ak-tux
Zen MBB Master
It practically is equivalent to the last S30s with a rigid frontend.
Theoritically, It should be a very fast bike! I wouldn't mind having it
.A Silvio 2.0 with an S40 frontend triangle would be super!
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An S40 update 350 miles in
- Thread starter Greg S
- Start date
Theoritically, It should be a very fast bike! I wouldn't mind having it
.A Silvio 2.0 with an S40 frontend triangle would be super!
Bill Wightman
Well-Known Member
BikeGary
Well-Known Member
Initially I was going to swap out my 165 cranks for 170's but so far I've been happy with the 165's. The issue for me is not smacking the handlebars with my knees at the top of the stroke. I have long legs and arms and a shorter torso, so pulling the handlebars back more makes me feel more trapped in the seat with less ability to do slow speed turns. I also ran into a guy with even shorter crank arms, custom made for his DF. He measured his heart rate on a local very steep hill and was able to climb it faster with less effort by spinning slightly faster.
I have 175's on my DF and like them. As standing up I feel like I have more power for steep climbs. That's not how I climb hills on my S30. Spin and spin faster seems to be the way to go.
I have 175's on my DF and like them. As standing up I feel like I have more power for steep climbs. That's not how I climb hills on my S30. Spin and spin faster seems to be the way to go.
@BikeGary I ended up changing the cranks back to 165's (as I said, I'm an inveterate tweaker). After a couple of days riding with the 175's I began to get a bit of soreness in one knee so I thought it'd be wise to go back. I still use 175's on my DF though, as I always have.
I've also been gradually bringing the bars back closer as I felt like I was reaching a bit. I noticed on a ride that my shoulders were forward from my chest somewhat when riding normally as they would be if you were reaching out for something. I now have a comfortable bend in both arms with my shoulders straight. I'm "normally" proportioned (if there is such a thing) i.e., no abnormally long or short arms/legs/torso so I've been able to get the S40 to fit me pretty well although I'm no longer running the stock bars as noted previously.
One thing I've been wondering about (perhaps worthy of its own thread) is longer chain stays. I've done a search here on the forum and have found a number of threads where people have changed their chain stays (usually to longer ones) but I've not seen any sort of analysis as to why you'd want to and what the trade-offs might be. It's fairly obvious that for a given leg length that longer chain stays would result in the cranks being higher relative to your body but I don't know enough about recumbent geometry to understand why or even if that'd be a good thing. Anyone care to fill me in or point me to a thread with all the answers?
I've also been gradually bringing the bars back closer as I felt like I was reaching a bit. I noticed on a ride that my shoulders were forward from my chest somewhat when riding normally as they would be if you were reaching out for something. I now have a comfortable bend in both arms with my shoulders straight. I'm "normally" proportioned (if there is such a thing) i.e., no abnormally long or short arms/legs/torso so I've been able to get the S40 to fit me pretty well although I'm no longer running the stock bars as noted previously.
One thing I've been wondering about (perhaps worthy of its own thread) is longer chain stays. I've done a search here on the forum and have found a number of threads where people have changed their chain stays (usually to longer ones) but I've not seen any sort of analysis as to why you'd want to and what the trade-offs might be. It's fairly obvious that for a given leg length that longer chain stays would result in the cranks being higher relative to your body but I don't know enough about recumbent geometry to understand why or even if that'd be a good thing. Anyone care to fill me in or point me to a thread with all the answers?
BikeGary
Well-Known Member
@Greg S I had the stock chainstays on my S30. I fell twice, once due to a catastrophic tube failure on the front tire, and once hitting a patch of sand. Both at speed and each time I went down hard on my side. (first the right, then the left) each time I twisted my ankle pretty bad. I attribute it to having my foot low to the ground such that it caught the pavement and was wrenched back and dragged.
I have since added a 100cm extension that I got directly from Cruzbike. This has moved my feet higher in the air. I'm hoping, although I have not tested it, that IF I fall again that my feet will be up and above the point of impact. I expect nasty road rash, but not twisted ankles.
While I have not had this as an issue, I have read that having your feet above your hips is generally not a good idea on a bike where you are still somewhat upright. Ie, you could lie flat on your back with your feet up, but then you'd have issues with too much blood in your head. The article mentioned that people sometimes have hip pain if their feet are too high. While I don't have a lot of miles on the extended chainstay (less than 100) I haven't had any issues in my hips.
Again I have not tested this, but if feels like I should be more aerodynamic with my feet higher than before as more of my body is in a direct line. But I ride with a flag, and don't go out of my way to wear drag reducing clothing etc.
I have since added a 100cm extension that I got directly from Cruzbike. This has moved my feet higher in the air. I'm hoping, although I have not tested it, that IF I fall again that my feet will be up and above the point of impact. I expect nasty road rash, but not twisted ankles.
