himespau 

So I have a frame that I'm trying to build up for my wife. I don't happen to have the frame on me because a nice member has it in an oxalic acid bath.

When it comes back, I was wondering where do I measure (or does it depend on the brake) to know how wide of tires I can fit in there and whether or not fenders will fit?

Is there one set place I should measure?

Before anyone suggests just throwing something in and trying it, all the wheels we have currently at the house are 26" and this frame was built for 27" wheels (though I'll be building a 700c wheelset for it).

I'm hoping to fit 32-38 mm tires and some fenders in there, but would like to know how to tell before I go wasting money on something that won't work.

The frame is a Fuji Gran Tourer SE mixte (probably from '80 or '81) if that makes any difference at all in where/how to measure or if someone has one and knows what will fit there.

I got the frame with some unbranded centerpull brakes that according to the previous seller had enough reach to do either 27" or 700c. I was planning on replacing them with some new sidepulls as they're rather beat up if there is an affordable option. Is there a good way of telling how much "reach" they have so I know what I should be looking for? At least, I see "reach" as the measurement listed on a lot of brakes, so I'm assuming that's what I need to know.

fietsbob

That Mixte, ? 559/26" is too small
More probably.. Yes, go to 622-32 .. wide range of tire choices then.
those center-pulls if the bushings in the pivot are un broken, should clean up nicely.
I'd leave the rear one at least. good leverage, so not much hand strength required.
And there is not going to be any arm sticking out to rub the leg against.

Dia Compe, Weinmann both made decent center pulls for them, back then.
yours may be that, just the label is missing.

You might find a dual pivot side pull for the fork. longer reach of course. Tektro
sells thousands, so should be easy to find a suitible one.
Ex GF , 30 years ago had a Mixte like that, branding different ,
but pretty much same.
Mudguards are just what you Do in Oregon

32 tire is probably sufficient, fit the mudguards on and if there is a desire,
next tire change buy wider If you choose., or let Her Choose, since it will be
Her bike.

... some people have used 650B wheels on 27" conversions,
the rim is Much larger than 26" ...

corynardin

There are several areas to measure for wider tires.

1) Chain stays
2) Seat stays
3) Brake clearance
4) Fork clearance

And while this will not likely be a problem for you, the overall diameter of the wheel (with tire installed) will get larger with a wider tire. This of course is not going to be a problem for you since you are going to a smaller rim. My guess would be that 38 would be too wide and wouldn't leave much clearance. I don't use fenders and have never dealt with them (and I am from Portland originally), although they really are a great idea. Sorry I can't offer any help on that.

Best of luck.

DCB0

I have found 'most' of the 27" -> 700c conversions I have seen will fit at least 35 mm wide tires with fenders... remember that 1-1/4 inches (the most common 27" tire width) is approximately 32mm, and 700c wheels will add some clearance as a result of the smaller diameter moving the tires 4mm away from the brake and chainstay bridges, and indirectly as the tire will likely be slightly closer to the axle where the stays are alittle bit wider.

FWIW, I am currently trying to sort out some tire clearance issues with my 27" -> 700c conversion and I am just a couple mm from fitting a 700 X 40C studded tire on the front with a fender. IT actually is only rubbing enough to make noise and not enough to cause significant drag.

himespau 

Oh, no I'm not going to put 26" wheels on it, I was just saying that I don't have any 700c wheels around already built up that I can test it and see what fits best, so I was hoping to find a good way to calculate what would fit.

I'll be building up a set of wheels for this bike, I just don't have it on hand yet to try and see what the clearance is. I was planning on going with tiagra hubs and cun CR-18 rims which Sheldon's tire to rim size chart says I should be able to get anything from 25 to 37 mm tires on (and then says that's conservative at the higher end). Since it's a townie, I was planning on hitting the higher side of that range to make a nice comfortable ride for my wife.

I suppose I could drop down to 650b wheels (assuming I could find some inexpensive rims, but I imagine that's going to lead to a need for extra long reach brakes if it's doable at all to go from 27" to 650b. On the other hand, I'm sure if that did work it'd give me lots of room for fat tires and fenders.

I'd really like to fit some fenders and mudflaps on this. I love the look of the fenders at Velo Orange and had been thinking of using a honey brown Brooks b67 to pair with the fatter tires for an extra cushy ride and then getting some of VO's honey brown mudflaps to go with the saddle. At least that's the plan anyway.

Good to know that the brakes might be serviceable (though would need a new pad as the one on there looks pretty hard), if I want to save some money (which is definitely not a bad thing. The annodized brakes from tektro are pretty, but saving money is nice too.

himespau 

In addition to this bike being called Gran Tourer, which would imply the ability to tour - though that could just be good advertising copy, the dropouts front and rear do have mount holes for fenders, so that would imply (though not prove) that it at one time was able to hold 27x1 3/4" tires and fenders, which is why I was expecting to be able to get decent tires/fenders on there.

But given that the only images of the mixte version I've seen are an old catalog which lacks fenders.

DCB0

ANother possibility is to measure from the point where the axle will sit in the dropouts and find the mark 311 mm (the bead seat radius - or one half the bead seat diameter) away along the seatstays, chainstays, and fork. THen add approximately 1/2 the width of the tire you are planning to use, then measure the space between the stays or fork legs. Also estimate the the full radius of the tire will be approximately the BSR + the width of the tire.

So... If you are planning on using 700 X 35C tires, Find the space between the stays/fork legs at approximately 329mm (311mm + 17.5mm) from where the centre of the axle will sit in the dropout, and make sure it is more than 35mm wide. ANd the distance from the axle to the chainstay or seatstay bridge, or fork crown, should be significantly more than 346mm (311 + 35).

Remeber that these are just estimates and tires have different profiles when installed on rims of different dimension.

Good luck!

himespau 

Looks like this old thread has a member who put fenders and a 27" rear wheel on. I've messaged him/her about clearance, but with a multi-year old thread, I don't have much hope of a response.

fietsbob

Given you can tour on anything that you can ride, that's safe ad copy.

could call it the Battleship Potemkin , but it wouldn't start the Russian Revolution, by itself.

fietsbob

some High end Randonneur bike builders are using center pulls in their builds,
as the classic constructeurs Herse, Singer, of the period they emulate, did the same.

himespau 

Ok, I'll give the centerpulls a whirl. Maybe I'm just prejudiced because they have the same sort of straddle hanger that was on the cheap canti's that came on my low end rigid framed mtb that were always a pain in the ass to get perfectly dialed in.

krome

Oftentimes it is the fork that is the limiting factor regarding max tire size. Fenders can be "pinched in" Tires don't give you the option.

DCB0

Are you sure they are the same? Most centrepulls that came on 10 speeds had a fixed-length cable and brake pads with little adjustment... even the cheapest cantilevers usually have adjustable pad placement and straddle angle or length.

FWIW, I have a set of centrepulls on my commuter bike and they work but not nearly as well as V brakes or a properly set up cantilever. I have never tried a modern long-reach dual pivot brake, but I cannot imagine them not working much much better than centrepulls.

fietsbob

You can buy set screw fixed barrels , and make up your own straddle cable.

Kool Stop Salmon Continental shoes would be good on The period side pulls,
that are not Mafac, which would use a plain post cantilever type.

With a longer bolt thru the fork crown there is the possibility,
to add a fork crown mounted cable stop, just above the brake itself.

himespau 

Yeah, the brake's not the same, but the straddle hanger (that hook, the straddle wire goes over) is and that gave me bad memories. There was a lot more to adjust on the cheap old canti's, but it didn't make them easy to get a good stop. At least for me. There was a lot of adjustments to get it just so.