Cycle Question?

[woodbloke]

Could someone with cycling knowledge please help. SWIMBO's bike has been fitted with 28x13/8 (I think that's correct) and she had a puncture that I sorted but the tyre keeps popping off the rim. The 07 spec indicates that 700 size tyres should be fitted. Are these smaller than those already fitted, 'cos if the tyres fitted are the incorrect ones I'm going to do a bit of counter thumping on the 'morrow. Thanks - Rob

 

[paulm]

Hi Rob,

Don't take it as gospel, but I make 700mm to be 27.55" assuming 25.4mm = 1" so I reckon your new tyres are indeed about 1/2" too big which is entirely consistent with them popping off the rims I would think.

Good to see your pics of the Swiss Adventure on your blog too by the way, looks a brilliant place to visit !

Cheers, Paul.

 

[Paul Chapman]

Hi Rob,

Yes, there's definitely something wrong - the tyres shouldn't be popping off the rims :shock:

I'm a bit out of touch with modern tyre sizes (it was all 27"x 1 1/4" in my day). Here's a link to a site from the Cyclists Touring Club which gives some useful information about tyre sizes. Hope it helps :wink: http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3802

Cheers :wink:

Paul

 

[woodbloke]

Paul(s) - thanks for the info, I'll have to get all the details off the tyres and then use the chart on Paul's link to work out if they are correct or not. It's funny, but when I put the tyre back on the rim the other day, I didn't need any tyre levers at all, the tyre just went on with gentle finger pressure. Normally, you really need to lever the last little bit on which is usually a bit of an effort, but not in this case...I thought then that it didn't seem right. Will check tomorrow. Many thanks - Rob

 

[Paul Chapman]

I'll have to get all the details off the tyres

You will probably find that the wheel rim size is stamped on the rim somewhere.

Yes, you are right, with the correct size of tyre it should be difficult to get the last bit of the tyre on using just thumb pressure (although that's the correct way to do it to avoid pinching the tube) but most people resort to tyre levers for that last bit. If the wheels have rim tapes fitted (that's a piece of tape or rubber which goes around the inside of the rim to cover up the spoke nuts) always make sure that is fitted correctly, because you can get punctures from the spoke nuts pressing on the inner tube if it's not.

Cheers :wink:

Paul

 

[Paul Chapman]

Just another thought, Rob. After repairing a puncture, it's not a bad idea to give the inner tube a light dusting with French chalk before replacing it. It has a lubricating effect and helps keep the tube and tyre in good condition.

Cheers :wink:

Paul

 

[woodbloke]

Paul - thanks for all the help, got Alyson's bike stored safely at work at the mo' so will collect it in the Landy tomorrow and bring it home, will then have a close look at the info on the tyre and rim and then your link, seems to be quite confusing to work out exactly what the compatability is...may also 'fone another bike shop in town (not the one where we got Alyson's bike from) to see what they think. My own gut feeling is that the tyres were the incorrect ones fitted by the place we got the bike from, but I can't be sure until I've had a much closer look - Rob

 

[Woodmagnet]

If she got a puncture then the tyre was o.k. in the first place. so could you be putting the tyre on wrong, have you made sure that when you
put the tyre on you push the tube up into the tyre and push the tyre into the groove of the wheel and pull the tube down onto the inside of the tyre before tightening the tube to the wheel. Could be wrong but it's something i remember happening to me many years ago. :wink: