105 5800 chainrings 36 to 34T

Overview Chat Bike Members News Women

This topic has 9 replies, 6 voices, and was last updated 5 years ago by joemmo.

Viewing 10 posts - 1 through 10 (of 10 total)

105 5800 chainrings 36 to 34T
Saccades
Free Member

Got rid of a compact SRAM rival11 chainset and replaced it with a semi compact 105 5800 chainset as I hated GXP BB lifespan (or lack of).

I’m about to do a hilly sportive kind of similar to the Fred Whitton and as I’m ~16 stone I am worried about the climbs, especially towards the end.

Can I just change the 36t granny for a 34t? It’s the same BCD (110) and will give me a quick and cheap option for just this event?

I can’t change the cassette without changing the derailuer.

Posted 5 years ago

cynic-al
Free Member

Yes but it won’t make much difference.

Posted 5 years ago

mikewsmith
Free Member

http://www.hopetech.com/products/drivetrain/bottom-bracket/

one of these fit? Save the crankset fix the BB

Posted 5 years ago

FGF 701 The Hydrate Or Die Edition

Saccades
Free Member

That link just defaults to the hope home page, but as it’s hope I am guessing it’s more than the thirteen quid from Merlin for a new ring?

About 6 % difference which is about 2/3 of a gear.

Posted 5 years ago

mikewsmith
Free Member

ah didn’t see you had already bought the cahinset

Posted 5 years ago

Saccades
Free Member

No worries, thanks for the idea for future reference.

Posted 5 years ago

n0b0dy0ftheg0at
Free Member

http://sheldonbrown.com/gear-calc.html say the gear inches for a 28T sprocket will change from 34.7 to 32.8, not even the equivalent of half a gear compared to having a 32T sprocket (where difference would be 30.4 to 28.7) with a 700x32mm tyre.

Posted 5 years ago

ghostlymachine
Free Member

Front mech might not like the extra drop, even 50/34 struggles with some set ups. Depending on the mech of course.

I can’t change the cassette without changing the derailleur.

You absolutely positive. i.e. because of what the manufacturer says, or because theirs physically no room?

Posted 5 years ago

theboatman
Free Member

https://www.sigmasports.com/item/Wolf-Tooth-Components/Road-Link-Rear-Derailleur-Hanger/DOQG?utm_source=google&utm_medium=base&utm_campaign=base&co=GBR&cu=GBP&glCountry=GB&gclid=CjwKCAjwur7YBRA_EiwASXqIHDwJ-PGhF-KLBfcWShGdKHf9CT0ycMWm_lsj6Q-vRAfnfUUdXaNYsxoC_Y8QAvD_BwE&gclsrc=aw.ds

And fit a massive cassette.

Posted 5 years ago

joemmo
Free Member

problem is if you fit a bigger cassette then you may also need a longer chain and / or a smaller front outer ring – and or a larger capacity rear mech…

Which rear mech and cassette do you have currently? You can usually get 2-4 more teeth than the recommended max sprocket size out of it so cheap cassette + a chain might be your best option.

You can also get cheaper versions of that wolf-tooth adapter on ebay for a few pounds – search for ‘derailleur hanger extender’ but check where its coming from. I ordered one and it came from china so not an instant fix.

Posted 5 years ago