Advertise on Bikeforums.net



User Tag List

Results 1 to 10 of 10
  1. #1
    Member
    Join Date
    Aug 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Tyre sizing trouble

    I have just thrown together a single speed bike using parts I had left over from another project and an old Raleigh frame my girlfriend found in the river.

    All went well, fitting a new bottom bracket gave it a near perfect chain line, just some fiddling to do with the bar height/style.

    Now I used an old wheelset I had lying about, The frame was obviously designed to use 26" or 700c tyres, these are 27". Coming a bit close to the top of the fork but the brakes line up with the rim ok and I quite like the funky "oversize wheel" look it produced. No room for a mudguard, but I don't intend to ride it in the rain anyway.

    Having had a sucessful test ride, I went to put new tyres on it, the old ones being a really badly perished set of "swallow" road tyres. How hard can that be? I'd read the size off the side of the old ones 27 x 1 1/4. and ordered with some Michelin "world tour" in the same size.

    Just put them on and they're rubbing on the top of the forks and the crosspiece of the frame the rear brake bolts to.

    They are clearly quite a lot wider and taller than the ones that came off (a good 5-6mm both ways).

    So what did I do wrong? Have they changed the sizes or something in the 20-30 years since the originals were made? Or do different makes have a totally different profile? That being the case, how do I know what to order? I could land up with a big pile of useless tyres.

    I'm pretty reluctant to try any of the bike shops in this area again because they are totally useless. I've had nothing but bad advice, poor service and screwed up parts orders from them, they also charge a good +50% on internet prices for the privelage.

    Equally, I'm not so keen on buying new wheels, kind of defeats the purpose of making a bitsa. Also, they are perfectly good wheels with smooth, quiet hubs fitted to straight and true steel rims which fitted fine with the old tyres.

  2. #2
    Member
    Join Date
    Jun 2009
    Posts
    25
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have noticed that all tire makers have a different size of the same size tire if that makes any sense. If memory serves me right they mada 27x1 tire I would give that a shot. Go to a local bike shop and see if they have any that size and have them put them on to see if they fit. As to the 50% more paid at a bike shop think about what you get for that, like knowledge and the ability to return something and the fact that you are supporting a local business not one on the other side of the country. Best of Luck

  3. #3
    Member
    Join Date
    Aug 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dabee1106 View Post
    As to the 50% more paid at a bike shop think about what you get for that, like knowledge and the ability to return something and the fact that you are supporting a local business not one on the other side of the country.
    Well, I generally get bad advice, surliness, outright lies and the wrong parts or more often leave with nothing because they either "don't do that" or have to order it in and quote a delivery time measured in weeks when I can have it next day off the internet. That's if they can find the time drag themselves away from standing in the corner discussing how "gnarly" the move was they pulled on the way to work to serve a square/customer.

  4. #4
    Senior Member
    Join Date
    Nov 2008
    Location
    Bay Area, Calif.
    Posts
    4,703
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    There is considerable variation in tire widths from the nominal listed sizes by various manufacturers. And a number of years ago it was very common for the actual size to be consistently smaller than what was listed - that way the maker could give the impression that his tire of a given width was lighter than someone else's.

    But there are a number of widths available for 27" tires, so if 1 1/4" ones are too big you can try 1 1/8", 1", or even 7/8" ones instead.

  5. #5
    Member
    Join Date
    Aug 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    This is slowly driving me insane.

    I decided to go to a bike store and ask (not my local one, I've officially fallen out with them, I'm not going on a 50 mile round trip to stand there again and be talked to like I'm some kind of ****** by someone 10 years my junior). I told them the size of the old tyre: 27 x 1 1/4". I gave them the ISO size as per Sheldon Browns article: something skinny x 630.

    The guy produced several tyres of varying widths and styles. All were marked as 700 x somethingC. Having just read said article, a 700c would be ISO 622 which is different and Sheldon said "Generally, if this number matches, the tire involved will fit onto the rim; if it doesn't match, the tire won't fit.". I queried this and was told "Oh, they're interchangeable.", I directly asked "So a tyre marked 700C will fit on my old, 1970's rims which previously had a 27" tyre on?". "Yes".

