Cutting/Shortening Seatmast on Speedvagen

[Cloudofheaven]

Has anyone have experience cutting the seatmast on a Speedvagen in order to lower the saddle height? I recently purchased a used Speedvagen Superlight and it is on the way shipping over to me. It has a carbon seat tube, and unfortunately the minimum saddle height on it will be too high for me. I have short legs and long torso and arms. The saddle height built for the bike is 75.5cm whereas my preferred saddle height is 69.8cm with a 155m crankset. Link to details regarding the bike below.

https://r.tapatalk.com/shareLink/top...ink_source=app

I reached out to Speedvagen, however I haven’t heard back. I believe they are still transitioning into a new space and reorganizing their company so I’m not sure when I will get a response. I’m hoping there is someone out there that has experience cutting or shortening the seatmast on a Speedvagen and if they can help guide me.

[crankles]

One issue you're going to encounter is having enough of the stainless sleeve left to clamp the enve topper.

[PJN]

Originally Posted by Cloudofheaven

I believe they are still transitioning into a new space and reorganizing their company so I’m not sure when I will get a response.

popcorn

[Cloudofheaven]

Originally Posted by crankles

One issue you're going to encounter is having enough of the stainless sleeve left to clamp the enve topper.

I’m thinking about cutting up an aluminum soda can and using it as a shim in between the seatmast and topper or would it be okay for the topper to be clamped onto the bare carbon seat tube? I’m certain that there won’t be enough stainless sleeve left once it is cut to my preferred saddle height.

[David Kirk]

Originally Posted by Cloudofheaven

I’m thinking about cutting up an aluminum soda can and using it as a shim in between the seatmast and topper or would it be okay for the topper to be clamped onto the bare carbon seat tube? I’m certain that there won’t be enough stainless sleeve left once it is cut to my preferred saddle height.

I think you are in a very tough place. I can't say with certainty but I seriously doubt the carbon seat mast was not designed to deal with the clamping force from the seat topper. So even if you somehow manage to get enough Coke can in there it's all too possible that when you tighten the topper it will compromise the fibers.

I doubt this is what you want to hear but I think you should sell this frameset and wait for one that will allow for the proper saddle high without the stainless top being cut off.

dave

[Kyle h]

Honestly, if there’s no SS part left, I think I’d just cut it off using a steerer cutting guide and nice blade. The OD of the carbon seat tube is probably narrow though so you might need to find a shim of some sort anyways.

I personally wouldn’t hesitate to clamp on the carbon tube, lots of makers use carbon seat tubes and clamp the topper without a reinforcing like the sV uses.

[krooj]

Originally Posted by Cloudofheaven

Has anyone have experience cutting the seatmast on a Speedvagen in order to lower the saddle height? I recently purchased a used Speedvagen Superlight and it is on the way shipping over to me. It has a carbon seat tube, and unfortunately the minimum saddle height on it will be too high for me. I have short legs and long torso and arms. The saddle height built for the bike is 75.5cm whereas my preferred saddle height is 69.8cm with a 155m crankset. Link to details regarding the bike below.

https://r.tapatalk.com/shareLink/top...ink_source=app

I reached out to Speedvagen, however I haven’t heard back. I believe they are still transitioning into a new space and reorganizing their company so I’m not sure when I will get a response. I’m hoping there is someone out there that has experience cutting or shortening the seatmast on a Speedvagen and if they can help guide me.

You kinda lucked out with this, since it's a carbon ST. You could have the right carbon person make that cut and bond an appropriate replacement for that stainless sleeve.

[Peter P.]

Originally Posted by crankles

One issue you're going to encounter is having enough of the stainless sleeve left to clamp the enve topper.

THIS.

Originally Posted by David Kirk

I think you are in a very tough place. I can't say with certainty but I seriously doubt the carbon seat mast was not designed to deal with the clamping force from the seat topper. So even if you somehow manage to get enough Coke can in there it's all too possible that when you tighten the topper it will compromise the fibers.

I doubt this is what you want to hear but I think you should sell this frameset and wait for one that will allow for the proper saddle high without the stainless top being cut off.

dave

I'm with Dave on this. The wall thickness, and the O.D. of the tube, may not have been designed for what the OP wants to do.

Originally Posted by Kyle h

Honestly, if there’s no SS part left, I think I’d just cut it off using a steerer cutting guide and nice blade. The OD of the carbon seat tube is probably narrow though so you might need to find a shim of some sort anyways.

I personally wouldn’t hesitate to clamp on the carbon tube, lots of makers use carbon seat tubes and clamp the topper without a reinforcing like the sV uses.

Speedvagen likely machines that sleeve to a specific diameter, bot I.D. and O.D., not something easily replicated.

If the O.P. is lucky and Speedvagen eventually responds, maybe they can retrofit a new metal sleeve. I think that's the best outcome if not, as Dave Kirk recommends, sell the frame.

[Hilltopperny]

Originally Posted by Peter P.

THIS.







I'm with Dave on this. The wall thickness, and the O.D. of the tube, may not have been designed for what the OP wants to do.







Speedvagen likely machines that sleeve to a specific diameter, bot I.D. and O.D., not something easily replicated.



If the O.P. is lucky and Speedvagen eventually responds, maybe they can retrofit a new metal sleeve. I think that's the best outcome if not, as Dave Kirk recommends, sell the frame.

The stainless sleeve is paper thin. The carbon seat tube is the same diameter as the carbon seat tubes used by many others who don't use a sleeve at all.

The saddle height I had with the frameset was 74cm to the top of the saddle. A 4-5cm cut to the carbon still allows a good amount of mast and a machined cap should not be an issue.

Fwiw my LBS would have cut it with a guide and saw blade without issue. He has 25 years experience, used to assemble the early No22 bicycles whom use carbon with no sleeve on their bikes. He does have a metal lathe, so if necessary could make a sleeve or cap.

Rob English and others also make custom caps for seat mast equipped bikes as well.


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[pdonk]

Easy enough to measure the ID of the topper and the OD of the seat tube and send the numbers to a machine shop and see what they would charge for turning a tube down for you. I'd expect the shop minimum or maybe try a service like sendcutsend or emachine shop.

An out there idea may be a simple 3d printed delrin or other strong plastic bushing to bond onto the seattube.

[Cloudofheaven]

I appreciate the feedback and advice from everyone. I’m deciding to hold onto the bike until Speedvagen responds back, hopefully within this year. Luckily, I have other bikes in the stable to ride in the meantime.

I will post Speedvagen’s response once I receive it in case there is anyone out there who is in the same situation as I am.