50 to 52 tooth make any difference?

[psycle]

Hello,
I am new to this forum, and would appreciate some advice!
If I changed my triple chainset (which has 50 teeth on the outer chainring) to a chainset which had 52 teeth, would I need a slightly longer chain?

And would these 2 extra teeth make much difference?

Basically, I have 9 speed 105 with a sugino triple chainset, and want to put a ultegra triple on instead.

What do you think?

Many thanks,

Psycle

 

[adscrim]

It wouldn't make too much difference. It would be a bit like changing (for the purposes of when in the big ring) from a 12-25 cassette to a 11-23. You would not need a longer chain.

 

[swee'pea99]

+1. And certainly no new chain. The only hesitation I'd contribute is it depends what else you're changing. Back in the day, I changed from a 52/42 to a 53/39, and tho' there was no great difference between the 52 & the 53, the difference in the gap between the 52/42 and the 53/39 did make a noticeable difference.

 

[psycle]

Thanks for your help on this. Was going to put a 10 speed ultegra triple chainset with a 9 speed 105 front mech/9 speed 105 rear mech and 9 speed cassette..

 

[marinyork]

If you want a few figures to play around with try www.sheldonbrown.com/gears/

 

[e-rider]

it would make the equivalent of 2/3 (two thirds) of one tooth on the rear cassette.

 

[psycle]

As i understand it , when in the outermost chainring and outermost sprocket, you could obtain a slightly faster speed?
(Sorry, what do you mean by two thirds?)

 

[andrew_s]

If you increase the large chaining by 2 teeth, the length of the shortest usable chain increases by 1 tooth (and a smidgen). You can only change chain length in increments of 2 teeth (1 inner + 1 outer link).
Whether you need to increase the chain length will depend on how close you are to the limit at present

 

[PpPete]

I've changed t'other way. It makes a difference only on the speedo for those hills you can pedal down.
50 x 11 at 90 rpm is something like 30 mph anyway. Do you pedal downhill at that speed?

 

[hubgearfreak]

would these 2 extra teeth make much difference?

around about 4% difference, approx.

 

[psycle]

Woah. Never thought about gearing on that kind of level!

 

[RecordAceFromNew]

There is a chance of your having to move the front mech up the seat tube a bit to stop it clashing into the bigger chain ring. The 52T ring's radius is just over 4mm larger.

 

[e-rider]

As i understand it , when in the outermost chainring and outermost sprocket, you could obtain a slightly faster speed?
(Sorry, what do you mean by two thirds?)

all I'm saying is: 3 teeth increase at the front (chainring) is the same and 1 tooth decrease at the rear (cassette)

this should give you a better idea of what difference it would make.

 

[MacB]

A rear cassette normally goes down to an 11 tooth cog:-

50x11 = 119.5 gear inches - or 30.2mph at 85rpm and 42.7mph at 120rpm
52x11 = 124.3 gear inches - or 31.4mph at 85rpm and 44.4mph at 120rpm

this is using a 700x23 tyre size