Fork Leg brace for 34mm front end

[richard]

I couldn’t find a fork brace for my XS1B so I decided to make one. The bike has a the 34mm XS2 front end that it came with and appears pretty sturdy, but since I have had a fork brace on every one on my bikes I decided if I couldn’t buy one I’ll make one. I figure how long could it take? Two or three days max in my spare time. OK so it took a lot longer than three days after all, but now I am probably the only one with a fork brace on a XS1.

This is how it starts. Some left over T-6 aluminum and a felt pen.



I milled the mating surfaces and countersunk two threaded holes and joined each of them then mounted them on a mandrel I made and mounted that on a rotary table



I used an end mill to cut a slot in the block making the shoulder for the boot to fit on, then I milled the slot wider and wider until there was room for the boot and clamp to hold it on.



Next I cut away to get the offset to clear the fender. I just kind of eyeballed itnext to the fork, but when it was close I fit and measured it removed material until it cleared the fender completely. Since the bore on both sides was exactly 50mm it was a tight fit getting it on and off. I never clamped it very tight until it was finished. With a 1 to 1 fit it would be pretty snug once it was on.




Once the brace was roughed out then it was just a matter of removing excess material and measuring the distance between the clamps, for the block to connect them together. The center of the two clamps has to be right on so it won't bind or blow the seals. There was a lot of measuring and and milling, but once I had things where I wanted I countersunk the holes and milled the plate to match the clamps.






Once I had everything on I made sure it moved freely with no binding. Then attached the boots and clamps.



It took considerably more than three days to make the brace by the time it was done but it seems to work well so far.



I don’t know if the brace was necessary but it was fun making it and it seems to work well.

[5twins]

Well, I can tell you they really help on the later forks so I'm sure it will on your 34mm ones. MikesXS now sells progressive springs for yours (I think). You might consider them. His springs for the later forks are pretty crappy but for the 34s, they're made in Germany (ooh, aah). If I had the older forks, I would probably "spring" (lol) for them.

[5twins]

Oh, and that design looks somewhat familiar .....

[richard]

Thanks 5twins
Well it’s good to hear my time wasn’t wasted. There seems to be a difference but I haven’t ridden it enough to be sure. I installed a set of those German progressive springs which made a big difference over the originals which were pretty weak. I’m sure age was a factor. My design for the brace was off the top of my head and memory of the braces on my other bikes. The difference was the rise of the fender over the legs, which was a lot more than any other. I just figured to start with a really big block fo aluminum and cut it away until it matched the profile of the fender. It seems to have worked. I like soft tires and as little flex as possible so the bike is predictable. They are just a lot more fun when you feel comfortable with how they handle. That brace on your bike looks great! That's a clean design

[Tom Graham]

Hi Richard,

Shortly after I installed my T-Kat fork brace I rode over a section of rough road in an industrial area. This route was one I take once or twice a week so it was familiar. The forks and the entire bike felt solid and more planted. Up until I hit those sharp bumps of the repaired pavement I did not know if the brace was worth the money. It certainly is and you will be happy you have it every day. Plus, it looks great!

A sweet addition to a sweet bike.

Tom Graham

[5twins]

On mine, what demonstrated to me the need for a fork brace was simply grabbing the front brake and pumping the forks up and down in my driveway. Watching the front fender over the tire as I did so showed the fender moving side to side over the tire as I pumped the forks. If it had this amount of flex just sitting in my driveway, I could imagine what was going on while I was driving down the road, especially when I grabbed the front brake or pushed it hard through a corner.

[richard]

That’s interesting I’ll have to try that. On my other bikes braking into a corners is where I noticed the difference. It eliminated the chatter which can be pretty spooky when it happens. I probably shouldn't be going that fast, but it happens:-)

[XS Rod]

Totally BA Richard... Totally, excellent job!!

[richard]

Thanks :-)

[650leo]

Very well done, any idea on what you might charge for a set?

[richard]

Thanks 650leo

LOL How much do you have :-)

Well I have about 40 hours into this one so it’s there is no way to break even on making one from scratch. I just worked on it as I had the time.

A better choice would be a company that is online called “Fast from the Past” they have just about every fork brace for any vintage bike for around $120 bucks. That would be the place to start if you are looking for one. I have thought about it and the most efficient way to get a fork brace for a bike like mine would be to buy a brace with the right diameter clamps and sufficient rise over the fender then modify the piece that crosses over the fender to fit your bike. The problem I had was that no one made a 50mm clamp with a rise that would match my XS2 front end. That’s why I resorted to making one from scratch. I could mill a crossover block for your fork brace , but a custom brace wouldn’t be cheap even If I charged $10 and hour.

Here is a sizing chart
www.fastfromthepast.com/PDF/fork_brace_dimensions.pdf

I do have a Paolo Tarozzi # 25-0026 RD400 brace I never used if anyone is interested. I made some 2mm shims for it to match the 50mm leg but it didn't have enough rise to clear my XS2 fender so I set it aside.