Dogmans racing bike

[dogman]

Now I can't find the thread where battery placement was being discussed on this bike. Too many posts, too few brains.

So I'll just pick up the subject here, with a proper build thread on this bike. The bike is a Yokota Quicksilver, vintage after 1 1/8 headset came in, but before canti brakes went out. Cromoly no suspension 26" MTB. Of many many used bikes I bought to trade with at the used bike shop, this one rode too good to trade away, so I figure it might make a good platform for practicing high speed cornering for racing. Canti brakes replaced with V brakes, Handlebar stem and handlebars mounted upside down. 56 tooth crankset added mostly for cool looks. 72v lipo will make pedaling less likely.

There is room in the triangle for some batteries, but I still have the idea I'll actually race on a bike with full suspension that has no triangle space. Most likely the Giant, depending on what 72v does to steel dropouts. So I want to work out battery solutions for carrying the battery, about 10 pounds I think, on the rear. Initially, I will likely just use this box, with some coroplast spacers inside to keep em put.

Possible lipo box.jpg (69.85 KiB) Viewed 2796 times

But the plan I've been working on is for two metal and wood panniers designed just for 5000 mah lipo in 5s or 6s. Four per pannier, with each block of lipo cushioned in a coroplast sleeve. It should be easy to swap out packs between heats with this system, and they will be very well protected if I lay it down.
In the pic, the cardboard box is a mock up of the size and shape I'll be making the pannier boxes.

Lipo box mock up..jpg (69.16 KiB) Viewed 2796 times

The panniers will be about 2.5 inches wide, and should fit nicely into the wind shadow of my legs. Possibly coroplast fairings from seatpost to the boxes? And some kind of fairing on the bars?

Edit... After a quick test ride at 48v,,,, maybe this is the race bike. It corners sweet with all my weight lower than on a fs bike. 15 pounds of battery on the rear wheel felt fine to me. But I could easily fit 4 bricks of lipo in the triangle, just have to work out how to quick change them.

[wineboyrider]

Are you really going to do this?

[dogman]

What do you mean? put the lipo in a cardboard box? That is just a mock up, the real lipo container will be wood with alluminum sheet sides.

Or do you mean ride it 45 mph? I was doing 35 last night pretty comfy. I'm definitely racing, any race I can afford to travel to! Untill the next race, I'm the current US electric bike champion. After June, I'll only be the west coast champ.


Finally bike racing I can do without having to be as fit as Lance Armstrong! I raced as a teen, but not for long after seeing how strong the competition was. At the time, I didn't understand they all were dexedrine heads in the 70's. Now I can race as a lipo head.

[Drunkskunk]

Have you considered putting those lipo in the frame?

the further back the weight is from the pivot point (the head tube) the slower the bike will react.

Also, in the frame, they are protected by your legs, but behind you, they are were other bike wheels, axle nuts, and handlebars are going to be if things get tight on the track

[torker]

Yea I would try to come up with a triangle solution. In tight race traffic it would be much better and you would probably like the handling improvement. Does that frame have bottle mounts on both tubes or just the one?

[nicobie]

I think the bike will handle ok with the batteries mounted saddlebag style.

Just be sure to get them as far forward as possible. On my Electra Townie I was able to get almost all the weight in front of the rear axle.

I wrapped 2 - 6s packs in some scrap Formica I had laying around. It was easy to hot glue along all the edges. I can still take them apart if I want and should provide all the impact protection needed.

My bags allow me to put them next to each other crosswise in the approx 4" wide bags. What you see in the picture holds a 48v/20ah split ping, a 22v/10ah lipo, my controller w/added heat sink and 2 relays (to switch between 54v and 76v). I even have room for a small tool kit.

[johnrobholmes]

Handling OK is OK for commuting, but if he is going to race the bike I will support the call to put the batteries mid frame. The bike will handle like a pig with the weight behind your cranks.

[dogman]

True, true, true. But we aren't talking about a load of nicads are we? If I do race this bike, I most likely will put the battery, or at least part of it in the triangle. But unless I am confused, the weight will be about 10 pounds. My EVG bike, with 25 pounds of lead aboard, felt real good with the weight along the bottom of the frame triangle. But ten pounds is not so much weight. A 15 pound ping back there felt good last night. I'd try the ping in the frame but it just won't fit, its only a 14" frame.

This is a practice bike. I really hope to do much better for the death race. I may choose to go for the benefits of suspension. One corner of the track is very bumpy everywhere, and others have enough ripple in em from braking carts to make suspension a good idea. Let us not forget, the best suspended bike on the track won. So I may be riding a bike with no triangle at all.

My original idea was to put the battery protecting panniers up front, but only 5ah of 72v fits well up there,( on a fs bike) and I wasn't so pleased with the aerodynamic effects of it either. But two slim panniers with a fairing would tuck nicely into the wind shadow of my legs in back. Better handling will only win if you still beat fairracing 31 to the corner. Handling does need to be very good though, to corner at 35+ mph on that track. At some point I''ll weigh the bike with two scales and aim to have the same weight on each tire with me sitting on it in a tuck. Or is that wrong? What ratio should I be aiming for? I will want both tires to stick.

