Jed Charlesworth
Member
Yes correct the rim was re-dished at shop and I will take it back in 600 to 1000 miles. just to check.
Exploding Rear Tires?
- Thread starter Rick Huizinga
- Start date
Yes correct the rim was re-dished at shop and I will take it back in 600 to 1000 miles. just to check.
Jed Charlesworth
Member
Yes
Rick Huizinga
Active Member
I've received the replacement tire from Stromer, and decided to check to see if both wheels have been trued and dished properly. I knew that the front wheel wasn't quite true, as I could see it wobble back and forth while riding the bike, and suspected that if the rear wheel wasn't true, it could have contributed to the de-lamination shown in the OP.
First, I can confirm that the Stromer version of the Schwalbe Big Ben tires are indeed custom. The standard Big Ben's have RaceGuard protection, LiteSkin sidewalls and a white sidewall stripe around the circumference of the tire. The Stromer custom Big Bens have GreenGuard protection and thicker rubber sidewalls with no stripe. See http://www.schwalbe.com for information on the different product features.
For the front wheel, I trued the wheel and verified that the dish was even.
For the rear wheel, it needed very little adjustment to true the wheel - it was already pretty good. I doubt that a poorly trued wheel was a factor in the de-lamination. The dish of the rear wheel was way off, but this appears to be by-design.
The spokes on the gear side were tightened so that they were nearly vertical, whereas the spokes on the brake side were longer and have a big angle to them. See photos:
Camera aligned to gear side of rim. Note that the spokes are nearly vertical and can't be seen. Also, the edge of the rim on this side is roughly in-line with the edge of the motor.
Camera aligned to the brake side of the rim. Note that you can see the spokes angle outward.
To properly dish the rim so that it is centered to the axle, the rim would need to move left, towards the tight/nearly vertical spoke side by another ~8mm, This obviously is not possible as the spokes on this side cannot pull the rim in this direction any further.
The wheel, as-dished, is perfectly centered to the frame when mounted so I believe the wacky dishing of the wheel is by design.
And lastly, a note to anyone needing to change a flat on the rear wheel: be very careful when re-mounting the wheel to the bike as it is very easy for the brake disc to cut into, or damage the wiring leading to the rear axle. The spring loading of the rear derailleur and tensioner push the wheel and edge of the brake disc right into the cabling while attempting to re-insert the wheel.
****Note from EBR Admin, the images that would've been here are missing from the web; please everyone, upload pictures from your computer, NOT a link to some other site. That way we store the images and they can be seen since they will live on EBR server.*****
First, I can confirm that the Stromer version of the Schwalbe Big Ben tires are indeed custom. The standard Big Ben's have RaceGuard protection, LiteSkin sidewalls and a white sidewall stripe around the circumference of the tire. The Stromer custom Big Bens have GreenGuard protection and thicker rubber sidewalls with no stripe. See http://www.schwalbe.com for information on the different product features.
For the front wheel, I trued the wheel and verified that the dish was even.
For the rear wheel, it needed very little adjustment to true the wheel - it was already pretty good. I doubt that a poorly trued wheel was a factor in the de-lamination. The dish of the rear wheel was way off, but this appears to be by-design.
The spokes on the gear side were tightened so that they were nearly vertical, whereas the spokes on the brake side were longer and have a big angle to them. See photos:
Camera aligned to gear side of rim. Note that the spokes are nearly vertical and can't be seen. Also, the edge of the rim on this side is roughly in-line with the edge of the motor.
Camera aligned to the brake side of the rim. Note that you can see the spokes angle outward.
To properly dish the rim so that it is centered to the axle, the rim would need to move left, towards the tight/nearly vertical spoke side by another ~8mm, This obviously is not possible as the spokes on this side cannot pull the rim in this direction any further.
The wheel, as-dished, is perfectly centered to the frame when mounted so I believe the wacky dishing of the wheel is by design.
