hello. greeting to everyone.
a minute old newbie, and my very first post here.

ok. to make a long story short:

interested in building one with carbon drive system (GateŽ?), using a vintage frame namely an 80-90's steel road frame. one thing bothering me is that the carbon drive belt needs a split or an open end in the triangle as it only comes as a closed loop.

if i have somewhere on the seat stay like near the dropout cut and re-welded, would it significantly risk/harm rigidity of the frame?

it will be used for a light city cruising, and i am 5'08"" tall, weigh around 125lbs.

please re-direct me if this is not the right place ie) custom forum etc — to ask such a question as well.
many thanks in advance for your kind insights/inputs.

orangeology/nyc

S and S makes some couplers for small diameter tubes,(down to 5/8")
as well as for main triangle tubes.
a frame builder that does retrofits can fix your bike,
and has the account with S and S for the parts.
https://www.sandsmachine.com/

has a current builders list.. many .

Bike Friday has made an opening with a hand shake like pair
of machined steel pieces that bolt to each other .

a straight forward job for a small machine shop,
doesn't even have to be a frame builder.
seek out a local machine shop.

many many thanks for the useful infos and insights, fietsbob.
awesome.
using couplers seems definitely a nice option than just re-welding, as it's scalable for future repair/upgrade.
S&S couplers do seem to come up with smaller diameters, although they mainly suggest doing on the big tubes for the original purpose -- packable bike.

for the carbon drive sys idea, it can be applied on both seat stay and the chain stay, i guess.
so excited. my next assignment is looking for a machine shop!!!

For a belt drive setup, it is generally on necessary to place an S&S coupler on the seatstay, this maintains the original rigidity of the chainstay but allows the belt to be installed by gently flexing the seatstay. Good luck!

Cheers
lverhagen

Another German builder to open the rear triangle, has the dropout plate 1/2 as thick, in each part

1 piece has the chainstay tube attached to it, the other piece the seat stay tube .
1 small machine screw , and the axle nut/QR clamp the 2 together.

I think Paragon Machine offers a sliding dropout /frame end and
then you also get the tensioning right.
https://www.paragonmachineworks.com/c...&category=BA06

thanks, iverhagen!
you mean, just one open end on seat stay will do the job by being flexible, correct?

and thanks again, fietsbob.
paragon machine ones are indeed attractive as well.

so glad there are some neat options.

don't know how long it is going to take but i will definitely post the result when done.
still shopping the frame, as a matter of fact.

orangeology, nyc

consider a Bike Friday Tikkit, they offer the bike made up with the belt drive.
Shimano IGH As an option..
folds up, and you can take it in with you to not be stolen off the NYC streets.

I wouldn't consider this if I didn't already have a frame I had my heart set on.

Much better to get hold of a purpose-built frame than go down this road, IMO... at the very least, you avoid the hassle of repainting.

Orange, there is a framebuilder's forum here.

Rob English's belt-drive winter bike uses a split double dropout as described above.
https://www.englishcycles.com/bikepics/rob/winter5.jpg

FWIW: Rob's day job is building frames at Bike Friday.

again, thanks for all the valuable inputs, folks.
this forum is great!


guess i am leaning toward the paragonmachineworks one.
relatively cheap and easy to order, most of all. seems easy to apply at a local welding shop if i am not mistaken?

S&S couplers: can't retail order and none of the listed builders are nearby.

orangeology