# Alfine 8 Speed - Spoke Length how to



## mtb101 (Jan 7, 2009)

Hi guys, first wheel build with IGH on my 29er Single Speed.

Can someone advise me on the spoke length required?

I have a Shimano Alfine 8 Speed 32 - I got from Planet-X-Bikes & a 29er Sun Rim from CRC.but I'm just not confident enough to work out the correct spoke length. Can anyone assist? I know there are online caluclators, but how to work out exact details required. Thanks.


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## BJKremer (Jul 26, 2007)

My first wheel build was with an Alfine and a flow 29er rim. Have used hub and rim dimensions from he manufacturer and calculated spoke length with spocalc
http://www.sheldonbrown.com/rinard/spocalc.htm
I used the DT swiss website to double check. Worked out fine. A lot of people do advise to measure the rim yourself and not rely on the manufacturer ERD. So if you can measure it or try to find some real life info on the net from others who have measured your rim.
I really like building my own wheels even though it was a slow process. Take your time - plenty of info on here and on other sites. Good luck!


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## Corporal Punishment (May 26, 2011)

I just bought an alfine 8, spokes, etc. Doing my first wheel build next week when the stuff arrives. I used spocalc to get the measurements. Wish me luck LOL... I'll post back when its complete.


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## pursuiter (May 28, 2008)

Looking at sunringle's web site, EQ25's erd=608, I'd use 610 to include nipple height:
http://www.sun-ringle.com/wp-content/uploads/2010/05/SUNRingle_rim_chart.pdf
Alfine hub dimensions can be found here: 
http://bike.shimano.com/publish/con...0015-downloadFile.html/08) Hub Dimensions.pdf

flange diameter; 92.6mm
center to left flange = 31.8mm
center right flange = 25.5mm

I use this website for calculating spoke size:
http://www.bikeschool.com/tools/spoke-length-calculator

for 32H I calculate 290.9mm and 290.3mm, I'd buy 291mm for both sides

for 36H I calculate 285.2mm and 284.6mm, I'd buy 286mm for both sides


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## mtb101 (Jan 7, 2009)

pursuiter said:


> Looking at sunringle's web site, EQ25's erd=608, I'd use 610 to include nipple height:
> http://www.sun-ringle.com/wp-content/uploads/2010/05/SUNRingle_rim_chart.pdf
> Alfine hub dimensions can be found here:
> http://bike.shimano.com/publish/con...0015-downloadFile.html/08) Hub Dimensions.pdf
> ...


thanks for advice everyone, build is on the way, just need to work out ratios for an mtb 29er. Thinking 20 on rear and 40 tooth on front, guy at bike shop said 2:1 ratio. Dont' know yet will see.


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## pursuiter (May 28, 2008)

MTB with a 40Tx20 is gonna be hard to push. I run 32x22, gives me a 23" low gear on my 29er.


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## BJKremer (Jul 26, 2007)

Same here, also 22 rear 32 front. Spin out quickly on the road but is perfect on the trail, gets me up someshort but steep climbs. I would think 40x20 would be nice for commuting. Depends on your terrain of course, if you do not have any climbing you might get away with it - or if you are superman of course.

Would put a 32 up front and play with the rear cog size, easier and cheaper - 32x16 would give you the same ratio with cleaner looks and better ground clearance due to the smaller front ring.


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## mtb101 (Jan 7, 2009)

ah thanks, now you got me thinking ... guy at LBS keeps saying 2:1 ratio so 20:40 on 29er, for alfine 11 specs say 1:9. 

So I'm thinking 38:20, it's been a single speed for a year so I can nearly push up anything. I commute on bike path then hit some single track on way home, with some nice climbs - it's not my main bike, but my commute/training bike, so want a bit of top end to pass a few roadies.


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## bsieb (Aug 23, 2003)

I would use the same gearing as you use for your single speed. 34/20 has worked well for me, gives you 4 lower and 3 higher, 5th is direct drive. For commuting I would use a 16, and a 22 or maybe even 23 for bikepacking in the mountains. The cogs are easy to change, you just need a small screwdriver to pop the retaining snap ring.


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## wschruba (Apr 13, 2012)

bsieb said:


> I would use the same gearing as you use for your single speed. 34/20 has worked well for me, gives you 4 lower and 3 higher, 5th is direct drive. For commuting I would use a 16, and a 22 or maybe even 23 for bikepacking in the mountains. The cogs are easy to change, you just need a small screwdriver to pop the retaining snap ring.


The fact that it is an (almost) 8 year old thread notwithstanding, I feel compelled to post:

Use a pair of lock ring pliers.










These Lisle pliers are under $10 most places, and will make it much easier to remove the square circlip from Shimano drivers.

This does remind me though; I have to go replace the axle assembly in my Alfine.


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## Steveroot (Dec 15, 2011)

It's a good idea to measure the rim's ERD rather than accepting the published value, in case there are differences. This is very easy to do, as described here: https://www.parktool.com/blog/calvins-corner/measuring-effective-rim-diameter


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