Safe's Electric Bike Project #001

[safe]

Is it more important on the front tire? I could see a totally round profile on the back being more rideable, depending on the steering tube angle.

The rounded tire will tend to let go with a feeling of "lightness" as it happens. A pointy tire tends to feel solid as a rock until it let's go to zero and then will reconnect so powerfully that the recoil is scary. (my too pointy rear rear tire is producing frame frex at high enough speeds as it grips and then let's go over the bumps) Tires that have lips/edges to them start to feel a little light but if they let go a little they then recapture traction just as gradually as they lost it.

My bike is completely wrong... my front tire is more flat and with a lip and my rear tire is pointy...

Ideally this would be the other way around with a front that is slightly more pointy than the rear. You want a wide and flat rear tire with a lip so that you can get the rear to drift out a little. I'm starting to use some rear brake now as I go into the turn because if you are careful with it you can get the rear end to loosen up a little and that seems to help the front end feel more firm. (it transfers weight forward) I can't swap the tires because I need the rear tire for it's stronger sidewall support because of the weight of the bike.

To be honest there are times when I think:

"Argh... this bike I have and even the one's I'm building are so technically crude and primitive compared to what I have in mind."

...but my fabricating abilities are not that great and the parts I have to choose from are not great either. (I'm constantly searching for parts) We live in primitive times when it comes to a genre that "doesn't exist" yet. (this is more or less by definition... how can I expect parts to exist for an idea that has never been realized)

But I don't have the resources to do it all... so I do the best I can and if I keep at it long enough I'll at least get closer to the ideal.

Patience, patience, patience... :wink:

 

[John in CR]

It's difficult to believe that performance motorcycle tires don't already exist that would suit your needs. Is it that you are too "cheap" instead of "safe", or do the tire already out there need more speed and/or weight for the performance to kick in?

John

 

[AussieJester]

im placing my bet on the "cheap" side as he I believe might have mentioned on 'occasion'

Would throw your gearing out a bit i imagine but -->

 

[John in CR]

im placing my bet on the "cheap" side as he I believe might have mentioned on 'occasion'

Would throw your gearing out a bit i imagine but -->

Sweeeeeet, but where's the electric motor?

 

[Link]

↑ All I can think is, "Damn, you could fit a lot of battery in there."

 

[safe]

The idea of using motorcycle tires is very attractive.

I've been trying to use things that are "standard" to the bicycle and avoided anything that came with motorcycle dimensions. However, there is an argument for getting something like a thin high quality front tire from a motorcycle and using them on a bicycle.

It's hard to "pull" a big tire though.

The small motors we use have to accelerate the bike, but it also has to accelerate the mass of the tire, so if the wheel weighs 10 lbs rather than 2 lbs that means the motor has to build up the momentum and it will take longer. (slowing you down) Not only that, but adding weight to the wheels is adding "unsprung weight" at the worst possible place... as a rule the wheels and tires need to be super lightweight... it's one of the most important things to get right on the bike.

From a performance standpoint my present lightweight bicycle tires are "pretty close" to being right. In fact, after getting run off the road recently and replacing the rear rim I've realized that this new rim is about twice as strong as the previous one. Those unicycle rims at 47mm wide (1.85") look to be really strong, so I think you can get away with what is needed for now with the existing options. Using a wider rim will change the shape of the tire, so you should be able to improve what's already being used. In the long run I think keeping the bicycle standards is the best thing to do. This is about "Electric Bicycle Road Racing" after all... I still want to be compatible with regular bikes. (it's just that specialized products for road racing need to become available... someday)

http://americancycle.com/itemdetails.cfm?ID=8890

So the simple answer is that motorcycle tires are too heavy.

I just passed 4,800 miles today...

 

[vanilla ice]

Sava out of Slovenia makes a 2.25x17 high performance moped tire. That may be light enough. 62mph rated.

http://www.mopedshop.com/Moped-Tires-Tubes-s/72.htm

 

[Toorbough ULL-Zeveigh]

I just passed 4,800 miles today...

me too also I did.
but not today.
about 840 miles ago.

 

[safe]

...about 840 miles ago.

I was two thousand miles behind you at the start of the summer and now I'm only 840 miles. So in my book I'm catching you. One wonders when I actually make the pass and gather the title of "Endless Sphere High Mileage Leader".

So if you don't want to get passed you better keep up a heavy riding schedule...

 

[johnrobholmes]

pshhh, I logged a fat 9 miles today running errands and seeing friends :lol:

Still $2.25 saved in gas and equal in wear and tear on my car.

 

[Toorbough ULL-Zeveigh]

...about 840 miles ago.

I was two thousand miles behind you at the start of the summer and now I'm only 840 miles. So in my book I'm catching you. One wonders when I actually make the pass and gather the title of "Endless Sphere High Mileage Leader".

So if you don't want to get passed you better keep up a heavy riding schedule...

I ride all winter long, & actually, no one is wondering.
But you're going have to ride *reel* fast (>c) if you wanna make it to 5 grand b4 me.
BTW, how does my dust taste anyhoo? 8)

 

[D-Man]

You're going to run out of Toys R Us parts before you catch T.B.

 

[safe]

I ride all winter long...

That's a big advantage. I've got maybe 5-6 weeks left for this year and then I'll be stuck indoors for the winter. Six months later it's warm enough to venture out again. Sometimes it's frustrating how short the useful seasons are here in the midwest, basically 50% of the year is useless for anything outdoors. (which includes both extremes of hot and cold) It makes it really hard to both try to ride and also spend enough hours on the projects.

