Bicycle Mechanics - Switching from 27 inch to 700c

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Switching from 27 inch to 700c


lemniaalsa
12-16-09, 03:33 PM
Hello all

I just recently bought a used Nishiki road bike and didn't realize that the back wheel was a 27 inch and the front was a 26 inch, so I've decided to change both to 700c wheels. The bike has a 5 speed cassette and the spacing between the frame for the back wheel is about 120mm. I was wondering if I could buy a 700c wheel (campagnolo) with an 8 speed cassette and replaced the hub and cassette with the ones in the rear wheel of my bike (the 27 inch) so that the 700c wheels would fit.
Thanks ahead of time.

andy


Bianchigirll
12-16-09, 04:12 PM
Hi Andy. there is alot going on there. first of all why does the bike have a 27" RW and 26" FrntW? should both wheels be 27"

when changing from a 27" wheel to 700c wheel the first thing you need to consider is will the brake pads contact the smaller diameter rim?

in theroy yes you can put the 8spd Campi wheel in the frame but you would have to use a friction shifting system unless you intend to change the shifters and rear derailleur. which could become expensive.

is this a frankenbike, a women's geomentry, or TT/Funny bike? pics?

PS there are dozens of post both here and on the C&V forum about changing from 27" to 700c wheels

Road Fan
12-16-09, 04:30 PM
If 27 inch is the OEM size for both wheels, by far the easiest thing to do is to buy a complete 27 inch front wheel from, say Niagara, for well under $100.


lemniaalsa
12-16-09, 04:45 PM
Yes both wheels should be 27, I'm not sure what the previous owner was thinking.

The break pads will reach for sure, there's a lot of room for adjustment going down and my bike has friction shifters. It's an old Nishiki :)

Im scared that the wheel will not fit in the frame because the frame only has room for a 5 speed cassette. Can I just use the hub and casettes off the old wheel and use them in place of the 8 speed hub/cassette? Will that make it small enough for a 120mm wide drop out?

Thanks.

garage sale GT
12-16-09, 05:00 PM
While relacing a wheel is not as tough as some think, the fact is spokes are expensive. You will need 2 different lengths and the cheap ones are sold in boxes of fifty or by the gross. I have seen certain sizes of stainless steel spokes on sale for $12 for 18 spokes but not regularly and only in a few lengths.

You can buy a 700c wheel in 120mm, I believe. Niagaracycle.com or bikepartsusa.com have them, unless you're doing this to get an aero rim. The 120mm 700c's look like "old tenspeed wheels". They'll say 5/6 speed because of the ultranarrow suntour ultra-6 freewheel. Should be about $25/wheel.

You can easily respace a steel frame to take a 130mm road wheel and at least some old derailleurs seem to be able to handle all 8-10 speeds of a modern cassette, but you would then need to buy a cassette and chain, and a 10spd chain may not fit your front rings. I mean for a 10sp cassette. They are much narrower. Your bike is currently equipped with a freewheel, not a cassette and there'd be no place for it on the new wheel. See sheldonbrown.com for instructions on spreading a frame.

You could just buy a 27" front wheel. Or a 27" or 700C wheelset from ebay.

They make great touring, training and cyclocross tires in 27", some as modern as any comparable 700C (but not racing tires), as well as old school, low end tires with no flat protection.

What's wrong with the old wheel?

Al1943
12-16-09, 05:20 PM
Is the fork a 27" or 26"? If a 26" I doubt if it will accept a 700 wheel. Test to see if a 27" or 700 mm wheel will fit.

Al

Steve530
12-16-09, 05:24 PM
The hub is the part of the wheel that determines which rear spacing you need. 120mm for a 5 speed, 126mm for a 6/7 speed, and 130 for 8, 9 or 10 speeds.

So, yes, you can use the hub you have with the rim on the Campy 8s speed wheel. Or you could just buy a new 700c rim and have that laced to the 5 speed hub. Or you could spread the rear of the bike to fit the Campy 8 speed hub.

garage sale GT
12-16-09, 05:44 PM
You'll save a lot by going with shimano 8/9/10 700c's unless you know of where you can get a campy wheel for a good price. You can get store brand cassettes at online retailers for $20 in any size you are likely to need.