Edit, looks like if I redesign the panniers just a bit, they would both fit in the triangle so I can do that and try it both ways. For sure, if this was a rear hub bike, forward battery would get a lot more important. The 6x10 dirt bike has a bit too much weight in back and that bike does have poor handling by comparison. But the commuter, balanced for and aft perfect, handles nice till you start putting more batteries in the rear bags.

It's a work in progress, that's why I need to try different stuff now. But one of the key things I want is the ability to swap batteries as easy as I could with the pings in a toolbox. There simply isn't time to run a bike, charge it ,and run some more in the time avaliable between heats. Some of you may have that kind of charging capability, but my plan is to show up with lots of bricks of lipo and quick change them. So I need something better than lipo taped all over the triangle for sure!

For sure, one of the 1# requirements is for the lipo to be protected enough wherever I mount it, because a crash is going to be happening at some point. I can't see racing without ever laying it down.

[torker]

I guess I was still thinking of a rear hub so getting the batts in the triangle is not near as important. As far as weight distribution I would shoot for 50-50 but the main thing I would probably do is make sure the front tire is a lower or the same durometer/softer so no chance of the front washing out. My son leaves for basic training tomorrow and will be at Ft Wachuka in Ariz. for 48 wks. so hopefully we can hook up this winter when we go see him.

Oh I almost forgot, if you end up wanting shorter cranks for pedaling in the corners you might check out bmx cranks. I put 145 mm cranks on my recumbent and they are cheap. Only thing is the bolt circle is different than most so I had to buy a sprocket to go with it.

[johnrobholmes]

10lbs is still 10lbs that will wag the dog from the tail, so to speak. If you do have the ability to try it in both places easily, give it a shot. You will find that mid frame handles so much nicer. Any centralization of mass is good on a bike.

[dogman]

I'm sure that's true. I had a motorcycle once that had an extra tank on the rear carrier. I allways burned it empty first because a couple gallons of gas did affect handling mounted real high in the back. The sla packers all report though, that handling significantly improves if they move the sla boat anchors down closer to the axle. So I'm thinking of a pannier style mount to get the weight lower than I carried it this year for sure. But I will very likely go triangle mount battery if I race this frame. Having run the track with suspension and seeing others struggle in one particular corner without it, I still really lean towards suspension for the unlimited class death race. Below 30 mph in 1000 watt, suspension won't matter as much as areodynamics.

But still, I have to insist, that the setup I've chosen for 6000 miles of riding doesn't suck. 15 pounds or less on a non wobbly rack rides real nice balanced with a front hub, and I feel no sketchiness at all riding that way. Make it 25 pounds though, and the trouble starts. It should ride ok If I do it pannier style I think, if I choose a suspension bike. I'd feel it for sure if it was bad, Iv'e ridden everything just about. My roketta scooter was hard to ride till we modified the seat to allow the butt to be in the right spot. Thing was designed for two 90 pound riders, not one 180 pounder. So I can feel the difference and won't stand for something that is bogus.

One other candidate for a race bike just arrived last night.

Mongoose Blackcomb.jpg (86.63 KiB) Viewed 2593 times

Same bike as Dr Bass if I'm not mistaken? He seems to handle some megawatts on his, and attaching boxes to the frame of this one would be easy as pie.

[dogman]

Went out on my commuter bike, with the tall rear rack and panniers, and did some higher speed cornering close to 30 mph.

Ya'll are dead right about the handling. I'd never felt bad cornering that bike, but never really tried it above 25 mph. Below 25 fine. Above 27, scketcy. By 30 mph downright scary.

So its full speed ahead now for low hardtail for racing , and frame triangle mount battery. Thanks for slapping some sense into me.

[amberwolf]

Better us than the road surface.

[dogman]

Well, that's inevitable too, only one way to find the line you don't cross. That's to cross it and live. 35 mph cornering in the hairpins would win the race I think. 25-30 is the norm. Easy to talk about, hard to do at all, let alone the whole day. 29 mph was my best speed in the hairpin for the day.

[amberwolf]

I'm too chicken to try even regular street intersection 90-degree corners at speeds above 15-16MPH on DGA. Just feels like it's gonna come out from underneath me. When CB2 is back up, I'll take the pods off and see if I can do it on there without having a heart attack or needing new underwear.

I'm such a wuss.

[dingoEsride]

So its full speed ahead now for low hardtail for racing , and frame triangle mount battery.

You're da man dogman, have you considered though putting front shock fork's on the rigid frame?

[dogman]

Yes, but the fork would raise the front end, changing the angles of the rake. It screws up the forks action, unless it's a springer, and alters the geometry enough to screw up cornering too.

