What is wrong with this picture?

[greenspark]

Tire = 700-32C. Ordered rim with motor and specified 700C size. Installing the tire was easy. My air pump needed a part, so it only filled the tire to about 35 pounds, which allowed testing, but was not near the 75 pound minimum written on the tire. Got the part today, and filled the tire to 75 lbs. Noticed the bulge, so I went into the house to look up tire sizes on the internet. Two minutes later I hear what sounded like a gun shot. Went down and saw the bike on its side. The tube had exploded. Went to the bike shop and bought a new tube. Put it in, put in 50 lbs of pressure and a second bulge appeared. Deflated the tire and came inside to research the question. Can't seem to get clarity on what size the rim might be.

As can be seen, the tire is too big; the bead does not hold and it presses the tire off. Is this because of shipper error (he did not send me a 700c rim as ordered), or is specifying 700c not enough.

I don't want to replace the tire, since it is part of the Globe Specialized Live 1 design... I like the color and reportedly it is a very durable tire. My choices are to ask the vendor to send the correct rim (if it was his error), or re-spoking the old rim with the new motor... something I would rather avoid, as now I can always easily undo the motorizing and go back to an original bike.

But first I need to understand what is going on. What is the rim size? What variables are there? Advice appreciated.

 

[Ykick]

I only deal with 26" wheels so I can't help you with the rim size. But I've had this happen before and it was due to not properly centering the tire on the rim while it's being aired-up.

I can only get a good bead fit with the wheel/rim laying horizontally, use a little soapy water on the bead and pause filling with air a couple times to check the centering of the tire and make sure everything's fitting as it should. If not, let enough air out so that you can work the tire with your hands to help the bead seat.

As you learned you should never top off a tire with high air pressure until you're sure everything's fitted correctly.

 

[MadRhino]

You just discovered that rims, and tires, are not born equal. Some pairs don't like each other, not that they aren't good, they are just different. This is more frequent in 700C size, that is easily confused with 27, 28 in.

Since a rim and wheelbuild cost much more than a tire, your easy solution is to buy a tire that fits the rim. A tire doesn't las very long anyway, and if it does, it is because it is made with hard gum that has poor adherence. In any case, you will want a wider tire with a hub motor.

 

[wesnewell]

Yep, I've blown up a couple of tubes by not checking the seal of the tire evenly on the rim. But I'm 65 and half blind. What I do now is air up the tire to about 30psi then run my hand around both sides of the rim to make sure there's no bulge, then take it to 40 psi and check again. The ones that I blew up did so just after 40 psi, and I've caught a couple that weren't seated good at 40psi and would have blown with more pressure. I caught one by spinning the wheel and the bulge caught on the brake pads.

 

[amberwolf]

Unfortunatley I think you've simply run into a not uncommon problem of tires that are the right size not fitting a rim that's also the right size, because one or both of them isn't *actually* the right size.

I have a Kenda Kross variant that someone gave me because it would not stay on their 26" rim, yet my apparently identical rim it *does* stay on--because my 26" rim is some tiny amount larger in diameter, or perhaps the bead seats on the rim are deeper, or both. The MTB tire that came off my rim easily fit onto theirs and AFAIK is still on there today, over a year later, without problems. But the original fit problem they had showed exactly the same problem as your pictures.

I've also had tires that were identical in markings and very similar in style, by the same manufacturer, where one is easy to get on the rim and the other is nearly impossible because the fit is so tight.


Sometimes a tire is meant for a different width rim, too, and on the wrong width won't let the bead lock onto the rim, even though the diameter is the same.

 

[The Apprentice]

Just a thought,
I note that in the picture the bulge / failure is at the valve, perhaps the wide valve section of the tube is below the tyre bead and pushing it off the rim when inflated. It may be worth pushing the valve most of the way into the rim before inflation this can get the wide part of the tube's valve section above the tyre bead, which then pulls the tyre bead into the rim on inflation rather than pushing it off.

