Tomahawk test ride

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Sep 17, 2020
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Ohio
I just went on the first test ride on a tomahawk I'm building. I still need to finish a few small details before paint but it was good enough to test.

Wow this thing is super twitchy, it has one hell of a learning curve

 
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Yes, your balance whilst laid down is much harder to achieve. It also gets harder the nearer you get to the ground. That chrome front wheel is very shiney.
 
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Ok 3 things :-

Actual

1) all that tiller is not helping when setting off



If you could build a stem that rotated up it would help you getting on and off and allow you to start off with it up thus reducing the tiller

2) your seat is very laid back , good for speed , again not helping when setting off , try using the vars and pulling yourself upright when setting off or at low speeds.

Possible

3) it is possible you have to much wheel flop ?
Simple test ? if you have an ordinary bike push it by just holding the back of the seat , it should just travel in a straight line and if it does veer off easily correctable WITHOUT touching the handle bars.
if the bike starts to turn and digs in with the front wheel rapidly swinging all the way into the frame AND not correctable just by holding the seat then you have a lot of wheel flop.

Compare with your build

Then practice practice then go out and practice some more ...

Paul
 
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Find a gentle downhill slope. Start off by merely getting your feet off the ground like a balance bike, keeping them close to the ground to catch you. Once happy at that, start off as per a balance bike then move your feet to the pedals. Once that is mastered then, still on the slope and with the initial drive pedal at 11 o'clock practise the set off. When you've got it sussed on the downhill try it on the flat and then slightly uphill last.

 
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Messages
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Ohio
Ok 3 things :-

Actual

1) all that tiller is not helping when setting off



If you could build a stem that rotated up it would help you getting on and off and allow you to start off with it up thus reducing the tiller

2) your seat is very laid back , good for speed , again not helping when setting off , try using the vars and pulling yourself upright when setting off or at low speeds.

Possible

3) it is possible you have to much wheel flop ?
Simple test ? if you have an ordinary bike push it by just holding the back of the seat , it should just travel in a straight line and if it does veer off easily correctable WITHOUT touching the handle bars.
if the bike starts to turn and digs in with the front wheel rapidly swinging all the way into the frame AND not correctable just by holding the seat then you have a lot of wheel flop.

Compare with your build

Then practice practice then go out and practice some more ...

Paul
I dont know what tiller is? I'm guessing it has something to do with the handlebars i think i need to try ones that curve because right now they're normal wide ones from a mountain bike and it feels like i have to much leverage.

the seat should match the plans i didnt do anything different with it other than i need padding on it which will move me forward more, does it ssem more laid back than it should be?

No clue on wheel flop, I'll have to try that. I can ride it a little, its the first one I've ever rode, and took about a half hour to get being able to move on it. I only have one brake on it so far, i am going to add the back brake now that i know it is at least somewhat useable. Then I'm going to take it for a longer ride, luckily it being ohio, i dont have to worry about hills for miles and miles.
 
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Tiller which is also causing some leverage is the piece you welded between the goose neck and the handlebars clamp.
It is magnifying the turning input and also causing the bars to swing out maybe to far.

Your forks also seem to have no axle offset from the steering pivot datum line ?

Try this Rake and trail.

So if the bars pivoted at the goose neck as in my picture the more vertical they are the less tiller you have when starting off ?

I believe this is a low racer ? so a laided back seat comes with the territory however that does not make a good starter recumbent ?

For learning you could make a temporary seat that has the back more upright ?

Paul
 
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Ohio
I'll upload a side picture of the forks and neck, i did tilt them back the correct angle but the forks i used have shocks in them, I'm not sure if thats cresting an illusion, problem, or both.

thanks for the input
 
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A lot of tiller is a given with this style of bike. It's absolutely necessary in order to reach the bars and any similar commercially made bike has just as much tiller too. I do agree though that it's not an easy bike to ride. All it should need is perseverance.
 
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Update: I went on a 16 mile ride today, it's considerably easier to ride now. I modified the handlebars, smaller is better. I had handles that were lower and further apart, but it was still a pain to ride, so i moved the vertical parts up and closer together and now it's rideable. I also added a mirror so i don't ride off the road when i try to check behind me. The bottle holder is zip tied to see if i like it. I'm going to make a bracket for it, and also hold a guide tube for the chain as well. I think Im going to get smaller shifters, the twist grip works but buttons will take less room



 
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There's something about the Tomahawk that just looks right. The bike is just so well proportioned. Those bars look much better though welding the more vertical parts in the middle looks to have left too little room to slide separate brakes and shifters on just above the grips. Maybe a combined brake and trigger shifter with just the one clamp will fit? Might I also suggest some welded on cable management to go with mounting the bottle cage. It'll get rid of a few extra cable ties currently doing the job. Any ideas on colour yet?
 

Radical Brad

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Nice work!
Glad you have found tweaks to make it feel better. Soon it will feel like an extension of your body!
At first, it took me a while to get used to this style as well (SWB), but I was doing no hands on mine after a few days.
Please keep this thread going, especially when the paint is on.

Brad
 
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There's something about the Tomahawk that just looks right. The bike is just so well proportioned. Those bars look much better though welding the more vertical parts in the middle looks to have left too little room to slide separate brakes and shifters on just above the grips. Maybe a combined brake and trigger shifter with just the one clamp will fit? Might I also suggest some welded on cable management to go with mounting the bottle cage. It'll get rid of a few extra cable ties currently doing the job. Any ideas on colour yet?
You're right there is not enough room above for both, when I was testing having both above, felt really uncomfortable, it seemed like a good idea but didnt feel right, I thought just like you did, a 2 in one, but I saw online a small almost push button shifter, so I'm going to try that on the horizontal bar and move the break up to where the shifter is. If it all works/feels i can shorten the bottm of the bars some.

you read my mind on the cable management. I don't want zip ties so i bought weld on ones from framebuilders this week. I have been going riding with velcro wraps and test the cables in different places, then if it seems to work i zip tie it to make sure, and if i like it I'll weld on the cable guides. Same with the bottle holder I bought weld on bosses to ditch the test zip ties

Color, i like the copper color in the PDF. I think I'm going to powder coat it, I found a local place that charges about 100 bucks. paint/primer can easily run 40 to 50 and I have to do the work, and powder coating is considerably more durable. I'm building two more warriors right now, so this will be the test powder coat, if it goes well, I'll get both of them done as well.
 
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I've had a powder coating job on a bike. It cost me £60 for frame and fork and that included the sparkly bits which were £20 extra. Sod all more than a decent paint job and a lot less effort as you say. Don't forget to put a bolt part way into any threaded holes before you drop it off. You may have some issue around the adjustable BB mount though with the coating thickness. One way around would be to do away with the adjustability and weld the BB to the end of the boom once cut to length.
 
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I asked them about threads and the fit caps they said they just plug them, most threads I can retap if need be, I used spacers when i made the BB to try to account for the thickness but no telling if i allotted for enough.
 
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