More diesel motorcycle madness

[dethmachinefab]

Originally Posted by SSSRodeo

Nother stupid question.
If you're planning on getting 6 grand out of your motor, is that big rear sprocket going to be too big for that rpm?

I just looked at my Triumph rear sprocket and it looks to be in the 34~ 38 tooth range. This of course is for a 3 cylinder gas motor thatl turns 6 to 8 grand. I'm thinking since my Diahatsu diesel will only turn like 3400 tops, I'm going to need to set my gearing up more like a Harley Big bike to use the lower RPM.

So I guess what I'm trying to think through is, just how big is that front sprocket on the tranny going to be? Care to share some insight on the gear ratios you're planning for?


The picture of your new belt sprocket got my gears turning, as with a blank belt sprocket I can drill the mounting bolt holes where I want. Like say, for a Triumph rear wheel.

Nice, and I'll bet that aluminum chunk set you back a little.......

Ill check tomorrow on the front pulley size im running i think its 32t. With your engine i would recommend a 72t rear pulley. Help with aceleration and still give highway speeds. Im thinking you can get at least 3600rpm if not more from yours. PM me and well talk more details.

Im running a 72t on this build. We will see how it works.

[TURK]

Originally Posted by dethmachinefab

Thats for shure Ive lost many pants to open primarys. Show up to somewhere with one leg in pants and the other leg in boxers.

Yes i don't have any doubt on that belt holding up. The bdl set up moves the belt further inboard, better for the trans shaft and centering the engine another inch or so.

Most of my jeans have at least a little tear on the left pant leg . Seems worse if you put a belt guard on it. Pants get eat up between the belt and the pulley, and between the belt and the guard. Double knot lace up boots!


As long as you stay clear of the clutch basket, you should get by with a bruise on your ankle every now and then.

You have some good skills, and the mind of a fabricator. Keep it up!

[dethmachinefab]

Rough cut, bored, and installed bearings in rear hub. Hub will be cut to finished dimensions ( the large part that spaces pulley from rim) when tire and trans are centered and mounted.

Tires ordered. Need to source some buell front calipers and order rotor material.

[usmcdoc14]

the 4 piston blast's or the 6 piston everything else? There are a bunch on ebay right now

[dethmachinefab]

Originally Posted by usmcdoc14

the 4 piston blast's or the 6 piston everything else? There are a bunch on ebay right now

The 6 piston perimeter style calipers. Ive found a place parting them out online i need to call tomorrow.

[dethmachinefab]

Hub rolling on 7075 aluminum axle. Keeping it light.

[dethmachinefab]

Now making the perimeter rotors. Layed out and center punched mount holes. Now i need to decide to cut them with the plasma or bridgeport. Heres a pic of a rear rotor mocked up for plasma cutting. Replace dial indicator with fixed plasma torch.

[LucasFury]

Did I miss how you plan to mount the caliper? Are you just gonna have a rear brake or both?

[dethmachinefab]

Originally Posted by LucasFury

Did I miss how you plan to mount the caliper? Are you just gonna have a rear brake or both?

Both front and rear. I was going to make something like a standard caliper mount but with the caliper reversed. Still intend on going that route, but i may have a frame mounted adjustable mount if i don't like it. I have 1/4-3/8 of axle to hang a caliper mount on, which should be fine if made from 7075, as it just locates the caliper and a link caliper to frame will absorb the force.

I made the hub this wide (dropout to dropout) to minimize any deflection under load, keeping the bearings as far outboard as possible.

[LucasFury]

Originally Posted by dethmachinefab

Both front and rear. I was going to make something like a standard caliper mount but with the caliper reversed. Still intend on going that route, but i may have a frame mounted adjustable mount if i don't like it. I have 1/4-3/8 of axle to hang a caliper mount on, which should be fine if made from 7075, as it just locates the caliper and a link caliper to frame will absorb the force.

I made the hub this wide (dropout to dropout) to minimize any deflection under load, keeping the bearings as far outboard as possible.

Second and third questions-
Are you doing it solely for styling or are you considering other reasons? Will they be linked via proportional valve and a single lever or independent like typical? Buell's were linked, weren't they?

[dethmachinefab]

Originally Posted by LucasFury

Second and third questions-
Are you doing it solely for styling or are you considering other reasons? Will they be linked via proportional valve and a single lever or independent like typical? Buell's were linked, weren't they?

Styling mostly. Swept area, mechanical advantage, along with better cooling is what im thinking of as additional benifits. I have decided to try to use a diffrent caliper than buells, a modified mcp kart caliper. Compact, look good, and use a 3/4 bore master cyl. That lets me use the nice kart master for rear and a standard motorcycle handlebar mounted master and lever.

I don't know if some buells were linked, sounds scary to me.

[LucasFury]

I may be mistaken about the Buells having linked brakes. I know Goldwings use a linked system for the foot lever, but the hand lever still controls the front alone. Motoguzzi used to do something similar as well.

I know some bobber builders that never build anything with a front brake, and I truthfully very rarely use my own so I'm debating on whether I want to attempt a linked system vs no front brake at all on an upcoming build (or series of builds).
I feel like a linked system with something like 65f/35r ratio (possibly with a delay to the front) on a foot lever would work well for people who know how to downshift properly for decel in situations where heavy front braking would be dangerous. ..obviously not on "performance" machines or people who use a lot of front trail braking (I use rears), but no one is worried about cleaning up the handlebars on that type bike anyway.
I was hoping I was gonna be able to steal ideas off you.

