same functional height out of a shorter pair of forks by lowering the top triple tree clamp relative to the stem.
Things like axle diameter are also important if you wish to keep the wheels from your original front end; there are many more factors to consider when it comes to keeping the front wheel but that is outside the scope of this article.
Orientation refers to the orientation of the forks – whether they are right side up or upside down. Right side up means that the chrome stanchion is at the top of the assembly, upside down (shortened to USD or sometimes called inverted) means that the chrome sliders are at the bottom. There may be an advantage to having USD in that there is lower unsprung weight but they seem more commonly lusted after for their appearance!
Pay particular attention to the steering stem figures if you are considering a new front end – this can be the difference between simply getting a bearing kit or having to press out/in a steering stem (or have a stem modified or fabricated). This is part of the reason why some front end swaps are considered easier than others – if the stem is comparable and all you need is bearings it can be a whole lot easier. Note that there’s more to it than just the stem length – if the positioning of the two threaded sections on the upper part of the stem are different the length being the same may not help you.
Note that with some new forks there are top-out springs which prevent the fork from “relaxing” to it’s full length. Simply letting the weight of the wheel pull the forks down (i.e. lifting the front wheel off the ground while the forks are still on the bike) should be enough to get an accurate measurement of the length of the forks.
Click on any heading (somtimes you have to click twice to get it started) to sort the table by that column.
We are measuring the steering stem length from the flat surface that the bearing sits against (i.e. where the stem enters the lower triple) to the very top of the stem.
In the future we are planning to add a calculator where you can put in which front end you are swapping to, which bike you have and it will provide a figure for how it will alter your rake/trail. That’s in the works.
Finally, why should you care about the overall length of the forks when you are considering front end conversions? Picking a front end that is overall longer or shorter than your existing one will change the rake and trail of your motorcycle, which could profoundly affect the handling – and not always for the better. Scroll down for the table.
Year | Model | Fork diameter | Fork top to axle center | Orientation | Axle diameter | Steering Stem Diameter | Steering Stem Length | Top Triple Vertical Offset | Wheel size | Tyre size | Tyre type | Notes |
---|---|---|---|---|---|---|---|---|---|---|---|---|
1978 | CX500 | 33mm | – | Normal | 15mm | – | 223mm | – | 19″ | 3.25S (~100/90) | Bias Ply | – |
1979-1980 (USA) 1979-1981 (AU) |
CX500 Custom | 33mm | – | Normal | – | – | 223mm | – | 19″ | 3.50 | Bias Ply | – |
1981-1982 | CX500 Custom (USA) | 35mm | 760mm | Normal | – | – | – | – | 19″ | 3.50 | Bias Ply | Leading axle |
1979-1980 | CX500 Deluxe | 33mm | – | Normal | 15mm | – | – | – | 19″ | 3.50 | Bias Ply | – |
1982 | CX500E Sports | 37mm | – | Normal | 15mm | – | – | – | 18″ | 100/90 | Bias Ply | TRAC on left fork |
1982 | CX500 Turbo | 37mm | – | Normal | 15mm | – | – | – | 18″ | 100/90 | Bias Ply | TRAC |
