spoke tensioning

[yello]

Does anyone use one of those Parktool gizmos? Any good? Worth the dosh?

Or is it just as easy to do it by hear/feel?

 

[PapaZita]

You mean the TM-1 spoke tension meter? I have one, and I think it's pretty good. It's quite expensive for what it is, but if you're planning on building a few wheels I reckon it's a worthwhile investment. I'm sure it's possible to build an OK wheel without one, and perhaps a master wheel builder can build great wheels just by feel, but as an occasional wheel builder I haven't developed that skill yet, so the tool helps.

PZ.

 

[yello]

Yes, thanks PZ, that's the gizmo - the TM-1.

Wheel building was something I'd like to get into (maybe) but at the moment I just need to tighten up some spokes. As you say, they're not cheap, so I didn't know if tensioning was something I could do by ear.

 

[dodgy]

I've got one, too. It's great if you're a novice at truing wheels as going on feel takes a bit of practice. It's particularly good at ensuring spoke tension is higher on the drive side than the non drive side on rear wheels, and also ensuring roughly consistent tension around the wheel.
I got mine imported from the US via eBay for about £31 delivered.

Dave.

 

[dodgy]

I meant to add, there are other bike tools that should be bought before something like this. Don't buy it if you haven't already got:

• A workshop stand
• Quality Cable cutters
• Decent allen keys (preferably with ball ends)
• Chain whips and sundry tools for removing cassettes
• Bottom bracket tools (crank puller if required, or other specific to your BB tools for removal).
• etc

It's pretty near the icing on the cake for a home workshop tool kit.

Dave.

 

[yello]

I got mine imported from the US via eBay for about £31 delivered.

Yes, I saw that. As they're the equivalent of around £85 (!!!) here in France, that's a pretty darned good deal! I could get one from the UK for about £55, so that's a bit more reasonable but the US option does seem a bit of a no-brainer... except if I get charged import tax!

I've got all those other tools btw so home wheel building is the final step!

 

[MessenJah]

Lol who needs a spoke tensiometer? Just tighten it up until it snaps, then get a new spoke and tighten that up slightly less than you tightened the old one

 

[Saddle bum]

Lol who needs a spoke tensiometer? Just tighten it up until it snaps, then get a new spoke and tighten that up slightly less than you tightened the old one

Almost right.

Today's top quality spokes are almost impossible to overtighten. The screeching of the nipple and spoke bed should give ample warning.

 

[robbarker]

I have one and it works very well. I would like the (expensive) DT Swiss one one day, but the Park has proved perfectly adequate for both building and truing.

 

[barq]

I use the Park tool as well. It is useful for learning about wheels. If you download the spreadsheet from their website and plug the tension reading in for each spoke you get a nice graph of DS and NDS tension. You can build a well trued wheel with extremely even spoke tension. That's not something many amateurs can otherwise achieve.

 

[AcademicX]

I found this thread informative when researching wheel building (along with Roger Musson's Wheel Building book).

I'm about to embark on my first wheel build and just got all the bits (including the Park TM-1) this morning. Out of curiosity I tested the TM-1 on a variety of factory built wheels I have in the shed and pretty much all the spokes had tensions lower than I expected (allowing for the obvious differences between NDS & DS, 20-spoke vs. 32-spoke wheels, DB vs. aero spokes).

Out of interest, what determines the level of spoke tension when building a wheel ? Do you have a look at the rim manufacturers spec. and build to this ? Do you just get a feel for the correct tension ? Or do you just nip them up as tight as you can (on the basis that the tighter the spokes the stronger the wheel) ?

 

[PapaZita]

Out of interest, what determines the level of spoke tension when building a wheel ? Do you have a look at the rim manufacturers spec. and build to this ? Do you just get a feel for the correct tension ? Or do you just nip them up as tight as you can (on the basis that the tighter the spokes the stronger the wheel) ?

It's limited by the strength of the rim. As such, the rim manufacturer's spec. is probably a good guide, if perhaps a little conservative. Too much tension and you may find the rim buckling as you build - a telltale sign is that you make the corrections that ought to help, but the buckle gets worse. In this case you can slacken off a bit and provided the buckle wasn't too severe then no lasting harm is done. Alternatively, you may finish the wheel but have it fail later, e.g. cracks radiating out from the spoke holes.

I've read of various tricks to enable wheels to be built to such high tensions that the nipples become difficult to turn. I'm not sure that I understand this. I've been up to and slightly beyond the manufacturer's tension recommendations with only a drop of oil on the spoke threads. In my experience the rim becomes impossible to keep true long before the nipples get too hard to turn.

I think the manufacturer's spec. is the thing to aim for. More tension makes for a stronger wheel only up to the point where something breaks, or where it only takes a little knock for it to ping into a more stable but less round shape.

I know what you mean about measuring wheels and finding the tension surprisingly low. I've got a book that describes the Campag Shamal rim as being able to take up to 2000N. The drive side rear on mine is nearer 1000N (i.e. about the same as the Mavic's recommendation for an Open Pro). These are old wheels though - no idea what they were when new, or whether you'd expect any of the tension to leak away. I think it's best to measure tension with tyres deflated as tyre pressure will reduce the reading, but how much I'm not sure. Not a huge amount, I wouldn't have thought.

PZ.

 

[robbarker]

I agree with PZ - the rim manufacturer's recommendation is the safe bet but I agree they are conservative.

Mavic rims are only supposed to take 900N, but I build them to 1200N for my own wheels and have had no problems with eyelets pulling through or cracking in several thousand kilometers. The extra tension makes the wheel stronger. I'd get a written disclaimer if building to this tension for anyone else though.

http://www.tech-mavic.com/tech-mavic/technical_manual/data/docs/products/2_119.pdf

DT Swiss rims are designed or higher tensions nd I shall be trying some for my next build.

Modern rims won't pretzel when over-tightened like old ones used to, so that's not a reliable guide. The captain sensible thing to do is stick to the manufacturer's recommendation. If you do go tight, remember the safety glasses!

 

[AcademicX]

Just finished building my 1st wheel (DT Swiss RR1.1 rims and 240 hubs with DB spokes). Took it slowly and made sure everything was going by the book (see earlier post). The Park Tool TM-1 spoke tension meter was very useful and well worth the money. I also used the Park Tools spreadsheet which plots the tension of the wheel and calculates average tension, etc.

I started with the front wheel as I figured this would be easier, next it's the rear !!

 

[robbarker]

Good for you - nice feeling when you build your first wheel isn't it?

As long as you have the right spoke length, the rear wil pretty much dish itself, so just do it systematically according to Roger M's book and you'll be fine.