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medium SX trail steerer tube length

2K views 22 replies 7 participants last post by  snowforner15 
#1 ·
im getting a 06 sxt next weekend but am looking for a 07 vanilla that i have already found for SUPER cheap to avoid some of the travel blowing problems ive heard of 06s.. with the thompson stem, how long are you steerer tubes on a medium sxt2? (the fork steerer tube that is...)
 
#9 ·
Just do the math.

108mm head tube + your headset stack height (FSA pig 29.5mm) + Standard Thompson stem stack height (42mm) = 179.5mm or 7 1/16" your steerer tube length you need + your spacers your spacers you would normaly under your stem 3 or 4 - 5mm spacers.

Start with 7 5/8" steerer tube = 193.68mm - 108mm head tube - 29.5mm headset- 42mm stem = 14.18mm of spacers + 2mm stem cap gap = 16.18mm of spacers or 5/8"

That's 3 - 5mm spacers and you could probably get away with 4 (3/4"+) and be close stem clamp tolerance (Thompson recommends no more than 3mm or aound 1/8") Should be enough spacers. If your bars are not high enough you could get a higher rise stem.

Someone can double check my math, but I think it doable. With 4 spacers your steerer tube will be 1/4" below the top of you stem. With 3 spacers you will have to file a little off the steerer tube to get 1/8" below.

If I'm off in any of my calculations, someone chime in and let him know, I'm just trying to help.

Hope this helped and good luck.
 
#10 ·
rocketmanmtb1 said:
If you use a king head set you will ovalize the head tube. Costly mistake.
could you elaborate...?
the previous owner was running a king hs.. should i stay away from this? its got havoc wheels, gamut guide, xt cranks and some other upgrades for less than 2000. but if theres a "costly problem" maybe not worth it...
 
#12 ·
snowforner15 said:
ovalized head tube?...
If you're going to use it for trail riding you should be fine with the C.K. If you plan on using the bike for FR ,big jumps and drops, get a beefy headset.

I'm thinking rocketmanmtb1 was just thinking of the FR side of things, since the bike is for more FR type of riding than trail riding.

I'm thinking of getting one of these SXT bikes in the future.
 
#14 ·
snowforner15 said:
oh im just not fimiliar with the chriskings ovalizing headtubes.. ive seen a bunch of demos and v10s running CKs....? what causes a ck to ovalize the ht?
Not sure? I'm just guessing that's what rocketmanmtb1 was getting at. I know personally I wouldn't take a standard type headset and install it on a bike that was going to be used for DH or FR and risk ruining the headset or frame.

I wouldn't think a standard C.K. headset is what you're seeing on those type of frames.

Might be a a steelset.

http://www.chrisking.com/headsets/hds_steelset.html

How did you make out on your steerer tube length decision?
 
#15 · (Edited)
This is what I'm getting at..............
YOU WILL OVALIZE YOUR HEADTUBE .Specialized uses a 34.0 HT diameter,The Chris king is a 33.9.

Edit: NO, I would not buy that frame if it had a CK headset on it previously unless it was a CK 40.
see if this helps

The standard headtube ID for 1 1/8" headsets is 33.9mm which mates up with our cups which are designed around this standard. Lack of a press fit between the cup and the frame can lead to damage of the cup or less likely the headtube. You can see a complete list of headtube and cup specs on our web site, http://www.chrisking.com/specs/headsets_all.html, as well as installation procedures at, http://www.chrisking.com/tech/tech_headsets.html. In cases where the headtube bore is oversize or has been ovalized we produce 4 sizes of oversize cups which correct the press fit. In order to determine which size oversize cup would be appropriate, a measurement of the headtube bore to within .002" or .05mm would be necessary. Existing bearings can be swapped into oversize cups or complete headsets can be purchased with any combination of oversize cups. Your local Chris King dealer can help determine which size oversize cup you need and can order oversize cups and bearings or order a new headset. You can also obtain a return authorization number by calling the 800 number below and send your cups to the factory and we can install your existing bearings in oversize cups. Oversize cups retail for $25.00 each. There is no labor charge to swap bearings.
The torque spec. of the stem cap is correct at 5-10in.lbs., not to exceed 15in.lbs. By torquing the stem cap to 40 or 50in.lbs. it is most likely helping to hold the cups which have an inadequate press fit in the headtube. The stem cap would eventually fail and the steering would become stiff, possibly damaging the bearings with this much preload. Correcting the press fit would alleviate the need for the excess preload. Let us know if you have any other questions. Thank you for your time and have a good day.

Adrian Knapp
Tech Warranty
King Cycle Group
2801 NW Nela St.
Portland, OR. 97210
800-523-6008
 
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