Save gumwall tires.

[horsefarmer]

Picked up nice middlleweight Ross Central Park bike (mid 80's vintage).
Bike is in good shape and tires hold air and look sound and ride great. Only problem is there is a narrow band of gumwall that is rotted and peeling. I think it is just cosmetic. Anyone put plasti-dip or silicone over this or would it not hold?

 

[Fv2]

I don't think it would hold well, my understanding of gumwalls is that it is a weaker part of the tire as is.
I don't know why that would be, just been told that.

 

[Bicycle808]

Without seeing pics, it's tough to say for sure...but my guess is that the tires are toast.

 

[user 135]

Gum-wall or skin-wall? Did you know there is a difference? My guess is you have gum walls and the sides are completely cracked off. The tires are probably readily available online cheaper than any fix.

Some reading on differences.
https://www.reddit.com/r/FixedGearBicycle/comments/1lbcqh/discussion_skinwall_vs_gumwall_confusion/
https://www.facebook.com/PorkchopBMX/photos/a.175599920414.125043.140562000414/10152784631780415/

 

[horsefarmer]

Well here you go.

I'm thinking it must be a "Gumwall" sure looks like minimal Threads Per inch. When I got home from the auction I aired up this bike (a mid 80's Ross central park) and went for a 7 mi ride and the bike rode perfect.

Yesterday took it on another 7 miles and fine again. But I notice now there are cracks in the tread starting so I'm going to deflate the tubes now and change the tires!

 

[Bicycle808]

Gum-wall or skin-wall? Did you know there is a difference? My guess is you have gum walls and the sides are completely cracked off. The tires are probably readily available online cheaper than any fix.

Some reading on differences.
https://www.reddit.com/r/FixedGearBicycle/comments/1lbcqh/discussion_skinwall_vs_gumwall_confusion/
https://www.facebook.com/PorkchopBMX/photos/a.175599920414.125043.140562000414/10152784631780415/

Definitely a difference; horsefarmer's bike almost certainly has gumwalls.... and most skinwall tires are all black, bead-to-bead. The "skin" refers more to the rubber's thickness, and not at all to the tire's coloration.

In my experience, skinwall tires are not fat-guy friendly.

FWIW, Kenda* makes a k53 in gumwall; killer tread pattern, decent tires, usually they go for $10 to $15. They offer them in both 1.75 and 2.125 in the 559/26" size; measure your frame and see how wide you can go....
http://www.niagaracycle.com/categories/sunlite-mtb-raised-center-tire-26-x-1-75-black-tread-gum-wall
http://www.niagaracycle.com/categories/kenda-k53-26-x-2-125-center-ridge-tire
*sometimes marketed under the Sunlite name

 

[Bicycle808]

Well here you go.

View attachment 22431
I'm thinking it must be a "Gumwall" sure looks like minimal Threads Per inch. When I got home from the auction I aired up this bike (a mid 80's Ross central park) and went for a 7 mi ride and the bike rode perfect.
View attachment 22440
Yesterday took it on another 7 miles and fine again. But I notice now there are cracks in the tread starting so I'm going to deflate the tubes now and change the tires!

Cool bike.... yeah, i'm not surprised those tires still hold air, but they are way past their prime and i wouldn't trust'm....not too long before they blowout. I'm glad you've decided to change them...and yes, they are definitely gumwalls.

 

[Chad T]

Definitely looks like time for tires.

The thing I notice with skinwalls is you can see the texture of the cords through the thin layer of rubber on the sides.

 

[Bicycle808]

Yep.

 

[horsefarmer]

I should hope I learn by experience, 808! We bought a couple lightweight Schwinns last year and on the second ride my wifes rear tire sidewall blew out! original 1970 Schwinn blackwall. After only 45 years!

 

[Bicycle808]

45 years?!?!?! If a tire doesn't last at least half a century, it's GARBAGE! They sure don't make stuff the way they used to...

 

[user 135]

Porkchop has some skinwalls http://porkchopbmx.com/kenda-k50-comp-3-bmx-bicycle-skinwall-tire-26-x-2-125-black/

 

[Chad T]

He gives a great description of the difference on there too. Gumwall is basically a fake skin wall. At least that's the way I've always looked at it.

 

[horsefarmer]

The tire on there is 26 x 1.50 so if want to keep those sweet fenders prob not gonna rock 2.125 rubber.

 

[Chad T]

Niagra cycle has these for under 10 bucks a tire if you want to keep the gumwall and 1.5 width. I'm guessing you could fit a 1.75 maybe 1.95. 2.125 might be close.

http://www.niagaracycle.com/categories/sunlite-mtb-raised-center-tire-26-x-1-5-black-tread-gum-wall

Tons of tires on there for not a lot of dough.

 

[horsefarmer]

Thanks for all the help guys! I have a couple new 1.75 tires in the shop. I'm gonna try one on the front and see if it clears. If not I have options.

 

[Duchess]

Originally, I believe the idea behind gumwalls was that the gum section lacked the durability and strength of the carbon black added to the rubber for the tread, but lack of it also made the rubber more supple. The idea of the gumwall sidewall was to try to achieve the best of both worlds—durability on the traction area, suppleness for cushion on the side. I've never done a blind back-to-back test with tires that were identical except for one having gumwall and the other without, but I suspect the difference is more cosmetic than anything. If anyone has better experience otherwise, I'd love to hear (read) it.

 

[franconuevo]

H.F. I just asked a similar question a little bit ago about an '84 Schwinn World that I redid. The gum-walls on this one were so hard that I had to cut them off.
And although I know that the gum walls were authentic to the original bike..I ordered some blackwalls from eebay, I believe....based largely on similar advice I received, just like on this post.
They were cheap...and I'm glad I made the choice to go with them.
about a year ago I fixed up an old Schwinn Collegiate....replaced with new gumwalls, and even new, the tires seemed..I don't know..kinda soft and spongy. Think blackwall...or..skinwalls If you like that look...(skinwalls are a bit pricier)
Franco

 

[horsefarmer]

I would probably go with blackwalls if I can find a size that fits under the fenders. I got a deal last year at AA for a pair of duro 26 x 2.123 in red. Put em on an old mountain bike just to see how the look - awesome ! Maybe find 1.50 wide 26 inchers in red or tan? I've got a pair of blackwall 1.95" I'm gonna try today, they have kind of a motorcycle tread.