Chainring sizes - 50t/40t/28t

[trailstar82]

Made a passing bid on some lovely Middleburn chainrings from the bay wasn't paying enough attention to the listing and later realised they are closer to Road/Tandem ratios. Question
- what is the largest gears you've run on your Retrobikes?
- how long did you run them before changing again?
- Is 50t too big for a 30lbs hardtail?

 

[konacarl]

I had 48t triple bio pace on a Kona a few years ago. It wasn’t a problem and I rode it for 5 or 6 years before selling the bike.

 

[KermitGKona88]

Some very old mountain bikes did run 50/40/30, but generally 48T is the largest, given the condition of those rings and the fact they are original Middleburn (not BETD). I would try with some other rings first

 

[hamster]

If you run a cassette with something like 13-34 it will be fine. 50:11 will be overgeared!

 

[trailstar82]

My other concern is the shifting capacity from the xt m737 front mech it’s top swing bottom pull.

 

[KermitGKona88]

Will probably be okay.

 

[hamster]

I think you'll be OK with a stock (high band) M737, I've run one with 24/38/48. Your chainring size difference is less. The most likely problem will be if you have a very slack seat tube angle.

 

[ishaw]

I ran a 52 for a while on a commuter MTB. Was fine, just didn't use the smaller rear cogs much.