The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Sam C on 27.04. 2016 15:22

Title: very basic question from newbie: tyre size!
Post by: Sam C on 27.04. 2016 15:22
Chaps

I'm really new to classic bike ownership so excuse the daft question(s)!:

My 1959 A10 Golden Flash has been safely tucked away from the winter, but it's about time I took her out for her first blast of 2016.

However: I've noticed a slow puncture in the front tyre. I need to order a replacement inner tube, I guess. And I'm going to need to learn how to use tyre irons too, I guess!

Questions:

(1) What size inner tube do I buy? I was looking on the burton bike bits site, and there seem to be quite a few sizes to choose from! See here:

http://www.burtonbikebits.net/innertubes.htm

(2) Any tips on replacing this?! I'm sort of expecting it to be like a 'really big bicycle tyre'. I do have a Haynes and a couple of old workshop manuals too. And some  classic bike fans on my road, who I'm hoping will keep an eye on me (and maybe lend me those tyre irons!). I love my bike though and don't want to scratch / bend / damage anything!

Cheers all

Sam


Title: Re: very basic question from newbie: tyre size!
Post by: Beezageezauk on 27.04. 2016 16:20
Hi Sam and welcome to the crazy world of Classic Bike Ownership where you never stop learning no matter how deeply you get into it.

The tyre/innertube sizes you should have on your A10GF are 3.25 X 19 on the front and 3.50 x 19 on the rear.  Some tubes even have 3.25/3.50 X 19 on them.  You will find the sizes on the sidewalls of your existing tyres.  They might even show modern equivalent sizes.  If they are do a "Google" search for "motorcycle tyre equivalents".  But blow that tyre up and check the valve for leakage.  You might not need to change the tube.

If you need to take the tyre off the rim always start at the valve and the replacement should always finish at the valve.  It's difficult to explain exactly in writing what the procedure is in refitting a tyre but there are a few videos on Youtube that can show you exactly how it's done.

Roughly, whereabouts in the UK are you?  If you are reasonably close to the Teesside area I would be happy to guide you through it..

Good luck,

Beezageezauk.
Title: Re: very basic question from newbie: tyre size!
Post by: Sam C on 27.04. 2016 16:26
Ah thanks mate - that's brilliant.

When I get home (I'm slacking off at work here) I'll check the tyre size and work back from there.

I'm in the South West, but thank you nonetheless for your kind offer!

I'll look for those youtube videos too (when I get home: boss will probably notice that one!)

Cheers

Sam
Title: Re: very basic question from newbie: tyre size!
Post by: Greybeard on 27.04. 2016 17:41
What Beezageezauk says about starting and finishing at the valve is so that the tyre bead, (the edge of the tyre with strengthening wire inside it) can go right down into the wheel well without the valve stem getting in the way. So, remember that the tyre bead must be pressed right into the well; this will allow the opposite side to fit over the wheel edge. Understanding this should make the job easier.
Before fitting the tube make sure the rubber wheel band is in place over the spokes.
Be very careful with tyre levers so that you don't nip the inner tube.
When you have the tyre back on partially inflate the tube and make sure that the tyre is concentric with the wheel all the way round.
I find a workmate type of surface is good as the wheel can sit flat with the hub in the gap between the two bench parts. It's also at a useful height.

I tend to use a water and washing up liquid solution brushed onto the beads to aid fitting.

Valve caps are essential; without valve caps you are very likely to have slow leakage from the valve.

I used to work at a Firestones Tyre & Auto depot when I was a nipper, (of 20 or so). Also having ridden a bicycle to work for many years I have changed a LOT of tyres and tubes!!

For those of an American persuasion tyre = tire

Title: Re: very basic question from newbie: tyre size!
Post by: duTch on 27.04. 2016 20:48

 Hiya Sam, Some tubes are naturally a bit porous anyway, best you pump it up first and see how long it takes to lose pressure.
 Even with new tubes on, I need to add air every week or so (sometimes I don't check 'em for a while though)
 I had 'butyl' tubes fitted on my XT years ago, and they held air better Haven't researched 'butyl' yoo much, I more or less took the guys at the bike shop word for it, but I went there often.

 Another thing I learned/was told at a young age, is to never use levers to refit a tyre (potential pinching) *work*- Use a rubber mallet with care, it shouldn't take much.
 
Title: Re: very basic question from newbie: tyre size!
Post by: trevinoz on 27.04. 2016 22:47
I wouldn't use a butyl tube. They tend to tear when pierced and deflate the tyre instantly. With a rubber tube you will usually feel it going down at a slower rate and have time to control the bike to a stop.
Title: Re: very basic question from newbie: tyre size!
Post by: BSA_54A10 on 28.04. 2016 11:31
And it is well worth the effort of chasing good quality tubes.
I still have some Carslile tubes and Michlean ones.
The one I bought for the M20 was crap.
Made is indonesia and you can cut it with the your fingernail.
Anything less then $ 30 appears to be junk.