Campy FW axle question

[bfd]

On another forum, a question was raised about whether Campy NR freewheel rear hubs were more durable than the later Campy C-Record freewheel rear hubs. The problem appeared to be the axle. Its my understanding that Campy NR fw rear hub almost never had broken axles. In contrast, Campy C-Record fw rear hubs did.

Personally, I don't recall breaking an axle or even seeing a broken axle on Campy NR fw rear hub. Yet, in about a 2 or 3 year span, I broke 2 Campy axles and 1 Wheel Mfrg axle. Was there something weak in the C-Record rear hub design or just my fat ass :butt: ....it should be noted that when I switched over to DA cassette rear hub or Campy cassette rear hub with the oversized axle, I haven't broken an axle or anything else in the last 12+ years....Good Luck!

[mpetry]

Functionally I think the two hubs are equivalent, however the main difference is the width of the dropouts, the "over locknut" dimension.

Since the C-records were used on bikes that had 7 and sometimes 8 speeds, they frequently had over locknut dimensions of 130mm. At 130mm, the bearing on the hub drive side is pretty close to the wheel centerline! So there's a bending moment on the axle and a stress riser at the inner edge of the drive side cone.

NR axles were usually set up for 120 or 126mm over locknut.

And of course, a heavy rider with a powerful sprint will put far more load on the rear axle than a small rider.

The quest for more rear cog speeds is part of what led to the cassette hub which has an extra bearing at the end of the axle, near the drive side dropout.

Mark Petry
Bainbridge Island, WA

[R2D2]

Both C-Record and NR had a slot washer to prevent the lock nut from coming loose. The end of the groove cut in the axle was the weak point and broke just as often on C-record or NR/SR in my experience. A big butt and a big bump and Snap. My early C-record hubs were spaced at 128mm but I think later versions went to 130mm. A couple mm's isn't much anyway.

[oldpotatoe]

On another forum, a question was raised about whether Campy NR freewheel rear hubs were more durable than the later Campy C-Record freewheel rear hubs. The problem appeared to be the axle. Its my understanding that Campy NR fw rear hub almost never had broken axles. In contrast, Campy C-Record fw rear hubs did.

Personally, I don't recall breaking an axle or even seeing a broken axle on Campy NR fw rear hub. Yet, in about a 2 or 3 year span, I broke 2 Campy axles and 1 Wheel Mfrg axle. Was there something weak in the C-Record rear hub design or just my fat ass :butt: ....it should be noted that when I switched over to DA cassette rear hub or Campy cassette rear hub with the oversized axle, I haven't broken an axle or anything else in the last 12+ years....Good Luck!

The hub design was essentially the same, the axles and overhang was larger on C Record since it was 7s(126mm), with NR often being 5/6s(120mm).

Biggest reason axles break is misaligned frame dropouts. I use C Record hubs exclusively, adjust the drive side axle end to be the minimum length required for a DA 7s freewheel and don't break axles(I'm .1 offa ton).

I think if the driveside length is kept to a minimum and the frame dropourts are aligned, you won't break axles.

[93LegendTG]

I never broke either of them, but bent both of them all the time. When Campy went to the freehub design, I never had another problem.

[ultraman6970]

Another reason because axles bends is because the bike rear end is not straight, with some tubing like 531 for example, if the rear is not right and you are too strong axles will crack like made of butter. THat's one of the reason campy and others went oversize.