Carbon vs Steel Fork

[DebW]

Thnaks these are all great suggestions. What I have been struggling with is that I want a bike that does it all since this will be my only travel bike. Sure, most of the time I just wanna go somewhere, and do loops of fast riding from a central location, but other times I may want to tour. What I still don't understand, is how I might expect these 2 frames to handle with a load, given that one bike was built for touring (classic) and one for racing (isis). My 19" terry isis has a 73 degree STA, 72 degree HTA, 16.7" chainstay and 38.2" wheelbase while my 17.5" terry classic has a 73 degree STA, 71.5 degree HTA, 16.9" chainstay and 38.2" wheelbase. Both bakes have the same trail, cuz while Isis has a fork rake of 1.9" Classic has a fork rake of 2). The other big difference is the classic has cantilver brakes so accepts fenders and wider tires. What I don't get is whether Classic is more suitable for touring becasue of the cantilver brakes, fenders and wider tire features, or the subtle difference in frame geomety. What I know from riding the 2 bikes I have (I already have a ti isis with carbon fork, and I just bought a steel isis frame to build as a travel bike) is that the classic feels more sluggish than the isis, even when outfitted with identical wheels/tires. Is that cuz it weighs more (my classic is much heavier than the new steel isis or old ti isis by several 3-4 lb) or the frame geometry. Cuz if its just the weight, then I really like the idea of having the new fork built to accept a front rack an cantilever brakes, obviously with the 1.9" right rake to give the right trail for the 72 degree STA. If I think this bike could REPLACE my classic which is rusting, I could just transfer the cantilever brakes from her as well as all the other parts). But if I am still gonna need a real touring bike, I don't wanna do that. I did check and could fit a wheel with a 32 wide touring tire in the new isis frame, but there wouldn't be much room to mount side pull brakes but my cantis would fit.

I believe that steering feel depends entirely on trail, so 72 STA + 1.9 rake and 71.5 STA + 2.0 rake would give identical handling. And both bikes have identical wheelbases (but slightly different chainstay length) which is important for loaded touring. Is the bottom bracket height the same? So it looks like differences in the feel of your classic and isis could be due to both weight and frame material (tubing stiffness) but not geometry.

[Triskeliongirl]

I believe that steering feel depends entirely on trail, so 72 STA + 1.9 rake and 71.5 STA + 2.0 rake would give identical handling. And both bikes have identical wheelbases (but slightly different chainstay length) which is important for loaded touring. Is the bottom bracket height the same? So it looks like differences in the feel of your classic and isis could be due to both weight and frame material (tubing stiffness) but not geometry.

The bottom bracket height on Isis is 10.3 and Classic 10.4, which I consider vitually identical. Please clarify why the slight difference in chainstay length is important for loaded touring. Is it just to be sure that my feet can clear rear pannier bags, cuz Isis comes with rear rack stays and I have never had a problem with that, or would it have a significant effect on bike stability under load. The reason I am asking, is that while probably 90% of the time what I plan to do with my traveling Isis is fly in somewhere, and then go on fast group/solo rides, if I do not have to give up anything, it seems having her be capable of loaded touring (by loaded touring I don't mean tents and sleeping bags though) is a plus. Also, I was just planning a trip to Santa Barbara, and thought of riding to Solvang but then read that touring tires are recommended since a few parts of the ride are off road, so again having her be capable of something like this would also be nice. The other advantage of knowing this bike could do loaded touring is that it would let me let go of my classic, which is rusting but has brand new parts I could use for the build.

I also realize that she will still be steel, albeit light steel, and together with the s/s couplers weigh more than my racier ti bike. Therefore, building her up as more of a general use travel bike may make the most sense. That was how I used my bike friday. I bought a pocket rocket pro which was more of a racing model, but I still would use it for touring on packed dirt by putting on a rear rack and 1.35" wide tires. So it seems like if I build this same flexibility into my new travel Isis, its only gonna be a plus.

Another question, do you think center pull canitlivers or long reach side pull breaks are best? I know I should be discussing this with the frame builder, but since he is just retrofititng my bike with couplers and doing the fork, he doesn't seem interested in being real chatty about it all, I presume relative to a customer for whom he is building a complete bike.

[DebW]

The bottom bracket height on Isis is 10.3 and Classic 10.4, which I consider vitually identical. Please clarify why the slight difference in chainstay length is important for loaded touring. Is it just to be sure that my feet can clear rear pannier bags, cuz Isis comes with rear rack stays and I have never had a problem with that, or would it have a significant effect on bike stability under load.

