96 Zaskar bottom bracket size 68/73

[EarlofBarnet]

I'm looking to buy a bottom bracket for my newly acquired Zaskar. I seem to remember they were a 73mm shell, but you can fit a 68mm bottom bracket to them? I've tried a 68x113 b/b in the frame with some Deore cranks and they width doesn't seem too far off being right. I recon if I can get a 68 x 118mm b/b then I should be away.

Is there any problems with fitting a 68mm b/b in a 73mm shell frame? Would it be better to get a 73 x 118mm b/b instead of a 68 x 118?

Any help would be much appreciated. I've read a few threads and can't seem to spot what the difference between the two sizes are.

Matt

 

[jimihendrix]

The 68 will fit in the 73 shell but the problem i've found when i've done this is the non drive side cup screws in too far and the splines on the tool have a hard time reaching it, best to get a 73 BB i'd think.

The only difference between the two is the width of the body of the BB, axles are the same regardless i.e a 68x113 will have the same axle as a 73x113

A 118mm axle sounds a bit wide for the Zaskar though, unless you are using straight cranks, mine has a 73/113 and works fine with offset cranks.

 

[legrandefromage]

The 68 will fit in the 73 shell but the problem i've found when i've done this is the non drive side cup screws in too far and the splines on the tool have a hard time reaching it, best to get a 73 BB i'd think.

The only difference between the two is the width of the body of the BB, axles are the same regardless i.e a 68x113 will have the same axle as a 73x113

A 118mm axle sounds a bit wide for the Zaskar though, unless you are using straight cranks, mine has a 73/113 and works fine with offset cranks.

my axle 122mm... M730 cranks

the thick rear stays require quite a wide axle

 

[EarlofBarnet]

Thanks for the replies. Guess as I've got to buy a new b/b anyway, might as well get a 73mm one. CRC seem to do a few, so I recon I'll be sorted.

Thanks again

 

[Eddie King]

Hi all....I asked the very same question myself back in February...

Forum member gm1230126 was kind enough to reply with the following information which you may find helpful:

http://www.bikepro.com/products/shimano ... table.html

Scroll all the way to the bottom of the chart where it shows the 47.5 and 50.0mm chainline figures. From what I remember most all the GT's were built to a 47.5mm chainline so that would be a 107mm spindle. Just looked and a couple of my Zaskars have the M737 crank and I can see 107 stamp in the spindle.

Shimano's own published chart shows the same thing and one of the mods should make this link a sticky....very valuable for those of us building up bikes.

http://www.shimano.com/publish/content/ ... 0Chart.pdf
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[EarlofBarnet]

Thanks Eddie, most helpful