T50 with a Thor seat

[rx7mark]

Hi Everyone, just thought I would give you an update on my T50. I recently mounted a large GS Easy Thor seat. I chose the glass fiber version, which Greg recommended due to my weight, it is rated for 100kg. With shipping and a standard Ventitist cushion it was under $200, but took almost 6 weeks to arrive from Poland. It was well packaged and arrived in perfect condition.

My goal was to not only improve the seat comfort but to move the seat back a little and lower the seat bottom a little in order to improve the seat bottom to bottom bracket relationship. I am 6'2", have a 34 inch inseam and a 45.5 in X-seam and the original seat in the most rear position left the bottom bracket fairly low relative to the seat bottom. You can see the improvement if you compare the old picture to the new one. The new picture also has the Soma Gator bar on it I installed earlier

To mount the seat I reused the lower seat mount, but cut off the aft portion of the bracket with the swing link, and then reversed the bracket so what was the forward part of the bracket mounts to the aft frame mount position. See the picture. I used rubber blocks ala Rick Youngblood method, with 1/2 inch thick at all bolts except the lower aft seat mount bolts, where I had to use one inch rubber in order to get the seat angle correct.

The hardware is all 1/4 x 20 stainless pan head bolts with fender washers and self locking nuts.

For the aft mount I had to fabricate a new bracket as the stock bracket was too wide, and if I shimmed enough to clear the Thor seat rail it would put a big moment arm on the bracket mounts. So the new bracket was hand hammer formed from .125 thick aluminum plate. I also had to cut the seat struts down quite a bit to mount to the new bracket and get an appropriate seat angle.

And last I had to change my stem to move the handle bar farther aft to match the new seat location. I also added rubber trim around the edge of the seat for protection from nicks and dings. The final addition was a Bent cycle aero bag. This has worked great, it has two bottle holders, one I use for a water bottle the other gets my tool kit. The bag has enough room for all my other items required for commuting, and just stays on the bike all the time.

Let me know if anyone has any questions.

Mark

 

[cpml123]

Very impressive!

 

[rx7mark]

Here are a couple more pictures of the bracket fabrication. Basically I made a cardboard template, then transferred that to the aluminum, then I used an old 2x4 and a rasp to add big radii and bolted the aluminum sheet to the 2x4, then used a big hammer, you can see it on the bench, to bend the flanges. And then last of all a hack saw to cut it out, and a fine file to break the sharp edges. In the last picture you can see the rubber mounting blocks, about 1/2 inch thick.



Mark

 

[ak-tux]

Very nice!

Now you should try the @Emeljay steering mod and you will have a super setup!
https://cruzbike.com/forum/threads/qx100-steering-mod.10853/

 

[rx7mark]

Funny you should mention the Emeljay mod, I have started collecting parts for the conversion already. I did not want to make 2 big changes at the same time, so the seat came first.

Mark

 

[psm0115]

I am new to the Cruzbike family. Recently purchased an S40. Love the bike and adjusted to the nuances of riding a Cruzbike quite well. I've been on a Catrike Expedition for the past 5 years. My only issue with the S40 is seat comfort. My lower back is not doing well after longer rides with this stock seat. Any thoughts on a Thor seat or Volae for the s40?

 

[ak-tux]

I am new to the Cruzbike family. Recently purchased an S40. Love the bike and adjusted to the nuances of riding a Cruzbike quite well. I've been on a Catrike Expedition for the past 5 years. My only issue with the S40 is seat comfort. My lower back is not doing well after longer rides with this stock seat. Any thoughts on a Thor seat or Volae for the s40?

Check out these two threads showing Doug Kline's S40 with a Thor seat:
build: https://cruzbike.com/forum/threads/s40-build-notes.11777/
and
Seat notes: https://cruzbike.com/forum/threads/s40-thor-seat-modification.12080/#post-141005

 

[psm0115]

Thanks for the links. This looks like the answer for me.

