Your theories on why spokes break.

[Conquiztador]

Would that therefore mean BMW has got the ultimate spoke now? (those straight ones fitted on their big RGS's).
Or is there still a good engineering principle to use the bent ones. (some form of lateral shock absorption maybe).

Straight spokes are phucking hard to tighten!! They just keep on spinning when the nipple is turned. You end up grabbing them with a set of polygrips or similar. Butted spokes is the go where they are 90 or 45 degree bend. (Butted = thicker gauge at the bended end)

But yes, as long as the spokes are of good quality then the straight ones are hard to brake.

Also, replacing a broken spoke in a wheel with straight ones is a breeze. No need to take any of the others off. If you have a broken one in a wheel with bent ones and the spoke is going to the inside you end up taking a few others off to get it in. Added work!!

[tri boy]

Straight spokes are phucking hard to tighten!! They just keep on spinning when the nipple is turned.

Ahh haa, that will explain why the new GS's have a torx type head at the hub end of the spoke.
Thanks for the info. Ya learn something new each day.

[limbimtimwim]

This isn't really related, but this is a timely in my case.

Guy at work parks his cheap push bike for a year, gets back on it last week and.. All the spokes on the back wheel snap in the middle. Each spoke had got a scratch from something and corroded right into the middle.

Another guy at work got a cheap small BMX for his son, and he decides to show his son who to do wheelies. First wheelie; all the spokes on the back wheel break.

His son found this hilarious.

[Paul in NZ]

Or they could check out some perfectly good spokes they made over 50 years ago.

From MY experience only, back in the day - all makers at one time or other had 'issues' with spokes....... Usually if they introduced a new ub or re used an old hub on a bigger model or something...

Since we are discussing Triumph spokes.... In the 50's and 60's Triumph always had a pretty low tech approach to wheels. Hubs were simple cast iron / steel affairs and it was BSA and AMC that went with the lighter alloy full width hubs etc. The bigger brakes and full width hubs others used meant shorter spokes and stronger wheels. (remembering tyre technology was pretty bloody basic too)

Triumph never really had many issues with front wheels - probably because their forks were so spindly and their brakes so megre that little strain was placed on the wheel. The later 2LS wheel is very strong. Triumph were late comers to swinging arm rear suspension as well. Their sprung hub was not much chop as suspension but it's width and diameter did make for a bloody strong wheel (I still have nightmares about lacing up a 16" alloy rim to a polished sprung hub using stainless spokes without scratching anything)

Triumphs weakness was rear wheels....

Triumph made 2 basic types of rear hubs (forgetting the smaller bikes and odd balls). The std bolt up design and the QD hub (for 'quickly detachable'). The QD hub was made up of a spool hub with a spline that slotted into the brake hub (brake hub had it's own bearing) so the wheel could be removed without disturbing the chain or brake. The bolt up hub was similar except there was no 3rd bearing or spline - the brake attached to the spool hub with 6 (I think - or 8) bolts)

The spool hub means the spokes were mounted inboard of the brake and were thus fairly long and terminated on a narrow hub. This lead to a comparitively weak structure - especially when modern tyres appeared - more sideforce often broke the spokes.

Triumphs always used a 'waisted' or butted spoke (thicker at the hub end) and it was not uncommon to find busted spokes in the rear which if you had a bolted up hub usually meant a bit of a mission as they usually broke on the brake side - if you look at my bike - I fitted thicker stainless spokes 17 years ago - no problems since.

BSA QA hubs were better because they had the crinkle hub spool and allowed straight spokes which seemed stroger in rough service (like a dirt bike)

Lots of info on the web on all this..

http://www.central-wheel.co.uk/cwc/s...e_details.html

Later bikes with disks have similar challanges but the hubs are wider and stronger and the engineering better understood. All makers have had issues - I remember Suzuki TS400 Apaches shaking their rear wheels to bits...

[SPman]

Any spoke will break, given enough incentive..............

[Motu]

BSA QA hubs were better because they had the crinkle hub spool and allowed straight spokes which seemed stroger in rough service (like a dirt bike)

The BSA QD and 8'' front brake (the steel one with the 6 frost plugs) were the best wheels around,real strogy they were.I had an 18'' and 19'' rear and 19'' and 21'' front so I could swap things around on my old BSA.QD wheels were great,you didn't even need a stand - just lay the bike on it's left side,pull the axle and lift the wheel out,then set the bike upright again,maybe propped up with a rock.30 secs max to remove a wheel.One day the Japanese will reinvent the QD hub and be praised as sooooo inventive.

[motorbyclist]

on my dirtbike i've managed to break 3 spokes in one bang, and kept riding unaware for 3 hours before finding that i couldn't roll my bike backwards - one of the spokes had wrapped itself around the hub and was interfering with the sprocket

rear rim hasn't been quite straight since

[cynna]

anyone know where to get a broken spoke fixed in chch? was going to get a new tire at cycletreads tomorrow so will give them a ring later so see if they can. failing that any other suggestions will be appreciated

just noticed a broken one at the hub when cleaning my bike....

[Ixion]

on my dirtbike i've managed to break 3 spokes in one bang, and kept riding unaware for 3 hours before finding that i couldn't roll my bike backwards - one of the spokes had wrapped itself around the hub and was interfering with the sprocket

rear rim hasn't been quite straight since

3 ! Pah, Petal on one notable journey managed to break 24 spokes in the rear wheel! And still made it home. Mind you it took all my effort just to contain her with a single lane, in a straight line. 6 inches of lateral movement at the wheel rim. As to why? Who knows. But I do know that once a couple go the rest start coming out in sympathy real fast.

[Kickaha]

anyone know where to get a broken spoke fixed in chch? was going to get a new tire at cycletreads tomorrow so will give them a ring later so see if they can. failing that any other suggestions will be appreciated

just noticed a broken one at the hub when cleaning my bike....

Wheel Building Services 71 Buchan Street, Grey coloured building, bastard to find
ph 366 4706

[Motu]

As to why? .

The fleet of 25 FA50 rentals I used to look after were always breaking rear spokes.The bikes had a weight limit,but it was never observed....lots of overweight people on them wrecked the spokes real fast.As to why Petal did in those spokes?......

[cynna]

Wheel Building Services 71 Buchan Street, Grey coloured building, bastard to find
ph 366 4706

thanks for that. now just have to get the wheel off and get it there