Probably barking up the wrong tree but it may help.


Cheers
Giles.

 

[dogman dan]

Not every tire fits the same, despite what's written on the side.

Let me guess, it was really easy to slip onto the rim. When you have a loose one, it's crucial that you carefully seat the tire on the rim evenly. You got it on there egg shaped, and as you added air it popped off the rim on the loose side.

Chuck the tire and try another, or when first inflating get the tire on the rim more evenly. For a loosie, I inflate to only 5-10 psi, then bounce the tire a few times as you rotate the rim. If still not on the bead evenly, deflate some and try again. If the tire just won't get on the bead evenly, screw it and get another tire.

Seems to be a problem more likely to happen with small tires, like road bike tires.

 

[miuan]

Ditch the tube and get a Stan's tubeless strip. Carefully drill the valve hole to make place for the bulge around strip valve. Install the tyre and see if the fit is tight. If not, remove the strip and put a layer of rim tape underneath it, then repeat as many times as needed to get the tyre fit very tight, being almost impossible to install even with steel levers. Then insert the sealant and seal the system. Use a compressor to inflate the tyre to 40psi, give it a short ride and top the air.
If this doesn't work, just get a white edition Schwalbe Fat Frank in 2.35 size and be happy, keeping this tyre as a backup for the other wheel.

 

[MadRhino]

...just get a white edition Schwalbe Fat Frank in 2.35 size and be happy, keeping this tyre as a backup for the other wheel.

That is how to do it.
Messing with tape and tubeless to make it fit, isn't worth the the hassle IMO, unless you value your time very cheap.

 

[dogman dan]

Yeah, if you can't mount it even fairly easily, don't waste any more time on it. If convenient, return for a refund.

 

[miuan]

Messing with tape and tubeless to make it fit, isn't worth the the hassle IMO, unless you value your time very cheap.

I admit it's quite frustrating and time consuming at times, but I have NEVER had a puncture with Stan's tubeless, on or off road. That includes thousands km on cargo ebike, and 2 years riding MTB, including numerous national DH races. Tubes do seem to work for the rest, they just always let me down...

The amount of confidence makes it worth, especially with e-bikes where repairing a flat may be a matter of hours, and you don't really want to do it on the road. Getting a flat tyre at 40mph in the middle of traffic may be lethal, no matter how good the rider is. Until I start riding moto tyres, I prefer this security measure for my bikes.

Anyway, I agree, for the sake of tyre thickness alone, go for the Fat Frank NOW. Looking at your tyre's bead lock, it's horrible for tubeless conversion anyway.

 

[Ricky_nz]

e-bikes where repairing a flat may be a matter of hours

Only if you insist on starting with a rubber tree and making your own tube :lol:

 

[dennyt]

I think can be solved entirely by changing your mounting technique. I worked in a bike shop for six years, repaired hundreds of flats in that time.

1) Inflate up to 20psi. Spin the tire. Check for bulges / high spots / low spots, where the bead isn't seated right.
2) Push the tire around until it's seated right. Or, deflate & start over.
3) Reinflate to 20psi, spin it. Does it look good?
4) Once it looks good... air it up, off you go.

Once the tire is properly seated, the "hook bead" feature of the rim will use the tire's pressure to keep it from unseating itself.

Happy trails!

 

[Ricky_nz]

I think Dennyt has it right.
That small bulge looks as if distributed around the wheel there won't be a problem.
Definitely take it slow and check before too much pressure. I have good success putting 2.5" hookworms in narrow rims (18mm and 20mm) if I am careful but the one time I did it tired in fading light and cut corners I blew it off the rim at about 50PSI :lol:

 

[greenspark]

I think I worked out why it went on misaligned. The new rim is neither round nor true! Have a look at this video: http://www.youtube.com/watch?v=4rtsA8aqOi0&feature=youtu.be.

