Fork brace dimensions

[Rasputin]

I do not currently have a Special in my stable to measure everything required for this form. Can one of you fill it out so I can return it to the fork brace outfit. We would also need a measurement from top of forks to top of fender which is not shown on the form.
Even though they are a bit pricey, at least they would be available for all of us. They currently only have a brace that fits the Standards but are willing to add a model for the Specials.
Thanks to anyone willing to help out.

[jetmechmarty]

I have a Special with TKat brace. I’m not willing to take it apart right now because too many irons in the fire. If this isn’t answered in the next few weeks I’ll offer up some information.

[Rasputin]

I have a Special with TKat brace. I’m not willing to take it apart right now because too many irons in the fire. If this isn’t answered in the next few weeks I’ll offer up some information.

Sounds good Marty as I have had a TKat brace before and to copy his dimensions would be the perfect solution. Hopeful that we have a few who participate.

[Appie]

Ok here goes, Rasputin

I have a leaking front fork so needed to remove the dust seal to inspect. The bike is an ‘81 Special. ?European model

1. Stanchion (Diameter 1) 37mm
2. Fork leg (Diameter 2) 57.93mm
3. Outer stanchion to outer stanchion 220mm so centre to centre approx. 184mm
4. Depth/length of rim (top of fork leg) 7.92mm
5. Undercut diameter 53.92mm
6. Undercut length 7.4mm
7 Top of fork to mudguard 440mm approx (in position on bike)

I’ve attached pics so you can see where I got the numbers. Sorry, they aren’t attached quite in sequence. If you need any more measurements or pics I’ll take them for you.

Should be correct unless my caliper is inaccurate, maybe someone can give a second set of readings to correlate before you send them off to the manufacturer.

[Rasputin]

Looks good. I like your idea to have back up numbers before submission. Far better to send them the correct dimensions rather than have a bunch made that do not fit correctly I think the closer to the lower triple tree the better for measuring center to center on the fork tubes as the bottom can be moved a bit. If it goes anything like when I fitted the brake lines for XJ4Ever one will be made and test fit first. Whoever test fits it will probably be able to keep it for free, but that is not a for sure thing. I do not have a Special model right now so I would send it to someone who contributes as you have for the test fit. Thanks for doing that

[Appie]

I went back and measured right below the triple clamp and another from a spare one. You’re correct, that first measurement was taken by the mudguard and is slightly less lower down where the forks have been clamped at the wheel axle .

[cajun31]

I just wanted to comment but wasn't it true that the specials that we received in the USA were never introduced in the European market? I believe they got the sports. The dimensions were different and I believe Tarozzi has a fork brace available for the sport that doesn't fit the specials we have here in the USA. Really need to wait until Marty or someone gets the measurements from a US based special for comparison.

[DiverRay]

I'll try to get to mine today. I plan on riding it anyway, as it's in the lower 900's here. I KNOW mine is a stock '79 Special built for the US market.

[bikerphil]

Diameter 1: 37MM
Diameter 2: 58MM
CD: 185MM
Depth: 15.7MM
Undercut diameter: 8MM
Undercut depth: 53.7MM

[DiverRay]

Center distance MUST have at least 2mm adjustment available. Tkat had about 10mm so brace could be centered. The lower legs may need to move up to 3mm each for the brakes. This is for the Special and the "special" brakes they have.
Also, cross bar for the brace needs to be about 40mm ABOVE the fork leg to clear the fender. This is a guess until I get a bit of time to measure with some tools.

[jetmechmarty]

I'm covered up right now, or I would remove my brace and measure. It may be a few weeks.

[DiverRay]

OK, here is what I have from my '79 Special. I do not have the tool to get a good center line measurement. This distance DOES need to be adjustable by 2 to 4mm due to brake design.
Dia. 1 37mm
Dia. 2 57.8mm
Depth at top of fork 15.4mm
Undercut Diameter 54mm
Undercut length 7.5mm
Arch, YES! 20mm
Dust seals Yes

[Rasputin]

Good point on the adjust-ability due to movement in the front forks. I probably would have forgotten that,