2021 Q45 Seat Angle

[rfneep]

That's pretty much what I was thinking for a crude fit check. To avoid too much stress, it would likely require a fishmouth transition on the spacer tubes to match the curvature of the large tube. Even then, this could be chockful of stress risers and may not be strong enough without reinforcement or thick walls on the tube, and/or a thick cross tube. Also, I'd look closely at whether a straight tube would give too much seat tilt. It's pretty far from the present steer tube. So anything one tries is at your own risk!

I do not recommend actually trying anything without some more thinking. Maybe it's time to find a local frame builder /shop who can whip up something...

 

[Rampa]

An interesting challenge. What about mounting an adjustable stem to the straight tube? Then remove the stem faceplate and you have a nice set of four bolt holes where you can bolt it to your seat back.

Is the seat post a compatible diameter for a stem?

 

[PeterZ]

benphyr writes:
Thank you Robert and Cruzbike for (as we have come to expect)
...
I couldn't have said it better. I'd add
7. for your continuing efforts to improve and make things right

It would be wonderful if the things we try to do worked out fully right all the time, but since they often don't, let me say
Your responses to and handling of this issue are, in my experience, rare and delightful (and are what I had hoped they would be). Thank you.

I also want to add that I've not been involved at all with this online community for the last 12 years of my Cruzbike riding - mostly (despite all my time & effort & dreams 35+ years ago to help establish a well functioning internet online) because I've chosen to focus on other things which have pulled me far away from the internet.
That's a shame, really, because this forum - that is to say y'all - seem a wonderful bunch of people and are a great resource to have.
Keep on!

Be Happy!

 

[Robert Holler]

Thanks all! The kind words are much appreciated.

Also if it is taking a bit longer to get back to inquiries and issues - know that over 70 bikes went out to people in less than a week, and we are getting more inquiries than ever before - all around many supply chain issues due to covid. Luckily we have great relationships with all of our manufacturing peeps and we can remain fluid to get things done.

I also want everyone to know for this bike in particular - yes indeed the specs online were a bit wrong listing the 30 degrees. The old seat tube allowed for that much adjustment. The new tube went a bit too far - but again - the reality is that very very few people can get much more reclined on this seat past about 40 degrees without it being uncomfortable for their backs.

The seat is not tall enough for a headrest, so that eliminates most reclines past about 40 degrees IMHO. So just because it can adjust to 30 doesn't mean its usable. In recumbents in general there can be a lot of ranges but within that range is almost always a smaller "usable" range - on both ends of the spectrum.

I have had people ask for a seat that is closer to 80 degrees like a dining room chair - and have actually put one that steep for someone to test. It's not a rideable potion on any day of the week - so just because it could go there didn't mean it should.

I do like the idea of a straight tube with another adjustable section as opposed to a bent tube. So that can go into the drawing board for the future. The seat post is indeed a 31.4 standard size. Currently getting tubing alone is a challenge.

Right now the bike industry is getting hammered in EVERY direction. Raw material availability. Component availability. Shipping companies are REALLY taking advantage of the Covid situation (shipping prices have tripled in 4 months and there is NO end in sight.) The US dollar is slipping a LOT to the Yuan and NTD - so that makes everything cost more... this will not change in the short term y'all - so get used to shortages of everything from tubes to chains and everything in between and all of it taking much longer than normal. If you have spare parts - they are gold. If you need spares for this season and don't want to get stuck not able to find tires/tubes/etc - get them NOW.

Just to paint the picture for you - I am having to switch up the chains for next batches of bikes because the chain we use right now is currently on a 500 day wait list. Thats five hundred days. And other parts like levers/calipers/hubs..even grips... all are in various stages of months long backlogs.

 

[billyk]

An interesting challenge. What about mounting an adjustable stem to the straight tube? Then remove the stem faceplate and you have a nice set of four bolt holes where you can bolt it to your seat back.

Is the seat post a compatible diameter for a stem?

Nice thinking outside the box. Good idea! (Even if it might not work in this case)

 

[PeterZ]

Right now the bike industry is getting hammered in EVERY direction. ... get used to shortages of everything from tubes to chains and everything in between and all of it taking much longer than normal. If you have spare parts - they are gold. If you need spares for this season and don't want to get stuck not able to find tires/tubes/etc - get them NOW.


Robert you’re scaring me (as I suppose you meant to).
I knew things were funky, but not that bad - 500 days for chains!