Using Dennyt's advice I have been able to get it to hold air and not pop the innertube, but I probably will need to take the original rim (that came with the bike and fits the tire) and have it re-spoked for the ebike motor... however, since the motor I bought is noisy, I probably am best buying a new motor of a different make and tossing this noisy motor and out-of-round rim in the shed.

Live and learn.

- - -
P.S.
I am still in correspondence with the kit supplier, so until the vendor either makes good or begs off, I won't document what motor or vendor.

 

[greenspark]

In the ongoing saga of the tube-popping rim, on Christmas Eve (it's summer down under) I was delivering Christmas presents and about halfway to my destination the front tyre just went pfff. Nothing out of the ordinary in road conditions, no bad-fitting lump (I followed the good advice given in this forum), it just gave up the ghost. I had to call the guy I was giving the present to and have him pick me up. Thankfully, the best pizza cafe on the island (real Italian) was nearby so we had a Christmas pizza and Peroni. Then came the panic-realisation that in about two hours New Zealand would shut down and not reopen for at least two weeks. Truly, everyone just closes the door until the first or second week of January, so forget buying anything other than food, fuel or summer holiday stuff.

So on getting home, I left a phone message and sent an email for Bruce O'Halloran at Adventure Cycles http://www.adventure-auckland.co.nz/adventurecycles/about_studio.html in Auckland, asking if he had a thorn-proof 700c inner tube and if so, if he could drop it off at the ferry terminal. Next day, Christmas Day, I get a call from a bloke who says this fellow came up to him at the ferry terminal and asked if he would take a package over to the island and ring me. He gave me the address of his house, saying it would be in the mailbox. When I went over to Bruce's shop after the holidays to pay him, he said he got to the terminal and saw that the ticket office was closed, so he picked a stranger out of the crowd... that's another reason why I love living in New Zealand. But I digress...

When I pulled off the old (err... 3-day old) tube I found the rim had put a very small hole in it even though I had rim-protecting tape around it. When I stopped by to pay Bruce this week, he explained that it was likely the Chinese rim has some slight metal sticking up from where they drilled the holes. The new thorn-proof inner tube is tough as nails, and I expect it should put up with the rim until I replace it... soon.

At this point, I have given the vendor the opportunity to make good on the complaints and he has done nothing other to say he has never had a complaint like this before and the rim must have been damaged in shipping (the box was fine and it was well packed). So, as promised, I will disclose who.

I bought the Cute100F kit from Steven Deng http://elifebike.com, a Chinese vendor, who I think broke away from BMS battery and set up his own business. Despite his poor English, he does try harder than BMS, but is still is in the Caveat Emptor class of Chinese vendors. I doubt he inspects his products before he sends them, and returns to China are impractical, so as long as there are virgin buyers, he will remain in business. For the price of a meal for two including wine (US$110 plus shipping) you get a complete ebike kit (sans battery) and everything you need is in the box. If you buy from him, be sure to purchase all the accessories you need, because the shipping is expensive for the minimum order, but not much more for the extra stuff.

