Help on a Giant DH rear wheel

Brian HCM#1 · Apr 30, 2004

It's too bad Blue Pig doesn't have a downloadable spoke calculator anymore, I deleted it from my old computer and with that program you were able to calculate wheel offset. It was the best one I've ever used.

NateH · Apr 30, 2004

with a ringle hub laced to mag 30 i used 250's on non drive and 252's on non drive. Take it to you local shop and ask them to check for you, and buy some spokes from em or something, come on dude support the LBS

vitox · Apr 30, 2004

you can go to www.dtswiss.com and use the spoke calculator there, youll just have to edit the standard value for offset.

otherwise just do a google search for spoke calculator, plenty will show up.

Matt D · Apr 30, 2004

I just built a wheel for a Giant Team DH with a Ringle hub and Atomic Laboratories Trailpimp rim. I used DTswiss's spoke calc and got 249.7 and 248, and ended up using 249 and 247's. How much this had to do with not knowing the rim ERD for sure (I went by what the website said, but found conficting info from other sources), I don't know.

What really sucks is that the spokes are so short, no one has them in stock and you usually have to pay for whole boxes instead of just what you want. Mainly b/c shops don't like to stock things they know they won't ever use again. I had a local guy cut them for me with his Phil Wood spoke cutter.

Good luck, it was a pain in my ass figuring out how to build that wheel.

Matt D · Apr 30, 2004

Originally posted by vitox
you can go to www.dtswiss.com and use the spoke calculator there, youll just have to edit the standard value for offset.

otherwise just do a google search for spoke calculator, plenty will show up.

I just checked and they don't list his hub, he can measure it by hand and plug it in, or find the dimension elsewhere.

vitox · Apr 30, 2004

Originally posted by Matt D
I just checked and they don't list his hub, he can measure it by hand and plug it in, or find the dimension elsewhere.

ah thats right, hmm, you know, formula makes a ton of hubs for different "brands", maybe you can check that hub and see if its "suspiciously" similar to some other brands hub and use that one instead, worth a shot if you dont have calipers.

Repack · Apr 30, 2004

Originally posted by Rockin Johny
I inquired a while back regarding a Giant DH rear wheel and had my suspicions confirmed about the offset. Called Giant and was told the rear wheel has a 22mm offset...closer to the non-drive side hub end.
.................

First, let me say that I have never built a wheel for a Giant, but I have built hundreds of wheels. Something just sound wrong about the figure that they gave you. The total flange distance could be 22mm wider than a normal hub, but I do not see how you could offset a wheel 22mm to the left. On most "oversized" rear hubs I have seen, they end up being 0 dish- one of the reasons to go oversized in the first place.
I would measure it by hand. Internet spoke calc DB's are ~notorious for being wrong. Measuring is easy. Just google "spoke calculator" and you'll get some in excel form, some with detailed instructions.
Wouldn't be the first time that someone called a mtb tech line and got an answer that was related to the truth without actually being the truth.

buildyourown · Apr 30, 2004

I remember your earlier post. Like I said before, I recently built a wheel for a giant dh and didn't realize it was offset. I had the wheel all done and then figured it out when I went to put the wheel on the bike. I was able to dish it out with no problem. I used the same length spokes on each side. If you are breaking spokes, it doesn't mean your spokes are the wrong length. It means you are over tensioning them. Take the hub and rim to your LBS and have them measure with the sticks. I never trust manufactures claimed ERD, its almost always off. Buy the spokes from the LBS. If they are a decent shop, they will have a good selection in stock.

oly · Apr 30, 2004

Originally posted by buildyourown
If they are a decent shop, they will have a good selection in stock.

....or they might also have a spoke cutter.......

Repack · Apr 30, 2004

Originally posted by Rockin Johny
Yes, it does seem odd. But after doing some quick dimensional checks on the frame it becomes apparent why it is like this. The drive side chainstay is offset outwards on the drive side, which offsets the wheel to the drive side. If Giant had used a 155mm hub and made the chainstays offset the same amount this could have been avoided. Anyways, this is just what I have found and may be off base with this conclusion.

That makes sense. For example, Big Hits are 135mm, but the rears are welded 6mm offcenter towards the drive side. This gives the bike a 0 dish rear wheel. Also, b/c of the offset, you get a better chainline. Chainguides tend to sit further away from the frame than a reg cassette (duh).
My guess would be that Giant is doing something similar. You could even use some sort of atraight edge with the hub in the frame to measure the offset if you don't have a number that you trust.
One thing you could do is measure the flange to locknut distance on each side of the hub. If the driveflange-to-nut side is wider, then it is likely a 0dish wheel.
Please remember that I don't own that bike. These are just what I have seen from working on other, similarly designed bikes.

Matt D · Apr 30, 2004

Originally posted by buildyourown
If they are a decent shop, they will have a good selection in stock.

I don't know of any shops that stock spokes less than ~252. The only application is DH wheels, which is not a huge seller at 99% of shops, hence, no stock.

Spoke cutters are rare too, the Phil Wood one costs about $1300 retail if I'm not mistaken! :eek:

I recall previous threads saying the offset was ~12mm; 22mm sounds like a lot more than what I had. I put the offset in the wheel by mounting it on the bike and centering it.

