650b conversion

[stephenmarklay]

I was thinking about a wheelset for my cheapo SS. I did some quick measurements and it looks like a 47-48 might just work.

The bike came with a 700 x 32 tire. I think I would have to push back the wheel a bit in the dropouts to get good clearance but I think it would fit.

The bike has a mid reach brake but I think I might need more.

Any thoughts on doing this?

[stien]

Having recently done it the cheap way, I would spend more money on the wheelset (like Pacenti) or just live with 700c. I went back my tricross with 700x47c slicks. The ride quality was there but man the cheap 650b wheel sets on eBay are boat anchors.

[marciero]

Originally Posted by stephenmarklay

I was thinking about a wheelset for my cheapo SS. I did some quick measurements and it looks like a 47-48 might just work.

The bike came with a 700 x 32 tire. I think I would have to push back the wheel a bit in the dropouts to get good clearance but I think it would fit.

The bike has a mid reach brake but I think I might need more.

Any thoughts on doing this?

The bead seat diameter (BSD) for 650b is 584 vs 622 for 7700c. So a 38mm difference, or 19mm difference in the radius. Do you have 19mm of adjustment (in the right direction) in the slots for the pads on your brakes? If so you might be able to get away with it. In most cases you would need to go with longer reach. One consideration is that the braking performance is going to deteriorate as pads are lowered, however they get lowered.

[AngryScientist]

there are a few threads floating around about it, but it's a worthwhile experiment that can breathe new life into some cool frames. as above, you need to determine if you can get brakes that will work.

Here's mine, converted from a nice old Allez that had clearance for about 700x24 max, but swallows some nice plump 650's.

check out this excellent resource page for lots more info:

https://www.bikeman.com/bikeman-blog...sion-guidlines

[azrider]

Are you converting the CSI ??

Lots of info on here about 650b conversions.........first link below was mine. It was lot of fun. Found cheap bombproof wheelset on fleabay and had to buy longer brakes. My Ironman only fit 28's so i'm sure the bike you're mentioning will have plenty o' room.

Good luck !


https://forums.thepaceline.net/showt...ght=dave+scott

http://www.bikeman.com/bikeman-blogs...sion-guidlines

https://forums.thepaceline.net/showt...ght=dave+scott

[stephenmarklay]

Originally Posted by marciero

The bead seat diameter (BSD) for 650b is 584 vs 622 for 7700c. So a 38mm difference, or 19mm difference in the radius. Do you have 19mm of adjustment (in the right direction) in the slots for the pads on your brakes? If so you might be able to get away with it. In most cases you would need to go with longer reach. One consideration is that the braking performance is going to deteriorate as pads are lowered, however they get lowered.

Thank you and I thought of that. I would need longer. I also thought of the degradation but with the super cheap breaks and wheels without any brake track the braking is meh already I will probably improve with better equipment.

[stephenmarklay]

Originally Posted by azrider

Are you converting the CSI ??

Lots of info on here about 650b conversions.........first link below was mine. It was lot of fun. Found cheap bombproof wheelset on fleabay and had to buy longer brakes. My Ironman only fit 28's so i'm sure the bike you're mentioning will have plenty o' room.

Good luck !


https://forums.thepaceline.net/showt...ght=dave+scott

http://www.bikeman.com/bikeman-blogs...sion-guidlines

https://forums.thepaceline.net/showt...ght=dave+scott

Thank you so much! No just a cheap single speed

[stephenmarklay]

Originally Posted by stien

Having recently done it the cheap way, I would spend more money on the wheelset (like Pacenti) or just live with 700c. I went back my tricross with 700x47c slicks. The ride quality was there but man the cheap 650b wheel sets on eBay are boat anchors.

For sure. I want to get a nicer lighter set than stock.

[Ed-B]

I just bought another set of the prebuilt 650B wheels on ebay from seller "uglyrm". Rims are Zac19 and the hubs are Shimano 10speed RS300 series. Laced 36 holes, and drilled for Shraeder valves.

https://www.ebay.com/itm/BIKE-650B-W...72.m2749.l2649

The rear weighs 1139 gr and the front 911, weighed without the included skewers but with my rim tape applied.

The wheels were tight and relatively true out of the box, but they needed to be stress relieved and fine tuned. Dishing was perfect. The rear hub axle was a little tight, which probably came from Shimano that way. I'm going to insert the valve adapters for presta tubes.

https://www.ebay.com/itm/WHEELS-MANU...72.m2749.l2649

For the money these are pretty good wheels, and certainly right for a "cheapo SS" conversion, or a test the waters kind of 650B conversion. This is the 2nd set of wheels in this configuration that I've bought from this seller, and the other set was of equal component and build quality.

I think you'll have to pay a lot more than what these cost to buy or build lighter and better wheels. And these would be a good 2nd set even if you decide to do that, too. That's my opinion, FWIW.

Ed

[stephenmarklay]

I read through a couple of articles…

On BB height, this bike is a track/commuter but spec’d with a 60mm BB drop. So from what I understand this is fine and allows some flexibility on tire size as a bit smaller diameter would be fine. That is not bad as I may opt to go smaller with something middling like a 42. Not sure on that.

[marciero]

Regarding BB drop, a lot of older production bikes had high bottom brackets (so less drop) to lessen the potential of pedal strike. This was essentially a safety issue, like lawyer tabs on forks. If you are not racing criteriums (or mountain biking and maybe gnarly gravel) most of us dont need to worry about that. We stop pedaling when cornering aggressively. I've found the lowering of the frame resulting from putting 650b on a 700c bike to be a good thing.

[AngryScientist]

Originally Posted by marciero

We stop pedaling when cornering aggressively.

as long as he isnt running it fixed gear and can stop pedaling, i agree.

[marciero]

Originally Posted by AngryScientist

as long as he isnt running it fixed gear and can stop pedaling, i agree.

Had forgotten to consider! My fixed-gear days are over but I've had one or two "WHOOOPS!" back in the day

[stephenmarklay]

Cool and thanks guys. I do think this bike will be a fun 650b conversion.