Tyres don't fit!
Tyres don't fit!
I recently had my rims replaced (Alessour Edeavours (sp?) for Rigida Sputiks - basically the same rim) but now my Conti Ultragators don't seem to fit. I think they are too small as it is hard to take them off but it's causing a 'flat spot' so when I ride it feels like I'm going along a rippled road. Does this sound right? I can't decide if there was a problem before that I put down to the fact that the rims were worn out and had therefore gone oval or if it's a new problem. Could it be a faulty batch since I've never had a problem before or has something changed? I don't want to go and spend 40 quid on new Contis if I'm going to get the same problem.
I have conti ultragators on sputniks and it is OK. Mine are 26" wheels but it should not matter much wether it is 559 or 622 wheels.
If both tyres are wrong on both rims then it makes you wonder.
I use 28mm tyres which is the minimum reccomended for the rim.
Have you checked that the wheels have been built truely?
If both tyres are wrong on both rims then it makes you wonder.
I use 28mm tyres which is the minimum reccomended for the rim.
Have you checked that the wheels have been built truely?
Yma o Hyd
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thirdcrank
- Posts: 36780
- Joined: 9 Jan 2007, 2:44pm
ZZ
It may be that the flat bit is formed when you stand the bike up with flat tyres before inflating them. From what you describe, it sounds as though the tyres are not properly seated on the beads.
Try this:
Check to ensure that the inner tube is not twisted or trapped between the casing and the rim. (Unlikely on both wheels but important before the next bit.)
With the tyres completely flat, take the weight of the bike off the tyres, either by suspending it in a workstand or lying it on its side. If the wheels are out, lay them down. Inflate the tyres slowly and very hard preferably using a track pump (i.e. the sort like somebody detonating dynamite) - it ought not to be necessary to go beyond the recommended max., - and you should find that the tyres will seat themselves properly. You should hear a definite noise when it happens. I'd go so far as to say that if they don't seat properly, then there is something wrong. You get dodgy tyres that are funny shapes but Conti are a top make.
Edited to add
I've found this on SB
http://www.sheldonbrown.com/flats.html
It covers everything about punctures etc in detail but scroll down to the relevant bit about bead seating - as usual, full of wisdom.
It may be that the flat bit is formed when you stand the bike up with flat tyres before inflating them. From what you describe, it sounds as though the tyres are not properly seated on the beads.
Try this:
Check to ensure that the inner tube is not twisted or trapped between the casing and the rim. (Unlikely on both wheels but important before the next bit.)
With the tyres completely flat, take the weight of the bike off the tyres, either by suspending it in a workstand or lying it on its side. If the wheels are out, lay them down. Inflate the tyres slowly and very hard preferably using a track pump (i.e. the sort like somebody detonating dynamite) - it ought not to be necessary to go beyond the recommended max., - and you should find that the tyres will seat themselves properly. You should hear a definite noise when it happens. I'd go so far as to say that if they don't seat properly, then there is something wrong. You get dodgy tyres that are funny shapes but Conti are a top make.
Edited to add
I've found this on SB
http://www.sheldonbrown.com/flats.html
It covers everything about punctures etc in detail but scroll down to the relevant bit about bead seating - as usual, full of wisdom.
Last edited by thirdcrank on 23 Jan 2009, 4:03pm, edited 1 time in total.
zenzinnia wrote:Yes the rims are certianly true (the Sputniks are such a solid rim it's hard not too!). It's easy to see where the tyre hight suddenly dips by about a cm or more.
One cm certainly means something's not right. Unless the tyre is clearly at fault, and the rims are OK, the most likely culprit is imperfect seating in the well. The bead could be failing to contact the edge of the rim. I'd deflate the tyre,pinch the cover to peer in & check that the sidewalls are in full contact with the rim edge.
meic wrote:I have conti ultragators on sputniks and it is OK. Mine are 26" wheels but it should not matter much wether it is 559 or 622 wheels.
If both tyres are wrong on both rims then it makes you wonder.
I use 28mm tyres which is the minimum recommended for the rim.
Have you checked that the wheels have been built truely?
The way I understand this there is a significant difference between 559 and 622 wheels, almost an inch in diameter!
I know that with my Trike I can fi 406 tyres abut 451 are far too big.
If in doubt the rim should be marked with an "ERTRO" number - match this to the tyre size. Having said that some tyres are notoriously difficult to fit anyway!
Two thoughts - if it is a single point in the rotation is the valve seated properly and the tyre bead fitted correctly around this point. If it is at several points, check the seating of the bead alll the way around.
You misunderstood me.