So - I’m thinking (as you said) I should quickly order a few parts that need to be periodically replaced so I have them on hand.
Chains, tires, tubes and brake pads. Cables? Anything else anyone can think of?

Which begs the questions -
• Is the chain you’d recommend the SRAM PC1130/70, NX Eagle)? A generic 11 speed? Whatever one can get?
• What are the brake pads to use? Size (best) or model #? (Tektro seems to have 2 models of brake in the same line, and which ones did you use as the pads are different?

Another question:
I realize that 30°- 40° recline will need a headrest, and I expect to fiddle with making one.
Would the current S40 headrest be relatively easy to modifiy for the Q45 (I don’t have one to look at) or would it be better to start from scratch?

Thank you for the heads up

Be Happy!

 

[Rampa]

Nice thinking outside the box. Good idea! (Even if it might not work in this case)

Yeah. That would require a 28.6 seat post diameter for the stem to clamp to. But the frame needs a 31.4. But bit of aluminum tubing replacing the post, and a shim to fit the 28.6 tube in the frame, might work pretty well.

 

[Mrnelson]

Thanks all! The kind words are much appreciated.

Also if it is taking a bit longer to get back to inquiries and issues - know that over 70 bikes went out to people in less than a week, and we are getting more inquiries than ever before - all around many supply chain issues due to covid. Luckily we have great relationships with all of our manufacturing peeps and we can remain fluid to get things done.

I also want everyone to know for this bike in particular - yes indeed the specs online were a bit wrong listing the 30 degrees. The old seat tube allowed for that much adjustment. The new tube went a bit too far - but again - the reality is that very very few people can get much more reclined on this seat past about 40 degrees without it being uncomfortable for their backs.

The seat is not tall enough for a headrest, so that eliminates most reclines past about 40 degrees IMHO. So just because it can adjust to 30 doesn't mean its usable. In recumbents in general there can be a lot of ranges but within that range is almost always a smaller "usable" range - on both ends of the spectrum.

I have had people ask for a seat that is closer to 80 degrees like a dining room chair - and have actually put one that steep for someone to test. It's not a rideable potion on any day of the week - so just because it could go there didn't mean it should.

I do like the idea of a straight tube with another adjustable section as opposed to a bent tube. So that can go into the drawing board for the future. The seat post is indeed a 31.4 standard size. Currently getting tubing alone is a challenge.

Right now the bike industry is getting hammered in EVERY direction. Raw material availability. Component availability. Shipping companies are REALLY taking advantage of the Covid situation (shipping prices have tripled in 4 months and there is NO end in sight.) The US dollar is slipping a LOT to the Yuan and NTD - so that makes everything cost more... this will not change in the short term y'all - so get used to shortages of everything from tubes to chains and everything in between and all of it taking much longer than normal. If you have spare parts - they are gold. If you need spares for this season and don't want to get stuck not able to find tires/tubes/etc - get them NOW.

Just to paint the picture for you - I am having to switch up the chains for next batches of bikes because the chain we use right now is currently on a 500 day wait list. Thats five hundred days. And other parts like levers/calipers/hubs..even grips... all are in various stages of months long backlogs.

Thanks for this, it is very helpful and appreciated.

 

[Robert Holler]

Which begs the questions -
• Is the chain you’d recommend the SRAM PC1130/70, NX Eagle)? A generic 11 speed? Whatever one can get?
• What are the brake pads to use? Size (best) or model #? (Tektro seems to have 2 models of brake in the same line, and which ones did you use as the pads are different?

Really any SRAM/KMC/FSA 11 speed chain is good. I would steer clear of Shimano chain with the SRAM gear we use.
We had Avids on the last batch, but for this one had to change brands. For pads I like sintered pads - the stocks or KoolStop are good.

I think that there will be small parts at shops - some may dry - its getting larger QTY for manufacturing that is hardest for sure.

Another question:
I realize that 30°- 40° recline will need a headrest, and I expect to fiddle with making one.
Would the current S40 headrest be relatively easy to modifiy for the Q45 (I don’t have one to look at) or would it be better to start from scratch?

The headrests we have I think will all be too short to be effective with the stock Q45 seat.


Thank you for the heads up

 

[benphyr]

The stock seat does not go up to the top of the shoulders. For me (5’8”) it ends between the shoulder blades at the top of the vertical central portions. I don’t have any issues riding with a pretty low seat angle without a headrest but it is important to note that I started with a higher seat angle when I first was learning and slowly lowered the seat back incrementally as I learned the position, handling, strengthened the position, etc.

