Board Track Racer Projects

[DareDevil]

Hi...Im new to this forum and have been lurking around for about 3 months gathering information as to what my projects would be....I have two that I will start but there will a time laps some t
imes as Im in the middle of a major reso job on a car..and I need to get it finished...Im starting these projects as I need something different to swap to as working on the same thing day in day out get a bit daunting sometimes..The first project will be a similar setup as the Thor (Steveboardracer) type build...Havent decided what engine to use as I have a 38cc zenoah or a 49cc CR opposed twin...Here in Victoria we can have up to 50cc before its called a Moped.....Have been hunting around for parts to start this project ..
The second project is a full size Board Track Racer...I like the Excelsior with the 1910 rear frame set up and the 1919 front clip..recently a very excellent reproduction was built ..I will never be able to replicate it but would like to build similar with what parts I can make...I have a V250cc engine and some 21" wheels ..My next task will be to draw these two up full size on working sheets...I need to build both the frames together and get that behind me and then I concentrate on the Thor project.....DareDevil

 

[harry76]

Gday mate. Good to see more Aussies on here.

Looking forward to see what you do with these projects.

Im really a big fan of "Hillbillys" "Thor" boardtrack replica, unfortunately i cant find much info on that bike..... I know hes a fellow Aussie but there is very little info on his "Thor" ride. Id love to see more of it........ i have this link to that bike http://bikerodnkustom4.homestead.com/gallery403.html ............... if you have a different link id love to see it.

 

[DareDevil]

Hi Harry...What I know about the "Thor" is some thing I saw on the Ozzroders site about 6 months ago..this is what inspired me to build.. I think he maybe a fellow hot rodder...he is in Qld and his name is Steve ????...its a great looking bike and very well finished...this is the bike I would like to riding around the estate on....My other build the Excelsoir will be a big boys toy......

 

[Lurker]

Excellent! I thought about using the 250 v-twin for my project but decided to go with the briggs instead. I am very interested to see what can be done with the cool little engine. Best of luck on you project.

 

[DareDevil]

Hi .. Thanks Lurker...It took a while to find one...theres not a lot of them here and even less being dismantled..its weight is about 75lbs... very light..I will change the carby to a old type Amal to try and keep the early look...starter motor is missing but I will put a freeze plug in the hole....I'm doing a full size drawing today to work off and will post it later.....was looking at the Lifan motor.. but heard there is a problem with quality control of the product...The v 250 I brought has a few miles on it but its not like I will use it very often...hope it blows a bit of smoke when it starts ...

 

[DareDevil]

Hi ..I have done a scale drawing...have allowed the tyres 1 1/2" oversize....have used the 50" wheel base "axel to axel" which I think most of them are built... I might have to extend it to 52"...need some comment on this..I will redraw the wheels with the right size tyre OD ...not quite sure of the height of the tire for the 21" XL wheels and if comes to 26'"..The engine is 13.1/2" over the crank case area and through bolts back and front is 11"....not going to start cutting tube untill its right......

 

[RicksRides]

Hi ..I have done a scale drawing...have allowed the tyres 1 1/2" oversize....have used the 50" wheel base "axel to axel" which I think most of them are built... I might have to extend it to 52"...need some comment on this..I will redraw the wheels with the right size tyre OD ...not quite sure of the height of the tire for the 21" XL wheels and if comes to 26'"..The engine is 13.1/2" over the crank case area and through bolts back and front is 11"....not going to start cutting tube untill its right......

21in rim with avons are 27.1 inches tall

 

[DareDevil]

Hi RicksRides....Thanks for the infomation...probally have to extent the center of the frame by 2 1/2 " this will make the wheelbase to 52 1/2" .......

 

[RicksRides]

Hi RicksRides....Thanks for the infomation...probally have to extent the center of the frame by 2 1/2 " this will make the wheelbase to 52 1/2" .......

daredevil, Research actual BTR's and youll find a wheel base of 55-58 inches depending on make,model,year,etc...remember to give yourself enough rake and trail. If you dont have enough the bike will handle like crap twitchy,wobbly,you get the idea. on 58 inch wheelbase I like about 4.5-5 inches of trail. Check out the old motorcycles of the turn of the century youll see what I mean.

