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Thread: Fork Spreading

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    Fork Spreading

    Just picked up an old Raleigh frame and I am concerned with the front fork spacing. Is there a proper way to respace the fork (cold set?) at home or is it more advisable to have a shop perform this? The respacing would be in excess of 10mm. Thanks in advance.

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    Front hubs, hence front forks are extremely well standardized. It'd be exceedingly rare to come across a fork or a front hub built to a differing standard. If your fork needs spreading it's a good indicator that something out of the ordinary has happened to it at some stage. Give it a CLOSE inspection before riding.

    Apart from that there's nothing about the way the shop would approach this task that can't be replicated at home. The tricky bit is to bend both fork legs in equal amounts.
    You could think that it'd be as easy as putting a threaded rod in the dropouts and simply use a couple of nuts to push them apart but you'd be wrong. What you need is a good line of reference, I've read of one guy who shoved a broom handle into the fork crown and was able to dial in the fork legs with reference to that. There are also various methods of extending a line from the steerer tube and check the position of the dropout WRT that.

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    Bicycle Repair Man !!! Sixty Fiver's Avatar
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    Old Raleigh forks are narrower than the modern standard of 100 mm and the droputs were made to accomodate a smaller axle so fitting a modern hub takes a little work.

    The inside edges of the dropout can be filed to add a little space and this should be done with a good file and the fork should be placed in a vice to minimize vibration. You also want to make sure the work to either dies remains even as to not cause a mispositioned wheel.

    The forks can also be spread by hand to allow a modern hub to fit.

    The dropouts may also need to be filed to allow for a larger diameter axle and this should always be done from the bottom so that the wheel stays aligned.

    I have used a combination of using thinner lock nuts, a little filing, and spreading the fork to allow a modern hub to fit and just recently installed a Shimano hub on my Phillip's 20...the axle width was fine but the width of the hub was greater than the dropout spacing. the fork blades in a 20 inch do not flex very much at all as they are very rigid.

    The rear dropouts also had to be modified a small amount to accomodate a modern axle.

    You can also cold set the fork if you have the proper jig.

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    Yeah, my wife's Schwinn mixte has a pretty narrow fork, into which I jam a newer hub. I just pry apart the fork blades every time I install. Getting it on the Thule rack is also fun. That's the beauty of steel, though.

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    Quote Originally Posted by Sixty Fiver View Post
    Old Raleigh forks are narrower than the modern standard of 100 mm and the droputs were made to accomodate a smaller axle so fitting a modern hub takes a little work.

    The inside edges of the dropout can be filed to add a little space and this should be done with a good file and the fork should be placed in a vice to minimize vibration. You also want to make sure the work to either dies remains even as to not cause a mispositioned wheel.

    The forks can also be spread by hand to allow a modern hub to fit.

    The dropouts may also need to be filed to allow for a larger diameter axle and this should always be done from the bottom so that the wheel stays aligned.

    I have used a combination of using thinner lock nuts, a little filing, and spreading the fork to allow a modern hub to fit and just recently installed a Shimano hub on my Phillip's 20...the axle width was fine but the width of the hub was greater than the dropout spacing. the fork blades in a 20 inch do not flex very much at all as they are very rigid.

    The rear dropouts also had to be modified a small amount to accomodate a modern axle.

    You can also cold set the fork if you have the proper jig.
    You can also file the axle of the wheel with parallel flats. Taking off just the cut threads will be perfectly fine
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    Quote Originally Posted by operator View Post
    You can also file the axle of the wheel with parallel flats. Taking off just the cut threads will be perfectly fine
    Thanks operator. This is in reference to the axle diameters right? If so I have filed the dropouts enough to accommodate the larger axle diameter. Since the the Raleigh has a "keyhole" slot, this seemed like a viable option. Though, correct me if I am wrong (I am obviously a newb).

    Quote Originally Posted by tellyho View Post
    Yeah, my wife's Schwinn mixte has a pretty narrow fork, into which I jam a newer hub. I just pry apart the fork blades every time I install. Getting it on the Thule rack is also fun. That's the beauty of steel, though.
    Thanks tellyho. With springing the hub out (up to 10mm) would this add excessive pressure to the hub?

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    Quote Originally Posted by dabac View Post
    Front hubs, hence front forks are extremely well standardized. It'd be exceedingly rare to come across a fork or a front hub built to a differing standard. If your fork needs spreading it's a good indicator that something out of the ordinary has happened to it at some stage. Give it a CLOSE inspection before riding.
    Many Raleighs from the 60s and earlier used 90mm fork spacing. This was also standard track fork spacing until pretty recently.

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    Quote Originally Posted by JohnDThompson View Post
    Many Raleighs from the 60s and earlier used 90mm fork spacing. This was also standard track fork spacing until pretty recently.
    Yeah, my fork spacing is 90mm. I am just not sure if respacing 10mm wider is going to compromise the fork. Every time I try to respace, the forks still spring back to the initial spacing (also worried about symmetry issues). Plus, it seems that all the shops in my area are not equipped to perform this service. Guess it is my fault for going the Raleigh route in the first place.

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    Quote Originally Posted by operator View Post
    You can also file the axle of the wheel with parallel flats. Taking off just the cut threads will be perfectly fine
    Thanks for adding that... I think that pretty much completes the how to deal with old forks lesson.

    Lacing new wheels to the old hubs is another option... I am working on a 1954 Raleigh Sports and am upgrading the wheels to 700 c from the 26 by 1/4 to make the bike more serviceable as an every day ride and am using the stock hubs since they are in such nice condition.

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    Quote Originally Posted by JohnDThompson View Post
    Many Raleighs from the 60s and earlier used 90mm fork spacing. This was also standard track fork spacing until pretty recently.
    So maybe I should have started it with "where I'm at"...
    I've never seen a Raleigh IRL and w/o a velodrome in the country track bikes aren't exactly commonplace either. There's the odd hipster fixie, and some window dressing in shops, but that's about it. I might have a front hub from an old 17" kids bike that's narrower than 100 mm though.

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    Another option is to replace the fork. As I recall...the threading on the headset is often special, and dosen't work with normal modern headset parts. I repaced the fork on my hotrod R20 with a fork for a recumbent. I got the 100mm spacing,better headset choices and canti posts. That worked out really well! There are lots of good used forks and new replacement forks out there. A good LBS can help out quite a bit here.

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