 

[Frank Costantini]

I am new to the Cruzbike family. Recently purchased an S40. Love the bike and adjusted to the nuances of riding a Cruzbike quite well. I've been on a Catrike Expedition for the past 5 years. My only issue with the S40 is seat comfort. My lower back is not doing well after longer rides with this stock seat. Any thoughts on a Thor seat or Volae for the s40?

If lower back pain is the issue, there is a simpler/cheaper solution. I made a lumbar support out of minicell foam, that fits under the Ventisit (or standard) seat cushion, on the stock S40 seat. The attached photo shows one on my T50, but I have a similar one on my S40, and it works well. Just use Velcro tape to attach it.

 

[rx7mark]

I have back problems also, and tried to add foam and sculped the stock seat, but could not get it to a point that was comfortable for more than 20-25 miles.

So I decided to try the Thor seat after reading all the posts. Solved my issues completely, I have done 40 mile plus rides now with no issues and confident I could do a century ride now, which is my goal.

The glass fiber version, Ventitist pad, and shipping was only $200. Worth trying, in my opinion, as it has worked for many of us with back problems.

As you can tell, I am now a Thor fan, and would order a new one the moment I decided to order a new bike.

Mark

 

[Brad R]

If you order a Thor, you might want to measure your back and compare to the seat dimensions.

I am on the small end of the height listed for a large, so I bought a large. I think I would probably fit better on a medium.

Also, while others seem to love the lumbar bulge, I find it more prominent than I really want. I am working on fine tuning the cushions.

 

[psm0115]

Thanks for all the insight. Heading to the website to look at the Thor seats.

 

[dtseng]

I am 5'6" and have a medium sport G Thor seat. I feel it is a bit too short for me. I should heed ratz's recommendation order one size larger.

 

[rx7mark]

I'm 6'2" and on the hi end of the large size, or small end of the X-large, and went with the large per Greg's recommendation. It fits great. I also love the lumbar support, but that is probably just my back issues. YMMV

Mark

 

[ak-tux]

Thanks for all the insight. Heading to the website to look at the Thor seats.

Sorry to hijack this thread, but if you are good at DIY and have some wood tools, time and patience you can make one for yourself and, if on a budget, save some money.

I made one using a jigsaw powertool, plywood and some fibreglass. It weighs about 1.3Kg (Thor fibreglass seat weighs about 1.2Kg). I've built three of them (for myself and my cycling buddies) and improved the weight with each build.

Interestingly enough, without the fibreglass overlay the wooden seat alone weighed only about 800 grams! It was strong, but however, it was not tough enough when I accidentally dropped it, the edges cracked. The fibreglass is necessary if using thin 3-ply plywood as I did. In the future I will try thicker wood strips without fibreglass (or using only very thin fibreglass cloth ).

I sketched a template on a paper cardboard using Thor seat size measurements from Thor website. I was also guided by my old steel seat. The result was a custom shape that is supper comfortable for me.

It's basically two pieces of 7-ply plywood as the ribs/cradle with strips of 3-ply plywood as top glued and screwed together. I then covered it with fibreglass for reinforcement and water proofing. If I had used epoxy resin it would have been even lighter, but I only had access to polyester resin which is locally used here for automobile repairs.


Edit: I have put the details on a seperate thread here: https://cruzbike.com/forum/threads/custom-wood-strip-composite-seat.12398/

 

[yangmusa]

I made one using a jigsaw powertool, plywood and some fibreglass. It weighs about 1.3Kg (Thor fibreglass seat weighs about 1.2Kg).

Wow, that's really nicely done! The structure reminds me of the seat on my old Challenge Hurricane - Challenge seats were aluminum, but similar in concept, and certainly comfy.

I tried looking at your old threads, but as far as I can see there's no write up about the seat. I bet a lot of others would be curious to see more pics/description of the build too!

 

[cpml123]

Sorry to hijack this thread, but if you are good at DIY and have some wood tools, time and patience you can make one for yourself and, if on a budget, save some money.

I made one using a jigsaw powertool, plywood and some fibreglass. It weighs about 1.3Kg (Thor fibreglass seat weighs about 1.2Kg). I've built three of them (for myself and my cycling buddies) and improved the weight with each build.

