Position for long distance riding
 

Hi there. I would need some help with a fit question, regarding long distance riding.


I want to return to brevet riding, but with small wheeled bikes. Love the way they ride, and the lack of storing space needs and ease of transportation were also nice. I got a Brompton (I'm actually thinking about doing the brevets with the english mistress), and I got a fairly weird Giant Mini 2 which I would love to build for that.


I built the bike, but something always felt wrong. Then, after riding my Brompton (which I used a lot together with a 700c wheeled bike and never got a problem) and then the Giant I saw the deal: the saddle position is just a LOT different. Stupidly behind. Even with a seat back post turned FORWARD, still a lot behind what I used to hide. I usually start with KOPS and then work from that. Comparing my Brompton and my Giant, the Giant is still behind like 3 cm.


Measuring with an mobile app, the seatpost angle is 68 degrees, in a hardtail bike. I need to get a lot of seatpost to get proper heigth (a whole 410mm on the "max" line). I searched a bit, and this kind of seatpost angle was used in old (really old) racing bikes, but with those 7 shaped seatposts, which moves the saddle forward to a proper racing position.

https://cimg6.ibsrv.net/gimg/bikefor...805124b2ce.jpg



So, the question is: I really don't need a racing position. My best Brevet (not in time, but in fun and confort) was 300km made in a 26" mtb, with unlocked suspension, 1.95 slick tires and a single 32 tooth chainring. I don't want to go fast, but I want to go painless (as much as possible :P ). Will this laid back position mess with my knees after a day of riding? By the way, I will be using flat pedals, so my feet can move at will. Should I ditch the Giant (use it just for urban riding) and use the Brompton, or even a Dahon for Brevet (would mess with the Dahon position a lot, without care for the maximum foldability. It would be almost a mini velo)? A Dahon with proper handlebar positioning (with a stem to move if forwards) and my Kojaks would just fly!


By the way, a "proper" bike is completely out of question.


Thanks for any ideas, and also sorry for any english mistakes. Not a native speaker....

You definitely need an upright position for that. The seat angle has rotated your hip to crank position back. There is a minimum hip angle that humans can tolerate. If you have problems with your butt, then this is going to make those worse because very little weight will be on your hands. But your hands should be pretty happy.

I know you posted on fit and posture, but I am curious, have you given serious consideration to how low your gearing will be with small wheels? The photo looks like a standard road double.

I have no idea what will work for you. But i do know that a small wheel bike changes the lowers the center of gravity and that is the BIG reason it feels comfortable and stable. However the small wheels must rotate at a higher rpm for any given speed - this costs you efficiency as well as shock resistance in the long run.

Good luck.

Recumbent.

I'm pretty sure all the things discussed above can be adjusted to where you want them.

Gearing shouldn't be a problem. chain rings up to 53t are everywhere, up to 62t only a little more challenging. if you were happy on an MTB with a 32t, I don't anticipate any issue you can't fix.

Small wheels rotate faster. We all get that. But does effiency suffer from this? I really doubt it.

So to your question, I'm sure you will find a way to get the saddle farther forward. Some saddles have longer rails than others-- you should look for one that can be cantilevered forward more. Doing thus you may risk breaking the rails-- but it's still worth a try. Some seat posts have more setback than others-- you should find one with zero setback. I realize you need a very long one, which will narrow your choices, but BMX riders use some pretty long posts, so you may find something.

Note also, shorter crank arms will help bring the pedals under your knees a little bit too. Putting a fat tire in the rear and a skinny one on front will make a difference as well-- but that's the last thing I'd try.

One way or another I'm confident you can get comfortable. One of my bikes is from the WW2 era and it has the 68⁰ seat tube you mentioned. i have the traditional saddle clamp, separate from the straight post, with the clamp in front of the post (whereas behind the post is more usual). this compensates for the frame geometry nicely. I don't know whether that's an option for you, but again, worth a try. You may even be able to use your existing seat post backwards.

I don't know what the right position for you is, but if you're looking to move your seat forward, there are seatposts especially for triathlong bikes that have forward-set clamps. Nitto made an interesting one, Profile Designs makes one, and Redshift Sports makes a "convertible" seatpost that flips between a conventional road position and a forward triathlon position. Not sure if any of these reach 410 mm extension.

Also make sure that whatever seatpost you get has the right diameter.

missionary

Now that winter has arrived I will be doing a lot of riding on the DL-1 with 66 degree seat angle. Saddle clamp behind the post. Putting the clamp in front completely changes character of bike, I just like the way back feel.

When used for local trips there is no problem. Longer rides reliably cause knee issues. It will be behind the knee and more in the tendons than in bone. There is never any acute pain, it sneaks up. Noticed first while walking, not while riding. Then one day stand out of saddle and sit back down real quick. Not because of pain, because it feels like nothing is supporting weight. Finish the ride entirely sitting in saddle.

It always heals fairly quickly. This would be with daily rides of twenty miles (enough in winter on a DL-1) and occasional fifty mile rides. Would not even dream of attempting 300k with the 66 degree seat angle.

The ancients did not all reverse the seatpost. Somewhat more recently Steve Bauer raced Paris-Roubaix and a couple other early season races on a 62 degree bike. Then did the remainder of his last pro season on 67 degrees. All with seatpost in the normal position. That episode was an extreme outlier, still shows that it is not impossible. I would not try it.

Small wheel comfort is even more dependent on tires than it is with big wheels. The Giant looks like ISO 406? There are lots and lots of high performance tires in the BMX world. It is a different world, takes some time to find your way around. The old standby has been the Panaracer HP406. Fast, comfortable, reliable, even lightweight. Wife has them on her Raleigh Twenty, bigger change than any of the other mods.

DL-1, are you talking about the vintage Raleigh with cottered crank and rod brakes that has been around for over a century?

Yes. Mine has been modified with canti brakes as they stay in adjustment. And stop the bike. And are pounds lighter. Initially had cotterless but have gone back to cottered.

Most of the year an errand bike. In winter the balance and stability on wet roads is just wonderful. Have slid out a few times on black ice and managed to recover. In some situations where others are falling the DL-1 does not even notice. Riding two or three mph slower means it is warmer. Maintenance is vastly simplified and the old bike seems to take anything in stride. In olden days many did ride long tours on these, don’t think I could.

I don't think there will necessarily be any physical issues with the set back position. KOPS really has nothing to do with knee comfort. However the issue I see is the extreme unweighting of the front wheel when in the saddle. Maybe that's OK, but it looks a bit scary to me. I'm assuming that the photo is your bike, set up for you.

With your butt that far back, I'd be sure to do daily floor stretches, stretching back, hams, glutes, calves. But with your bars at saddle height, I don't see an issue with hip angle. You'll be in a normal moderate road position, just rotated counterclockwise when looking at the photo. It's true that many randonneurs ride with bars level with saddle and seat much more forward, but there are also randos who ride with bars much lower than seat, thus with about your hip angle. You're going to lose power climbing in the saddle with weight that far back, one of the reasons for the proportions of the standard road bike.

the photo does not look too orthopedic, and it seems to me that for long distances it will not be very stable. There will be a lot of fatigue, which will take away the attention from the rider.