Cassette spacer question
 

I am rehabbing an old GT Rave (late 80's beauty). I already replaced the downtube shifters with SORA 3x7's. Now I am replacing the Exage wheelset with a set of Shimano WH R501 wheels. The problem is that the spindle for the cassette on the WH R501's is longer than the one on the wheelset I am replacing. I am assuming that I can just put a few spacers on the new wheels to compensate but wanted to make sure that I was not missing something that made it more complicated that I was assuming. TIA.

pspence, Welcome to the forum.

I think that you're facing a drop out width difference. Your rear drop outs are probably 126 mm wide and you're installing a hub intended for 130 mm spacing. With the wheel removed measure the distance getween the inside surfaces of the rear drop outs to see what I'm referring to. Because the difference is so slight, many simply use their thumbs to spread the drop outs outwards and install the wider hub.

If the distance is less than 126 mm, you may need to cold set the frame and realign the drop outs. A 130 mm wide hub can also have the spacers replaced with thinner ones to be closer to 126 mm, but a redish of the wheel is required.

Brad

Sounds like an 8-9-10 speed Free Hub BODY?
You'll need to add a 4.5mm cassette spacer. (Google it)

Is the hub going to be too wide for your drop outs?

Mercifully, the hubs appear to be the same size. I fitted the new wheel and it fits no problem. Thanks for the heads up since I hadn't measured before ordering the new wheels to see if the hubs would work. If you look at the attached pictures, you can see that the inside of the old wheel has larger permanent spacer than the new one. That seems to be the issue. Agree?

no... the new wheel has a slightly longer freehub body on the wheel hub

as mentioned above by Brad, you will have to have your frame reset to 130 mm....... or change the axle spacer on the NON-drive side, then have the wheel re-dished to compensate for the changed axle width.... one of the two choices...

and then, to install the 7 speed cassette, you will need the spacer mentioned by Bill.... the hub/freehub in the WH-501 wheels are meant for an 8,9, or10 speed cassette, not a 7 speed cassette... the freehub(ratchet) length of a 7 sp. is 32mm... the 8-9-10 is 35mm... spline pattern is the same.

i'd advise resetting the frame to 130mm... that way, in the future, you can just install the much more common 130mm hubbed wheels, and not have to mess with redishing/respacing the wheel/axle again.... and you can also upgrade to 8,9, or 10 speeds, if you choose...

and whatever you choose, do not try to reduce axle length on the freehub side... seen it... the guy messed up a high end italian frame.... "the chain only rubbed every now and then!"... he'd removed a single 1mm washer from that side.......

Thanks maddog34. Of course, you are correct. I'll have to decide whether to return the wheels, bend the dropout (yes, I know about the Sheldon Brown instructions), or try to find some decent second hand wheels. Thanks.

pspence, If both rear wheels fit the frame alike, then there is no problem with spacing. If you are going to use a 7S cassette, you will have to install a 4.5 mm spacer before installing the cassette. No spacers are requitred for an 8S or 9S cassette, but you may need to install a 1 mm spacer if going with a 10S cassette.

I maybe incorrect, but I think the old free hub is an UG (Ultra Glide) and the cassette for it will not work with the new free hub as it is a HG (Hyper Glide).

Brad

I used one smaller sprocket off an old, worn 8 speed cassette and one spacer from that cassette to place a 7 speed cassette on a 8-9-10 speed freehub. Fills the gap just right.

Yep, you are gonna need a new HG cassette, like Brad says...

The old freehub looks like an early HG with redundant external threads for UG backwards compatibility. (a UG-only freehub would have the end sealed off flush, no recessed area around the axle)

so his old cassette could potentially be either UG or HG, but my guess is HG.