Tyre roundness

[User16625]

How far out of true or roundness does a tyre have to be before its considered unacceptable?

 

[Dusty Bin]

If it was square, I'd probably complain. Have you fitted it to the rim?

 

[User16625]

Yeah. Theres a slight oscillation of the tyres. I didnt feel any added vibration when I went for a short test ride but just wondering if less than perfect roundness is ok.

 

[Dusty Bin]

Tyres all come out of the same mould, so unless you have a particularly cheap/nasty set of tyres I would suggest that they are already round enough. Presumably the bead is correctly seated?

 

[02GF74]

I hav found some expensive tyres can do that - you can spend ages reseating the tyre, pulling, pushing, tugging, swearing but it is futile. MTB tyres seem to suffer from it and althoiugh yu may feel it on the road, it is not noticeable off road.

I cannot give you any figures as to what is unacceptable.

 

[biggs682]

i would say as long as you cant notice it than dont worry about them if only just out of shape

 

[Deleted member 1258]

If they're seated on the wheel right and they feel OK then they are OK, I had to scrap a tyre that still had a good mileage in it after it got damaged or had started to fail, it looked like the carcase of the tyre had got damaged or was failing and it developed a flat spot that could be felt as I rode it, I decided it was best not to risk a total failure and I scrapped it.

 

[totallyfixed]

On the flip [very very bad pun] side if it is on the rear wheel and your bum has acquired a life of it's own by leaving the saddle and feet leaving the pedals at every revolution [if clipped in you are doing a fair impression of someone riding a kangeroo] I would venture to suggest all might not be perfect.

 

[slowmotion]

I've had strange lumps a couple of times after repairing a @@ncture. I have deflated the tube and checked that there is no part of the tube trapped against the bead, and the lumps still reappear when I re-inflate. There's not much you can do if you want to ride home. In both cases, the lumps have mysteriously disappeared after five miles. I have no idea how or why.

 

[robgul]

I've had a problem with some 20" Schwalbe (Durano?) tyres on my folder - however they were fitted/refitted they gave an "undulating" ride .... bought from, and replaced by without quibble, Avon Cyclery. It seems that there had been a bad batch - with reports of similar issues from other users, especially 20" wheel recumbents.

A bit of research (obvious though) is that the smaller the wheel the more significant the issue with non-roundness and getting a bumpy ride

Rob