Brain fork build

[Uncle Stretch]

Ok this could be bike talk related ,but since it will be built and on my next build...I think bike build.
I decided to try a couple differant fork builds. I went to my friendly fab shop and he cut out and drilled holes for the John Brain springer. He charged me $25 for both of my designs.....I thought was dang cheap. The second was a 2'' wide piece of 1/4'' thick steel with a 1'' hole drilled in for the tube, 4'' wide. I'm not sure how this will turn out but it should look beefy. I have most of the stuff to do the Brain springer , with the exception on the freeze plugs. Need to read the post again and see how to put it together. In case anyone missed it ,here is the link http://bikerodnkustom3.homestead.com/brainfork.html . So sometime this week I should have a couple new forks...I will keep everybody posted on the progress.

 

[user 135]

Please document well so this can be indexed in the HOW TO Manual.

The other fork design looks beefy....

 

[sidsky]

nice!!!!! so you decided to use flat bar instead of tube, nice!!!!
i want to do this too, hopefully a friend can help me drill holes and cut me some 1/4" steels.
can't wait to see the finished look!!!!

 

[Uncle Stretch]

Ok snag one. The scedule 40 pipe I wanted to use for the larger legs of the springer wound up being 1 1/8'' od . I have some tubing that is 1'' ,but its kinda thin. I'm still deciding which would be better the thin stuff that fits or the thick stuff that I will have to make fit. I have the option of having a friend turn the 1 1/8 '' thick pipe down some to fit or take a die grinder and grind out the holes to the bigger size. It will be alot easier on the next one if I get the guy to drill the holes 1 1/8'' to fit the stronger tubing. Still rounding up materials.

 

[Uncle Stretch]

nice!!!!! so you decided to use flat bar instead of tube, nice!!!!
i want to do this too, hopefully a friend can help me drill holes and cut me some 1/4" steels.
can't wait to see the finished look!!!!

On the big thick one I'm not sure if I'm going to taper it down near the dropouts slots or not. It was just an idea caused by boredom :lol:

 

[sidsky]

eigther way you do it, i know it will look custom sick!!!!!
can't wait!!!
what spring are you using?? i'll prolly use the spring from the fork of my old yamaha fazer, the bike is junk anyways, prolly take some stuff there that i could use.

 

[Uncle Stretch]

Snag number 2
On the plan he says to drill 5/8'' holes in the plates. Its so the 1/2'' rod in between the two sets of springs wont bind in the hole . He dosent tell you to drill a 1/2'' hole in the 1/4 x 3 1/2 x 12'' spring plate. Make sure its not a 5/8'' hole like I did. It will have to be reduced for the 1/2 '' rods to fit in tight. ooops.

On a positive note...A piece of 5/8'' ID schedule 40 pipe will slide inside the wimpy 1'' OD tubing and give you a lot stronger tube. If you stick it out about a 1/4'' at the top and then drill the two holes 7/8'' ,instead of 1'' you could weld a small nut in each pipe and be able to bolt on the top plate . If you drill a couple holes in the sides of the 1'' tubing top and bottom you can plug weld them and then flap disk them back to smooth to hold the pipe inside of the tubing. I will try to get some pics to explain this as I go along.
One more thing for those that don't know....Pipe is measured by inside diameter thus I.D. and tubing is measured by outside diameter thus O.D. Lesson for the day Kids
It looks like to me that since nothing on this fork has to be any certain size ...find the pipe or tubing you have or can buy and then drill your holes to match, instead of useing the sizes he has . It will still work and look good .

 

[AussieJester]

As you know i have also built the John Brain designed springer, ill give you a tip DONT squash the springer tube
per the instructions, use rose joint ends. Following the method outline it will wear quickly and produce a very sloppy fork, rose joint ends are cheap and contain sealed bearings. I plan to redo my fork tube using large rose joint ends in very near future do to the frequent adjustment due to wear. Also i HIGHLY recommend the welding of nuts in the top of the fork tubes so you can bolt the top plate down rather than just have it sit loosely over the forks tubes, it flexes horribly the way outlined in the plans, i believe John does add a side note regarding this addition in the plans. They are an excellent fork though, i suggest using a basic jig to hold and all in plates and fork tubes when welding too ti ensure they don't move during welding.

Picks of the ends of my springer tubes and how i added the rose joint ends

Additon of the nut in the top of the fork tube

Core plusg make GREAT spring retainers too Uncle-->

I originally made my own but the core plugs are definately the shot and cheap as chips from Auto Shop.