The bad news is

• the rim: out of round, not trued, not the same 700c as the 700c it replaced (its a bit smaller) and it pops innertubes (2)
• the motor: very loud under load (despite using the "learn" connection). I mean really loud, obnoxiously loud. Perhaps amplified by the wooden carrier tray.
• the motor or the controller: under-powered going up our NZ hills (yeah, they are short but steep)
• the disk brake kit: It fit the motor (that's good), but the screws sent with it were too long. With the disk properly screwed in the motor would not turn. I ended up removing them and tossing the disk kit aside; the calliper brakes are good enough
• installation: Not so much bad news, but a caution. The controller comes with its connectors installed, and Steven provides some good instruction sheets on his web site, but if you do not know how to carefully figure out what is what and how to solder best to take it to a professional. I used a label machine to label each wire before I began and managed not to mess it up, but it's not easy for the inexperienced. It ain't plug-and-play. The benefit of not having pre-soldered connectors on both ends is that you get to cut the wires to size. With Paul - Cell Man's kit the connectors come plug-and-play, but this means possibly having longer wires than necessary or clipping them and installing joint-connectors. I prefer Paul's approach.
• shipping: Deng advertised DHL as the cheapest, which I selected. I then got an email from him saying that DHL won't work and I had to send extra money. I called him twice on his cell phone, but his Chinglish is so bad that I could not comprehend what he was saying (I was trying to get the tracking information). It took him two weeks to get the stuff shipped, which sort of defeats the purpose of fast shipping. I am unclear if this was bait and switch, because exactly the same thing happened with BMS Battery who took three weeks to ship out the 36v 8.8 amp "bottle battery" they offer (which is fantastic, fits on the bottle holder and looks great). It may be that DHL just pulled the plug. The EMS tracking info is somewhat unreliable, but in the end the kit arrived.

The good news is:

• the motor: the size (front) is great and the silver finish looks OEM, hard to tell it is an e-bike
• the accessories (brake handles, thumb throttle, controller) all work fine
• the online documentation: Steven has some pdfs and jpgs that show how to wire common controllers... and they are in English
• His prices are amazingly cheap, and yes, the kit he sent me does work. As long as the hills are not too steep (and some of mine are), what he sold me works.

As noted, I bought the battery ($199) from BMS Battery. In part it was because Steven did not offer that design, but also because I wanted to compare the three different Chinese vendors (the 3rd being Cell Man from whom I had bought a MAC Torque kit before he went on holiday in December). The BMS service was inexcusably bad. In my day job, we do business in China (domestic) and the Chinese expect goods they order to arrive at their home within three days of placing the order. BMS took three weeks to get the package to EMS. During the shopping part I asked some questions and it was clear that their English is so weak that one will get little more than what the web site provides.

What's next?

I am writing Cell Man (Paul) to get advice on his Mxus or Mac 350 front motor and matching controller plus some proper gauge spokes, and I will order what he recommends. I will have it put on the original rim that came with the bike, so I know I will have matching rim and tyre and no rim issues (aside from the issue with Steven's rim, what BMS, Deng and Paul ship is what they carry - unlikely to match what came with the bike - as can be seen in the photo below). I also will try the half-throttle grip, although I am beginning to appreciate the benefits of pedalec... among other things you can use your right hand to signal a turn (we drive on the left side of the road in NZ) while still applying power.

I would have bought from Paul in the first place, but it was the month he closed for vacation. His prices are slightly higher, but he says his motors are in a class above the Cute motors... and I reckon the savings on slow shipping evens it out. And even the slow shipping is a relative concept... he gets them in the mail within 48 hours, so even though slow-post may take longer for delivery, the time between order and arrival is probably the same as the more expensive fast shipping of BMS.

I already have the bottle battery, but I am encouraging Paul to offer it as part of his portfolio. As can be seen in the photograph, it does not look like a chunky battery. It is a breeze to install and it has an on-off switch on the bottom. It is lockable and removable, although I don't park in places where I need to worry, so I leave it in place. At present it is offered in 36v 8.8 amps, which is on the small end of the scale, but it suits my needs. Paul being a battery guru may figure out how to increase its capacity in Ah or volts within the same-sized case - here's hoping.

 

[valsislav]

Nicely done!

 

[greenspark]

Further update.

As can be seen on http://endless-sphere.com/forums/viewtopic.php?f=2&t=36033&p=522845#p522845, the Cute100F motor died. Some speculate it was the controllers, others think it was a bad Hall sensor. In any case, I have been in communication with Steven Deng who has been suggesting things to try. Not sure if, when he runs out of ideas, he warrants his products or not. If he does nothing, then I will strongly suggest people avoid wasting their money on him. A cheap price that lasts six weeks is not cheap. Very frustrating that its summer down under and the bike is dead in the shed. More to come...