I meant that if my 559 tyres fitted my 559 rims Ok I would expect 622 tyres of the same type to fit a 622 rim of the same type OK. While at the same time pointing out that I have only experience of the 559 case.
Without a doubt the two can not be mixed.
I was sold an innertube that claims to cover 406 and 451 tyres.
I fitted it in my 406's and it was not fit for use. The tyre bulged out where the inner tube folded back on itself!!
I meant that if my 559 tyres fitted my 559 rims Ok I would expect 622 tyres of the same type to fit a 622 rim of the same type OK. While at the same time pointing out that I have only experience of the 559 case.
Without a doubt the two can not be mixed.
I was sold an innertube that claims to cover 406 and 451 tyres.
I fitted it in my 406's and it was not fit for use. The tyre bulged out where the inner tube folded back on itself!!
Yma o Hyd
Just an update on this - I bought a new set of conti U.Gators to see if it was just a one off problem but the new ones have the same problem. It is definatly that the tyres are not quite big enough to go round the whole rim where they are meant to and are pulled tight round part of the wheels forcing the wired edge to sit lower within the rim and not push up againt the retaining hook profile. The valve is pushed up and the tyre sits properly around it, they are 622 rims and 622 tyres and they are a insert favoured expletive here to get on and off the rims.
I have a feeling that, because I've been spending a lot more time on other bikes, the problem mayhave been there and I've just ignotred it/ put it down to something else. Anyway it now bugs me and I'm going to try other tyres, which is a damn shame 'cos I liked the 'gators. I would like something reasonable light and sporty but puncture reistant. Any suggestions?
I have a feeling that, because I've been spending a lot more time on other bikes, the problem mayhave been there and I've just ignotred it/ put it down to something else. Anyway it now bugs me and I'm going to try other tyres, which is a damn shame 'cos I liked the 'gators. I would like something reasonable light and sporty but puncture reistant. Any suggestions?
I just cant believe that there are 4 Ultragators out there that are the wrong size.
Equally hard to believe that your Sputnik rims are a bit oversize.
It does seem much more likely that it is a seating problem but even that doesnt seem likely for four tyres on a row.
I have to agree that if it is as you describe it then either both of the rims or all of the tyres have been made out of the tolerance range. I cant think of any way to measure that acurately.
You have already bought another set of tyres which SHOULD show it is not the tyres to blame.
Equally hard to believe that your Sputnik rims are a bit oversize.
It does seem much more likely that it is a seating problem but even that doesnt seem likely for four tyres on a row.
I have to agree that if it is as you describe it then either both of the rims or all of the tyres have been made out of the tolerance range. I cant think of any way to measure that acurately.
You have already bought another set of tyres which SHOULD show it is not the tyres to blame.
Yma o Hyd
As stated above, I'd try it again with some kind of lubricant to encourage the beads to slide across the well & contact the rim flanges correctly. Overinflating the tyres may just help to give them that final push.
Later edit: Also, check that the wells are smooth, without any snags or rough areas which would inhibit the beads from sliding to their correct position.
Later edit: Also, check that the wells are smooth, without any snags or rough areas which would inhibit the beads from sliding to their correct position.
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thirdcrank
- Posts: 36780
- Joined: 9 Jan 2007, 2:44pm
I'll have to put my hand up and say I am baffled. 
If you have done everything right and the tyres still don't seat properly there must be something wrong with one or the other.
It's my general experience that if there is any size leeway on tyres / rims, it is that poor quality stuff is loose - the problems people report with difficulty fitting tyres are nearly always with top quality tyres which are tight because the makers are confident about their tolerances. However, the problems people report are all to do with getting tight tyres onto the rims over the flanges. I've never heard of a top quality tyre that would not seat on a rim of the right size.
Let us know how you get on.
If you have done everything right and the tyres still don't seat properly there must be something wrong with one or the other.
It's my general experience that if there is any size leeway on tyres / rims, it is that poor quality stuff is loose - the problems people report with difficulty fitting tyres are nearly always with top quality tyres which are tight because the makers are confident about their tolerances. However, the problems people report are all to do with getting tight tyres onto the rims over the flanges. I've never heard of a top quality tyre that would not seat on a rim of the right size.
Let us know how you get on.
I suspect the rims. I recently built up some Chrinas and completely failed to fit x28 Vittoria Randonee tyres which I would normally expect to be easy. Having tried fitting the tyres without tubes in an attempt to "stretch" them I ended up cutting them off rather than risk further damage to the new rims! Even x25 CHEAP Vittorias (normally slip on) were difficult.
I had planned on a set of Sputniks for the same bike with more off-tarmac rubber. Time to think again....
I had planned on a set of Sputniks for the same bike with more off-tarmac rubber. Time to think again....