owenmyers

So i just bought this 58cm Rocky mountain RC30 commuter frame with a racing frame geometry. I spent $115, it's brand new but your more than welcome to tell me if i payed too much. It has canti brakes and is 700c compatible, so i said to myself "Let's try cyclocross". I want to build up an entry level cx bike, Im trying to spend under $200 on components. Possibly a Truvativ, tek-tro, shimano, & easton set up. I already have my wheels: 700c Mavic open 4 CD w/ Shimano 105 hubs & 7 speed hyperglide. I also have my Sora rear derailleur. Please let me know what parts to get, and how much to spend on this thing.

https://www.ebay.com/itm/170775649078...ht_1404wt_1037

Thank you!

owenmyers

Thank you, it's great to know i didn't bid too high. Claims to be built in Canada so i will take their word for it. And it does have the 135mm spacing, will my wheels even work? if not i can always stretch the frame or use a different set of wheels.

LesMcLuffLots

Pretty sure? Your opinion is worthless unless it is accurate. Best not to talk about things you don't know much about. Can make you to look stupid.

Rocky Mountain was purchased by Procycle in 1997. Thus began the shift in production from Canada to overseas. Basically anything with an RMB 7005 or 6061 tubeset, or anything made of steel is coming from taiwan. Their newest carbon bikes are from overseas. They are just painted here and assembled in Canada. Thus the built in Canada sticker. Simply painting the frames here is often enough to get around the extra duties/taxes

owenmyers

Gritter -

I agree with you, If they can get away with saying made in Canada why can't we? These people who don't have anything good to say should just leave the thread alone. Because you don't know everything about every brand, part, frame, etc. Even if it is Taiwanese just compare it to a Giant or a newer Motobecane. It's really not that bad (pretty sure)! As for the axles spacing, I will have to look at the wheel and the frame and create my own solution. Pictures will be available soon!
Thank you -

owenmyers

Pictures -




The axle spacing will not be a problem. Do any of you agree that this is a solid entry level cx bike so far?

4Rings6Stars

Looks like you are off to a good start. If you don't have a parts bin or spare bikes with extra parts I suggest you buy used parts and come up with a Shimergo set up. I highly recommend it. Campy shifters are far and away my favorite for hood comfort, fd shifting, style, price...all of it.

Can you put an 8s cassette on that hub (will probably work with 7s too)? If so, get a wide range 8s shimano cassette, shimano rd and campagnolo 10s ergo shifters. Then a single or double (or triple) crank depending on your gearing needs and ride off into the sunset.

ColonelJLloyd just provided these links in another thread and I thought they might help you here.
https://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946

10s campy ergo shifters can be had CHEAP from UK retailers (also try Velomine).

https://www.ribblecycles.co.uk/sp/roa...es/CAMPGRSS105

owenmyers

Cool thanks for the links. I have a parts bin, but it's mostly vintage road bike components. Some components may work. I'm definitely using triples (cranks), campy STI's and i will upgrade to an 8 speed if you say so. As of brands, i don't really care if it's SRAM, shimano, campy, or whatever else, it just has to work. What tires should i buy? I need some really skinny knobby tires. And what Bottom bracket will i need? Also PM me if you have any CX bars, stems, brakes, or cranks you can trade me.

Thanks -

fietsbob

When you are done you can say 'built in : [city name here]'

owenmyers

True.

I still need to know what tires to buy. What are the largest size tires i can use 700 x ?. I don't necessarily need knobby tires, just something with decent treads. Something suitable for Road/Trail use.

Thanks -

alex jb

I'm just going through tire choice on my new build too.

a sugestion I have is...
take some painters tape, and put it on the frame where your current rear tire sits at it's widest in the rear dropout, mark it.
With your 23 tire compared to a 35 tire, the widest point of the 35 will be about 15mm closer to your BB, mark it.
if you now measure the clearance width at the new (closer to BB) mark you will see roughly what tire clearance you will have. for a 35 you are going to want that measurement to be 6+mm wider than the tire you are aiming for.