All three of the sources I mentioned can provide a 27" fork but you will need to paint it. I think you have a road fork though because of the chrome tips.

Do an online fit calculator (maybe prop the front wheel on something 15mm tall before measuring the bike) before you sink all kinds of money into it. What with working bikes going for $25-50 on cl, you don't want to ride an uncomfortable bike. It really makes a huge difference.

Also, a fact which soured me to road bikes till I figured it out, the seat has to comfortably span your sit bones.

lemniaalsa
12-16-09, 06:17 PM
This is the campy wheel i was planning to buy and do the hub switch: http://cgi.ebay.com/Campagnolo-Omega-700c-Wheelset_W0QQitemZ120505029114QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item1c0ea8d1fa

So just to double check and settle my paranoia... switching the hub in the above campy wheels with the hub in the original wheel will make the campy fit inside my 120mm frame with the original 5 speed cassette. Correct? If not, I'll just stick a 27 inch from one of the sites you showed me into the front wheel instead.

I've ridden the bike, it fits my sit bones well and is a joy to ride...even with the mismatching wheels and malfunctioning brakes :p

And the frame is a 27, the back wheel has a 27 inch right now.

Thanks a bunch!

lemniaalsa
12-16-09, 06:29 PM
On second thought, widening the rear triangle makes much more sense than replacing the hub. Widening it from 120 to 130 shouldn't be too damaging on the frame right?

garage sale GT
12-16-09, 06:42 PM
"never glued" means it's a tubular wheelset.

The Campy cassette may cost a bundle to replace when you need to.

The existing spokes may not be the right length for your hub, if you decide to relace the rear rim into your hub.

garage sale GT
12-16-09, 06:51 PM
You glue the tires to the rim. They start at $25 apiece and go up, and the lower end ones don't offer flat protection. You have to buy at least three because they need to be replaced when flat. Some say the sealants for them work, others don't like them. If you puncture one you can repair it at home but it is supposedly complicated.

They will probabaly have somewhat fragile sidewalls which are not too resistant to abrasion, but some standard racing and touring tires are the same.

They're supposed to have a great ride for such narrow, low rolling resistance tires. Some people love them. They're essentially racing tires.

There's no using standard tires on a tubular rim.

Sheldonbrown.com has a wealth of info on them, and there should be searchable threads here too.

I bet that price is going to go up though.

lemniaalsa
12-16-09, 06:52 PM
I'll just purchase a 27 inch wheel for the front then. Seems like the most cost efficient way to go.

Thanks for the help!

garage sale GT
12-16-09, 06:59 PM
OK, I hate to be a bother, but I see a lot of old road bikes with shot rear hubs. Lift the rear of the bike, grab the rim, and see if it wobbles from side to side on the axle. If so, it needs a new axle, cones, and bearing balls and it is possible the hub is also shot.

The rim and spokes are somewhat flexible but if the cones are shot or the axle's bent, you'll feel a slight sense of it clunking around on the axle. In other words, it will be ever so slightly loose on the axle.

If you ride it that way you can expect the looseness to rapidly deteriorate. It can break and the friction will go up.

operator
12-16-09, 07:55 PM
OK, I hate to be a bother, but I see a lot of old road bikes with shot rear hubs. Lift the rear of the bike, grab the rim, and see if it wobbles from side to side on the axle. If so, it needs a new axle, cones, and bearing balls and it is possible the hub is also shot.
.

Wobblling on the axle could mean a number of things, doesn't automatically mean it needs a new axle, cones or bearings.

garage sale GT
12-16-09, 08:01 PM
Wobblling on the axle could mean a number of things, doesn't automatically mean it needs a new axle, cones or bearings.Please elaborate.

Bianchigirll
12-17-09, 07:23 AM
I am begining he needs to walk this bike to the local shop and get a professional assment of what it really needs after he clean it a bit.

garage sale GT
12-17-09, 08:32 AM
I think ruined cones and a bent axle are very likely if the hub is a little loose on the axle.

Also, if someone misadjusted good cones, leaving them loose, the misadjustment itself would cause the cones to crap out unless it wasn't ridden or was ridden by a very light person for a short time.