While I have not had this as an issue, I have read that having your feet above your hips is generally not a good idea on a bike where you are still somewhat upright. Ie, you could lie flat on your back with your feet up, but then you'd have issues with too much blood in your head. The article mentioned that people sometimes have hip pain if their feet are too high. While I don't have a lot of miles on the extended chainstay (less than 100) I haven't had any issues in my hips.
Again I have not tested this, but if feels like I should be more aerodynamic with my feet higher than before as more of my body is in a direct line. But I ride with a flag, and don't go out of my way to wear drag reducing clothing etc.
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3bs
whereabouts unknown
@Bill Wightman i am lucky to be able to do a lot of art forms. stuff for other people i do as gifts mostly. i have sold some stuff, but for the most part ars artis non gratia. and i too view tinkering, carpentry, and fabricating art. i don't have a lot of free time, so projects of all types pile up. my bike and trike projects alone would take months to complete. its value to my sanity is substantial.
frame painting has become more prevalent in recent years long a go it was just pinstriping and detail work. there was some good fade work done in the 80's, but in the last 10 years there has been some beautiful stuff. likewise a lot of the modern bespoke work.
frame painting has become more prevalent in recent years long a go it was just pinstriping and detail work. there was some good fade work done in the 80's, but in the last 10 years there has been some beautiful stuff. likewise a lot of the modern bespoke work.
super slim
Zen MBB Master
3bs
whereabouts unknown
@super slim, i think bill was complementing my speckle job on my v20, as that is the only one i have ever posted. when you come to Michigan you will see it in person. i have no idea if i will have the fade job i have in mind for the t50 done by then.
BikeGary
Well-Known Member
@Greg S One other thing to note about longer chainstays. With my S30 and the 100cm extension, I now have to use 1 and 1/3 chains when I replace them. It's a slight extra cost, and to prevent manufacturers changing the link pattern on me, I buy 4 chains at a time for 3 chain swaps. Which of course means I have to be more organized with my storage of spare parts so that when the time comes, so I can find those chains.
velocio
Austrian roadside steckerlfisch (fish on a stick)
3bs,
Casn you give the full name of the "710"? I'm not a "truck guy" and just spent a fair bit of time Googling for that thing. I'm officially smitten with that "710" -- well maybe it's more lust, since my attraction is based solely on looks. Is it road legal or something one would use around their farm or industrial site?
velocio
Austrian roadside steckerlfisch (fish on a stick)
I didn't see this mentioned previously in this thread, but if it was and I missed it my apologies... Another thing to note about using a longer chainstay is that the BB will need to rotate upwards to accommodate the same leg length. Due to the well known teeter-tooter effect (well known to 2'nd graders and those of us with child-like minds) when the BB swings up the handlebars will swing down. To keep the bars in the same position you may need to lengthen the fork steerer, which is not easy, or purchase the curved slider (https://cruzbike.com/collections/all-products/products/curved-slider). Unfortunately the curved slider comes in only one curve, so it may or may not address the problem adequately in any particular fit situation.
I do wish that the clamp that ties the slider to the fork steerer had more vertical extension, so one could leave some spacers on the steerer above the clamp when cutting the steerer to an individual's proper length. A little adjustability here that doesn't involve non-reversible cutting of the fork steerer would be really helpful in fitting. As things are now if I buy shoes with thinner soles the BB rotates up slightly and the bars rotate down slightly, with no way to keep the bars in that carefully considered Goldilocks position that determined the initial steerer length. As with most things engineering, the devil is in the details ...
Cheers,
-Jack
paco1961
Zen MBB Master
On my S40 I run a standard chain stay (the one that ships with a new purchase), 48/34 up front and 11-36 on the rear. I order a 120-link Sram chain and don't need to splice any extra links into the line. Nice to be able to just open up a new chain and slap it on - and not have to worry about changing link patterns . . . or having to be more organized than my genetics allow.
So besides the reason given by @BikeGary (pedal not digging into the ground in a crash with resulting ankle trauma) why would you want to go to longer (or shorter) chainstays? As noted here, it obviously raises the cranks for a given leg length and as @velocio mentioned also lowers the bars but these are side effects once you've decided to change the chainstay length.
So why change them?
Obviously there's a design center that Cruzbike was targeting in terms of rider height, leg length, etc., and I'm sure the goal was to give riders in that center the best performance and ride possible. But what are the trade-offs if you're outside that center? Are there other reasons to change them besides performance (comfort, etc)?
Not really thinking of changing mine (though I do think I'm a few standard deviations away from the "average" rider in terms of height) but would like to understand the tradeoffs in doing so.