But, this is just a guide, don't bust my chops if you buy a 38 and it rubs

owenmyers

Oh okay. I was just worried about the compatibility of that big of a tire on my small rims. I was looking for something like 700 x 30 or 32. Let me know if that will work.

owenmyers

Okay, do you have rims like mine, or do you have wider rims made to fit that large of a tire?

kc0yef 

Does anyone know what bottom bracket length this would take ?

alex jb

I ran a 38 on a regular 19mm wide 700c wheel with no problems, I even ran sub 30 psi in it one day on some technical singletrack.

you will be fine with a 35 on there.

alex jb

what crank you plan on using?
regular square taper would probably be 113-115mm for a double.
check Sheldon Brown...
https://sheldonbrown.com/bbsize.html

owenmyers

I have a 70mm BB, kc0yef suggested a Shimano BB-UN26 Bottom bracket.

kc0yef 

Crank Sugino VT triple

GrayJay

If this is a budget build, just stay with your 7-speed casette. Going to 8-speed will require a wider freehub casette body, you cannot just put a 8-speed casette onto a 7-speed hub. It is possible to change the casette body and the casette to 8-speed but probably not good use of your budget if this is a low cost build.
For 7-speed shifting, either find some actual shimano 7-speed STI brifter but these are usually from lower end bikes as high end bikes were 8-speed by the time that STI became available in early 90's. Or, you can use the hubub alternate cable attachment to your SORA derailler and make it work well combine with a 9-speed campy Ergo shifter built before 2001 (in 2001 they changed the 9-speed cable pull ratio). Also note that 8-speed campy ergo shifters and an early campy 8-speed derailler will shift fine on a 7-speed casette with one extra unused click. (Casette spacing for 8-speed shimano was slightly narrower so 8-speed shimano shifters dont work well on 7 speed casette) You might also consider using friction or 7-speed shimano bar-end shifters if you dont have the budget for brifters.
For cyclocross, a triple cranks is not needed. Your VT cranks are 110BCD so can take down to a 34 tooth middle chainring, plenty of low range for CX. I would remove the inner 74mm BCD granny gear and run it as a double crank, might allow you to utilize a narrower bottom bracket (less flex, better chainline).

fietsbob

Owen, I got some 700c 32 wide WTB Allterrainasaurus tires, mixed use road paved or not..

put a pair of RBW Jack brown 33.3 wide near slicks on it and the rolling resistance dropped dramatically.

owenmyers

I want to keep my 7 speed cassette and use 7 speed Shimano bar end shifters. Whats your opinion on that?

GrayJay

Perfectly fine choice, having 7 gears in the back is plenty for most CX riding and racing conditions. Wider spacing between cogs is slightly less likely to pack with mud and 7-speed cogs are a bit wider so wear-out a bit slower than the progressivly thinner 8-9-10-11 speed cogs. Another nice benefit of a 7-speed casette is that it places the drive side hub flange about 5mm closer to the drive side dropout so that rear wheel spoke tension is more equal side-to-side, less wheel dish so a 7-speed rear wheel is a bit stronger and less likely to go out of true, break spokes.
You will likely need to troll e-bay for an old set of indexed 7-speed shimano bar-ends or else use bar-ends with a friction shifting option.
https://www.ebay.com/itm/GC-Set-of-Sh...item43adbcf5cb

If you find a good deal on 8-speed shifters, you could likely also get away with using 7 of 8 clicks of shimano 8-speed index shifters by altering the derailleur cable clamp attachment postition for a slightly higher effective derailleur cable pull ratio to compensate for the smaller cable pull per click of the shifter.
https://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

Cynikal 

Get these and use your 7 speed barcons.

https://www.bikerumor.com/2011/11/28/...or-cyclocross/

owenmyers

Im sorry but those retroshifters just look terrible. I would rather spend that $140 + the shifters i would have to buy, on some STI's. Thanks for the advice though.