View Full Version : weird njs hub spacing: 90mm front?
So I just got a sweet 3rensho track frame, a 1998 I think, but it has the odd 110mm rear spacing, a common thing for keirin bikes, but it also appears to have a 90mm front hub spacing? There aren't any paint cracks or scratches on the fork that would imply it got bent, and it looks super straight. Plus, a fork bending exactly 10mm seems pretty unlikely. So basically my question is, has anyone ever heard of keirin bikes running 90mm front hubs?
oldsprinter
11-11-07, 02:13 AM
Is the frame made for two 700C wheels? Or is the front a 650C?
700c both, it is an NJS stamped frame so I believe it was used for keirin not sprints or pursuit or anything.
CrimsonKarter21
11-11-07, 09:44 AM
NJS bikes need to use 90mm front's and 110's rear. I know you can get Dura-Ace hubs in this spacing, but since it's NJS spacing, you have to get 36 hole hubs, which is the only spoke count that is NJS approved. It's not impossible to cold-set the rear end if you give it to an LBS with an old guy behind the counter, as my Erba has been.
If you have the means, I highly reccommend either one. If not, you can resell it for a lot of money.
They definitely do not ALL need that spacing, because my Makino NJS bike had 120/100 spacing, which I believe they all use now, as Shimano has discontued their 110 hubsets (a respacing kit is still available). But my question was just about the front hub, I've never ever heard of 90mm fronts, on any kind of bike let alone track bikes.
CrimsonKarter21
11-11-07, 01:24 PM
They definitely do not ALL need that spacing, because my Makino NJS bike had 120/100 spacing, which I believe they all use now, as Shimano has discontued their 110 hubsets (a respacing kit is still available). But my question was just about the front hub, I've never ever heard of 90mm fronts, on any kind of bike let alone track bikes.
Actually, Shimano hasn't discontinued that spacing, I was flipping through the October-November catalog of one of my LBS's distributors and was thinking of another set of D-A hubs, and saw them in 90 and 110.
Well, were they the NJS ones? I think what I read was that spacing is unavailable in the NJS models. Anyways, it is exciting to know DA still makes 90/110; what distributor was it, EAI or something?
Some weird info above.
The most common current spacing is 120 front, 100 rear. However, back in the last century (not so long ago) it was more common to have a 110 mm front with a flatted axle (10 mm axle with two flats to fit in a 8 mm slot). The flatting was seen to be preferable because it kept the axle from spinning while you were tightening the track nuts. On the front, there were both standard 9 mm round front axles and also front axles flatted on two sides to fit in a narrowed 8 mm front dropout slot.
Go back a little further and there were 80 and 90 mm spacings on front hubs (and I've seen a 95 as well). On the rear there were 95 and 100 mm spacings. None of these survived in popularity. These dimensions were around back in the 60's to late 80's, mostly as holdovers from back in the 40's and later. There was quite a bit if incompatibility among various dimension standards, and it took a while to clean this up.
It's weird that a 1998 frame would be spaced this way. I'd guess, knowing the builder, that these were intended to be narrow front hubs for more aero performance (not unlike a couple of the German builders like Walser who use non-standard narrow bottom brackets and front hubs for the same reason). He liked to do trick equipment like this, not caring at times whether the equiment was compatible with everything else.
You can contact Phil Wood and they will make you a custom axle for one of their hubs. You can also go to Bike Tools Etc., Bike Parts USA, or a similar site and get replacement axle cones and locknuts that will give you the slight decrease in spacing. Or, since this is a steel fork, a builder can very easily and quickly put it on a jig and re-bend it to give you 100mm spacing. I don't usually recommend going to a builder if you're respacing the rear, but on the front it's a lot more work without a jig and it has more likelihood to end up uneven (and to cause steering problems as a result).
piwonka
11-13-07, 08:06 AM
The most common current spacing is 120 front, 100 rear. However, back in the last century (not so long ago) it was more common to have a 110 mm front with a flatted axle (10 mm axle with two flats to fit in a 8 mm slot).
are you tired? :D
you're getting front and rear confused aren't you...
but yeah, people should be able to make sense of that. I would just cold set the frame and be done with it. definately take the fork to a builder and since you're doing that let him set the rear spacing to 120mm too.
are you tired? :D
you're getting front and rear confused aren't you...
but yeah, people should be able to make sense of that. I would just cold set the frame and be done with it. definately take the fork to a builder and since you're doing that let him set the rear spacing to 120mm too.
Yes, other way around. I feel like I've written this so many times for this forum and no one ever seems able to do a search. Yes, I am tired.
piwonka
11-13-07, 10:33 AM
Yes, other way around. I feel like I've written this so many times for this forum and no one ever seems able to do a search. Yes, I am tired.
yeah i know. there is a new thread about cold setting the rear of a frame and i thought of the post you made about how to cold set and file the rear of a 110x8mm spaced keirin frame.
piwonka
11-13-07, 10:37 AM
b rowe, a present for you.
http://bikeforums.net/showthread.php?t=331776
edit: but that doesn't deal with the front. 11.4 already said you should have a builder do that for you.
Yeah, I knew all about the 110x8 rear, but was unaware of front hub variations. I am really just going to try to find some hubs that fit, I'd rather not mess with the frame if I don't have to.
CafeRacer
11-17-07, 12:01 PM
As far as I know to date Keirin frames are 113 in the back. It could be run as 110 but they are spaced to incorperate the chain tugs required.
Like mentioned above if you have a shop with an old guy behind the counter adjusting the dropouts so they're a little wider isnt such a task.
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