yourbuttonguy

2018 Giant Talon 3

Let me preface this my saying i'm an absolute NOOB when it comes to bike mechanics. I would normally bring this into my LBS, but my city is on lock down and i've been watching too much Seth's Bike Hacks and others...plus i'm trying to save some money and actually learn something. With that said:

Recently my pedal fell off on the right side of the bike. When I took a look at it I noticed that the threading was stripped (prob my fault, I know). So I did some research and determined that buying a new crankset was cheaper than trying to re-thread the current onet. I checked out the spec sheet from giant's website which lists the crankset asProwheel BURNER-101P, 24/34/42 ) but when I actually counted the teeth on mine it was 22/32/42 - so I ordered this set from amazon: Shimano Altus M311 7/8s 42x32x22 170mm along with a crank arm remover and some grease...

After getting it installed, the teeth on the new crank set hit the frame...What did I do wrong? Did I order the wrong size?

Thanks!

Ps. I can't post any pictures cause i'm new. I tried to post links to the spec sheet and the part I ordered but i'm new here and cannot.

katsup

You may need a longer bottom backet for the Shimano crankset vs the Prowheel.

SalsaShark

It looks like your original crankset was designed with a shorter spindle length on the bottom bracket. The new Atlus crank looks to be designed for a 123mm spindle length. You will likely need to replace the bottom bracket with one having the longer spindle length to allow for proper clearance of the chainstay. These square-taper cartridge bottom brackets are not an expensive part, but you will need the correct splined removal tool. The non-drive side cup will remove counter-clockwise, like normal. The drive side of the bottom bracket will be reverse threaded, so turn clockwise to remove this side.

yourbuttonguy

Thanks SalsaShark and katsup.

so am I better off buying a new bottom bracket and removal tool or finding the correct size Crankset? I wasn’t really trying to do much of an “upgrade” but I figured the Shimano would be better than the stock. I was mainly trying to take the cheapest route possibly as I’m not Crazy with my riding and this is a pretty entry level bike to begin with.

thanks for all the help!

dsbrantjr

Buy a new bottom bracket to match your crankset, going the other way is letting the tail wag the dog.

dedhed

That crank needs a 123mm BB. https://www.jensonusa.com/Shimano-Al...rankset-WGuard

YOu need to measure your BB shell width. It'll be either 68mm or 73mm wide and order the correct BB and a Park BBT-22 or equal tool . Typically a Shimano UN 26 or UN 55 BB

dsbrantjr

The UN-26 has a plastic non-drive side cup and the UN-55 has a metal one. Many people prefer the metal one but I have not seen any real difference between the two. I use Tef-Gel Teflon anti-seize compound on the metal ones, pedal threads, too.
And make certain to properly torque your pedals, loose pedals are the leading cause of stripped-out threads.

Moe Zhoost

If you only need to add a few millimeters for clearance, perhaps a few spacers between the bottom bracket and drive side shell will resolve your problem. You'll still need to invest in the spline tool to remove the bottom bracket.

yourbuttonguy

i guess i meant, instead of buying a new BB and the tool to remove it, am i better off buying the same original crankset as ...
The shimano crankset is prob only a very minor upgrade...?
idk.

yourbuttonguy

can you steer me in the right direction for some spacers?
thanks.

yourbuttonguy

Would this be a good BB replacement as well?

SHIMANO XT BB-MT800 BOTTOM BRACKET

dedhed

That'd be a great replacement if you were using the type of crank it was made for, which is a Shimano HT II cranket.
Please, do some research on bottom bracket types and do some measuring on your bike.

https://www.bikeradar.com/advice/buy...ket-standards/

dedhed

https://lmgtfy.com/?q=bottom+bracket+spacer&s=l

yourbuttonguy

you're right. I need to do more research. it's all a lot to take in for the newcomer. I read a few reviews on that BB and some said it was pretty flexible and widely used and others said it was specified.

thanks for all your help.

Russ Roth

Before you try spacing the BB over take a look at the non-drive side crank and make sure you have some clearance there as well. Won't help to space if you end up having the other side hit the frame. Better you just get the tool to install the BB and get the BB to go with it. You need a square taper BB, look up what that means so you know what you're getting; the prowheel isn't going to be easy to replace with an exact replacement so get what you need. for the new crank.

Moe Zhoost

Here's an example: https://wheelsmfg.com/products/botto...ack-alloy.html

You'll need to measure your shell to ensure that you get the right diameter. They come in various thicknesses so you should order what is appropriate, stacking them if necessary. If you think you will need more than 3-4 mm clearance, you'd be better off with a longer spindle.

Crossers

I have the same issue on a vintage Atala Columbus road bike i bought the other day. Would anyone not recommend using spacers to pack out on the drive side. I am also a newbie to Bike maintenance however have a lot of time on my hands now and fancy getting her working well. The teeth on the smaller chainset are rubbing against the frame. There is a gap between the bracket and crank on the non drive side, which makes me wonder if the spindle / BB was installed incorrectly? Hopefully will be able to post pictures at some point as I'm new to this page but if anyone has any advice would be great.

Cheers in advance.

yourbuttonguy

Updated:
I finally got a shimano un55 in - long story on why it took so long to get in - but that seems to be the right length now. Thanks for everyones help! I can finally ride this bike again!!!

Having said that, The new BB didn't seem to come with a dust seal and now there's a fairly large opening between the square crank spindle and where it goes into the BB. if that makes sense....? I'm sure i'm not saying that right