You could just ride it. It probabaly won't crap out catastrophically. You could decide if you like the bike before getting a new wheel.

Why am I diagnosing it sight unseen? The majority of vintage bikes I have seen have this condition. Maybe because my ideal frame size is a few cm larger than yours though. This old school tech is a bit less strong than newer bikes and has to be ridden with care over bumps.

operator
12-17-09, 10:20 AM
I think ruined cones and a bent axle are very likely if the hub is a little loose on the axle.

Also, if someone misadjusted good cones, leaving them loose, the misadjustment itself would cause the cones to crap out unless it wasn't ridden or was ridden by a very light person for a short time.

You could just ride it. It probabaly won't crap out catastrophically. You could decide if you like the bike before getting a new wheel.

Why am I diagnosing it sight unseen? The majority of vintage bikes I have seen have this condition. Maybe because my ideal frame size is a few cm larger than yours though. This old school tech is a bit less strong than newer bikes and has to be ridden with care over bumps.

100% wrong

Play in the hub means exactly that. Play. It could be a loose cone adjustment. Your routine experience with crap wheels has biased you. Even a wheel with a bent axle will have a tight/loose spot unless is just utterly destroyed in there. Even if the cones are pitted, they'd have to be extremely pitted to affect the final hub adjustment in an overhaul. It is not an ideal situation but telling the OP that it's extremely likely he'll have to replace nearly all his parts on a hub based one *one* symptom is just bad advice and at best ignorant.

garage sale GT
12-17-09, 12:53 PM
100% wrong

Play in the hub means exactly that. Play. It could be a loose cone adjustment. Your routine experience with crap wheels has biased you. Even a wheel with a bent axle will have a tight/loose spot unless is just utterly destroyed in there. Even if the cones are pitted, they'd have to be extremely pitted to affect the final hub adjustment in an overhaul. It is not an ideal situation but telling the OP that it's extremely likely he'll have to replace nearly all his parts on a hub based one *one* symptom is just bad advice and at best ignorant.

Ok, since you weren't listening, operator, a loose cone adjustment can produce pitted cones because it greatly accelerates wear. If you don't know that, then you shouldn't be calling other people ignorant.

Whether the cones are loose because the axle bent, or because someone like you assembled or serviced the bike and left them loose, it doesn't bode well for the cones.

How about that, everyone. The guy doesn't know you gotta take the play out of a cup and cone ball bearing to keep it from wearing out, and he goes around calling other people ignorant.

tellyho
12-17-09, 01:07 PM
Maybe I shouldn't wade in, but I don't think anyone would agree that a strong correlation between play at the rim and bearing wear automatically implies the need for a new axle, cones and bearings. I've certainly had plenty of dump finds which have not needed an axle transplant.

To the OP: the easiest thing to do is to figure out what the bike originally had and stick with that. Failing that, spreading the rear triangle is really easy.

garage sale GT
12-17-09, 01:22 PM
I don't think anyone would agree that a strong correlation between play at the rim and bearing wear automatically implies the need for a new axle, cones and bearings. I've certainly had plenty of dump finds which have not needed an axle transplant.Maybe, but only because many bikes are used so little before being tossed out. They say 75 miles from store to landfill is the average amount of use for low end bikes.

If the OP is planning to use the bike a lot it should be adjusted at a minimum.

I had a brand new, fixed rear wheel which loosened up during its first cruise. It was ok but I had gone less than 15 mi before catching it and walking home.

The kluge fix of the front wheel suggests maybe someone needed the bike on a regular basis and kept it rolling any way they could, which doesn't bode well for the "loose adjustment, no axle needed" theory b/c the bike may have been used regularly.

Of course, it would probabaly keep going for quite a bit with pitting cones and crappy adjustment, at the cost of extra drag and the risk of a snapped axle.

Incidentally, every freewheel bike I have ever had which had a rear wheel with play, inevitably also had a bent axle and pitted cones. However, I buy bikes sized for medium or larger guys.

canopus
12-17-09, 02:30 PM
Ok, since you weren't listening, operator, a loose cone adjustment can produce pitted cones because it greatly accelerates wear. If you don't know that, then you shouldn't be calling other people ignorant.
Your right it can but that doesn't mean it did and that is the point operator meant which you failed to explain. You wouldn't know what a misadjusted hub did to the races and and hub until you get into it, sometimes they are fine and all you have to do is to adjust them, other times they might be destroyed, don't just assume they are bad.