Interestingly enough, without the fibreglass overlay the wooden seat alone weighed only about 800 grams! It was strong, but however, it was not tough enough when I accidentally dropped it, the edges cracked. The fibreglass is necessary if using thin 3-ply plywood as I did. In the future I will try thicker wood strips without fibreglass (or using only very thin fibreglass cloth ).

I sketched a template on a paper cardboard using Thor seat size measurements from Thor website. I was also guided by my old steel seat. The result was a custom shape that is supper comfortable for me.

It's basically two pieces of 7-ply plywood as the ribs/cradle with strips of 3-ply plywood as top glued and screwed together. I then covered it with fibreglass for reinforcement and water proofing. If I had used epoxy resin it would have been even lighter, but I only had access to polyester resin which is locally used here for automobile repairs.
View attachment 6758 View attachment 6759

Very impressive!

 

[psm0115]

Sorry to hijack this thread, but if you are good at DIY and have some wood tools, time and patience you can make one for yourself and, if on a budget, save some money.

I made one using a jigsaw powertool, plywood and some fibreglass. It weighs about 1.3Kg (Thor fibreglass seat weighs about 1.2Kg). I've built three of them (for myself and my cycling buddies) and improved the weight with each build.

Interestingly enough, without the fibreglass overlay the wooden seat alone weighed only about 800 grams! It was strong, but however, it was not tough enough when I accidentally dropped it, the edges cracked. The fibreglass is necessary if using thin 3-ply plywood as I did. In the future I will try thicker wood strips without fibreglass (or using only very thin fibreglass cloth ).

I sketched a template on a paper cardboard using Thor seat size measurements from Thor website. I was also guided by my old steel seat. The result was a custom shape that is supper comfortable for me.

It's basically two pieces of 7-ply plywood as the ribs/cradle with strips of 3-ply plywood as top glued and screwed together. I then covered it with fibreglass for reinforcement and water proofing. If I had used epoxy resin it would have been even lighter, but I only had access to polyester resin which is locally used here for automobile repairs.
View attachment 6758 View attachment 6759

Sorry to hijack this thread, but if you are good at DIY and have some wood tools, time and patience you can make one for yourself and, if on a budget, save some money.

I made one using a jigsaw powertool, plywood and some fibreglass. It weighs about 1.3Kg (Thor fibreglass seat weighs about 1.2Kg). I've built three of them (for myself and my cycling buddies) and improved the weight with each build.

Interestingly enough, without the fibreglass overlay the wooden seat alone weighed only about 800 grams! It was strong, but however, it was not tough enough when I accidentally dropped it, the edges cracked. The fibreglass is necessary if using thin 3-ply plywood as I did. In the future I will try thicker wood strips without fibreglass (or using only very thin fibreglass cloth ).

I sketched a template on a paper cardboard using Thor seat size measurements from Thor website. I was also guided by my old steel seat. The result was a custom shape that is supper comfortable for me.

It's basically two pieces of 7-ply plywood as the ribs/cradle with strips of 3-ply plywood as top glued and screwed together. I then covered it with fibreglass for reinforcement and water proofing. If I had used epoxy resin it would have been even lighter, but I only had access to polyester resin which is locally used here for automobile repairs.
View attachment 6758 View attachment 6759

Verry cool. Do I have tools !! I’m a cabinet maker and stair builder. Never thought of this as an option. I could make this quite easily in my shop. Thanks for your post.

 

[psm0115]

If lower back pain is the issue, there is a simpler/cheaper solution. I made a lumbar support out of minicell foam, that fits under the Ventisit (or standard) seat cushion, on the stock S40 seat. The attached photo shows one on my T50, but I have a similar one on my S40, and it works well. Just use Velcro tape to attach it.

Thanks for the picture. I bought a yoga mat, cut three section out of it to laminate together. Trimmed them to the shape of the stock S40 seat and added the lumbar support you suggested. I will upload pics tomorrow. Anyway, rode 60 miles today with this new configuration. Must say it was my first ride where my back didn’t hurt. Very exciting. Thanks again for sharing your modifications.

 

[Frank Costantini]

Glad to hear that helps.