Repack · Apr 30, 2004

Originally posted by Matt D

Spoke cutters are rare too, the Phil Wood one costs about $1300 retail if I'm not mistaken!

Last time I saw one listed, they were ~$1800 WHOLESALE. SOrry for breaking the sacred dealer cost rule, but I think the spokecutter is an exception!
My shop had one and they are sweet. We actually went through 2. They were about 10 years apart, but the serial numbers had only changed by like 200 or something.

phillyvanilly · Apr 30, 2004

As an employee of a Giant Dealer and and owner of a DH comp, I strongly recomend ditching the fomula hub and getting the Ringle. The formulas have some pretty serious reliabilty issues. I dont have any direct experience with the 12mm rear hub, but all their other OEM hubs for the last few years have basically been crap.

vitox · Apr 30, 2004

the whole rear end on a giant dh is WAY out of line when you compare it to the front end

thats how they get away with a 100mm bb shell and a regular 135mm hub.

the law · Apr 30, 2004

I could sell you a hadley properly spaced for a giant dh

buildyourown · Apr 30, 2004

Originally posted by Matt D
I don't know of any shops that stock spokes less than ~252. The only application is DH wheels, which is not a huge seller at 99% of shops, hence, no stock.

Spoke cutters are rare too, the Phil Wood one costs about $1300 retail if I'm not mistaken!

I recall previous threads saying the offset was ~12mm; 22mm sounds like a lot more than what I had. I put the offset in the wheel by mounting it on the bike and centering it.

The shop I worked at stocked lots of 244, 246 and 248 spokes. Most mountain bikes are in the 247-249 range. Why would DH bikes have shorter spokes than regular MTBs? The flanges aren't any bigger and the ERD of the rim isn't smaller.

As for spoke cutters, lots of high end road geek shops have them. Rodrigez in Seattle for instance. I believe Elliot Bay has one too. If you build alot of wheels, its not that expensive because it means you have to stock fewer sizes.

ChrisKring · Apr 30, 2004

My team used to ride Giant's and I have built a ton of wheels for them. The number they gave you is "somewhat" correct.

The rear end is 11.25mm offset. When you have the wheel in the truing stand, you will have a 22.5mm space on one side with a 0mm space on the other side. If this is still confusing, PM me and I will throw a wheel in the stand and take a picture.

Matt D · May 3, 2004

Originally posted by buildyourown
The shop I worked at stocked lots of 244, 246 and 248 spokes. Most mountain bikes are in the 247-249 range. Why would DH bikes have shorter spokes than regular MTBs? The flanges aren't any bigger and the ERD of the rim isn't smaller.

As for spoke cutters, lots of high end road geek shops have them. Rodrigez in Seattle for instance. I believe Elliot Bay has one too. If you build alot of wheels, its not that expensive because it means you have to stock fewer sizes.

I don't know what kind of mountain bikes you worked on at your shop, but most mountain bikes have spoke lengths above 254. That's the reason DT makes every length above 254 (i.e. 254, 255, 256, 257) and below it only evens (254, 252, 250).

The reason DH bikes have such short spokes is because the flanges ARE bigger in some cases and the ERD is smaller because the depth of the rim is much larger than standard XC rims. These two factors together make the spokes shorter.

Now you know.

buildyourown · May 3, 2004

Originally posted by Matt D
I don't know what kind of mountain bikes you worked on at your shop, but most mountain bikes have spoke lengths above 254. That's the reason DT makes every length above 254 (i.e. 254, 255, 256, 257) and below it only evens (254, 252, 250).

The reason DH bikes have such short spokes is because the flanges ARE bigger in some cases and the ERD is smaller because the depth of the rim is much larger than standard XC rims. These two factors together make the spokes shorter.

Now you know.

Gee, Thanks for pointing that out. Maybe I have been building wheels wrong this whole time. Now that you have enlightened me, I'll know how to do it right.

Matt D · May 3, 2004

Maybe you have been building wrong if you don't know that the ERD changes and that the average spoke size for a standard mountain bike is not 247-249.

buildyourown · May 3, 2004

Originally posted by Matt D
Maybe you have been building wrong if you don't know that the ERD changes and that the average spoke size for a standard mountain bike is not 247-249.

What I do know for sure is the wheel I built last month for a giant took 248mm spokes on both sides. It had the stock ringle hub and a Ryno Lite rim which is pretty shallow. The spokes poked out the top of the nipples just a bit like they are supposed to.

ChrisKring · May 3, 2004

Originally posted by Rockin Johny
That makes sense...the wheel is actually offset the 11.25 mm from center but when it is measured with the dishing tool the 'gap' on the NDS is 22mm. Is that what you are saying?

Thanks

Yes

Help on a Giant DH rear wheel

Chimp

MMMMMMMMM BEER!!!!!!!!!!

Monkey

Turbo Monkey

Monkey

Monkey

Turbo Monkey

Turbo Monkey

Chimp

Turbo Monkey

skin cooker for the hive

Turbo Monkey

Monkey

Turbo Monkey

Chimp

Turbo Monkey

Monkey

Turbo Monkey

Turbo Monkey

Chimp

Monkey

Turbo Monkey

Monkey

Turbo Monkey

Turbo Monkey