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Discussion Starter #1
I have a new frame that comes with 34.9 ST. I noticed for the same post and travel some dropper posts are about 140gramms difference just going to 34.9. seems you could save some decent weight buying a shim and getting 30.9 seat spot. thoughts? should work fine. the new sworks stumpjumper evo comes like that since remote dropper isn't in 34.9.
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I've done it quite a few times, never an issue. In fact since the 34.9 has become more common, I've actually seen some bikes come from the manufacturer with a shim and smaller diameter post.
 

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I shopped pretty carefully for a 34.9mm 200mm dropper for my new Evo, they all weigh a lot. The lightest I found was 710 grams for the OneUp. That's a solid product with a great weight/ adjustability/ low stack/ and low weight for what it is. PNW told me they weighed one for me at 640ish and I ordered it, and it actually weighed over 750 grams so the order was cancelled. after that not sure I'd trust any of their measurements.

In the end, I realized that utilizing the included dropper shim and just reusing my 30.9mm 175mm KS Lev Ci, which weighs exactly 400 grams made a lot more sense.

Now if anyone releases a 34.9 diameter. 200mm travel carbon dropper that weighs less than 600 grams, I'm in. I'd take a weight penalty for the extra drop.

BTW, the included Spesh steel shim weighed 41 grams so consider that. Just ordered a Cane Creek Aluminum shim to replace it. Probably be the cheapest and most reliable 20+ grams I've ever saved.
 

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Discussion Starter #5
I shopped pretty carefully for a 34.9mm 200mm dropper for my new Evo, they all weigh a lot. The lightest I found was 710 grams for the OneUp. That's a solid product with a great weight/ adjustability/ low stack/ and low weight for what it is. PNW told me they weighed one for me at 640ish and I ordered it, and it actually weighed over 750 grams so the order was cancelled. after that not sure I'd trust any of their measurements.

In the end, I realized that utilizing the included dropper shim and just reusing my 30.9mm 175mm KS Lev Ci, which weighs exactly 400 grams made a lot more sense.

Now if anyone releases a 34.9 diameter. 200mm travel carbon dropper that weighs less than 600 grams, I'm in. I'd take a weight penalty for the extra drop.

BTW, the included Spesh steel shim weighed 41 grams so consider that. Just ordered a Cane Creek Aluminum shim to replace it. Probably be the cheapest and most reliable 20+ grams I've ever saved.
nice, good to know. I'm building up stump evo from frame. I'm just gonna use my 5 year old KS lev that I rebuilt recently and a shim. curious, people that want 200 drop, so 170mm drop isn't actually enough? I'd figure 7 inches even for steeps is plenty:)
 

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Stumpjumper 2021 S-Works frame is 34.9 and it comes with a shim to 30.9. It's actually a really nice shim included.
Weight of 34.9 posts is certainly a concern. I ordered a shim to 31.6 (since all of my other bikes are), but in the end decided to go with the native size. I could probably fit ~170 post into S3 SJ, but for safety decided to go with 150.

I had a bunch of 9point8 and PNW Loam before. I asked PWN about the weight of 150x34.9 and they said:
31.6/150 - 524g (I have this one, confirmed)
34.9/150 - 638g - oo!!

In comparison 9point8 150x34.9 is 548g on my scale. Their weights come close to spec. Also their 200x34.9 is 638g on specs. This is without the lever / cable.
 

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USE plastic shim should be lighter than aluminum if USE makes one. Never had a problem with shims on all my old standard posts.
 

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We did the same with my wife’s 18 sworks enduro. I wanted to get it as close to 28 pounds as possible.


Sent from my iPhone using Tapatalk
 

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If anyone can locate a 30.9 to 34.9 Aluminum shim I'd love a link.

I ordered one from Cane Creek that I was told is Al but it's a composite and heavier than the steel one that came with the bike.
 

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chasing simplicity
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Check Worldwide Cyclery.

 

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Saw that one, but won't order without confirmation it's Al as it looks steel or composite.

Sent from my SM-G892A using Tapatalk
 

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I forgot which one I ordered, probably Problem Solver but found an aluminum shim on ebay. Had to search but the material and weight were listed.
 

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Yeh Worldwide Cyclery actively sells on eBay...how they got started actually.
 

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I looked through my purchase history and cannot find it. Over 1.5 years ago. But I did just take it out of the bike and it's the one in the world wide link above. Addonized aluminum 80gr.
That's not Aluminum, that's a heavy composite. The steel one that is included from Spesh weighs 41 grams.

Al of the same size weighs right at half what steel weighs, so an Al shim should weigh about 20 grams. That's something I'm willing to pay $10-15 for.

I suspect that due to the thickness of a shim like this, that Al isn't the best choice, and that's why they are all heavy.

2 droppers on the shelf over here, both KS Ci 175mm travels. the one I'm using now is the 30.9 but I also have a 31.6 and the 31.6 only weighs 8 grams more.

I'm going to look for an Aluminum shim for 31.6 > 34.9. Thought I saw those out there. That will likely result in a lower net weight. However this might be getting too weight weenie even for me!
 

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I don't know why you guys are liking aluminum. Here's a note in my Excel spreadsheet from like 9 years ago:

Shim for seatpost, aluminum, 27.2->30.941g(USE shim would've been 22g!)
 
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