With only 1/4 inch difference in chainstay length it probably won't be noticable. There are 3 reasons for longer chainstays on touring bikes: pannier-foot clearance, pannier weight stability (ie. you don't want weight behind your rear hub), and a softer ride on rough ground (but there are other factors here as well). The more foot clearance, the larger pannier bags you can carry. Traditionally, a touring bike also had a lower bb to lower the rider's center of gravity (actually the opposite is true for your 2 bikes). You obviously aren't talking about a bike that is built exclusively for touring with a really long wheelbase and poor acceleration, but a do-everything bike for light tours and fast rides both. If you were comfortable touring on your old classic, looks like the new Isis should fill the bill as well.

Another question, do you think center pull canitlivers or long reach side pull breaks are best? I know I should be discussing this with the frame builder, but since he is just retrofititng my bike with couplers and doing the fork, he doesn't seem interested in being real chatty about it all, I presume relative to a customer for whom he is building a complete bike.

You can probably get by with either brake type if you're not carrying really heavy loads over really hilly terrain. But cantis are best for loaded touring. Does the new frame have canti bosses on the rear, or can you get them added? You also need cable-hangers for centerpull canti's, usually attached among the headset spacers on the front and on the seat post bolt or to a braze-on on the rear. Get the braze-on if you can.

[Triskeliongirl]

You can probably get by with either brake type if you're not carrying really heavy loads over really hilly terrain. But cantis are best for loaded touring. Does the new frame have canti bosses on the rear, or can you get them added? You also need cable-hangers for centerpull canti's, usually attached among the headset spacers on the front and on the seat post bolt or to a braze-on on the rear. Get the braze-on if you can.

The new Isis does not have canti bosses on the rear. I was thinking since he is building the fork he can build them in, and I guess I could ask him to add them to the rear when he is doing the s/s stuff. I have the set up you describe on my classic with bosses in front and rear and cable hangers attached to the headset and seatpost bolt using problem solver clamps. So, I have all the stuff already. What I am trying to understand though, is if I have enough room to install long reach brakes, since it seems what is gonna limit tire width is hitting the top of the frame/brake. With no brake in there the tire spins freely, but there isn't a ton of room so its hard to imagine how it will spin with a brake on there. Can I even install long reach side pull brakes if the bike was designed to accept standard ultegra side pulls which I assume are short reach? Maybe I just need to try and install my touring wheel on my titanium Isis with ultegra side pulls to see if it will fit. I think the problem is I don't understand how long reach brakes look to be different from short reach. If they look like I imagine, then they only work on a frame designed for them where the thing they screw into will be higher, to give more clearance for wide tires and fenders.

[DebW]

The new Isis does not have canti bosses on the rear. I was thinking since he is building the fork he can build them in, and I guess I could ask him to add them to the rear when he is doing the s/s stuff.

For the framebuilder to install canti bosses for your rear brake, I believe he'd have to remove paint from the seatstays, braze them on, and have it repainted. He may not be willing to do that, or the expense may be too much. You'll have to ask.

I can't answer your questions about long-reach sidepulls. Maybe someone who has them would know. You might also looks at some used brake calipers of older vintages for different amounts of clearance.

[Triskeliongirl]

UPDATE! I just finalized the plans with the frame builder and put down my deposit. I am so stoked. I had already decided to go with the steel fork so I could get a rack and canti bosses added, and then after taking some measurements the frame builder told me that the back ordered Terry Carbon forks wouldn't have even fit, so I am glad I had already decided on steel before finding out that I didn't have a choice afterall. He is gonna also modify the seat stays to have canti bosses and a hanger. So I'll get a light travel bike that can work with tires from 23-32c, with or without racks, for everything from go fast rides to light touring. The price was very reasonable, since it is a bigger job for him if he gets to do the fork, retrofit and rear mods. Now, the question is can I really build this myself. I am gonna have him install the headset and fork, but I'll do the rest. I'll have to take pictures and post them as this project progresses. BTW, her name is Feronia, a travel Goddess and also a fitting name for a steel bike.

[DebW]

Congrats. What a great bike you're going to have! You can definitely do the build yourself. Just take it one step at a time.

[Mimosa]

Now, the question is can I really build this myself. I am gonna have him install the headset and fork, but I'll do the rest. I'll have to take pictures and post them as this project progresses. BTW, her name is Feronia, a travel Goddess and also a fitting name for a steel bike.

The only problem you could have is the special tools required to install the bracket and cranck. But you could loan them from a friend or buy them.
The rest of the bike is easy.