I went to my local bike store today but it was very busy and I didn't want to take up their time.

At the moment I'm biking on a 54 cm frame with 28" wheels. A bike that I'm considering (that would be purchased online through my dealer) comes in only two sizes 51 and 60 (or 61 cm), but comes with 29" wheels.

Would a 51 cm frame with 29" wheels be comparable to a 54 cm frame with 28" wheels?

What do you want to compare? I think the short answer has to be "no, they are not comparable", but I'm not sure what you want to compare. Everything from the bottom bracket height above ground to the top tube length will likely be different (if the bikes are different models/styles), but it is impossible to answer without more detail.

Also, what types of bikes (old and new) are we talking?

Go back to the bike shop. They'll be glad to help you pick the right size. While you're there buy a bike from them -- not an online retailer.

The bike in question, if I buy it, would be bought through the bike shop though they would order it online. I'm looking at a Koga Signature with that Pinion 18 speed gear box that is mounted where the front derailleur would be located ... between the pedals. The frame of course is tailored to accommodate the Pinion though the frames are only offered in two sizes.

Koga Signature - Koga Signature... Fiets op Maat

The bike in question would be new. It's pricey ... and I'm just thinking about it. If more frame sizes were offered (from Koga to accommodate the Pinion) I would probably go with something in the neighborhood of 54 cm.

I'll stop by the dealer during the week when he's not less busy.

I believe that the only difference between 28" and 29" wheels is the size of the actual tire on the rim. Isn't 28" a Euro designation for what Americans call a fat 700c? (of course, we made the 29" size over here - just a fatter 700c!)

The difference in height due to the wheel size is really not that much. Something on the order of 10mm change for standover height is all. I had some 700x37 tires on my 29er mountain bike for the last several weeks because I was riding on dirt roads and didn't need the big knobbies. It feels the same fit wise with either set.

Jumping from 51cm to 60cm seems a HUGE change, maybe look at other manufacturers who make a better range of sizes

"Size"= seat tube length .. steeply sloping Top Tube can actually be quite tall in the front.


Sutherlands has 28" a 635, & 642 also calling them 700A, &700B

so using the ETRTO standard numbers is clearer, again

New 29er is the smaller 622 rim. 700C ..

Jumping from 51cm to 60cm, to me, suggests they sold the sizes in between and have yet to restock them on the sales floor ..

Jumping from 51cm to 60cm, to me, suggests they sold the sizes in between and have yet to restock them on the sales floor ..

I don't think that's the case. At that site you build your own bike within the constraints imposed by their choices. They only show two sizes and only for one frame that can be used with that Pinion. Maybe they will offer more in the future.

I've spent time at that site last year and if a particular frame was not available, you could still 'create' the bike you wanted though you would have to wait for the specific frame to arrive. I wanted a brushed aluminum frame for a specific bike I 'created' online, but they couldn't supply it. After months of delays I order the bike I'm presently using.

Oh this is More Pining for a Pinion .. tout terrain in germany looked into? Metropolitan XploreS





Seems Rohloff lists a lot of small builders that design around their Hubs,

a call or writing to Pinion may get a list of custom Builders around Europe .

gonna burn thru a big pile of Euros? might as well get a built to size custom frame.

Bob, at that site they only show two sizes of frames ... M or L. I'm curious to see how all this plays out over the next few years.