Project CB690 (KTM 690 engine in a CB550f frame)


Over 1,000 Posts
Hydraulic brakes shouldn't be a problem, but manual drums set up like that - if the torque stay should give any, it just grabs the brakes harder. I enjoyed a 65 mph slide down Folly Beach Road in the mid '70s from that.


Been Around the Block
The bike is all back together and ready for a test ride. However the weather is pants so went on to some other projects. The radiator trim needed doing. I got some 38mm wide aluminium that has a curved profile, and just cut and rounded the ends. This will be painted black later. I also got an OEM Suzuki radiator screen and side cover bits in an auction. I had to modify the side cover bits, as they are now top/bottom cover bits. All's good, I'm happy with it. Also need to mount the horn somewhere, and a number of other small tasks. As soon as it stops raining I'll go do a shakedown run and test the shortened swingarm.


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Over 10,000 Posts
That's a really nice torque arm, but torque arms are best in tension mode. If the load causes it to twist or bend, it can result in a locked up rear brake. The simplest set up is located on a peg in the swingarm, but if it needs a torque arm, it's better to have it in tension.

We had an RS125 racer years ago with a skinny little torque arm (in tension). The early GS 4 cylinder Suzukis used a 3/4" tube in compression, but a large diameter tube can handle more twisting/bending load than a thin rod. The larger the diameter, the greater the load it can carry, so a large diameter tube is stiffer than a small diameter rod.

How as the caliper retained on teh KTM wheel/swingarm combo and can that be replicated.

Richard Pitman

New Member
I've been reading your CD175 project with interest, even made a couple of suggestions, under the user name I M Band. This was a dig at Vertical Scope, who banned me for posting links to the new independent Vintage Honda Twins site, where most of us long time Honda Twins members moved to, following disgust at the way VS were / are running the original HT site. It'd be great if you'd look in at us over at VHT, all the old crew are there.

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