broken m5 front hub what now?

Discuss light weight issues concerning road bikes & parts.
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Joined: Mon Jan 16, 2012 3:05 am

by mauiguy

Depending on how you look at it I was either very lucky or very unlucky. I had just finished decending 6500 ft and was braking to a stop at my vehicle when I heard a cracking sound and my front wheel skidded to a stop. I had almost stopped when it happened so I didn't go down. My front wheel was badly out of true and rubbing on the brake pads. The hub flange had cracked off expelling three spokes! The 20 hole m5 hub was laced to an edge 25 carbon rim. When i got home I carefully loosened all the remaining spokes a little at a time around the rim until I had removed all the spokes. Can I reuse the spokes and rim? It's hard to tell but the spokes seem fine and the rim lays on a flat table with maybe a 1mm gap on one side of the rim.( the table may not be that flat)

I am new to building wheels and would probably have my local shop lace them up with a new hub if that is possible. Since I want to reuse the spokes the new hub must have a similar dimension to the broken M5 hub. I have measured the m5 hub and come up with these measurements. Hub flange diameter 30mm and outside of flange to outside of flange 75 mm or hub center to outside of flange 37.5 mm

Extralight ultrafront sx hub has the following dimensions : flange diameter 29mm center to flange 38mm. Do you think this hub would be a drop in replacement for the m5? Fairwheel bikes is out of stock on the hub does anyone know another US retailer of these hubs?

Am I silly to want to reuse the rim and spokes? the rim and spokes have less than 100 km and are almost brand new.

Disappointed to have broken my wheel but so happy it didn't happen while i was doing 40 mph getting ready to enter a tight curve.

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by theremery

I'd re-use the rim and spokes quite close is an AC hub? (Micro).......they are about 52g but nothing is as light as your M5 unless you go for a DASH hub. Dash Mira ('d have to contact Weston Snyder and see if he'd do you one) are about 30g.
Updated: Racing again! Thought this was unlikely! Eventually, I may even have a decent race!
Edit: 2015: darn near won the best South Island series (got second in age
-group)..woo hoo Racy Theremery is back!!

by Weenie

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by SWijland

Why not get a new M5 hub? As far as I know these hubs don't have a reputation for falling apart very often.

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Joined: Mon Jan 16, 2012 3:05 am

by mauiguy

I guess I'm not a true weight weenie, I will add 20 grams to my bike not to have a catastrophic front hub failure. Also the bearings and service from m5 don't seem up to snuff. Can one even order m5 front hubs right now? I did a quick online search and couldn't find one.

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