weight weenie ISP on custom TI build

[blantonator]

I hadn't seen this before, but if you are going full custom, why not? As long as you aren't changing your saddle, seems like a slick way to save some grams.

[bricky21]

It's nice and clean looking, but not WW. You could have a much lighter setup with a carbon or aluminum post.

[Ramjm_2000]

Not sure I agree. I would think this ISP setup would be lighter than 95% of seatpost clamps + seattube inserts + seatposts (inserted to required depth). The clamps look fairly light.

[BmanX]

Are you sure about that. Do you know what the weight of that section of ti is? The clamping mech could be lighter.

[Ramjm_2000]

Are you sure about that. Do you know what the weight of that section of ti is? The clamping mech could be lighter.

Me or Bricky?

[BmanX]

Bricky as I guess you and I were typing the same response at the same time.

[bricky21]

No I don't know what that section of seat tube weighs. I'm just guessing that combined with that clamp it's got to be 175-250 grams depending on length and diameter which is easily beatable with a WW seat post and seat clamp. I had a 31.6 Masterpiece seat post tuned to 137g. and a KCNC seat binder was iirc 12g.

HAHA...again

[blantonator]

I'm not sure why you think this would be so heavy. Ti is really light, an Eriksen sweet post is only 174 (with heavy clamp design). With this ISP, you have no sleeve, no clamp, no extra seatpost, and an ultra light clamping system. My guess is the extra Ti for the post weighs well less than 100 grams.

[Ramjm_2000]

No I don't know what that section of seat tube weighs. I'm just guessing that combined with that clamp it's got to be 175-250 grams depending on length and diameter which is easily beatable with a WW seat post and seat clamp. I had a 31.6 Masterpiece seat post tuned to 137g. and a KCNC seat binder was iirc 12g.

HAHA...again

On ti frames there is usually a sleeve of some sort in the seattube, usually 8-20gms? Without assuming the ISP is butted (odds are it is) and estimating around 140-150 mm of isp, my estimate would be south of the tunned Masterpiece + binder + sleeve. That said, I prefer a tradional set up myself. If I recall correctly, my modestly tuned 31.6 ti post is 175gms at a 255 length.

[bricky21]

Interesting...I didn't know most Ti frames have that sleeve. My Merlin CR doesn't ,but I have seen the sleeve your talking about on a few bikes. If the seat tube is butted it may be slightly lighter than my Masterpiece + seat binder + a sleeve. I had a Lynskey Ti seatpost(31.6) that was well over 200g. Can't recall the length though (somewhere around 275mm). As I said it is pretty slick looking.

[Ramjm_2000]

Interesting...I didn't know most Ti frames have that sleeve. My Merlin CR doesn't ,but I have seen the sleeve your talking about on a few bikes. If the seat tube is butted it may be slightly lighter than my Masterpiece + seat binder + a sleeve. I had a Lynskey Ti seatpost(31.6) that was well over 200g. Can't recall the length though (somewhere around 275mm). As I said it is pretty slick looking.

Yea the Lynksey post is over built but marketed more towards their MTBs. I had one as well it was 410mm and around 205gms in 31.6.

[Edster]

I just weighed a section of straight gauge Ti tube 27.2 x 178 mm at 63 grams = 0.35 gm/mm. I also happen to have the support bracket, clamps and bolts in Ti wt = 51 grams. Thinking about doing the same thing, but on a carbon ISP frame. So a 150 mm ISP + hardware would weigh 103.5 grams.

[Ramjm_2000]

I just weighed a section of straight gauge Ti tube 27.2 x 178 mm at 63 grams = 0.35 gm/mm. I also happen to have the support bracket, clamps and bolts in Ti wt = 51 grams. Thinking about doing the same thing, but on a carbon ISP frame. So a 150 mm ISP + hardware would weigh 103.5 grams.

Was going to weigh a piece of Ti steerer tube but figured the wall thickness was going to be way off (plus I got lazy when I got home).

[Timo]

Years ago there was a guy in this forum who showed us a titanium cyclocross frame he had custom build in China. It had exactly the same ISP design.

EDIT: found the topic and pics. It was in 2005...

viewtopic.php?f=4&t=11359

[blantonator]

looks like eriksen will do something similar...