Recumbent - 700c Versus 650c

I am converting my Optima Lynxx over from its current 20" front/26" rear to either dual 26" or dual 700c. Is there any reason I shouldn't go for the 700c? The frame will take the clearance, I can make some adjustments to seat and shock, and we think we can get the rear breaks to work.

Does anyone know the pros/cons of each choice? No one in my province that I know has any expertise in this area, and the nearest 'bent shop is 7 hours away, so my LBS will order what I ask for.

I like the 700c option, as I have fast race wheels already, and like the ability to swap with my DF bike. I am worried about what I don't know about why most 'bents don't seem to have the dual 700c option.

700c wheels will put your seat higher, but OTOH the selection of nice tires is incomparably better. You can choose from almost any brand, racing, training, touring, commuting, etc... and any width from 18-38mm. You can load up on good tires when you find sales, too.

650c tires max out at 23mm. Oh, and 'on sale?' What's that? But the seat can be lower.

700c wheels will put your seat higher, but OTOH the selection of nice tires is incomparably better. You can choose from almost any brand, racing, training, touring, commuting, etc... and any width from 18-38mm. You can load up on good tires when you find sales, too.

650c tires max out at 23mm. Oh, and 'on sale?' What's that? But the seat can be lower.

I have 25mm 650C tires. And 28mm tires are plentiful.

I am converting my Optima Lynxx over from its current 20" front/26" rear to either dual 26" or dual 700c. Is there any reason I shouldn't go for the 700c? The frame will take the clearance, I can make some adjustments to seat and shock, and we think we can get the rear breaks to work.

Does anyone know the pros/cons of each choice? No one in my province that I know has any expertise in this area, and the nearest 'bent shop is 7 hours away, so my LBS will order what I ask for.

I like the 700c option, as I have fast race wheels already, and like the ability to swap with my DF bike. I am worried about what I don't know about why most 'bents don't seem to have the dual 700c option.


I like you already had a set of 700c wheels so I did the I conversion to my Strada from a 26" to the 700c.. I had too make several changes like a new front fork and new rear brakes, but well worth the money. You will find a greater selection in the tire market and the differences that I've found has been, an easyer crusing speed and a higher top end speed and I believe just an all around better ride. The down side, if there is one is in climbing ability. Unlike a road bike you only have the one position on your bent so if you do alot of climbing it's could be alittle more difficult with the 700c. As for myself I really like the conversion and I'd never go back.

Is there likely a handling different between the two sizes? My only other worry, which a couple of you have already noted, is the change in seat height. I THINK I will be able to touch the ground. I guess I can swap a 700c on just to size and see...

Sounds like I will be going 700c after all. Hmmm... it will bump up my BB height a pile, but I want that... more speed!
Thanks for the help.

Seat height will be in the 24" range after the change. Based on my recent experience riding a Bacchetta Aero with 650c wheels two comments: If you are short, under 5'8" or 173cm you will have to sit up to touch the ground with your feet, at least to some degree. You might reach the ground with tiptoes but balance will be precarious unless you sit up. Second, short boom extensions and larger wheels may result in shoe strike on the tire in slow speed turns. I repeatedly hit the tires while tooling around in a parking lot getting used to the ride. In ordinary riding there is little liklihood of heel strike, but 90 degree or more turns at low speeds produced heel strike on the tire every time. If you are taller this is less likely.

Is there likely a handling different between the two sizes? My only other worry, which a couple of you have already noted, is the change in seat height. I THINK I will be able to touch the ground. I guess I can swap a 700c on just to size and see...

Sounds like I will be going 700c after all. Hmmm... it will bump up my BB height a pile, but I want that... more speed!
Thanks for the help.

I found there to be little or know difference in the handling of my Strada with the 700c wheels. I'm 5'11 so the difference in seat height was not a problem it was only a couple of inches.
People try and make it sound like such a drastic change and it's really not, the only thing I can tell you for sure is the performance of the bike is three times better with the 700c than the stock wheels and it's more enjoyable too ride. ( I'll never go back ):D

I have 25mm 650C tires. And 28mm tires are plentiful.

I based that comment on the fact I've never seen a 25x571 or a 28x571 in a catalog or a shop. But they could easily be obtainable by special order and I'd never know it. Or maybe I've just been in the wrong catalogs/shops? Anyway, now that I've been corrected, I'll have to look harder next time! I bet there's more 25x571 choices than there are for 25x507 road tires!

I based that comment on the fact I've never seen a 25x571 or a 28x571 in a catalog or a shop. But they could easily be obtainable by special order and I'd never know it. Or maybe I've just been in the wrong catalogs/shops? Anyway, now that I've been corrected, I'll have to look harder next time! I bet there's more 25x571 choices than there are for 25x507 road tires!

I thought Bontrager was the last manufacturer still making 25-571 tires, but I see Harris Cyclery has 25-571 in Continental at a fraction of the price of the Bontragers.

http://www.sheldonbrown.com/harris/tires/571.html


Panaracer (my 25-571 brand) and IRC discontinued that size about 4-5 years ago, but there is still IRC old stock around if you look hard enough or watch ebay a lot.

Terry is another maker of 28-571 tires, I believe there are a few other 28-571 tires.

25-520 tires are common, Panaracer still makes that size. Probably not any 25-507 tires out there.