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Old 02-26-2014, 08:18 PM   #1
Davis53 OP
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San Jose BMW front fork brace? Airhead

I am in search of a San Jose BMW front fork brace for my 1976 R90/6. I have a tire clearance problem with the side wall of the tire rubbing the fender brace, and hoping this will solve the problem.

Does anyone know what price these are going for? I know that they are not manufactured anymore.

This bike has a sidecar mounted to it and I switched to a set of raked triple clamps, with the new clamps the clearance problem started.
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Old 02-26-2014, 11:25 PM   #2
Rob Farmer
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Flat racer make a replica www.flatracer.com

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Old 02-26-2014, 11:36 PM   #3
ME 109
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Fit bike to brace, not brace to bike.
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Old 02-27-2014, 05:00 AM   #4
bmwrench
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San Jose makes a run of these braces from time to time. Also, check out Phast by Phillips.
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Old 02-27-2014, 05:56 AM   #5
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Quote:
Originally Posted by bmwrench View Post
San Jose makes a run of these braces from time to time. Also, check out Phast by Phillips.
I have two from San Jose; one on my R90S, and one on my youngest son's R90/6 which we are restoring - just finished totally rebuilding the front end. Recently purchase one from Phast by Phillips for my oldest son's R90S project - looks like a well made piece.
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Old 02-28-2014, 06:07 PM   #6
Davis53 OP
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Thanks for all the replies, I now have one on the way. Got it on Ebay, $200.
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Old 02-28-2014, 07:45 PM   #7
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Originally Posted by Davis53 View Post
Thanks for all the replies, I now have one on the way. Got it on Ebay, $200.
Man I'd make them all day long for 200 bucks a piece.
They look crap but I'd still make 'em!
Reminds me of Forrest Gump when he was a kid.
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Old 02-28-2014, 07:58 PM   #8
Davis53 OP
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You know I thought long and hard about building one myself. It is the bend on the fork leg mounting plate that looks kind of difficult to me. The fender loops don't look so bad.

Another thought about if it ain't straight it is going to bind the forks. It is a questionable if the one I have coming is straight.
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Old 02-28-2014, 10:12 PM   #9
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Old 02-28-2014, 10:16 PM   #10
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Originally Posted by Davis53 View Post

Another thought about if it ain't straight it is going to bind the forks. It is a questionable if the one I have coming is straight.

Doesn't matter a hoot if the brace is not straight. Within the realms of reason of course.
A brace should only be fitted to a known 'good enough' aligned front end. Any brace fitted to any front end without assessment and accurate correction, will be thrown out of court.

The shape of those 'chuck wagon' braces is just not sound engineering for a rigid structure. Nor is it for the oe pie plate brace.
Both braces will flex across three axis without a significant load so I can only assume that it doesn't take too much to keep our front ends happy.

If you're happy with the way your bike handles, go ahead and fit it up. Do it with the front wheel off.
If your axle does not slide reasonably easily in and out with no brace in position, don't fit the new brace until it does.
If it doesn't, find out why. Start with the axle, check for burrs, and straightness.
Check the axle bore in the sliders for burrs or damage from po's.
Slide the axle through each fork leg individually. If that's all good, slide the axle through both sliders.
If that doesn't happen, you have to climb higher up the tree, so to speak.

When the front end is ready for the fitting of a brace........there must be no gap, and no pressure, where the fork leg and brace touch in four places.
Those two contact surfaces (x4) need to be very parallel so as not to become 'under load' when the 4 bolts are fully tightened.
Tighten each bolt while spinning the axle. If you can tighten 4 bolts without the axle binding, you're a legend.
Otherwise, if you tighten a bolt and the axle binds, that brace/slider interface is not correct. Take the brace off and bent to suit, or shim it.

I really should be out mowing the lawns.
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Old 03-01-2014, 09:13 AM   #11
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If I was running a twin shock beemer, that design is the best fork brace available. It's probably the most rigid fork brace out there. I think it would be nice to make them out of thinner wall tubing but that makes bending the tubes thusly much more of a job. Those tubes are bent with a tube bender. The tubes have to be pretty thick to bend them like that or they would collapse. The setup would be just as strong with much thinner walled 4130 tubing. I always wanted to make myself a couple of sets out of much thinner walled 4130 while I worked there but I never got around to it. Those are made out of 1018.

ME's installation advise doesn't mention a crucial fact. The brace can fit perfectly AS IS and still bind the forks every time you tighten down the brace time after time until it doesn't. Do not start bending and shimming the brace until you you have tightened everything down every different way you can think of a half dozen times. Only then move on to shimming and such. Perfectly straight stuff rarely tightens down straight the first number of times. Randy Glass's fork alignment article fails to point this fact out as well. Good luck!
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Old 03-01-2014, 12:21 PM   #12
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If a perfectly fitting brace binds the forks when the bolts are tightened, it doesn't fit. Full stop.
That's why I didn't mention it.

As I mentioned........

When the front end is ready for the fitting of a brace........there must be no gap, and no pressure, where the fork leg and brace touch in four places.
Those two contact surfaces (x4) need to be very parallel so as not to become 'under load' when the 4 bolts are fully tightened.
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Old 03-01-2014, 01:03 PM   #13
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I can't speak for the Phillips brace, but I never saw a San Jose brace that didn't fit correctly. The difference in the way the bike steers with one has to be experienced to be believed. I can't say the same for the Telefix brace.

I was stunned to read that the SJ brace is made of 1018. I suppose getting 4031 to bend in short radius would be challenging.
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Old 03-01-2014, 05:06 PM   #14
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If a perfectly fitting brace binds the forks when tightened down it doesn't fit [and isn't straight]?? Complete and utter nonsense. When was the last time you worked with anything straight ME? There is a thousand ways to tighten down a completely perfectly straight front end with a fork brace or not that binds the forks.

4130 bends the exact same way 1018 bends. It's just that 4130 is a bit stronger in tension than 1018 and a lot stronger in compression than 1018 so the thinner walled tubes would be just as strong as thicker walled 1018. Pretty much the whole reason aircraft use 4130. Just as strong with less material adds up to just as strong with less weight. The thinner walled tubing that 4130 allows is harder to bend not for being 4130 but for being thinner walled. It's a lot trickier to bend thinner walled tubing without collapsing the tube.

I would not have a Telefix on my bike. We use to call them 'tellalawyer' fork braces. They are all wrong on numerous levels.

I can't remember for sure but I think some of those fork braces were made out of 1020. I would be surprised if 1020 stresses much differently than 1018 but it cuts SO much better. I like it just for that. I have not seen any new 1020. All the 1020 I have seen was real old stock. I have worked with some 1025. An old boss preferred that over 4130 for some stuff but I can't remember why right now.

supershaft screwed with this post 03-01-2014 at 05:29 PM
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Old 03-01-2014, 05:27 PM   #15
ME 109
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Quote:
Originally Posted by supershaft View Post
When was the last time you worked with anything straight ME? .
Cracks me up.

My forks 'were' perfectly straight, as was my triple tree. That was about three years ago. Who knows where things are at now.
Mind you I have no complaints with how my front end behaves.

''There is a thousand ways to tighten down a completely perfectly straight front end with a fork brace or not that binds the forks."

Yes, we know that. That's why the fit needs to be perfect, so as not to bind.
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