I'm very anxious to see the finished product and can't wait to hear your thoughts on how it performs vs typical rotors.

[dethmachinefab]

Originally Posted by LucasFury

I may be mistaken about the Buells having linked brakes. I know Goldwings use a linked system for the foot lever, but the hand lever still controls the front alone. Motoguzzi used to do something similar as well.

I know some bobber builders that never build anything with a front brake, and I truthfully very rarely use my own so I'm debating on whether I want to attempt a linked system vs no front brake at all on an upcoming build (or series of builds).
I feel like a linked system with something like 65f/35r ratio (possibly with a delay to the front) on a foot lever would work well for people who know how to downshift properly for decel in situations where heavy front braking would be dangerous. ..obviously not on "performance" machines or people who use a lot of front trail braking (I use rears), but no one is worried about cleaning up the handlebars on that type bike anyway.
I was hoping I was gonna be able to steal ideas off you.

I'm very anxious to see the finished product and can't wait to hear your thoughts on how it performs vs typical rotors.

Could possibly build a brake pedal like an adjustable balance bar used in dirt cars. That can work both to keep bars clean, but the only way i would feel comfortable with a single lever/pedal is with abs. For example, wet road stoping at stop sign. Front tire hits slick paint line and washes out. Or icy situation like a snowy/icy road where i would use no front brake.

[LucasFury]

Originally Posted by dethmachinefab

Could possibly build a brake pedal like an adjustable balance bar used in dirt cars. That can work both to keep bars clean, but the only way i would feel comfortable with a single lever/pedal is with abs. For example, wet road stoping at stop sign. Front tire hits slick paint line and washes out. Or icy situation like a snowy/icy road where i would use no front brake.

Yeah, those instances are good examples of why I'm thinking a delay valve would be a good idea (since you can't downshift past 1st). ABS is one thing I definitely don't want to get into.

[dethmachinefab]

Originally Posted by LucasFury

Yeah, those instances are good examples of why I'm thinking a delay valve would be a good idea (since you can't downshift past 1st). ABS is one thing I definitely don't want to get into.

Between trying to proportion, delay, etc your likely to be as involved as abs If dead set on empty bars, run 2 rear type masters side by side and a split pedal. Similar to how ag tractors have left/right brake. Simple and clean.

[LucasFury]

Originally Posted by dethmachinefab

Between trying to proportion, delay, etc your likely to be as involved as abs If dead set on empty bars, run 2 rear type masters side by side and a split pedal. Similar to how ag tractors have left/right brake. Simple and clean.

No shit.
The split pedal idea is new to me. Are we talking two skinny pedals next to each other where there is a possibility of pushing both at the same time (on purpose or not) or front/rear where you would have to rock your foot to or fro and be forced to choose? If I had to choose I would probably always use the rear, in which case I'd be more likely to just not have a front at all.

[deadmeat]

Linked brakes were come up with for the masses that bought a bike but don't really know how to ride.
So many accidents with people using rear brake only, so rear pedal operates rear and the front.
On some of them Hoda used a front caliper with 6 pistons, two were noperated by the rear brake pedal, the other 4 by the front.

Some bikes operate the rear some with the front lever.

Biggest problem for people who ride is there are times when you only want front only or rear only as mentioned earlier.

Nice build.

I wish i had some skills, would feel great to make something like that.

[bigun]

Your hub reminds me of one a buddy and I machined out a block of steel for his drag bike back in the late 80s. It took forever on his Enco lathe because the out side of the steel had been hardened from the cutting torch. That and we were only able to work on it a couple of hours at night.

[dethmachinefab]

Originally Posted by bigun

Your hub reminds me of one a buddy and I machined out a block of steel for his drag bike back in the late 80s. It took forever on his Enco lathe because the out side of the steel had been hardened from the cutting torch. That and we were only able to work on it a couple of hours at night.

I did this one on my 16" lodge and shipley. Took a little while, the chunk was 5" OD. Lucky for me this old lathe has serious horsepower and was able to take heavy cuts at a decent speed.

[dethmachinefab]

Cut the rear perimeter rotor today, rough cut with plasma contraption. Finished on rotary table. Here its siting on bolts to get an idea of how it looks. It will be much closer tward the middle. Standoffs are to be made after i get calipers. Rear is a 16" rim so its small. I also need to lay out all the vent holes.

[Sumo]

With the heat cycling that those fasteners will be subjected to, what about safety wiring them in pairs? Just a thought.

This is an awesome build.

[dethmachinefab]

Originally Posted by Sumo

With the heat cycling that those fasteners will be subjected to, what about safety wiring them in pairs? Just a thought.

This is an awesome build.

That would look cool too. I was debating on countersinking allens, looks like a rock ring. But cross drilled and safty wired allens would be badass.

[707offroad]

you could easily mount a little propane tank for some boost

[dethmachinefab]

Originally Posted by 707offroad

you could easily mount a little propane tank for some boost

If anything it will see nitrous

Might need water/meth depending on egt's. It will be fun hiding all this stuff and making it look good.

[redheep]

How clean are you trying to make the bars? Hidden throttle and twist grip clutch?

I kinda like seeing cables and stuff on a bike, but if you're going for hidden, you should go all out.

You do excellent work.