tok-tokkie
Race Dog
TW Rear Shock.
I wanted to upgrade the suspension on my TW. It is well documented that the shock from a Yamaha Banshee Quad bike fits well but the spring is a bit soft. *Linky*. Besides the TW I also have a BMW F650 Dakar which has lovely plush suspension. But there was something wrong with the rear shock when used Touratech suspension for the Dakar came on the market. I bought the Touratech suspension so I could transfer the Dakar suspension to my TW. This is about the rear suspension.
Those are the two shocks next to each other. Now you can see what was wrong with the Dakar shock – the lower clevis was broken on one side. The Dakar (Showa) shock was external reservoir (upper aluminium tank) and remote spring pre-load adjustment (lower steel tank without the knob in the photo). You can see that the Dakar spring is much stiffer by the thickness of the wire. Notice that the TW spring is ‘progressive’ – the pitch of the coils is less at the bottom than it is at the top. I put ‘progressive’ in quotes because this style of spring is popularly termed progressive when it is a two-rate spring. A proper progressive spring would have constantly changing pitch all along its length (or changing wire diameter or changing coil diameter).
Something that caught me out is the TW shock is fitted upside-down in the bike; the part at the top in the picture is fitted at the bottom on the bike which is not how most shocks are fitted.
Here is what I fitted to my bike. Martin Paetzold of MP Custom Valve combined the two shocks using the internals from the Dakar in the outside of the TW shock plus a new clevis end with rebound adjustment (black screw visible in photo). I made the bracket for clamping the external tank to the shock and also milled and tapped it so now it has adjustable compression damping – the screw on the external tank. Martin also fitted the remote spring pre-load adjuster to the shock. The original ‘progressive’ spring has been used.
That is the compression adjuster and the port I milled & tapped in the housing for it. Such a simple little thing ; it is pretty sad that BMW did not fit it as original equipment.
That’s it in the bike. I welded a small bracket on the frame tube on the left of the picture – the spring pre-load adjuster sits there now.
This shock is less harsh than the original because Martin has lessened the damping to match my weight. The stroke is slightly increased and the bike is a little higher. I have done a 2500 km trip with luggage and bottomed the rear shock a couple of times. The damping shims could be even softer I feel as I have both screwed right out to their softest and also the spring pre-load at its least. I prefer a soft spongy ride.
Fitting a Banshee shock would have been much simpler but I needed to fix the Dakar shock & had access to a used Touratech shock so this way worked out nicely for me.
I wanted to upgrade the suspension on my TW. It is well documented that the shock from a Yamaha Banshee Quad bike fits well but the spring is a bit soft. *Linky*. Besides the TW I also have a BMW F650 Dakar which has lovely plush suspension. But there was something wrong with the rear shock when used Touratech suspension for the Dakar came on the market. I bought the Touratech suspension so I could transfer the Dakar suspension to my TW. This is about the rear suspension.
Those are the two shocks next to each other. Now you can see what was wrong with the Dakar shock – the lower clevis was broken on one side. The Dakar (Showa) shock was external reservoir (upper aluminium tank) and remote spring pre-load adjustment (lower steel tank without the knob in the photo). You can see that the Dakar spring is much stiffer by the thickness of the wire. Notice that the TW spring is ‘progressive’ – the pitch of the coils is less at the bottom than it is at the top. I put ‘progressive’ in quotes because this style of spring is popularly termed progressive when it is a two-rate spring. A proper progressive spring would have constantly changing pitch all along its length (or changing wire diameter or changing coil diameter).
Something that caught me out is the TW shock is fitted upside-down in the bike; the part at the top in the picture is fitted at the bottom on the bike which is not how most shocks are fitted.
Here is what I fitted to my bike. Martin Paetzold of MP Custom Valve combined the two shocks using the internals from the Dakar in the outside of the TW shock plus a new clevis end with rebound adjustment (black screw visible in photo). I made the bracket for clamping the external tank to the shock and also milled and tapped it so now it has adjustable compression damping – the screw on the external tank. Martin also fitted the remote spring pre-load adjuster to the shock. The original ‘progressive’ spring has been used.
That is the compression adjuster and the port I milled & tapped in the housing for it. Such a simple little thing ; it is pretty sad that BMW did not fit it as original equipment.
That’s it in the bike. I welded a small bracket on the frame tube on the left of the picture – the spring pre-load adjuster sits there now.
This shock is less harsh than the original because Martin has lessened the damping to match my weight. The stroke is slightly increased and the bike is a little higher. I have done a 2500 km trip with luggage and bottomed the rear shock a couple of times. The damping shims could be even softer I feel as I have both screwed right out to their softest and also the spring pre-load at its least. I prefer a soft spongy ride.
Fitting a Banshee shock would have been much simpler but I needed to fix the Dakar shock & had access to a used Touratech shock so this way worked out nicely for me.
