markk900

Hopefully quick question, though I spent an hour or so searching for this one and even Sheldon doesn't seem to be able to help.

Working on an old (late 30s) CCM, and the wheels are much more recent replacements. Rims are Rigida and both front and rear are marked 27 x 1 1/4" (dated 1977 and 1979). Tires are very old red Dunlop Speedster tires (Made in Canada) with the size designation 28 x 1 1/4". (Completely rotted - need to be replaced).

From my research they shouldn't fit! Sheldon: 27x anything is 630mm; 28 x 1 5/8 x 1 1/4 is 622mm, and 28 x 1 1/2" is 635mm....what size replacement tires should I be looking for (or does anyone have any red Dunlop Speedsters lying around they wish to part with ..... no, didn't think so!).

prathmann

I'd go by the stated rim size and get some 27" x 1 1/4" tires (630mm x 32mm). The 28" designation on the tires is less standard and used to mean different actual sizes by different manufacturers.

rootboy 

Get yourself a set of these, if they have them up yonder. 1 1/4 or 1 1/8 is OK on those rims.
I prefer the 1 1/8 version.

https://www.modernbike.com/product-2...d-8aAkfV8P8HAQ

markk900

Thanks @rootboy. I have Paselas on a number of bikes and like them except the stupid label!

I did determine the original tires are indeed 630mm (ie 27x tires). I found a NOS Speedster (in black) but probably won't get it unless I can find a second.

T-Mar

I'm hitting my local CTC and picking up all the 27" Kenda K35 that they have in stock. They're currently on clearance for $6.33 CDN.

markk900

@T-Mar - WOW! I have the K35 and K40s on some bikes and they are fine. Tread is not classic but still $6!!

clubman 

Different tires had the same markings
There's two 28 x 1 1/4, one is the 630 mm K2 and the other is the enormous and obsolete 647 mm EA2

markk900

@clubman: interesting since the tire is marked "to fit Endrick rim", which appears from the chart to be the big one!

clubman 

any other markings at all on the sidewalls?

CliffordK

Measure the actual rim diameter. Subtract a 10mm or so fudge factor as in Sheldon Brown.

There are a number of red tires available.
27 red in Tires | eBay

I actually liked my Origin8 Elimin8er (700x25) tires, folding with moderate tread protection.

Here is ONE red one. If you could only find a mate.
27" Red Bicycle tire 27 X 1-1/4" bike clincher folding bead | eBay

markk900

@clubman: nothing special - Dunlop Speedster and Made In Canada with a number under it.






@CliffordK: I found a number of red tires in the right size, but frankly I think they are all a bit "too Red". Since the red tires were a factory option, unless I can get original style I think black will be less obtrusive.

clubman 

Cool tires . I think they are standard 27'/630 models. I'm pretty sure they were always made as Endricks as well so the Dunlop "to fit Endrick rim" doesn't mean too much. I have a set of the larger ones in the basement but can't measure them right now. One is a Speedster and the other is a Palmer.

T-Mar

The subject tyres should be 700C (622mm BSD). My inter-war CCM catalogues show references to Dunlop Speedster types in 28" x 1-1/4" size "to fit Canadian Endrick rims" and bicycle specs specifically state "28 x 1-1/4" Canadian size". The 1/4" narrower than standard Canadian width is due to the fact that the Speedster was intended as a road racing tyre. These tyres were OEM on the 1936-1941 CCM Road Racer and the 1936 CCM Flyer. After WWII, they appear to have been available in black only.

Edit: Ignore my above post. Per Clubman's chart, 28 x 1-1/4" is ISO 630. My mistake. Though why CCM would spec one bicycle model as 27" x 1-1/4 and another as 28" x 1-1/", in the same catalogue, is perplexing.

rootboy 

I've got a fix for that. PM me if interested.

ThermionicScott 

Thanks for posting that chart, @clubman. I'd looked for it earlier and couldn't find it.