There are several examples of headrests fitted or made for Q model Cruzbikes.

Here’s one: https://forum.cruzbike.com/threads/diy-headrest-for-q45.12323/#post-161231

 

[rfneep]

So I decided to cobble up a simple seat post that demonstrates what one can do while waiting for CB to source some new design. I used only readily available parts that require no complex machining , welding, etc. The main tube is Aluminum with a 1-1/8 in diameter and 1/8 in thick wall. A 1/16-in shim is needed to fix it into the main frame. The other end uses a surplus stem I had laying around that connects to the main tube and holds a cross-member to attach to the regular seat mount hardware. The cross member consists of two 1-3/4 long, 1/2 in diameter #10 screw spacers. These are fixed in the stem with a 1/2-in to 1- in Aluminum adapter. The latter was made by cutting a short length of Al tubing with 1 in OD and 1/2 in ID.

This simple seat post replacement can access very low seat angle if one mounts the stem backwards. With the stem facing to the front like a normal seat post, it also allows more angle adjustment in the region where the original seat post is limiting. The first picture shown has a seat angle of about 32 degrees from horizontal. It was limited only by my unwillingness to bend the seat angle more.

This is crude and was tried just as a proof of principle. It could of course be much nicer if I had access to a machine shop, but the pandemic doesn't allow that.

Anyway, this or some similar approach could be pursued in the near term by those who really want extreme seat angles on the new Q45, or just more seat angle flexibility than afforded by the present stock seat post. I would add the caveat that one should err on the side of caution and make sure all parts used are at least as robust as the original seat tube. Don't use tubes that are too thin or shims that are too short!

Enjoy

Ray

 

[benphyr]

@rfneep For some reason I get “you do not have permission to view media in this folder” when I click on the link.

 

[rfneep]

I think it is fixed now. Holler if not.

Thanks

Ray

 

[Tortue]

Great job Ray!
I think I'll dust off the TIG and order some stock from Online Metals.
I'm envisioning a straight tube of the same diameter as the stock bent unit, with a hole drilled near the top to accept a welded cross tube whose inner diameter is just a few thousandths larger than the skewer.
Hell, JB weld would keep the cross tube from sliding left or right.
Simple, right?

 

[Donald Harter]

Getting acclimated to my first recumbent and Cruzbike. Just getting the basics down, riding on city streets and some modest hills. Reading about the redesigned Q-45 seat post; I moved my seat pan to the forward position and mounted the seat back directly to the seat post. The U-bracket replaced with 6 brass washers as spacers. This gives about 4" of seat tube insertion into the frame which seems more solid. Seat angle, guessing about 50 degrees now. Very comfortable and greater spacing to the bars which I appreciate at 6' tall. Much better control. For my use, the new seatpost is just fine. Eliminating the bracket cleans up the seat back area.

 

[benphyr]

So I decided to cobble up a simple seat post...

Thank you for going all the way from suggestion, fabricating, testing, writing up and providing pictures for a solution!

On a separate note. Your Q45 looks somewhat similar in fit to your S30 now (and S40 previously). I know they are completely different machines but what are the differences when set up with similar seat angle from someone who rides both? Ride, handling, twitchy, road surface felt by back, bum, ...

 

[rfneep]

Great job Ray!
I think I'll dust off the TIG and order some stock from Online Metals.
I'm envisioning a straight tube of the same diameter as the stock bent unit, with a hole drilled near the top to accept a welded cross tube whose inner diameter is just a few thousandths larger than the skewer.
Hell, JB weld would keep the cross tube from sliding left or right.
Simple, right?

That was the approach I was considering but do not have access to welding capability. Without a strong weld, I'd worry about failure of the cross beam through the relatively thin-walled main tube. Seems like a recipe for a stress riser that would be repeatedly worked with a good fraction of the body weight bouncing up and down on it. I wouldn't trust it, even with JB weld. Hence, I just grabbed a robust stem for the joint in this test. It weighs a bit more but is very strong. I used a 1-1/8 inch diameter main rod to match the stems I have laying around. You can use a 1-1/4 in rod to match the frame but a stem with a 1-1/4 steerer clamp is a little harder to come by. There are some solutions available through AliExpress, though.

I'm sure there are lots of solutions for this....

 

[Tortue]

One of my projects...

Steel 40', home built from scratch.
Yeah, there are lots of ways to skin a cat...
I know a few.

 

[benphyr]

Wow

 

[rfneep]

That almost looks as complex as a seat post. Ha! Impressive...