    I then pictured myself trying to fit a tyre bead which is 8mm smaller than the one I took off onto the rim and decided to walk out with my money still in my pocket.

    So, was he blowing smoke out of his arse or should I feel silly?

    Further problems. I also wanted a front wheel to go on another bike. Now I thought this would be simple because I'm looking at more modern stuff, I have a 700c rear, I need a 700c front. No bother, asked for and got. Because 700C is a standard rim size yeah? With the C denoting the width of the rim?

    Well, either it isn't or I have once again been punked by a bike shop and sold something other than what I asked for. I have both rims in front of me and they are different widths. One is 14.42mm the other is 19.28mm (inner rim width).

    Does this randomness sound right or have I been had (again)?

  6. #6
    Insane Bicycle Mechanic Jeff Wills's Avatar
    Join Date
    Mar 2008
    Location
    other Vancouver
    Posts
    6,654
    Mentioned
    12 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stinkwheel View Post
    So, was he blowing smoke out of his arse or should I feel silly?
    He's certainly stupid or inexperienced.

    27" tires do not interchange with 700C tires. Back when 700C clincher tires were just starting to become popular, I had several 27" tires blow up when I mounted them on 700C rims. One went off right by my ear- I lost hearing on that side for the rest of the day.

    700C was part of a series: 700A, 700B, 700C. They were all intended to have the same size outside diameter, but smaller rims to allow for fatter tires. The 700C rim size stayed, but the tire that fit it got smaller.

    It's one of the paradoxes of the bicycle business. You read through Sheldon Brown's tire-sizing article: http://www.sheldonbrown.com/tire_sizing.html . In fact, read through it several times. Print out a few copies and sleep with one under your pillow so it really soaks in. Then take copies to both of those stupid bike shops and tell them to learn their trade or go out of business. (As a veteran of the bicycle business I can tell you that hundreds of bike shops go under each year. In some areas that's not enough.)
    Last edited by Jeff Wills; 09-06-09 at 09:18 PM.
    Jeff Wills

    All my bikes.

  7. #7
    Member
    Join Date
    Aug 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for that. 50 well kept in my pocket .

  8. #8
    Back on Bikes at 53!
    Join Date
    Apr 2009
    Posts
    33
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Stinkwheel, Michelin World Tours seem to be one of the tallest, largest cross section 27" tires available. I put a set on an 80's Raleigh Marathon(Which came originally with 27" wheels) and they fit, but barely. I've since decided to go with 650 tires on that bike. You may just need to go with a smaller cross section 27" tire, as others have suggested.
    You didn't mention what kind of Raleigh frame you have. If it's an old one designed for 26 x 1 3/8 tires, 27" would be a stretch.
    Unfortunately many LBS's seem to be full of people without enough interest or experience to deal with old stuff and off the wall projects. At least during the busy spring and summer season. Good Luck!

  9. #9
    Member
    Join Date
    Aug 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It's an old (early 80's at a guess) Raleigh Competition frame.

    The 27" ones DID fitwith their original tyres on but not with the michelin ones.

    I managed to find somewhere online with some continental 27 x 1/8" tyres and they seem pretty low profile. Worth a try.

    I'll try to remember to post a picture when I get it all together. It's a lash-up but it seems very comfortable for my size and shape.

  10. #10
    rebmeM roineS JanMM's Avatar
    Join Date
    Jan 2006
    Location
    Indiana
    My Bikes
    RANS V3, RANS V-Rex, RANS Screamer
    Posts
    11,449
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stinkwheel View Post
    I managed to find somewhere online with some continental 27 x 1/8" tyres and they seem pretty low profile. Worth a try.
    That would likely be 27 x 1 1/8". 1/8" would indeed be pretty low profile!
    RANS V3 (steel), RANS V-Rex, RANS Screamer

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •