I commute on a Specialized Sirrus Sport. I had been breaking spokes on my real wheel and out of frustration bought a Chukker rim with a Shim 105 hub and had it triple laced.

I rode today and found that either my fitness level shot way up or this hub and wheel have made a real difference. I was 3 MPH average faster and heart rate was 10-15 bpm lower on average.

my other wheel and hub were ofm.

Makes me wonder if I should change the front.

That seems pretty extreme for a wheel change. The difference in power you are suggesting, if real, would have been causing something to get hot and probably fail, e.g. the tire (i.e. if underinflated), or the wheel bearings (i.e. if dragging excessively).

Specialized uses cheap hubs (joytech) that are sealed with rubber stoppers that put undue drag on the hub. So yes when you replace the wheels with better hubs your going to see a performance gain.

I actually had a similar experience with a wheel I have on which I was breaking spokes on the non drive side (tubular Mavic reflex rims with 105 hubs). After about 5 spokes breaking and being replaced, I finally just went and bought a new wheel set I had been looking at for a while - HED Belgium C2 tubular rims with DT Swiss 350 hubs. I saw a significant improvement in speed and ride quality and I still can't figure out why but the training data doesn't lie. My wife agrees (we often ride together) and says that I'm definitely faster than before. My current thoughts are that the bearings are better and that there was probably some flexion in the rim that was causing issues, but I don't know. Anyhow, let's just say I'm really happy with my new rims.


J.

New wheels can make a big difference but chances are if it was that big and you did not move to a lighter wheelset that something was wrong with your old one. Bikes are very very rarely shipped with wheels being set up properly, hubs are almost always too tight and spoke tensions can be hit or miss.

Either way, glad you saw a large improvement with your purchase.

If the spokes on your old wheels were "sloppy loose", it could make a noticeable difference.

I agree with the others who posted that a new wheel shouldn't be the reason for such a large performance gain unless something was very wrong with the old wheel. But hopefully the new wheel will be more reliable than the old one.

See my earlier post.. I'm willing to bet the sport model came with the gosh awful joytech hubs.. When I rewheeled my '07 Sirrus to Shimano 600 hubs I got at least an additional 2 mph and I could compare the draggy Joytech to the new 600 and the difference in rolling resistance was significant.

Out of curiosity, what the hell are you guys doing on your commute that brakes metal spokes?

M.

In my case, i simply don't know. I'd be riding along and a spoke would just break. Always on the non drive side and always at the J bend where it goes into the hub. That means it had to be working the metal somehow.

I checked spoke tension all the way around and it meets Mavic's specs for the rim. I carefully adjusted them so that there was (on each side) not more than a 5% variance in spoke tension. The wheel was trued to within about 1mm or so - very true. So it's about as nominal a wheel as you can get. Yet, I broke 5 spokes in about a two week period all the same way. It's crazy. I thought about having the entire wheel rebuilt again, but this would be the second Mavic Reflex rim that I've had problems with. The rim before this one developed cracks at the holes in the rims and was replaced under warranty. My current theory is that this is not the Mavic Reflex of days gone by and that there is a design or manufacturing deficiency in the rims.

I fixed the wheel and I'm going to put it on my daughter's bike. She's a lightweight so the rim should not be stressed in any way and it would be a nice wheel upgrade for her. I'm betting that solves the problem.

J.

In my case I recognized the joytech hubs were crappy and I also wanted to build a dynohub wheel. Unfortunately the Alex 500 OEM rim was not available in the consumer market so I did a set of 3 based on the Mavic CXP 33 rim. (Non Genhub front based on Shimano 600/ultegra, a Dynohub front based on a 3N71 Dyno, and an Utlegra 8speed rear.). I then sold off the original wheelset..

Non drive side should be significantly lower tension than DS, anyway. So DS should be popping first. Non DS spokes should be more likely to loosen. Hmm.

Wondering if you had spoke damage on the non DS.
Perhaps a pannier strap/hook came off at some point and got caught up in the spokes ?
Or sometimes even damage from a bike rack incident ?
Ben Hur situation ?

Anyway, good luck with the new wheel.

I saw a performance gain of a couple of mph or so when I change my wheel set to a more sturdier version, but that was due to the rear wheel staying more centered, thanks to the better bearings, and not causing the wheel to rub on my rim brakes whenever I decided to put the hammer down.

I repacked the bearings on my rear hub last year and that made a huge difference. Perhaps your old hub was in need of maintenance? (although that doesn't explain the spoke issue)

I had the old hub repacked a few weeks ago when I replaced a couple of spokes.

My spoke problems really started when my pannier was sucked into the wheel one day when I had to sprint across an intersection. (I had the wrong kind of rear rack...no extenders to the rear to handle sway).

On top of that, I weigh 270. I average 14 mph on my commute most days, except when I do intervals. I also carry books etc. in the panniers and my briefcase.

I've been commuting an average of 4 days a week for a year now.

I bought the bike used on craigslist.

No spoke damage. Nothing unusual. My LBS had noted some problems with those particular rims on occasion. At any rate, the DT Swiss hubs were a major upgrade over the Shimano 105's for sure. That's probably most of the change.

I haven't built my own wheels yet simply because it's not expensive to get them built - the cost is in the cost of the components. That said, I do all the rest of my own bike work and true my own wheels etc... With this one, I even sprung for the Park Spoke tension gauge to make sure it was correct. I also thought it odd that the non drive side spokes were breaking.

Anyhow, problem solved and my daughter will love her new wheels. My wife has the same wheels and she's had zero problems with them. They hold true just fine too. So it's probably not a great rim to carry stuff on a bike and if you are not small person. Live and learn, I guess. That all said, that's the first wheel I've ever had in decades of cycling that ever had that problem.

J.

This site has a calculator for wattage as a function of various biking variables. I ran an example with a 3mph (5kph) difference in speed and got a difference of nearly 90W. Has anyone touched a 75 or 100W incandescent light bulb while it is on, or shortly after switching it off?

Very easy to pop spokes if the wheels aren't tensioned properly to start with.

Yes of course. I went over my entire wheel with a Park Spoke Tension gauge and adjusted the spoke tension to the Mavic's recommendation so that spoke tension was #/-5% spoke to spoke on a given side. Wheel was trued to within 1mm. Then I broke three more spokes. In 30 years of riding, never seen anything like it. I think it's the rims since this is the second rim I've had trouble with (but different problem - spoke holes cracking. Mavic replaced under warranty) and Mavic may be having QC problems with this particular rim.

J.

Not necessarily.

If the NDS spokes are at a low enough tension to actually go slack while riding, they can fail really fast.

Most manufacturers are going to have specify all of that - maximum spoke tension drive side and the spoke tension drive side relative to non drive side. You really don't get to just wing it, you have stay between the lines they specify.

J.

The damage was already done-

Don't think so. Everything was in spec before I adjusted it, I just made it perfect so it was much tighter to nominal.

I think it's a crap rim. There is no way a 32 spoke 3x rim that's in spec should be anything except bombproof. Especially when it's the second rim like that had problems.

J.

I have noticed that my bikes feel slower when my spokes are loose. I think the wheel has more spring/flex to it and absorbs more energy much like a tire with low PSI.

+1