There is no decreeable difference between 170 and 175. Cranks are hard to get now. I just scored a 170. What I found cost a lotsa. If you lower the gearing and fit the bike right she should be ok. I like to spin so I always used 165 when I could, but research has shown there is really no difference. I’m using 170 as a compromise as I’m not sure if I believe all the crank length talk and research and chose the middle for the bike I’m currently building. I started ordering parts this summer and so far everything is here except the rear derailleur. Some of the parts are used, wheels, longer reach stem and wider bars. It might be best to use what you have and see what is really needed and get those parts when you can find them. I couldn’t get a Shimano thread on cassette all summer and I’m told by the lbs that there is still no delivery date for them. I ruined a derailleur two summers ago and had to buy an old bike just for the derailleur. Right now I can’t get rim tape and tubes are not always available with the correct presta valve length. Parts availability is getting better but I don’t know when I’ll get my derailleur. I won’t ride this bike until May so I’m not in too much of a hurry but I have been working on getting what I want for 5 months. Tough times to build a bike.Ok cool. So those teeth bent in are deliberate? In that case, I just need a shorter crank arm. She’s a 170, and gets knee pain. it’s 175.
Thanks you
Thanks for this. We’re all good on the knee pain, she’s had a professional fit on her roadie, so all measurements are being based on that, but more relaxed up front.and dont worry about wheels, it will already be 135mm
any back wheel with a shimano freehub body designed for 8 spd will accept 7, 8, 9 or 10spd cassettes but just be aware, depending on the cassette, a small spacer can be needed for the 9 or 10 cassettes - obviously a larger one will be required if sticking with a 7psd.
Other brands are out there but Shimano are the easiest to source and replace with interchangeability throughout - you can turn old 6 or 7 speed hubs into 10spd with a twsit of a 10mm Allen key (theres a bit more to it but it is very easy)
knee pain is more likely overall seating/ riding position and can be very difficult to mitigate - my other half sits very upright with a short stem and swept back bars
9 speed is a good option to go for, its still widely available at a reasonable budget with plenty of good quality 2nd hand parts
Just remember SRAM and Shimano shifters/ derailleurs dont mix anymore but you can use SRAM cassettes and chains with Shimano shifters and cassettes
Sunrace make good cassettes but be very wary of 'cheap' chains as there seems to be a shit load of fake low quality ones. Look for chains with a recognisable brand name stamped on the links themselves - if it only says something like 'HG-72' these are fake