1981-1982 | GL500 | 35mm | 820mm | Normal | 15mm | – | 222mm | – | 19″ | 3.50 100/90 19 | Bias Ply | Steering head height 177mm (ref) |
1981-1982 | GL500 Interstate | 35mm | 845mm? (ref) | Normal | 15mm | – | 222mm | – | 19″ | 3.50 100/90 19 | Bias Ply | Steering head height 177mm (ref) |
1983 | CX650 Eurosport | 37mm | – | Normal | 15mm | – | – | – | 18″ | 100/90 | Bias Ply | TRAC on left fork |
1983 | CX650 Turbo | 37mm | – | Normal | 15mm | – | – | – | – | 100/90 | Bias Ply | – |
1983 | CX650 Custom | 39mm | – | Normal | – | – | – | – | 19″ | 100/90 | Bias Ply | Leading axle |
1983 | GL650 | 37mm | 806mm (ref) 795mm (ref) |
Normal | 15mm, 241mm long | 27mm | 222mm | ? | – | 3.50 | Bias Ply | Steering head height 177mm (ref) |
1983 | GL650 Interstate | 37mm | 795mm (ref) | Normal | – | 27mm | 222mm | – | – | 3.50 | Bias Ply | Steering head height 177mm (ref) |
1991-1994 | CBR600F3 | 41mm | 780mm (ref) | – | – | – | – | – | 17″ | 120/60 17 | – | |
2000 2001 2002 |
CBR929RR/CBR900RR | 43mm | 725mm (ref) | USD | – | – | 222mm (ref) | – | 17″ | 120/70 17 | ||
2003 | CBR954RR | 43mm | 725mm (ref), 717.55mm (ref) | USD | 25mm, 171.45mm long | 30mm at base, 26.5mm mid-up | 222mm (ref) | – | 17″ | 120/70 17 | Stiffer than CBR929RR. Front forks have stepless preload adjustment along with compression and rebound adjustment. Top stop of the CX neck has to be removed, bottom has to be shaved down a little |
|
2001 | CBR600F4i | 43mm | 750mm (ref) | – | – | – | – | – | 17″ | 120/70 17 | – | |
2003 | CBR600RR | 45mm | 725mm (ref) | – | – | – | – | – | 17″ | 120/70 17 | – | |
2004-2005 | CBR1000RR | 43mm | 710mm (ref) | USD | – | – | – | – | 17″ | 120/70 17 | Radial | – |
2005 | Honda CBR600RR | 41mm | 680mm (ref) 712mm (ref) |
USD | 22mm | – | – | – | 17″ | 120/70 ZR17 | Radial | Inverted HMAS cartridge fork w/spring preload, rebound and compression damping adjustment |
2006-2007 | Honda CBR1000RR | 43mm | 720mm | USD | – | – | – | 17″ | 120/70 ZR17 | Radial | ||
2006 | Honda CBR600RR | 41mm | 680mm (ref) 712mm (ref) |
USD | 22mm | – | – | – | 17″ | 120/70 ZR17 | Radial | Inverted HMAS cartridge fork w/spring preload, rebound and compression damping adjustment |
2007 | Honda CBR600RR | 41mm | 718mm (ref, ref) 710mm (ref) |
USD | – | – | – | – | 17″ | 120/70 ZR17 | Radial | Inverted HMAS cartridge fork w/spring preload, rebound and compression damping adjustment |
1974-1979 | Honda GL1000 Goldwing | 37mm | 785mm (ref) | Normal | – | – | – | – | 19″ | 100/90 19 | Bias Ply, Tubes | |
? | Hyosung GT250 and GT250R | 41mm | 775mm | USD | – | – | 217mm | Zero | 17″ | 110/70-17 54H | Radial, Tubeless | Shorter than CX500, not many threads for top nut – requires sleeve for one bearing |
1998-2001 | Yamaha YZF-R1 | 41mm | 740mm (ref) | USD | – | – | – | – | 17″ | 120/70 ZR17 | Radial | – |
2002-2003 | Yamaha YZF-R1 | 43mm | 725mm (ref) | USD | – | – | – | – | 17″ | 120/70 ZR17 | Radial | – |
2014 | Triumph Street Triple R | 41mm | 723.5mm (ref) | USD | ? | 30mm | – | – | 17″ x 3.5″ | 120/70 ZR17 | Radial | Adjustable for preload, compression and rebound |
2006-? | Yamaha R6 | ? | 745.5mm | USD | 21mm left, 28mm right | Top 29mm, bottom 30.5mm | 232mm | ? | ? | ? | ? | 210mm center to center (forks). 108mm radial brake caliper mount. Fork legs 160mm apart. |
2004 | G SXR600 |
Top triple 50mm, lower 51.5mm | 720mm | USD | 25mm | 30mm at top and bottom bearings | 233mm | 30mm | 17″ | 120/70 R17 | Radial | Thanks Tim! |