speedmd
10 MW
-dg said:
+1
A 4.5" roller is a bogus test. Total waste of time and money on this test.
RiBMo tires are amazing
- Thread starter liveforphysics
- Start date
+1
A 4.5" roller is a bogus test. Total waste of time and money on this test.
alsmith
100 kW
Now come on gents, how can you call the tests worthless or bogus? Do you *really* think you will never ride over a few miles of 4.5 inch undulations when this could very well be just the information you desperately need to keep your rolling resistance minimised?
You should obviously store the information away safely for that special day when it is exactly the thing you need to know, just as I will.
But be careful if you choose the same place as me someone could be around to stop you recovering it!
Chalo
100 TW
Supertux1 said:
That's fine, but with better tires you could skip all the other preventives, have much better ride quality, and go a little faster for the same power without incurring more flats. K838s have the advantage of thick tread, but they lack any other protection.
liveforphysics
100 TW
Since we got to wheel size and wheel aero drag, I will add I tried a bike with smaller wheels and track wheel covers and was very surprised. It felt like it gave me 5mph for free (this is my legs pedaling alone).
speedmd
10 MW
Wheels Aero drag is significant at speed. Just take your weed wacker/ string trimmer and a tachometer and see what happens when you go slightly longer and thicker string. Now multiply that by the number of spokes /lengths.
dgk02
100 W
Nobody mentioned Slime in tires. My BionX wheel (Bontrager tire) came with slime in it. Not something I'd do myself and it is a bit of a pain with the presta valve, but it does seem to hold down flats. With a normal bike I wouldn't use slime because of the increased rolling resistance, but with an ebike I don't care that much.
dgk02 said:
Would slime increase rolling resistance? It doesn't seem intuitive it would significantly affect the deformation of the tire's rubber on the road, but I could see it adding to the angular inertia. This would be a significant point because increased rolling resistance is associated with increased energy losses while angular momentum isn't so much when cruising over long distances (Few stops), just makes it harder to accelerate/decelerate.
speedmd said:
I can't say whether a 4.5" roller makes it 'completely invalid' or not, but it would seem to work for the purposes of comparison between the different tires and that's all I really care about. The fact that the tires you'd expect to have lower rolling resistance (Those designed specifically for it) do have lower rolling resistance is telling. However, the comparability between different sized wheels might be compromised given the difference in contact area between larger and smaller wheels that can't be tested with a roller.
Anyway, shwalbe thinks smaller tires have more rolling resistance. But, at speed, aero is still the predominating factor.
You're talking about a 2% difference in rolling resistance versus a 20% difference in aero, and at high enough speeds, the aero factor could be 4-10x greater, watt-wise, than the rollling resistance factor.
speedmd
10 MW
Take a tire with a stiff sidewall and one with a flexi sidewall. Guess which one will most likely handle the roller better at the same psi. Slightly smaller diameter, fatter, the same type of things going on. Thread depth! 
liner Not any good IMO.
liner Not any good IMO.
alsmith
100 kW
I've tried Slime, Dr Sludge and another type by OKO. All were fairly similar but with some differences- mainly the colour. I don't / won't use again after trying three types.
They seem ok at first but I stopped for a few reasons, one of which is they eventually bung the valve up and at some point the wouldn't blow up and stay up. Also when blowing the tyre up the valve could eventually stick open or part open- you need to take it out and clean off the goo. As it aged pumping got harder, it effectively increased pressure needed to compress the spring- this gave a false reading of tube pressure until you got to the point of overcoming that resistance- the last one was at about 65psi before air could pass, and the pressure gauge on the pump settled at 65 even when the tube was clearly only 10 or 15 psi. Once over that stick point the pressure . The sealant ages and becomes a lumpy goo inside the tube, it can take a fair distance to sort of balance it out in the wheel, and also ineffective at it's intended purpose. It couldn't effectively be cleaned out meaning a new tube was needed.
I'm going to try one of the puncture repair sealants next, it is only meant to be a temporary repair but could be convenient when away from home- especially if it is raining.
They seem ok at first but I stopped for a few reasons, one of which is they eventually bung the valve up and at some point the wouldn't blow up and stay up. Also when blowing the tyre up the valve could eventually stick open or part open- you need to take it out and clean off the goo. As it aged pumping got harder, it effectively increased pressure needed to compress the spring- this gave a false reading of tube pressure until you got to the point of overcoming that resistance- the last one was at about 65psi before air could pass, and the pressure gauge on the pump settled at 65 even when the tube was clearly only 10 or 15 psi. Once over that stick point the pressure . The sealant ages and becomes a lumpy goo inside the tube, it can take a fair distance to sort of balance it out in the wheel, and also ineffective at it's intended purpose. It couldn't effectively be cleaned out meaning a new tube was needed.
I'm going to try one of the puncture repair sealants next, it is only meant to be a temporary repair but could be convenient when away from home- especially if it is raining.
alsmith said:
Recently, I just pumped up my green slime filled inner tire and then deflated it, and then it was impossible to pump it up! lol. I had to order a metal valve remover in order to clean it out and now, thankfully, I can still use the inner tube.
majornelson
100 W
I use Schwalbe Big Apples and love them. They are heavy and they are big... but smooth out all of the road imperfections on my city streets...
Just need to have a lot of clearance to get them on.
Just need to have a lot of clearance to get them on.
Chalo
100 TW
dgk02 said:
Slime doesn't affect rolling resistance as much as thick tubes or thick tires. I recommend against it because it clogs valves shut, clogs valves open, and makes a mess that's difficult to patch.
It's nasty. As a bike mechanic, I fantasize about charging customers twenty bucks every time their use of Slime results in getting it on me. Fifty bucks if a tire blows off and baptizes everything within eight feet (which has happened before).
Chalo
100 TW
swbluto said:
The problem with a 4.5" roller test is that it turns every tire into a 4.5" diameter or smaller for the purposes of contact patch and casing dynamics. Since even a seat-of-the-pants dyno can tell the difference between a 26" tire and a 20" tire, we need a flat contact patch to evaluate the differences that matter.
voicecoils
1 MW
Chalo said:
Amen.
They kill floor pumps (or clog them past usability) and I hate getting sprayed or exploded on too.
Why anyone wouldn't choose to solve the core problem of using crappy tyres is beyond me.
The fingers
10 TW
Tried slime once, but I personally will not use it again. :|
Ykick
1 GW
I use and endorse a small amount of Slime because in more cases than not it alerts me to a puncture (pst, pst, pst) and gives me a little more time to reach a suitable place to repair the flat.
I've learned avoidance is the best way to prevent annoying/bothering bike mechanics, LOL...
I've learned avoidance is the best way to prevent annoying/bothering bike mechanics, LOL...
dgk02
100 W
Ykick said:
Yes, funny. I do my own flats so mostly the slime annoys me. And tubes are pretty cheap so if the slime eventually kills a tube, that's ok. But it does seem to help with avoiding flats which are super-annoying when biking in the winter. It does clog the Presta valves.
dogman dan
1 PW
It depends on where you live I suppose. I have zillions of goatheads in the area, and thick tubes are all you need for that. I just got used to dealing with slime, which though named well could better be called disgusting slime. It's just simply the only thing that works for me on thorns an inch and a half long.
Slime is gross stuff, but I decided I liked riding home better than pushing the bike.
Slime is gross stuff, but I decided I liked riding home better than pushing the bike.
Jolly Jumper
100 W
The ultimate tire for me is KENDA K-898 in combination with a long lasting latex milk. If you want buy yourself Aramid fabric cloth and cut from it 8cm stripes than put it between the K898 and Tube its hard work and needs time to get it but when you have it it protects very very well with the exeption of the tiny needle punctures the will come trough it but with aditional latex milk its solved perfectly 
I ride about 50% offroad and they are gr8 for both the back wheel i have against rotation for more grip.
Before them i have tried many many tires (i ride bicycle over 20 yeahrs) mostely the knobby MTB thingis but since i switched to these 1.95 K898 i never willl other tires !!!
They are chep they run good in wet conditions supergrippy and they last about double as long as the MTB knobbys watch there profile
in the middle. they last double as long and cost only 1/3 the tires i bought before.
Jolly Jumper
I ride about 50% offroad and they are gr8 for both the back wheel i have against rotation for more grip.
Before them i have tried many many tires (i ride bicycle over 20 yeahrs) mostely the knobby MTB thingis but since i switched to these 1.95 K898 i never willl other tires !!!
They are chep they run good in wet conditions supergrippy and they last about double as long as the MTB knobbys watch there profile
in the middle. they last double as long and cost only 1/3 the tires i bought before.
Jolly Jumper
The fingers
10 TW
Around here, glass and screws outnumber the goatheads approximately two to one; then there is the odd fool who throws handfuls of tacks onto the San Gabriel River Bike Trail for kicks. 
The fingers said:Around here, glass and screws outnumber the goatheads approximately two to one; then there is the odd fool who throws handfuls of tacks onto the San Gabriel River Bike Trail for kicks.
I'm having reservations about biking on the LA paths; I just get a bad feeling with the city's high young adult unemployment rate and crime/mischievousness in the city, especially on the fairly popular paths. And, I get the impression that it'd be extremely crowded...
liveforphysics said:
it's not a portmanteau.
it's a lowly plain ole acronym like RaDAR or LiDAR.
dogman dan
1 PW
In case I wasn't completely clear about it. Slime + thick tubes or tire liners pretty much destroys the performance and feel of the tires.
It's heavy, and has that thick feel to it for sure. Where I ride off road through the mesquite forest, and given the number of nails on the side of the roads, I just would rather run with exess slime than stop to patch tires. Once you do have to stop and patch anyway because a huge nail got you, it's a nightmare to get the tube clean enough to patch.
The trick for in the field, is wash the tube with dirt, then wipe dry with the one rag you carry.
It does mess up valve cores, so you learn to have the metal remover on the stem for a cap. Sometimes you have to ream the stem with a wire. You learn to wash out your pumps. And you carry a pump, because slime only works with full pressure.
As long as I live in a mesquite forest, and the sheetrocker lives next door, I'm stuck with slime.
Every tire worker, bike or car, loathes slime. I don't blame them. But you should only charge more for customers that bring in slime, and DONT tell you. You don't have to get it all over you, if you know it's there. Just have a slime tire station, with a nice tub of water that you place the wheel in to dismount the tire.
It's heavy, and has that thick feel to it for sure. Where I ride off road through the mesquite forest, and given the number of nails on the side of the roads, I just would rather run with exess slime than stop to patch tires. Once you do have to stop and patch anyway because a huge nail got you, it's a nightmare to get the tube clean enough to patch.
The trick for in the field, is wash the tube with dirt, then wipe dry with the one rag you carry.
It does mess up valve cores, so you learn to have the metal remover on the stem for a cap. Sometimes you have to ream the stem with a wire. You learn to wash out your pumps. And you carry a pump, because slime only works with full pressure.
As long as I live in a mesquite forest, and the sheetrocker lives next door, I'm stuck with slime.
Every tire worker, bike or car, loathes slime. I don't blame them. But you should only charge more for customers that bring in slime, and DONT tell you. You don't have to get it all over you, if you know it's there. Just have a slime tire station, with a nice tub of water that you place the wheel in to dismount the tire.
alsmith
100 kW
Jolly Jumper said:
...
What's with the excessively large font? You think everyone has got eyesight problems?
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