Dandankennedy

Hey guys, I am a very novice biker so please be a little understanding if I sound like I don't know what I'm talking about cause I probably don't.

I own a Canadian tire ccm excelsior 700 bike. I know it's gotten bad reviews but I've gotten three years and almost 2000k out of it. But now the BB is shot. I have a chance to by a Shimano BB SM-BB70 brand new for pretty cheap of kijiji. My question is will the shimano BB fit on the bike and what do I need to do to make it happen? I have to use the ccm cause I just had a newborn and the budget dosen't have room for a new bike.

jimc101

The BB70 is an external BB, does your current bike use this type? more info is needed on what BB type you have, the BB shell size, BB length etc

ultraman6970

Are u sure the bike uses that BB?? From the pictures it looks like uses a regular squared tapper to me. Since there is not even info in their website to confirm anything is hard to know what do you have in there dude.

Dandankennedy

Awesome questions. I really appreciate you guys taking the time to answer my question. so, it looks like I need a little more education cause I have no F-N idea what you guys are talking about. I called the Kijiji guy and put him on hold for now [no sense buying something I can't use] and I took my bottom bracket off and cleaned it up. I found out what the problem was, one of the bearing brackets was completed rusted and bearings were just flying around in there. Can you guys point me to a web resource that I could use to educate my self a little. Like I said I really want to do this myself, but don't have the proper base knowledge and don't want to waste your time with stupid questions. Especially if you are willing to answer my stupid questions.

JanMM

Much good repair info on the Park Tool site.
https://www.parktool.com/blog/repair-help

Lots of info from Sheldon Brown (RIP), too: https://www.sheldonbrown.com/

Dandankennedy

JanMM,
Thanks for the site. So it turns out I have a loose-bearing bottom bracket with square tape. I took the BB apart and one of the bearing cages was completed corroded. The balls where all lose and flying around. I cleaned it all up and got another bearing cage and put the thing back together. Wouldn't have been able to do that if not for the info you forwarded.

I guess my original question still strands, can the SM-BB70 work with my CCM exclseior. Although, the more I read the more I'm thinking No! If I am going to upgrade the BB what should I be looking for and considering.

rithem

Dan,

Your best bet is to bring it to a decent shop and have it looked at. Decide if the repair out-weighs the value of the bike, might be a quick fix, who knows though, take it shop and they may have a suitable replacement part on hand. I will be decidedly difficult to help you over a forum with what is basically a department store bike, not disrespect to your purchase; it's nice that it's lasted this long for you. If the part is available my guess is you would expect to pay about 15 bucks for the part and $40-50 in labor +/- $20. If the BB is in that kind of shape I'd be willing to bet that i needs a multitude of consumables replaced.

Mondoman

Yep, a decent cartridge-bearing square taper BB should run about $20. That's the only kind of "upgrade" I would think about for the BB. Make sure to get one with the same spindle length as the original BB.

Dandankennedy

Rithem,

I've already made the repair. It cost almost nothing for the part and about 45 bucks for the tools I needed. and there is no disrespect taken, my biks isn't Basically a department store bike, it is a department store bike. I am just starting to figure out just what kind of crap it it is.

Mondoman,

So I am unable to upgrade the BB at all? That sucks balls! what If I got a complet new cranksset. My long term plan is to buy decent components for this frame and then [eventually] buy a decent frame. Is this a stupid plan? I just had a newborn child so anything above 150.00 at one time is pretty much out of the questions...which means a new bike is out of the question.

Thoughts? Suggestions?

jeepr

You can replace your BB with a cartridge as an upgrade. I usually don't bother unless there is something physically wrong with the old spindle/bearing one (what yours has.) The one your using has been around a long time and still function just fine. Maybe I just like something I can service, I dunno. But if you are set on replacing yours, you need to remove your old one. This includes the fixed cup behind the chainrings which is left hand thread (and a lot of times a real chore to remove.) You measure your spindle and get a cartridge the same length. You will need a cartridge tool to install the cartridge. It goes in from the chainring side (left hand threads) and from there gets treated like your spindle arrangement.

Dandankennedy

Jeepr,

I'm more of a do it yourself guy as well. so I would perfer something I can service on my own as well. I'm starting to get the feeling that the BB is not the place for me to think about upgrading. If you had a bike with low end components, where would you start, I've already replaced the back wheel [spokes kept breaking].

dabac

I probably wouldn't. Bike parts are much more expensive bought piecemeal than as an assembled bike, so upgradeitis, can be very costly, and highly questionable in financial terms.

You can maintain borderline financial sensibility by replacing-with-nicer as and when something breaks, but even then you don't want to climb too many steps on the quality ladder. If you can see already that there are a lot of parts needing attention, try keeping the bike rolling with a minimum investment while setting any "upgrade" money aside for a whole new bike instead.

Sometimes people determine that they've found the frame of their lives, which just happens to be decked out in poor parts. In such a love affair obviously "sense" goes out the window. Then it's just a matter of picking the parts that fits.

The main killer of inexpensive wheels is poor assembly. It might be sensible to have bearing adjustment and spoke tensions checked before the new wheel has seen too many miles.

Mondoman

ddk, it sounds like you've basically been happy with the bike and gotten good use out of it. Given that, what are you looking to achieve by "upgrading" it? What specifically bothers you about the current setup?

As for keeping it performing well, here are some ideas:

Drivetrain:

• Replace the chain when it starts to show some "stretch" rather than when it's really worn. This will help the crankset and rear cogs (the more expensive parts) last longer.
• Your crankset probably has riveted-in-place gears, so when the gears eventually wear out, you'll have to buy a new crankset to replace it. Crankset and BB have to fit together properly, so that will be the time to decide if you want to go with a different type of BB as well.
• Make sure your rear derailleur hanger is properly aligned so its plane is parallel to that of the wheel. I had a similar dept store bike that the store couldn't get to shift quite right -- the RD hanger was slightly bent and aligning it properly finally allowed the RD to be properly adjusted.

Wheels/Tires:

• dabac is right about having the wheel(s) checked
• wheels are where manufacturers can cut costs in non-obvious ways.
• a quality set of wheels will last you a while (until the braking strips get worn down) and can be moved to another bike if/when you switch bikes.
• Look for aluminum rims, stainless steel spokes, brass spoke nipples, and Shimano cup/cone bearing hubs.
• On the rear, look for a freehub design rather than a freewheel design.
• Since tires are where the rubber meets the road, tire design, construction and inflation can really affect your ride and handling -- investigate and experiment.

Brakes: V brakes (what you have) are cheap and effective. However, pad material can make a big difference. Pick up some KoolStop salmon pads for your brakes.

jeepr

If it has steel wheels, I would probably start with wheels and tires. I think a decent set of alloy wheels is always a good investment. Keep the old set to put back on if you decide to sell the bike. Then look toward the drive train. I would check for used parts either at your local bike shop, bike co-op, or local flipper. You never know what someone might have laying around. You could even look for a complete donor bike. If your not looking for top of the line parts, they are all around. I have picked up some nice old bikes for less than a new crank set would cost.