Finished fork..OH i also added disk brake mounts on my rockers

Another additon if you planto use frot brake on the bike, little tubing welded to the springer
tube too run your brake cable through -->

Aslo...pit bike bar clamps can be used and screwed directly into the top of the fork tube if you wish
to do away with the 'standard' type bicycle stem-->

hope these 'tips' are of help anywayz

Look forward to seeing the finished fork...

KiM

 

[Uncle Stretch]

As you stick one of these together the need for changes becomes glaringly appearant. I couldnt believe he had the tubes just slid into the top plate. Yours turned out good. We call those things Hyme joints and I have a few ,but never found them to be cheap. I will have to check prices on them. Thanks for the tips. I guess if you were John Brain and giving away your ideas for free then people should be able to fix whatever problems they come up with.

 

[AussieJester]

We call those things Hyme joints and I have a few

I paid too much ($18ea) for the ones i used as i bought them from a rip off shop, 100 meters up the road is a better shop cheaper prices with turned steel
joints i paid8 bucks each for the two for the actuators, same size as the forks use :-S Live and learn.....DEFINITELY worth the $$$ though even at 18 bucks
as they improve the fork immensely IMO... For the fork tubes and the top plat, i also cut a round steel plate to weld over the hole in the plat, so yo have a recess for the top of the tube to slot into, not clear in the pics, then the aluminium circle is placed over that then the pocket bike bar clamp, makes the fork rock solid no flex, without they flex every time you turn the bars.

KiM

p.s Jouhn Brain actually left a comment on my trike youtube video was great to hear from him

 

[Uncle Stretch]

It did turn out looking nice. I'm going to try to get the rest of the stuff I need tomorrow and maybe get mine put together.

 

[user 135]

Ok no update? Whats the deal ..... Take a vacation day boy? :roll:

I figured you would be riding in comfort by now. :mrgreen: :mrgreen: :mrgreen:

 

[Uncle Stretch]

well I found the porch springs and the freeze plugs to fit them, But I drove to everywhere I could think and couldnt find the top springs or the hyme joints . I may have to run into Houston tomorrow and see what I can scrounge up. If you had all the parts you could weld this up in a flash.

 

[AussieJester]

HAHA i was the opposite Uncle i couldnt find the right size lower springs anywhere, my local hardware has assorted springs sizes but all were too small (initially i used them but too weak) I ended up getting a set from my mates ChoppersUS springer fork they have 4 of the same
size springs which isnt correct obviously, so mate gave me two and used the same ones as i got from harware on top
his fork works 100% better and so does mine hehe..... I can send you a set if you cant find any local mate you pay freight
i have some here i can give you.

KiM

 

[Uncle Stretch]

I will find some tomorrow . Houston has several spring companies so it just a trip to one. My dinky town is a small rural town,stuck on the south end of Houston.
Oh by the way nobody here has any Idea what 30 is there. Its either real hot or a little below freezing....Yall and that dang Metric system anyway.

 

[AussieJester]

Oh by the way nobody here has any Idea what 30 is there. Its either real hot or a little below freezing...

30 ºC = 86 ºF Metric FTW Uncle Stretch this inches and Fahrenheit business is old school USA needs to join the rest of the world and update

KiM

 

[deorman]

Actually, Celsius is pretty easy to remember. Store dead fish in a bucket of zero, make your lobster scream in 100.

 

[Dorian]

Thats great your making one of those forks. I wrote to John Brain about making my own once but I eventually gave up and got a set of tripletrees. I thought the dropout connection sounded kinda simple and he said hes had springers with that set up working great for years and just readjusts them once in a while. He said people would write him asking him to make one for them, so he made the springer plans so they could make their own for cheap. He answered every question I had which was nice. I think those plans are like 6 years old. I think he said he made that
springer in 2 days or something, looks easy when he does it lol. I want to make my own set now, your project is inspiring me.

Dorian

 

[Uncle Stretch]

It really isnt that hard. There are a couple things that can be changed and makes it a little better. I havent finished mine yet because I was trying to finish that bike build,now I have company for a week . I will get it done though. Seemed pretty easy to me.

 

[MeanOldManMike]

I used 4 Chevy valve springs and tack welded them together for my fork. Grab the retainers when you get them then you don't need the freeze plugs.
I thought the fork was really heavy so I built a second one using the 5/8 tube for both tubes. I know you don't worry about weight on your bikes.
If you are going for a long fork then I could see the 1" tube. I wanted a more stock length.
I also went for a different look and used one large spring, Something for you to play with later after you finish the first one.