 

[DareDevil]

Hi RicksRides...Thanks again for the infomation...going over some of the older threads I came across some info that Boardtrackracer had posted about his blue Exclesior and the wheel base was 53" and this measured spot on with an original...so I will go with this..as I said #8 I will have to 2 1/2" to the center of the frame..I wil use a light through a print out of the Excelisor to get the stance correct...the only worry is useing a late model engine....I had a J.A.P 1000cc about 55 years ago out off an 1930 NewImperial didn't think anything about it back than ..just an old motor...think I sold it to a farmer to drive a pump......

 

[Lurker]

Your design look pretty good but there are a few areas I would tweak.

The most noticeable thing for me is the wheel base. Last summer I had the opportunity to go to the national motorcycle museum and when I went I took a tape measure. I did not see one bike that was shorter than 55" from axle to axle. 55" was the shortest and that was on a 1923 hd flat track racer.

Second thing that sticks out to me is the height. A good general rule of thumb is that cross bar is the same height or lower than the top of the rim. When doing research for my v-twin build this was one thing that all the bikes had in common. Lowering the crossbar will also allow for the engine to sit lower effectively lowering the center of gravity of the bike. Also the bottom of the engine cradle is usually about 2" above the bottom of the rim

I hope you are not offended by this mini critique, I just want you to build something that looks authentic and that you are 100% satisfied with.

 

[DareDevil]

Hi Lurker...Thanks for the infomation...this is what I want so I can get it right before construction...definatly NO offence taken....The wheelbase is 50" on the first set up and does look stumpy...I will extent it to 55" and redraw it...I had made this drawing from a photo useing 5" squares and I knew it would be out a few inches...the info on the top and bottom bars is great and something to watch as I draw it up again..the only museum that is close to me is in another state...that would have anything resembling a board track racer...500 miles away...so I'm rely-ing on help from you guy's....still chaseing some shipping charges on tires to get them to Ozz......

 

[DareDevil]

Hi Lurker .. Have done another full size draw ... have increased the wheel base by three inchs...looks better.. not so stumpy...I have to get the engine out of the shed and do a profile so I can overlay it on the draw..the out line of wheels is 27"....the broken line is the tank area..I think the tank has a 2" beval at the front of it....I have photo of it somewhere looking down on it...its 2 pieces each side of the frame....might be able to do the engine profile tomorrow if its not raining...I have posted another photo of the Excelsoir ..its shows the cross bar is nearly level with the top of the rim....

 

[Lurker]

That looks so much better DareDevil. I really like how you designed the head tube area, very unique. Its little details like that, that make these builds so unique and different.

 

[DareDevil]

Hi ..Have spent a few hours on the computer working out how to print out a full size photo of the V engine....finaly worked it out...Can now move it around the drawing to fit and work out engine mounts...I am going to change the leading down tube...it will fit into the lower head tube and will have a curve in it...photo will show how the head tube should be set up......

 

[DareDevil]

Hi.. Forgot the head tube setup photo ..this is not mine.. but should be similar

 

[curtisfox]

Another AWESOME home build to watch love it ..........Curt

 

[DareDevil]

Hi Curt...Spent some time to day working on drawings for the front fork suspenion axle rocker and the rear fork axle brace...the front fork axle rocker will be 1/2" thick steel and the rizers I will machine up on the lathe and bronze them in place..the rear fork brace is 6mm plate and has a double sided spacer on the top ..do the same with this and braize into place...there is also a axle adjustment ferrel on the side will machine this up and drill.. tap thread and I will mig this into place....need to make these parts before I start to cut pipe...Will be looking for some tapered bearings tomorrow for the fork head....once I find what I want I will draw up the parts for the leaf spring forks..

 

[DareDevil]

Hi .... Any body know how stiff the spring rate is on a leaf spring front end

 

[Mr.B.]

Endless variables... Width, thickness, length, stiffness, and number of the leafs used...

Adjust as needed. "-)

-Kirk