I'm nearing the completion of my first front fairing (doing all the fiberglass work) and I'm hoping to actually test it in a few days. So far I've got the female mold, male mode, final product shell all completed, but there's still the mounting and all sorts of tinkering to get it to work.

 

[johnrobholmes]

5-6 weeks? I will be riding in the snow and ice!! Man up and get some studs on those tires :lol:

 

[AussieJester]

5-6 weeks? I will be riding in the snow and ice!! Man up and get some studs on those tires :lol:

sheesh...he aint even got pedals and now you tellin him to get studs on the tires...good luck with that

 

[johnrobholmes]

I don't have pedals either :lol:

Maybe you could build a winter bike safe? Something a bit more slack in the headtube and built for easy weight transfer? I would love to see what you could come up with in the geometry department.


Of course if you don't NEED to ride it is a bit pointless unless you were just doing "market research" to see what works best in bitter cold conditions. I have to get to school and back. Luckily I work from home so that commute is just downstairs

 

[TPA]

C'mon guys, give safe a break

5-6 weeks is Late September and early October, and you know how brutal October is in Missouri. :wink:

 

[safe]

...and you know how brutal October is in Missouri. :wink:

It's in the 50's and 60's a lot. You could ride, but it's not a lot of fun. And there is rain and fog often. So maybe I've got 8-9 weeks left. :?

 

[safe]

Low Quality SLA

On ebay I bought four 18Ah SLA's from a company named "directpower72" and the batteries are named "Power Battery". While I have gone at least a thousand miles on them there is already a "runt" in the litter that is becoming a problem. This "runt" started off low and has only gotten worse. In usage it would often end a ride VERY HOT and you could even feel the bubbling of the liquids inside. Taking an idea from someone else who posted here I tried taking the caps off the "sealed" lead acid and added some extra distilled water to this "runt" cell. Well, though it didn't seem to make it any worse it hasn't made it better. After a typical morning ride I ended with:

12.3 volt
12.3 volt
12.3 volt
11.0 volt

...and this happens every time.

So, I might just end the summer with this setup and replace the "runt" at the start of next year. We will see.

directpower72 no longer exists on ebay so they must have taken off in the middle of the night before their operation got busted.

Sometimes when you buy cheap stuff it ends up being just about as low quality as you might expect. (this "runt" cell was so from the beginning) The rest are still good, so if I replace the one I'm hoping to still get a few more thousand miles out of the rest.

As always... honesty in reporting results is my first prirority.

 

[vanilla ice]

For the winter load ole #1 back up with 28a SLA.. 4 of them. And get one of those outrunner 130Kv 6500w RC motors hooked up to your jackshaft already. Lets see what she can really do.

 

[safe]

I'm working so many hours on the other projects that every time I have to go back and spend more hours on this one it just sets me backwards. For the time being I can survive with the "runt" but it's definitely fading out. Maybe after I cross the 5,000 mile mark I might replace it. That's only about 140 miles away now.

This one cell was basically "defective" from the start... so buying cheap can mean that you get 3 out of 4 good cells. Does that make the cheap price worth it? Probably it's still worth it (they were only $35 each) so you just have to accept things sometimes go this way. Sometimes you get lucky and get all good cells, other times you get unlucky and get all defective ones...

 

[safe]

I just passed 4,900 miles today...

(but the "runt" is fading fast)

 

[safe]

Well I went ahead and ordered a replacement cell for the "runt". Another $44.20 (including shipping) goes into the "battery cost verses performance" calculation. :|

This particular cell was brand new and so there was something seriously wrong for it to have ended up with such a low capacity so quickly. It was heating up ever time I used it... what are the most common causes of a defective battery that heats up?

It used to heat up in a certain sub-cell... so I know that it is a very focused problem. Having gotten only about 1500-2000 miles on these cells is not so good compared to my old bigger cells. Maybe this is the kind of poor performance that others are used to? These small cells just seem less durable. (or this set was not so great)

The Solderless Tubes NiCad's have been flawless, so I've been able to ride with them carrying most of the load, but my range is down to more like 15 miles max.

 

[safe]

Oh Deer!

So I'm on a ride going downhill and I just go over a little rise before it drops off even steeper. I had checked my speed at 46 mph (which for that spot is fairly modest) and as I drop over the rise and am able to see what's on the other side I realize there are two baby deer standing in the middle of the road.

I'm glad I upgraded my brakes. :lol:

From the 46 mph I dropped the speed to about 30 mph in just a few seconds and by the time I was close enough to them they had started to run away. This experience helped to reassure me that having good brakes (and using them) can translate into being able to get out of situations if you do the right thing.

Every time I go over that rise it's a little scary because there is this one spot where you can't see until you get into it, but then it flattens out and you can see well afterwards, so I hate to have to slow down and give up all that good momentum. Momentum is like battery power, I hate to waste it.

Anyway... hope I make it to 5,000 miles without any more deer encounters so that I can join Toorbough ULL-Zeveigh in the "Over 5,000 Miles" club. (he's way out in the lead, but I'm trying to catch him )

Only 32 miles to go...

 

[Toorbough ULL-Zeveigh]

pls post on a per mile basis to count down the last ten ala dick clark/kasey kasem.

peep hole wuvs dem top ten countdowns.
Just ax dave the letterman.