Whether the cones are loose because the axle bent, or because someone like you assembled or serviced the bike and left them loose, it doesn't bode well for the cones. Axles and cones can take a lot of punishment before going bad. Perfect no, but on these bikes and these types of axles and cones they can take a lot.


How about that, everyone. The guy doesn't know you gotta take the play out of a cup and cone ball bearing to keep it from wearing out, and he goes around calling other people ignorant.
He does know, his people skills are lacking but he does know.

canopus
12-17-09, 02:35 PM
To the OP, do not get the tubular rims. An 8 speed changeover would require more parts than I think you need to tackle right now.
Especially in a frame spaced at 120mm. Replace the front wheel with a 27", probably from a dumpster find would be just fine. Later on after some riding and some more knowledge then you can decide whether or not you want to respace the frame and replace the drive train or find a new bike.

peripatetic
12-17-09, 02:39 PM
Why doesn't the OP actually just take apart the rear hub to assess what, if any, problem there is with it? Even if the cone is a little pitted, it's useable with new bearings and good grease. If you have to replace the cone, however, it's probably not worth the hassle unless you can find such a replacement very easily. Vintage cone replacement can be way more headache than it's worth and/or impossible to actually accomplish. Replacing either/both wheels w/ 27" wheels will probably be cheaper than 700c--look on your local Craigslist before Ebay.

garage sale GT
12-17-09, 02:51 PM
Why doesn't the OP actually just take apart the rear hub to assess what, if any, problem there is with it? I am sure you mean "if it is a bit loose on the axle".

I don't think there's a point to tearing into a perfectly good hub. If I ever run across one (all mine are usually busted) I will just try to oil it through the gap between the hub and dustcap. It might need a drop or two of lube if it's been sitting because grease can separate into oil and thickener, and the oil creeps out through the gap.

dr1445
12-17-09, 03:16 PM
if your going to mess around with old bikes you should have the $ for the lbs to service or the knowledge and/or willingness to dig into it yourself. repacking the bb/wheels and adjusting the bearings would be required to know all is in working order and for future confidence in your equipment. my 2 cents.

wrk101
12-17-09, 08:57 PM
I am sure you mean "if it is a bit loose on the axle".

I don't think there's a point to tearing into a perfectly good hub. If I ever run across one (all mine are usually busted) I will just try to oil it through the gap between the hub and dustcap. It might need a drop or two of lube if it's been sitting because grease can separate into oil and thickener, and the oil creeps out through the gap.

Huh? Out of the last 75 I have worked on, one had a bad axle, a couple had bad cones. Almost all of them needed new bearings and grease.

peripatetic
12-18-09, 08:06 AM
Huh? Out of the last 75 I have worked on, one had a bad axle, a couple had bad cones. Almost all of them needed new bearings and grease.

Yeah, I mean, the bike is over 20 years, something seems loose or wobbly on the rear wheel. Seems to me if you're wanting to ride such a bike, you should at least check your bearings. Even if you don't want to check them all, certainly the ones at points where things seem off. As someone who regularly services and sells vintage bikes, I always make it a point of checking and at least re-greasing bearings and adjusting cones and nuts.

In this situation, too, with the OP wondering if something's wrong with the axle, I'd say it's a requisite he just get in there and see if anything's actually wrong.

garage sale GT
12-18-09, 08:38 AM
I suggested the rear axle was likely to be busted, just because they usually are on the freewheel type bikes. Maybe the OP's isn't. It is a smaller frame bike. The OP didn't say it was.

I think that if the adjustment is OK, if the wheel isn't loose on the axle, oiling it before every few rides ought to be OK. If it was ridden occasionally before he got it, that would serve to stir up the grease and keep it from separating.

JFTR I am talking about when the rim wobbles from side to side without spinning the wheel. a wheel which wobbles when it IS turning has a bent rim, which is a different issue and needs to be straightened by adjusting spoke tension. It may, of course, ALSO wobble around on the axle when not turning-2 different problems at once.