Somebody got a nice chromoly frame, made for a front fork? I may end up on an aluminum frame, but I sorta wanted steel so I can weld brackets to it at will for battery mounts etc. I really would like a front fork, and I just scored a nice steel suspension fork yesterday. Front suspension would keep that overpowered front wheel sticking better for sure, and I'll be counting on power on in the corners to pull me through fast. Most of the track is pretty smooth, so no suspension could work well, but one corner is all messed up, and faster in that corner could be the difference in the race.

What I need is really a big hit vert ride hardtail frame, but those are pricy. I'll still be trying this bike though, once I get the lipo to attach to the frame.

Mongoose Blackcomb.jpg (86.63 KiB) Viewed 469 times

[dingoEsride]

Tough call, full suspension to keep all wheels on the ground or hardtail to minimize weight and have a lower centre of gravity and be a great handler

[GCinDC]

how long is the race? what's the track like? so you'll be running 20s lipo, swapping out 10Ah packs?

if 35 cornering will win, what are figuring for the straitaways?

[dogman]

You can see pics of the race at SpookyTooth Cycles website. Also some threads here about the race. The track website is here. http://www.p1kartcircuit.com/

.8 miles with lots of hairpin turns, a few of which most take at 25 mph max. Others have wider sweep, and go at 30 for sure, so getting up to 35 in those might win. The longest straighaway is about 700' So top speed is not so much the issue as top speed in 700' the other long straights are 400' and 500'.

The death race was 12 laps, and the heat races 8. Last years winner is claiming to be hitting 45-47 mph on the straights. 20s isn't going to do that most likely, but it will do enough to scare the piss out of me. That's my real goal, not really winning or placing well. I just want to run where there's some company behind me, instead of in front of me. And end the race with a little wet spot.

[dequinox]

But the plan I've been working on is for two metal and wood panniers designed just for 5000 mah lipo in 5s or 6s. Four per pannier, with each block of lipo cushioned in a coroplast sleeve. It should be easy to swap out packs between heats with this system, and they will be very well protected if I lay it down.
In the pic, the cardboard box is a mock up of the size and shape I'll be making the pannier boxes.

Lipo box mock up..jpg

The panniers will be about 2.5 inches wide, and should fit nicely into the wind shadow of my legs. Possibly coroplast fairings from seatpost to the boxes? And some kind of fairing on the bars?

Edit... After a quick test ride at 48v,,,, maybe this is the race bike. It corners sweet with all my weight lower than on a fs bike. 15 pounds of battery on the rear wheel felt fine to me. But I could easily fit 4 bricks of lipo in the triangle, just have to work out how to quick change them.

One thing you'll want to watch out for with saddle-bags is your heel clearance. I have a pair of bags that I quit using for batteries because they hit my heels when I pedaled...I'd have to space them up in order to get enough clearance. Your mock-up looks like it might be ok...but something to keep in mind before taking it to the track. I think you'll be fine without front suspension on asphalt...those tracks are pretty smooth aren't they?

[dogman]

Sort of smooth. One corner is pretty badly rippled though. In the 2010 death race I got passed there a lot because I thought maybe the smoother line outside was faster, but it was not. I was getting passed anyway, so I kept doing that line to let em by. The winner rode FS though.

I may end up mounting 10 ah of lipo in the frame after all, two bricks wide, it will fit. I was thinking rear mount to use a FS bike in the race, but now I'm liking the way the low hard mount bike corners. It's a pretty stiff cromo frame that might corner better than FS. We'll see after I get on it at 72v how I feel about hardtail. At 40 mph it might be pretty harsh, I won't know till I try it.

[AussieJester]

I may end up mounting 10 ah of lipo in the frame after all, two bricks wide, it will fit.

Could go for some inside and some below the
main bar-->

Mongoose Blackcomb.jpg (106.31 KiB) Viewed 406 times

Better to keep that weight lower than higer mid mount
is the shot IMO. You could fit a shitload of lipos and and
on the front of that frame though good choice for the
race bike DoGMaNz.

KiM

[GCinDC]

Not sure if you're planning on getting any power from pedaling. I pedal my FS and just bounce there!

With lipos though, I accelerate ahead of all but the nastiest cars at the light. No noticeable squat on the rear.

[dogman]

At this point. I haven't even gotten as far as finding a seat post for the blackcomb. It may get tried out as a race bike, if I can find a suitable front fork. For now I'm still working on the hardtail as a practice bike to keep the knee dragging skills honed. Do some testing of what kind of battery I need to finsih a race, etc. Once I have 10 ah of lipo, I think it can fit in the triangle making that bike corner good enough to take to the race.

Pedal bob varies a lot from one frame to another I find, and how you set up the preloads. The one I have with very little pedal bob is the specialized. The blackcomb does bob some, but I think that could be cured with a better shock. In the death race, pedaling does matter, giving a bit better pull out of the corners that have to be taken slower. Pretty tough to pedal hard for 10 miles though!