Tom, after doing a Bing search I found some of your old pictures by searching "Toms 1909 engine". It had a lot of your pics on photobucket, but I was unable to open any of them. More savvy computer people may be able to do so though. Also seen pics of the single cylinder you built previously. Everything you've done is super cool.
V-Twin Board track racer
- Thread starter Tom TG
- Start date
Thanks Rick and Curt is nice to know what people think of your work.
Butch I still have the pictures if there is some thing you would like to see. I was always told be carful what you
Put on the Internet because it will be there for ever now I know that's just not true.
Here is a picture of how I straightened the drop loop and the other bikes engine and wheels.
Butch I still have the pictures if there is some thing you would like to see. I was always told be carful what you
Put on the Internet because it will be there for ever now I know that's just not true.
Here is a picture of how I straightened the drop loop and the other bikes engine and wheels.
I have been working on the frame and need a little help. My engine is 23 inches tall and its going to be a tight fit to get the look I want. Look at the mock up picture below. I have about 26 degrees rake, 3.5" trail, 4" ground clearance and only 2" between the upper tubes. I think I need at least 4" between the tubes for the gas tank. I think if I decrease the rake, trail, and ground clearance I can gain the tank clearance and close up the gap between the tire and drop loop. I guess my question is what is the minimum rake, trail and ground clearance I can get away with.
Thanks Tom
Thanks Tom
Tom, I've went with 3" ground clearance on a stretched 53" wheelbase with no problems on my Simplex 5 speed build. I used 3" of trail with a dual spring fork, but with the girder I'd think an inch to 1.5" would be ok. So many things factor into correct trail that books have been written on it, but rule of thumb for me is at least 1" positive on the street at moderate speeds say no more than 50 mph...no death wobble & the bike should be pretty quick handling. 3.5" on a 55" wb would, all things being equal, be more stable & better for higher speeds on the highway. Flat track bikes were typically set at 0 to 1" negative back in the day and for slow and moderate speeds around town and on county roads say 40 mph I'd doubt trail would factor in safety wise, but with no trail or negative trail steering would be quick. I remember Lurker posted he was going to have 2.5" clearance on his V twin & his photos and videos look to be lower than my Simplex even.
On my current V twin build my design plan is 58" wheelbase, 2.5" positive trail & 3.5" ground clearance. I'm using a single spring fork.
Hope this helps. your bike will look great with a 3.5" to 4.5" tank...2" is really thin. Rick C.
On my current V twin build my design plan is 58" wheelbase, 2.5" positive trail & 3.5" ground clearance. I'm using a single spring fork.
Hope this helps. your bike will look great with a 3.5" to 4.5" tank...2" is really thin. Rick C.
Don't know if this will help, rake and trail........Curt
http://www.chopperhandbook.com/rake.htm
A diagram showing the effect of decreasing the head tube angle or the fork offset on the trail.
Trail, or caster, is the horizontal distance from where the front wheel touches the ground to where the steering axis intersects the ground. The measurement is considered positive if the front wheel ground contact point is behind (towards the
https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry
http://www.chopperhandbook.com/rake.htm
A diagram showing the effect of decreasing the head tube angle or the fork offset on the trail.
Trail, or caster, is the horizontal distance from where the front wheel touches the ground to where the steering axis intersects the ground. The measurement is considered positive if the front wheel ground contact point is behind (towards the
https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry
Tom these modest changes in geometry do yield amazing changes in space & won't greatly change the bikes road manners at modest speed.Though cosmetically the change will drastically improve the "eye appeal" of the completed bike. I've been intending to build a round tank, but can't seem to get 'round to it...should look great on yours however. Rick C.
What i used is track light cans 3 together end to end , worked good except got to be careful as they are thin, easy to dent let alone weld . But check thrift stores that's were i got mine, depends on the size some were heavier .........Curt
Rick my last bike I built was supposed to have a round tank making the tapered cone end became a problem so I built square.
I laid the engine on its side and tried the drop loop on it and it fit but it takes up all of it. With the engine setting on the loop the rocker arm has about 3/8 of a inch clearance and the exhaust at the heads have about 1/2 inch looking at the last picture I posted its hard to be leave its that big .
Curt how did you form the cone on your tank?
I laid the engine on its side and tried the drop loop on it and it fit but it takes up all of it. With the engine setting on the loop the rocker arm has about 3/8 of a inch clearance and the exhaust at the heads have about 1/2 inch looking at the last picture I posted its hard to be leave its that big .
Curt how did you form the cone on your tank?
Tom I understand what your're referring to on the non concentric cone, but I always thought that was due to poor fabrication on the early bikes. Some examples appear in photos as being pretty symetric, though camera angles often present misleading images. Practically all of the torpedo tanks I've actually seen, regardless of the makers marque, were of pretty rough construction.
Just barely fitting is actually a good outcome...some of the originals were very tight in their frames as well.
Tom are you planning to taper both ends of the round tank like the early cylinder style tank or round front & tapered rear of the later tanks ? I assumed by your previous post that you would taper only the back of the tank. I found a couple of photos that clearly, I believe, show the lower part of the rear tank taper flat & flush with the top of the lowest of the frame straddle tubes.
At any rate I don't think you are overthinking at all. Forgive me for this but I've been thinking for some time about fuel tanks balanced on one tube & clamped. The next tank I build for a single tube frame, round flat whatever, will have a tube channel rolled into it full length to at least partially saddle onto the bottom tube. Probably won't help get the look your're after on this one since you are replicating and I tend to customize in the style of an era, but your problem has solidified the answer to my next one lol. I looked for my handy sheet metal compendium & it's not to be found, probably loaned to never return, but the answer is in the geometry that I may have known but also seems to have disappeared.
Wret built a tank that has that taper, but his is flat on top and bottom, but viewed for the side it's a cylinder. Thread is in this forum (board track) titled "beginning to look like something" should be on the next listing of posts & the tank photos are very close to the beginning of his build...might help, his tank (and bike) is a beauty. Rick C.
At any rate I don't think you are overthinking at all. Forgive me for this but I've been thinking for some time about fuel tanks balanced on one tube & clamped. The next tank I build for a single tube frame, round flat whatever, will have a tube channel rolled into it full length to at least partially saddle onto the bottom tube. Probably won't help get the look your're after on this one since you are replicating and I tend to customize in the style of an era, but your problem has solidified the answer to my next one lol. I looked for my handy sheet metal compendium & it's not to be found, probably loaned to never return, but the answer is in the geometry that I may have known but also seems to have disappeared.
Wret built a tank that has that taper, but his is flat on top and bottom, but viewed for the side it's a cylinder. Thread is in this forum (board track) titled "beginning to look like something" should be on the next listing of posts & the tank photos are very close to the beginning of his build...might help, his tank (and bike) is a beauty. Rick C.
Found this, may help............Curt
http://weldingweb.com/showthread.php?22374-Layout-of-eccentric-cone
http://weldingweb.com/showthread.php?22374-Layout-of-eccentric-cone