I hope the OP doesn't buy steel rims if he wants to ride in wet weather because braking is poor.

canopus
12-18-09, 09:32 AM
I think that if the adjustment is OK, if the wheel isn't loose on the axle, oiling it before every few rides ought to be OK. If it was ridden occasionally before he got it, that would serve to stir up the grease and keep it from separating.


This thread has gone way beyond the OP's question but in response to the the above quote for any newbie reading... Please DO NOT USE OIL in your hub bearings and ride them. You aren't on a track and these aren't Campagnolo hubs that are torn down between races. The proper maintenance is to tear-down the axle and bearings, clean/replace them and re-pack them with grease. Oil only washes away/breaks down existing grease and does not have the retention/strength to maintain proper lubrication on bicycle hub bearings for any length of time.

garage sale GT
12-18-09, 09:48 AM
...DO NOT USE OIL in your hub bearings and ride them...Oil only washes away/breaks down existing grease and does not have the retention/strength to maintain proper lubrication on bicycle hub bearings for any length of time.Please consider that Sturmey-Archer hubs were oil lubricated before Sturmey moved to Taiwan, and Shimano 333 hubs were also. Sturmey AW's last 50 years or more.

If you add oil to grease which has separated and lost its oil and is now nothing but thickener, you get grease. You don't have to bathe the hubs in something thin like WD40 or automatic transmission fluid. If you add a few drops every now and then while making sure you don't wash grit into the hub, and making sure you don't add so much that streams of oil and grease flow out the other end, you will probabaly just rejuvenate the grease.

canopus
12-18-09, 10:46 AM
Please consider that Sturmey-Archer hubs were oil lubricated before Sturmey moved to Taiwan, and Shimano 333 hubs were also. Sturmey AW's last 50 years or more.
Your right in that context but those are oil bath hubs which do not exist in the context of this thread. Don't confuse an oil bath 3 speed hub to a cheap steel freewheel hub from the 80's. Stick somewhere around the subject please.


If you add oil to grease which has separated and lost its oil and is now nothing but thickener, you get grease. You don't have to bathe the hubs in something thin like WD40 or automatic transmission fluid. If you add a few drops every now and then while making sure you don't wash grit into the hub, and making sure you don't add so much that streams of oil and grease flow out the other end, you will probabaly just rejuvenate the grease.
No you get gunk with oil on top of it. These old hubs barely came with any grease to them anyway. You can't add oil to dried out grease and get good grease "probably". And then you can't keep oiling it and expect it to stay in place. Stop being LAZY. WD-40 is light oil/cleanser/rust inhibitor (which doesn't mean rust proof). Transmission fluid is hydraulic fluid with so many detergents in it that I consider a cleanser also. I used to love it when I got a transmission to rebuild at the dealerships I worked at... that meant I could finally get my hands clean from all the line work I did.

garage sale GT
12-18-09, 11:37 AM
Blah, blah, blah. One would almost think those 3 speeds came with oil seals, listening to canopus jive. They simply don't. there's a 333 right in front of me. The bearings on the end had a bit of a raised lip which would keep the oil from running out of the cups themselves unless you lay the bike on its side, but the larger bearing between the hub and sprocket carrier doesn't even have that, so neither do the internal parts because your "oil bath" would exit just inside the sprocket. Some sturmeys have a felt washer outside the large bearing so it wouldn't GUSH out. Most parts inside those things were lubricated by wetting.

garage sale GT
12-18-09, 11:40 AM
No you get gunk with oil on top of it. These old hubs barely came with any grease to them anyway. You can't add oil to dried out grease and get good grease "probably". And then you can't keep oiling it and expect it to stay in place. Stop being LAZY. WD-40 is light oil/cleanser/rust inhibitor (which doesn't mean rust proof). Transmission fluid is hydraulic fluid with so many detergents in it that I consider a cleanser also. I used to love it when I got a transmission to rebuild at the dealerships I worked at... that meant I could finally get my hands clean from all the line work I did.Since you didn't read post #32 I said you don't have to drown the hubs in a thin high detergent oil or wd40. You use thicker oil, a few drops at a time. And it's nice how you like to sound as if you knew what would happen when you put a few drops of motor oil on the hubs. Nice guess.