Thanks for educating me!
So why change them?
Obviously there's a design center that Cruzbike was targeting in terms of rider height, leg length, etc., and I'm sure the goal was to give riders in that center the best performance and ride possible. But what are the trade-offs if you're outside that center? Are there other reasons to change them besides performance (comfort, etc)?
Not really thinking of changing mine (though I do think I'm a few standard deviations away from the "average" rider in terms of height) but would like to understand the tradeoffs in doing so.
Thanks for educating me!
3bs
whereabouts unknown
@velocio street legal and famous world wide steyr pinzgauer 710m that is a mid 70's gas model
Austrian made by same company that makes the G wagon. arguably the greatest 4wd ever made. air cooled in line 4 gas, locking front rear and middle diff. metric one ton capacity. portal axles so great ground clearance on small tires. a little under 6 foot wide and and under 7 feet tall, great trail truck. l learned about them as a teenager in the 70's and dreamed of owning one. i started collecting them in the 1990's when the 25 year rule let you bring them into the states. many different models and configs. 4x4 and 6x6. also related is the halflinger which was a metric halfton a true predecessor to all of these side by sides around now. much more practical than the full size unimogs.
here is a picture of that old truck (we used to call it barney) on top of wise mountain in colorado. just a little over 12,000 feet elevation.
Austrian made by same company that makes the G wagon. arguably the greatest 4wd ever made. air cooled in line 4 gas, locking front rear and middle diff. metric one ton capacity. portal axles so great ground clearance on small tires. a little under 6 foot wide and and under 7 feet tall, great trail truck. l learned about them as a teenager in the 70's and dreamed of owning one. i started collecting them in the 1990's when the 25 year rule let you bring them into the states. many different models and configs. 4x4 and 6x6. also related is the halflinger which was a metric halfton a true predecessor to all of these side by sides around now. much more practical than the full size unimogs.
here is a picture of that old truck (we used to call it barney) on top of wise mountain in colorado. just a little over 12,000 feet elevation.
Attachments
velocio
Austrian roadside steckerlfisch (fish on a stick)
I just swapped the stock medium chainstay for a short on my S40 and the improvement in fit is dramatic. Last time I checked I was at about the 40'th percentile height for U.S. adult humans, but apparently the S40's one-size-fits-some frame was targeting a much taller subgroup of the population. With the stock medium chainstay installed the chainstay was oriented not all that far off from vertical in order to shorten up the "reach" to the pedals adequately. This results in the BB being as far from the ground as possible for us untall folks, but also the height of the BB above the seatpan was at a maximum and far from ideal. The BB swinging up for those with shorter leg length is exactly opposite of what you'd like to see in a recumbent design. I had a similar, but much worse, issue with my Bacchetta Giro, where the shorter a rider's legs are the further the seat climbs the stick frame "ramp", resulting in short legged folks having the highest seat. At least in that design adjusting the seat for shorter legged folks also reduces the seatpan to BB height delta.
With the chainstay swap my handlebars are now, maybe, 3" higher than before. I can cut the fork steerer down to try to compensate, but then the steerer is cut forever and there's no going back if I change my mind, change my shoes or the bike needs to fit a slightly taller rider. I'm pondering a DF bike stem extender such as the following to try out bar positions prior to hacking off the steerer: https://www.ebay.com/itm/Adjustable...er-Accessory-LJ/303133161812?var=602065934561 Something like that seems to offer a lot more fit options without irreversible steerer chopping or purchase of a $120 curved slider that offers a single option of a new position.
-Jack
benphyr
Guru-me-not
With the fore/aft movement of the slider + the rotational -2" to +2" or so that should allow for pretty good dealing in ability! I believe there are other similar devices that allow attaching without sliding onto the handlebar. i.e. They have two bolts per bar that they clamp to so you can take both halves completely apart so you don't have to remove bar tape/grip, cables, etc. slide them all the way up the bar.
Don't forget about fork spacers as an option too.
Don't forget about fork spacers as an option too.
Rods
Member
I used a fork stem extender on my V20 for this exact problem. It has worked very well. I didn't need the full length of the extender, so it was cut off. Much easier experimenting with a $12 extender!
velocio
Austrian roadside steckerlfisch (fish on a stick)
What is a fork spacer?
The curved slider should allow a good range of height adjustment (as mentioned by Benphyr, fore/aft movement of the slider + the rotational -2" to +2" of flipping the slider), but this height adjustment is coupled to the the reach adjustment. Set the height properly and it would only be by luck that the reach to the bars is what you would have chosen otherwise. I'm glad the curved slider is available as a fit aid and I may be ordering one in the near future, but I wish there was a Cruzbike approved way of decoupling the bar reach and height adjustments.
-Jack