And lastly, a note to anyone needing to change a flat on the rear wheel: be very careful when re-mounting the wheel to the bike as it is very easy for the brake disc to cut into, or damage the wiring leading to the rear axle. The spring loading of the rear derailleur and tensioner push the wheel and edge of the brake disc right into the cabling while attempting to re-insert the wheel.
****Note from EBR Admin, the images that would've been here are missing from the web; please everyone, upload pictures from your computer, NOT a link to some other site. That way we store the images and they can be seen since they will live on EBR server.*****
Ravi Kempaiah
Well-Known Member
- Region
- Canada
- City
- Halifax
yes, it is true of most hub motor bikes. The cassette side needs more clearance so that spokes are laced a bit differently.
pxpaulx
Well-Known Member
Not just hub motor bikes, pretty much any bike with rear gears has an offsetting dish in order to be centered in the frame.
Rick Huizinga
Active Member
The only place that I have seen, that presumably ships the Stromer custom version of the tire is: http://www.elektrofahrrad24.de/spezial-ersatzteile-stromer#.VYtCAXpViko
To purchase locally, your local Stromer dealer should be able to order replacement parts, if asked.
Rick Huizinga
Active Member
Well, it finally happened. My front tire exploded after 4060 miles of wear. Fortunately it happened in the garage overnight, and not while riding.
The tire delaminated from the wire bead so that the sidewall was no longer supported. With nothing holding the tube, it exploded:
You can see on the far left, that the delamination happened near one of the "cut" marks on the sidewall on the tire. Whoever installed the tires on my bike at the factory damaged both the front & rear tires when mounting to the rim. The cut marks on the rear tire were worse than the front tire, so I only had Stromer send me a replacement for the rear.
The tire delaminated from the wire bead so that the sidewall was no longer supported. With nothing holding the tube, it exploded:
You can see on the far left, that the delamination happened near one of the "cut" marks on the sidewall on the tire. Whoever installed the tires on my bike at the factory damaged both the front & rear tires when mounting to the rim. The cut marks on the rear tire were worse than the front tire, so I only had Stromer send me a replacement for the rear.
I had a wire bead Continental Gatorskin with about 200 miles on it fail like that. I was pretty new to cycling so I do remember wrestling pretty hard with a tire lever to get them on the rims. So it very well could have been my fault. It failed in the middle of the night and sounded like a 22 being fired. Scared the crap out of me 
I'm running the 28x2.0 Schwalbe Marathon Almotion tires on my Cross Current. They have a nice low rolling resistance for a touring tire and the 3mm Greenguard from the standard Marathons.
I'm running the 28x2.0 Schwalbe Marathon Almotion tires on my Cross Current. They have a nice low rolling resistance for a touring tire and the 3mm Greenguard from the standard Marathons.
Aloha Rick, Thanks for all the info. on Big Bens. Unfortunately your alignment pictures didn't come through on my android phone or Windows pc. Just an exclamation mark. I have a Park trueing stand on the way, and sure wish I could see your pics. Any ideas ? Still never heard from Electrfarrad.de on OEM Big Bens. Lost in translation maybe. With the weight our tires carry on a St2 , I think we should change twice a yr. at least rotate. My Mr Tuffy is doing it's job so far on the rear, I was having a rash of punctures for awhile.
Trail Cruiser
Well-Known Member
I see major significant factors that contribute to the tire issue.
1. Speed
2. Weight
3. Rigid frame/no suspension where the tires (and your body) are forced to solely absorb and soak up all the road impacts.
Slowing down kills the joy in ebiking. The ebike cannot reduce weight but the rider can. Putting suspension makes more sense here. Rockshox in the front, bodyfloat with Brooks B67 saddle at the back will make your tire and your body happy.
1. Speed
2. Weight
3. Rigid frame/no suspension where the tires (and your body) are forced to solely absorb and soak up all the road impacts.
Slowing down kills the joy in ebiking. The ebike cannot reduce weight but the rider can. Putting suspension makes more sense here. Rockshox in the front, bodyfloat with Brooks B67 saddle at the back will make your tire and your body happy.
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