Fact me up on tyre / wheel sizes

[H12rpo]

ok just bought a 70’s BSA primo. Needs lots of tlc and I’m going to restore it but regarding the wheels and tyres.........I’ve looked on Baldwin’s which seem to be decent priced but can’t really identify my current set up which I’d like to replace. .
Wheels have the following marks on them 18 x 622 (28 x 2.578.? ) and tyres have the following: 25 x 622 1700 x 250cL or could be 25cL
I’m confused ......can anyone point me in the direction of a suitable replacement set of ally wheels and tyres sizes? Or tell me what wheels and tyres i need ?
Cheers!

 

[mjr]

Look only at the aa-bbb numbers, with a dash not an x. That's the ISO standard. All else is messy, obsolete and confusion. The three digit number is the diameter, the two is the tyre width. Diameter must be spot on. Width can vary a bit, but nine-fifths the width of your rims (internal width) is a good rule of thumb.

So it looks like 37-622 are a good tyre size for your wheels bit anything from 28 to 46 may fit, if it doesn't snag the guards or frame.

 

[Racing roadkill]

ok just bought a 70’s BSA primo. Needs lots of tlc and I’m going to restore it but regarding the wheels and tyres.........I’ve looked on Baldwin’s which seem to be decent priced but can’t really identify my current set up which I’d like to replace. .
Wheels have the following marks on them 18 x 622 (28 x 2.578.? ) and tyres have the following: 25 x 622 1700 x 250cL or could be 25cL
I’m confused ......can anyone point me in the direction of a suitable replacement set of ally wheels and tyres sizes? Or tell me what wheels and tyres i need ?
Cheers!

You’ve got 622 ( 700 c) rims with 18 mm internal diameter, taking 622 ( 700c ) 25 mm tyres. So you want 700c 25mm tyres as replacements, and 700 c 18c wheels.

 

[raleighnut]

^^^^ Wot e sed,

Although you may need to revise the age of the bike down unless someone has converted it to 700c wheels (from 26" - 27" as they were still using Imperial sizes until the 80s)

 

[mjr]

Are you sure the wheels say 18 not 13? I think 25mm tyres on 18 wheels is an unusual choice.

 

[SkipdiverJohn]

A lot of cheaper drop bar bikes used to come with steel 27" rims and many of these will have become pitted with rust and replaced by 700c alloys to save weight and give better wet braking. Most derailleur geared bikes that are old enough to call "vintage" have probably had their wheels replaced at least once by now, so I would not take it as gospel that a bike is of a certain age just because of it's wheels. I would also look at other things like frame design, fork shape, general livery, decals, headbadge design etc, and try to find a dated catalogue showing that particular model if possible.

 

[midlife]

Welcome by then Bsa were Raleigh owned and should have a Raleigh number stamped somewhere.

 

[H12rpo]

Certainly the brakes are Raleigh branded. The rear Derailleur is a Suntour VX with a date code of WG ....this is 78 isn’t it?
Both wheel rims are different one is ally and one chromed steel. The tyres are completely shot so I’m planning on replacing them both anyway but just want to know what sizes are ‘period’ and will suit the brakes

 

[gilespargiter]

Pictures?

 

[H12rpo]

There’s one or two in my introduction thread

 

[gilespargiter]

We always used to ride 27x1 1/4" aka 700x32mm (still do actually) for general commuting/wkend/light on off rd touring. Looking at your pictures, though not that clear, it seems you have a steeper angled frame with less clearance, more towards fast paced road work. So, as someone already mentioned probably more like 27x1" aka 700x25mm.

 

[raleighnut]

We always used to ride 27x1 1/4" aka 700x32mm (still do actually) for general commuting/wkend/light on off rd touring. Looking at your pictures, though not that clear, it seems you have a steeper angled frame with less clearance, more towards fast paced road work. So, as someone already mentioned probably more like 27x1" aka 700x25mm.

NOTE, 700c tyres/wheels are 622mm whereas 27" tyres/wheels are 630mm so as long as there is 4mm of available adjustment on the brake calipers they can be easily swapped.

 

[MikeG]

Fact me up? FACT ME UP!

Take this grammar-heathen to the rack........

 

[H12rpo]

Ahhhh we have grammar nazis here too then? (I’ll fit in well then). P.s. there’s no hyphen in grammar heathen Just sayin’ like !

 

[MikeG]

Is this Skitt's Law in action, or Muphry's Law? Or is that a false dichotomy, and you have simply fallen for the obvious self-deprecation in that question (and it wasn't the only one)? Whichever, "fact me up" is like farting in a lift: wrong on so many levels.