[Phil_S]

I've been working at lowering the BB on my 08 Spot. I have a Lyric fork set up 147mm, CK headset, 2.3 Nevegal on front, 2.4 WTB Moto Raptor on back, Mavic 719 rims, and have just put on some 06 Seat Stays ( thanks Wilks). BB height is still over 14 at about 14 1/8.

Outside of cranking the fork down to XC geometry, any ideas for geting the BB lower?

Also, I've been informed by trustworthy guys that offset shock bushing give problems like twisting around and are not the best idea. With the 06 Seatstays, I'm also at about 1/8 inch rear tire to seat tube clearence on the in the garage test.

Thanks for any input.

 

[jncarpenter]

Have you tried letting some air out of your tires?

 

[keen]

14 1/8" on a Spot ??? 13.6" is spec'd w/ a 515mm fork. A Lyrik @ 147mm travel has a new a-c height of 532mm, so your bike is 17mm taller up front. That 17mm shoud raise your BB no more than 1/4" ? My RFX w/ a 520mm a-c Pike 2.4 / 2.35 tires has a 13 7/8 " BB height. The a-c height difference from spec. is 15mm - close to your change. Are you measuring from the floor to the center of the crank spindle ?

 

[Phil_S]

Are you measuring from the floor to the center of the crank spindle ?

Yea, I'm pertty sure I'm measuring to the center, as best as I can by myself.

14 1/8 just seems higher than makes sense for it to be. One of the reasons I posted all the little odds and ends that could effect BB height.

 

[ncbiker]

I hear a stuck down RP3 will give you a lower BB. Have you tried that?

 

[S-Works]

Barring using a stuck down RP3, you could find yourself some pre-07 seatstays. DT raised the BB with the newer 5.5 rockers by changing the length of the seatstay. Putting an older set on would lower it.

So you would need to find some 06's stays, being that's the only year of TNT and pre 5.5 rockers, or a complete rear tri before 06.

Another option would be to have Darren custom make you a shorter i2i shock. But who knows how much beer that would cost

 

[derby]

In your situation a 1/2 inch longer chain stay is the only way to lower the BB about 1/4 to 3/8 inch, and keep your tire from hitting the seat tube at bottom travel. If your wheel wasn't already so close at bottom travel you could use a shorter seat stay, or different rocker angle, or asymmetric shock mount instead.

With a 1/2 inch longer chain stay it would slack the frame nearly 1 degree, bringing slower steering and a more rearward seat position. You could bump the seat forward to maintain the same effective seated position over the pedals. Your travel would increase by nearly 1/2 inch and may want a slightly stiffer spring or more preload if coil.

I know all this because my early Intense Tracer had an adjustable chain stay of 1/2 inch and those were the geometry differences.

Check with Gregg at Turner, he’s the most knowledgeable there in experimenting with various stock linkages.

 

[wilks]

Barring using a stuck down RP3, you could find yourself some pre-07 seatstays. DT raised the BB with the newer 5.5 rockers by changing the length of the seatstay. Putting an older set on would lower it.

So you would need to find some 06's stays, being that's the only year of TNT and pre 5.5 rockers, or a complete rear tri before 06.

Another option would be to have Darren custom make you a shorter i2i shock. But who knows how much beer that would cost

s-works give yourself an eye test! he put on 06 stays (see his original post) good suggestion on seeing if push can make a shorter eye to eye shock though.