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TravelTrailer 02-05-14 11:02 AM

breaking spokes- looking for solution ideas
 
I don't know if I am in the right area but here it goes.
Long story short. I work for the fire department and commute to work on my bicycle with all my gear, and uniforms. I an riding in urban areas with mostly bike lanes but occasionally I have to get on a side walk or share road. I am riding a Redline Metro Classic and I pull a single wheel BOB trailer. (Please don't tell me to get a trailer with 2 wheels not an option. It is too unstable at the speeds I ride) The whole set up (bike, gear and trailer) weight well over 100 lbs. There is 35lbs on the front wheel, 50lbs on the rear wheel and 35lbs on the trailer wheel. I am over 200lbs. The average ride is about 20 miles but the longest is right at 30 miles.
I am having trouble breaking spokes (14 gauge) on the rear wheel. On my previous bike I upgraded to 12 gauge spoke but had issues with the 700c tires fitting properly. I haven't looked into a 12 gauge spoke, disk brake, 700c wheel yet.
What I am wondering is if a BOB trailer with a suspension would soften the bumps and lessen the shock load to the rear wheel? Any Ideas?

noglider 02-06-14 12:29 AM

No, you don't need heavier spokes. You need to build your wheel with adequate tension and even tension. 14 gauge spokes are fine for your load. Also, the trailer should not be a factor in these troubles.

SHBR 02-06-14 04:03 AM

1 Attachment(s)
How many spokes are in this wheel? I had major issues with machine built 28 spoke wheels that came stock on my hybrid a few years ago. I upgraded to hand built 32 spoke wheels and they have been solid for more than 10,000km with 100kg loads.

Is this your bike?
http://redlinebicycles.com/bikes/2014-metro-classic/

Those wheels are probably machine built and are not capable of carrying a lot of excess weight, I would build up a set of heavy duty 36 spoke wheels for peace of mind if nothing else.

fotooutdoors 02-06-14 07:39 AM

Following up on the other replies, if you rebuild your current wheel, I would consider replacing all the spokes. You have already stressed them, as evidenced by multiple spokes breaking. the other two posters are right on.

fietsbob 02-06-14 01:58 PM

Wheels don't stay perfectly trued and tensioned by themselves ..

Service after the sale is what Bike Shops Do ..

TravelTrailer 02-11-14 10:04 AM

1 Attachment(s)
Thanks for the replies.
I stay with my bike shop because of the customer service they provide. A little history on the shop. they have been in business a number of years. They are one of the few surviving shops because of the customer service. Several years ago a corporate shop chain bought out most of the shops in the area. Long story short the corporate shop doesn't offer the customer service and the few remaining independent shops are actually doing quite well because of it. I post the question here so as I am discussing bike stuff with the shop I am a little more informed.
This is the bike.
http://bikeforums.net/attachment.php...hmentid=363868
I think the spokes are good for the normal riding stresses even with the added weight. I think the problem is the lateral load when I am starting from a complete stop and/or climbing. The only real climbs here are bridges that have a 5%+/- grade. This seems to be when they break
I should add to the original post that when I said I upgraded to 12g spokes I had actually replaced the entire wheel and had issues with the 700c tire seating properly leading to premature tire failure.
In the past on my old bike I would replace the spokes as I broke them. I know that the others were weakened but if I replace all the spokes every time I broke one I would go broke. Instead I replace them individually and when I started to break multiple spokes at a time I would do them all.
I am sending the wheel off to have the hub and wheel drilled and rebuilt with 12g spokes. I guess I will see what happens.

wahoonc 02-11-14 01:14 PM

How many spokes in the rear wheel? If less than 36 I would get a new properly hand built and tensioned rear wheel with 36 spokes. You are basically doing loaded touring. Double butted spokes might not be a bad idea either. My strongest wheels are 700c, 14/15/14 ga spokes 36 hole eyelet rims. My current favorite are the Sun-Ringle CR-18, Mavic makes some stronger ones that are all but bullet proof.

Aaron :)

noglider 02-11-14 01:47 PM

Heavier gauge spokes don't always make a wheel stronger. They sometimes make it weaker. When spokes stretch (very slightly), they relieve the spokes that are bearing the most tension. It spreads the tension around the wheel. This has been proven. You want the lightest gauge spokes you can use. 14/15/14 might be ideal for you. This is one application where butted (aka swaged) spokes might make a real difference for you. They cost more, but they could prevent or delay the need for a new wheel.

I'm glad to hear about your shop, but I'm also glad you came here for advice. The shop may not suggest (or even agree with) 14/15/14 spokes. It's what I recommend.

I agree with Aaron in recommending the CR-18 rim. It's not too light but not too heavy. It can withstand a good amount of tension, which you want.

fietsbob 02-11-14 03:27 PM

A DB spoke rebuild will be pricy, but having the LBS do the job, then dropping back in occasionally for
retruing and tension checks will help.

chriskmurray 02-11-14 08:10 PM

Quote:

Originally Posted by noglider (Post 16487153)
Heavier gauge spokes don't always make a wheel stronger. They sometimes make it weaker. When spokes stretch (very slightly), they relieve the spokes that are bearing the most tension. It spreads the tension around the wheel. This has been proven. You want the lightest gauge spokes you can use. 14/15/14 might be ideal for you. This is one application where butted (aka swaged) spokes might make a real difference for you. They cost more, but they could prevent or delay the need for a new wheel.

I'm glad to hear about your shop, but I'm also glad you came here for advice. The shop may not suggest (or even agree with) 14/15/14 spokes. It's what I recommend.

I agree with Aaron in recommending the CR-18 rim. It's not too light but not too heavy. It can withstand a good amount of tension, which you want.

I will second all of this. There are plenty of powerful tandem teams that have tens of thousands of miles on 14-15-14 gauge spokes and going for a 12g spoke will put a lot more stress on the rims for reasons posted above. The key is a quality build with sufficient and even spoke tension, switching to a higher quality rim like the CR-18 is not a bad move either and that is a very affordable rim for how durable it is. If you really want piece of mind you can look at something like the DT Alpine 3 spokes which are 13-15-14 gauge or the Wheelsmith DH13 which are 13-14 gauge but your standard double butted spoke with a good build will hold up to thousands of miles.

john4789 02-11-14 08:35 PM

Buy a 40+ spoke wheel intended for tandem riding in addition to a properly built wheel. I ride 48spoke (velocity chukkers) on my FG intended for bike polo. I will be shocked if I ever break one.

fietsbob 02-12-14 01:42 PM

If you want a 40 or 48 spoke rear wheel , because Shimano's tandem cassette hub
still uses at its core , the 10x1mm axle, just ships with a longer one ..

the competent Shop can substitute a shorter axle in thehub and then build up a wheel around It,


My several bike tours, solo ..bring the camp gear .. I used a Screw on Freewheel hub, (Phil Wood)
and 48 spokes (700c-35 tire) one spoke break was no issue ,
having built the wheel, a bit of spot truing , on the bike and the rim ran evenly between the brake shoes again.

Met a nice person with a big adjustable spaneer , and pulled the freewheel and replaced the spoke ,

a few days later, on up the road, then had a few pints with my helpful Local . :beer:

LeeG 02-16-14 04:30 PM

Quote:

Originally Posted by TravelTrailer (Post 16469830)
The whole set up (bike, gear and trailer) weight well over 100 lbs. There is 35lbs on the front wheel, 50lbs on the rear wheel and 35lbs on the trailer wheel. I am over 200lbs. The average ride is about 20 miles but the longest is right at 30 miles.
I am having trouble breaking spokes (14 gauge) on the rear wheel.
Any Ideas?

Your load is so outside the intended use of the bike or it's wheels. 85lbs on the bike? 50lbs of dead weight on the rear wheel? Or are you saying there's 55lbs of load on a 30lb bike?

$.02 if the wheels were up to the load the frame would go eventually. Looking at Redlines website the stock wheels are 32 spoke 480 gram rims. That's totally inadequate for a rear wheel especially if they were machine made and not handmade wheels.

your history breaking spokes indicates you started out with poorly built wheels or inadequate to the task.

If you are seriously putting 50lbs on the rear of the Metro you need the largest tire and rim that can fit in the frame, spoke gauge isn't the issue it's the total build.

ok, re-reading it looks like 50lbs on a 35lb bike. If 35mm tires can fit in the frame I'd go for a 36spoke Sun Rhynolite rim with butted 13g Wheelsmith spokes for the most economical setup. I wonder if disc brakes put more stresses on spokes for heavily loaded bikes than rim brakes?

fietsbob 02-17-14 02:20 PM

Or .. extracycle, the edge runner uses a really simple way to build a lot stronger rear wheel

its a 406 20" http://www.xtracycle.com/edgerunner/ front is a 26" one ..

load C of G is lower ..

Stresses of trick BMX riding has made 48 spoke rims available .. low cost, too..

prathmann 02-17-14 03:20 PM

I agree with the comments that going to a wheel with more spokes is better than increasing the spoke gauge. We had problems on our tandem that we used for both commuting and loaded touring with just a rear rack carrying all our stuff. Tried progressively thicker spokes and they just started breaking even earlier (I suspect the thicker gauges had poorer quality). Then went to a 48 spoke wheel with butted 14/15 gauge spokes and didn't have any more problems. You have much less of a load than we did so I'd expect a 36 or 40 spoke wheel should be adequate.

Am a bit puzzled by your comment about 2-wheel trailers. I've frequently had my Bike Friday 2-wheel trailer over 50 mph on downhills with no issues at all. How fast are you planning on going that would make one "too unstable at the speeds I ride?" But I doubt that the BoB trailer is a major contributor to your spoke issues.

coldbike 02-18-14 10:15 PM

FWIW I ride a cargo bike that I regularly carry 300 pounds plus 180 pounds of me on. I have 32 14/15/14 spokes on the wheel and I don't start breaking them until I try to carry 350 pounds. A well-built, evenly tensioned wheel will carry a huge load.

dscheidt 02-22-14 08:55 AM

Quote:

Originally Posted by fietsbob (Post 16473419)
Wheels don't stay perfectly trued and tensioned by themselves ..
.

Barring a crash or other abuse, yes, they do. Wheels that don't weren't built right, or are built from components that aren't designed for long term durability.

wahoonc 02-23-14 09:43 AM

Quote:

Originally Posted by dscheidt (Post 16517342)
Barring a crash or other abuse, yes, they do. Wheels that don't weren't built right, or are built from components that aren't designed for long term durability.

I completely agree! :thumb: I have a pair of wheels that I built from decent components back in 1977 for a cross country tour, after the tour the wheels went on my "training" bike. I still have those wheels today and they are still in decent shape. In 15 years of regular riding they have only needed a couple of brief tweaks, not so much because they were out of true, more because I was being anal at the time.

Aaron :)

TravelTrailer 02-24-14 09:39 AM

Quote:

Originally Posted by prathmann (Post 16503571)

Am a bit puzzled by your comment about 2-wheel trailers. I've frequently had my Bike Friday 2-wheel trailer over 50 mph on downhills with no issues at all. How fast are you planning on going that would make one "too unstable at the speeds I ride?" But I doubt that the BoB trailer is a major contributor to your spoke issues.

My experience with a two wheel trail was not very favorable. I will admit that the trailer I tried was low cost and/or quality but that would not change the physics and/or riding dynamics. You claim you have hit speeds of 50 mph on the on the downhill and I am not questioning that but I have to ask what speeds do you make any type of turn? With the two wheel trailer the forces applied to the rear of the bicycle will push the rear wheel to the to the outside of the radius much like a motorcycle with a side car or a 4 wheel vehicle. With a single wheel trailer the trailer tracks the same path as the bicycle leaning into the corner. The BOB trailer is the same width as the bike which which is helpful to keep me in the narrow lanes that I ride. I do not have any elevation that would give me the opportunity to hit speeds of 50 mph but I have made turns at 20 mph. I found the two wheel trailer was a situation of the tail wagging the dog.
I posted the comment to not tell me to use a two wheel trailer because my question was about my wheel and when I have had wheel discussions in the past most would say to use a different trailer even though the people recommending that I use a two wheel trailer have never pulled a trailer with a bike. I wanted to keep the discussion based on my wheel not the trailer and as you stated we both agree that the trailer most likely is not a major contributor to my problem.

TravelTrailer 02-24-14 09:46 AM

The wheel is back on the bike and depending on the weather tomorrow morning I will ride it to work in the morning. Unfortunately I had a short period of time just after I posted the original post that I wasn't able to ride the bike so I sent off the wheel to be rebuilt with the 12g spokes. In the mean time I did read the replies last week about the tandem wheel. I will give the 12g spokes a chance and update with what I find. If it doesn't work out I will get a tandem style wheel. I don't think is should be too hard to find one with a disk hub.
Thanks again for the replies and I will update on how the 12g spokes are working out.

kevbo 04-24-14 07:14 PM

I used to break lots of spokes before I learned to build my own wheels. No broken spokes on the 8 wheels I have built.




First off, know that spokes rarely break due to overload, they break due to fatigue, and this due to the spoke tension being too low for the weight the bike is carrying. When the tension is low, then the spokes go slack as they go past the bottom, or from pedaling or disk brake torque. It is this alternating slack-tension cycling that fatigues the spokes. The spokes must be brought to
high tension when the wheel is built. Once it has been ridden a ways with too low tension, the fatigue cracking has begun, and tensioning the wheel will not help unless all the spokes are replaced.


One thing I did not see yet in this thread is stress relieving. Sheldon's site explains how to do it. It seems like voodoo if you are not a metallurgist, but the science is sound. This also needs to be done prior to riding the wheel.

If you are on a budget, it is less labor to get a cheap machine-built wheel (low tension) and increase the tension and stress relieve it.

On a derailleur (highly dished) rear wheel, consider half radial lacing. Lacing the left side radially, heads-out will help keep those spokes from going slack. You can also use the next size smaller spoke on the left. Which will also help. Normally radial lacing a hub that has previously been conventionally laced is a no-no, but the left side of a dished rear wheel has such low spoke tension that the risk of hub failure is minimal. Locking compound may be needed on the left side nipples.


finally, consider a suspension seat post. Not only does this reduce the shock on your butt, but also reduces the jolts that all bike components including spokes. The telescopic type are not expensive, and you can crank the preload up so that you do not bounce at all when pedaling on smooth pavement.


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