seagrade 

Many thanks, that’s very useful. I grew up on Suntour and Campagnolo but always liked the grey Dura Ace 7402 aero levers, which seem to be SLR. Not cheap and nor are the replacement hoods if eBay is anything to go by, but I’ll start looking.

Presumably the key point is whether or not the levers are SLR rather than whether the cables are exposed or not?

The frame is 1997 and I’d prefer not to run exposed brake cables on this particular bicycle - even if it’s a Reparto Corse frame converted to 650b…

ehcoplex 

Some Kool-Stop pads might be a cheap thing to try first and see if/how they improve braking (unless those are KS pads on the calipers already....!).

Piff 

No, unfortunately there is a whole range of 'SLR' brakes with varying ratios but look very similar. The 7402 should have the high ratio pull. Indeed pricey though, before purchasing I would first do some more research on setting up centerpull brakes and how to improve brake power. I always felt I had enough braking power using my vintage Gran Compe 610 brakes.

mountaindave 

Occasionally some levers even turn up on eBay with white hoods (the height of late 80’ fashion!). Unless they are cracked or torn, they typically can be rehabilitated. NOS replacement hoods even turn up from time to time.

I prefer tricolor SLR’s, but that’s merely for aesthetic, not functional reasons. I believe they are all aero style.

RiddleOfSteel

I recently scored a lovely 650B rim brake wheelset as I've batted the idea around more than once in my head. I've briefly tested a different (and very nice) 650B wheelset out for myself thanks to a forum member, but ever since, have had a lonely set of (very cheaply, Bike Works-sourced) Compass 650x42 extra lights waiting more road riding duty. 2nd generation/later Pacenti SL23 rims laced to Shimano 105 hubs. Look sharp, nice weight, and at 50 PSI give or take, measure out to 38mm or so. Maybe more now that they've been inflated for a bit. EL-spec Compass/RH tires do tend to stretch. I have a few bikes that I'd thought were potential candidates, regardless of my views of 650B wheels on huge frames (as in, they don't look that great, and look much better on a 56cm frame). So, for future reference for those of you seeing this now or for those in the future, I wanted to post!

Firstly is a first-year 1983 Cannondale ST300 frame (ST500 as a complete bike). Acres of vertical room and good lateral room between the fork blades. Rear wheel at the seat stays is also quite accommodating. The chain stays, while allowing tire rotation, are super tight. 700x32mm with fenders are tight but doable. The question is if the change to 650x38s is worth it? Fender room is epic, but to comfortably clear 38-42mm 650B tires, those chain stays would have to be modified, and I am ignorant of doing so on a post-heat-treated aluminum frame.






The next candidate was my 1980 Trek 510. While the big toobs of the Cannondale proportion out well enough to the voluminous all-black Compass tires, the standard-diameter steel tubes, IMO, do not. [this looks a bit worse in person] Tan wall 650B tires plus fenders would be the way to go. If not, as previously stated, this all being on a smaller frame. Like the Cannondale, fork clearance is great, seat stay clearance is also capacious, and again like the Canndale, chain stay clearance is tight. The benefit here, as we know, is that dimpling steel chain stays is a non-issue. And since this 510 is geometrically identical to its contemporary 710 and 910 brethren, consider them as equally viable options.

seagrade 

Near four hours on the 650b-ianchi today in cool gusty conditions over hilly terrain. Rides remarkably similar to how it did with 700c wheels and 25/28mm tyres. The 650b Conti GP5000 S TR tyres with tubes set up nice and round on Velocity Quill rims, unlike some older Contis which seem taller with a thick and narrow tread cap. They ride and corner well.

Closer examination indicated the stock GC610 pads on,y look like Kool Stop, but are darker as well as older and drier/harder, so that’s the first avenue of refinement for the underwhelming centrepulls.

ehcoplex 

Alas, no- aluminum can’t be safely dimpled/altered. Go with the Trek.

gugie 

^^^this^^^

RiddleOfSteel

...after heat treating, that is what I thought, but I left that statement open-ended just in case someone had done or knew about a reliable-yet-easy-enough way of doing so that didn't compromise the metal. The Cannondale will run 700x35s anyway, so in fenderless form, there's no loss from not being able to go 650B. The Trek frame looks outmatched for all the black rim + tire visual mass, but yes, it can have its chain stays dimpled and that would make it an instant fenders-with-ease bike. Too bad about the Cannondale--vertical dropouts are nice. At least with the Trek, I could mount the fenders well below the inner arch of the caliper brakes, thus, finally, allowing me to have a caliper and fender relationship that 1) doesn't have them clacking upon use of brakes and 2) finally would allow the complete opening of the calipers (via QR lever) to facilitate easy tire removal (when inflated), which has been more or less my White Whale in that realm. Caliper brakes for the ease of setup, braking effort, and effective stopping power, versus, say, canti.

mountaindave 

Agreed. If one does fenders on a bike like the 510, things start to look a lot more normal, as my 710’s can attest (links in my sig in desktop version).

