Tyres for dummies

[Racey Rider]

Another tyre question:

Are radials the be all and end all of everything?

Under what conditions would Cross ply or Bias Belt construction be a better option for a bike?

[Maha]

I think ppl have answered your question. Maybe it's time to let Maha out of the kitchen, and ask him

That is dangerous. Take it back and demand the correct tyre as soon as possible. Your rims are designed for a 130 size, not a 180, that is 50 mm or 2 inches wider. Your handling will be affected, your ride height has changed, your steering geometry has changed. Overall, that is an accident waiting to happen.

Crisis overted, with specs on and once the eyes have focused, I can clearly see its a 130 not a 180. A 3 can look like an 8 in some in a certain light...

[Ntoxcated]

So the ride height changed because the previous tyre was that bald?

[doc]

I can clearly see its a 130 not a 180. A 3 can look like an 8 in some in a certain light...

Still blind with rage from shoppin then. At least she lets you out of the kitchen then.

[merv]

If your bike really is meant to have a 130 width tyre I am surprised a 180 fits without clashing with the run of the chain. How close is the chain to the tyre now?

Someone has given you crap service and you need to go back an get them to sort it.

[Latte]

Different tire pressure, different manufacturer could increase height of tire.

[MSTRS:Me]

Crisis overted, with specs on and once the eyes have focused, I can clearly see its a 130 not a 180. A 3 can look like an 8 in some in a certain light...

Pleased to hear that. Going up one size from recommended is not usually a big problem, but five? One would question it being possible, due to width of swingarm and run of chain.
As for 'feeling' like the bike sits higher...certainly possible.
1. There is the new depth of tread. Minimal to be sure, but noticable.
2. Different brands have differing tyre profile shape. ie. the '90' is the sidewall height (common to all) but the curve of the tread area will vary to hell. A greater curve means higher in the centre.

[Mishy]

Another tyre question:

Are radials the be all and end all of everything?

Under what conditions would Cross ply or Bias Belt construction be a better option for a bike?

When the only size available for your bike is a crossply, and that is often the case!

Radial is best - just take my word for it, but many smaller, or older bikes have a rim size that dictates the use of a Bias ply tyre (one step better than crossply)

Always fit the reccomended size (unless you have compelling information to the contrary) and if that means a crossply, then crossply it is.

You can tell what you have from the making on the tyre. 180/55ZR17 means Radial construction - the R in the description tells you that, and a "B" tells you Bias ply.
No extra letter would normally mean crossply.

There are not many sizes where you can get both radial and Bias ply, so people who deal with tyres a lot can tell you what you get from the size alone.

I hope this is useful.

[matdaymon]

Apologies for reviving an old thread,

I was looking at the specs of my tyres on my GT250 today after doing 1500km around and about the Coromandel over the Christmas/New Year period and now need to start planning for new tyres in the very near future.

I understand the first few numbers etc but mine have extras on top of these at the end; Example my Shinko brand rear tyre reads 150/70-17 M/C 69H. I Understand that its 150mm wide, 70% of that width in height and a 17inch rim, but what does the 69H mean? (I'm taking the M/C to stand for Motorcycle here). The Front's measurement (also a Shinko) is 110/70-17 M/C 54H if that means anything also.

Any light shed on my mysterious numbers would be appreciated

[cs363]

Apologies for reviving an old thread,

I was looking at the specs of my tyres on my GT250 today after doing 1500km around and about the Coromandel over the Christmas/New Year period and now need to start planning for new tyres in the very near future.

I understand the first few numbers etc but mine have extras on top of these at the end; Example my Shinko brand rear tyre reads 150/70-17 M/C 69H. I Understand that its 150mm wide, 70% of that width in height and a 17inch rim, but what does the 69H mean? (I'm taking the M/C to stand for Motorcycle here). The Front's measurement (also a Shinko) is 110/70-17 M/C 54H if that means anything also.

Any light shed on my mysterious numbers would be appreciated

Those codes relate to the load & speed rating of the tyre, 69H being 325Kg & 210km/h. 54H is 212Kg and same speed rating.
(Number being the load rating and letter being the speed rating)

[matdaymon]

Awesome, thank you very much. Gotta say after coming from a car background all the extra stuff relating to bikes is a bit confusing for my rather sluggish student brain.

I take it there is some kind of list relating to the number then and how they relate to load weights floating around somewhere or some kind of crazy algebraic formula?

[cs363]

I take it there is some kind of list relating to the number then and how they relate to load weights floating around somewhere or some kind of crazy algebraic formula?

Here you go, this will tell you most of the stuff you need to know about tyres:

[matdaymon]

Very helpful that, thanks very much