I also like nothing smaller than 38mm on a 700c to 650b conversion, or things will look weird on a large frame (I ride 60-62 cm). See my Bridgestone - it has 38mm tires without fenders and I think it looks ok. And it rides wonderfully.

RiddleOfSteel

You know, guys, I can't keep all my vintage Treks...

Sure, I have my purple 510 up locally, but I still think it's just a cool color, fading and all. Definitely needs tan wall tires regardless. I at least have fenders that should work...

mountaindave 

I can send you my shipping address.

RiddleOfSteel

All we'll have to do is arrange payment!

seagrade 

Braking vastly improved by new Kool Stop all salmon pads.

hellojoben

Whoa this thing looks awesome. How are the GP5000s? Are those the 32's? I was wondering how wide they'd end up being on the quills.

seagrade 

Cheers thanks. Yes, GP5000 32s. They are about 31mm wide on the Quill rims. Much like GP5000 28s on H Plus Son TB14s a millimetre or so narrower than the label. Pretty tight fit with a Conti or Ritchey, I forget which, plastic rim strip but better with two layers of Kapton tape instead and on the reinstallation after a few days at 80psi…

The 32s are a very round tyre on the rim and provide confidence-inspiring grip as a result. The transparent skinwall versions seem a shade slower than blackwall, although that could be heavier tubes. The 650b-ianchi will probably accept 35s, it won’t take 38s, but I should wear out the 32s and some Rivendell 33.3s in stock as well first…

jPrichard10 

I haven't posted near enough photos ogugie doctored Competition. Doesn't 'ook like this anymore, so I'll have to update the photos soon.

non-fixie 

When I noticed a while ago that I could buy a simple but complete new 650B wheelset for about $60, I decided I wanted to give these wheels a try and see what all the fuss is about. Ordered a pair of Pari-Moto's as well and dug out my Vista Islena Covid-19 lockdown build to serve as a test mule.

ehcoplex 

Test-build of my '79 Raleigh Competition G.S. 650b conversion. Cyclone mechs & Campy crankset borrowed from my Holdsworth Pro that is waiting to be painted, wheels (V-O hubs & rims) borrowed from my Trek 400t conversion. 1 RAID, 1 Vainqueur caliper, Nitto rando bars, Tektro levers from the parts bin. Chain stays crimped (or is it 'dimpled'.....?) to (just) fit 42c tires. I'm either going to crimp a bit more, or go with 38c. Plan is to build up another set of 650b wheels with the original Campy GS hubs & Soma Weymouth rims, use a 49d crankset I've got as either a compact double or 1/2-step + granny triple, and see if I can make the original GS mechs work (maybe with a long cage from Soma). Fenders at some point, too. Ride is fantastic.

non-fixie 

Nice build!

WRT the ride: I am still not sure. With a lower pressure the ride over cobbles and such is very nice indeed, but on smooth tarmac it all feels a bit, erm, cumbersome. I have been experimenting with different tire pressure levels, but haven't found the sweet spot yet.

And, I have run into another potential problem. Over time the tires seem to have grown in width, and are now approaching the chain stays. The vertical drop-outs are not helping either. Not rubbing yet, but ...



I need to find me another frame ...

bulgie 

OK if you want, but indenting this one some more is an option. It's actually easier to increase an existing indent, because the tool naturally aligns with the valley.
Or you could use smaller tires. The Pari-Moto is a nominal 38 mm, right? Maybe try a Hutchinson Confrérie des 650, or a Grand Bois Cyprès. Pari-Moto also came in wider sizes, I wanna say 42 and/or 48 mm (check me on that), so if you have those, then you just need the 38 mm P-M or some other tire that wide.

Another frame might be the most fun way though. Early-70s PX-10 or lots of similar vintage French bikes with the factory-indented 531 stays comfortably fit 42 mm tires with no extra indenting needed.
Builders from any other country could have used those same stays, but not many did, I mostly see them on Frenchies. My '58 Follis for example, full 531 DB racer, intended for 28" sew-ups, but is quite happy with 650x42b (GB Hetre).

Aubergine 

Not a PX 10, but a lowly AO-8 frame with good parts. I'm running 42mm Herse tires. It's a delight to ride.

ehcoplex 

Yup, it's tricky indenting 'round' stays- helps to have several trigger clamps on hand to hold all the elements in place until the indenting 'slug' starts to bite!

Amen- a '72 or earlier PX-10 is an easy peasy conversion.

non-fixie 

The tires are 42mm. Going smaller would be an option, but now I've got those wheels I really want the full Jan H. experience.

And, as you say, it is a fun opportunity to try yet another frame. I don't have an early 70's PX-10, but a search in my attic yielded this former parts donor. Originally sold as a touring bike by Frederick W. Rushbrooke's hardware emporium 'Halfords', it was probably made in Belgium by Superia, as it sports the 'R.C.' tube set.



Bonderized tubes:



Much better clearance: