PDA

View Full Version : Rims.. I need help!



cwalksride
07-18-2014, 09:14 AM
I am new to cycling and I have really really become addicted to cycling and bikes... I LOVE IT!

I have recently bought a vintage specialized sirrus and it might be a little tall for me but I really want to keep the bike... I would hate to resell it since I just got it.

Is there any options for me to make it perfectly fit for my height... I am 4'11 and I believe the bike is 49cm I am not 100% sure but with standover I would have to tip toe.

It rides fine.... do you think switching from 700c rimes to 650c rims would make a difference?

Wahine
07-20-2014, 10:25 AM
I am new to cycling and I have really really become addicted to cycling and bikes... I LOVE IT!

I have recently bought a vintage specialized sirrus and it might be a little tall for me but I really want to keep the bike... I would hate to resell it since I just got it.

Is there any options for me to make it perfectly fit for my height... I am 4'11 and I believe the bike is 49cm I am not 100% sure but with standover I would have to tip toe.

It rides fine.... do you think switching from 700c rimes to 650c rims would make a difference?

The overall radius difference between a 700c and 650c wheel is about 2 cm. Since the height of the frame off the ground is determined by the radius of the wheel, not the diameter, you'd only gain 2 cm. That would give you more stand over for sure but it may not be possible or at least a simple thing to do because it will change the position of the braking surface of the wheel relative to the frame. I don't know how adjustable the brake set up is and if it would accommodate a 2 cm change in rim position.

Keep in mind that your bottom bracket will be dropped so you won't have as much clearance under the bike, that's not likely an issue unless you're jumping curbs or riding off road. But that also means that your pedal will be closer to the ground and that could be a factor in cornering.

In short, I doubt it would be advisable.

Wahine
07-20-2014, 04:01 PM
Told my lovely house spouse about this when he got home. He confirmed that the drop in height of the frame would likely cause problems with pedal clearance while cornering, he said you can get around the brake issue by using brake extensions, but he also said that the geometry of the bike would be altered and would negatively affect the steering.

His last statement was, "absolutely not recommended".

Sky King
07-24-2014, 06:41 AM
If the bike seems to fit other than having to stand on tip toe is you are straddling the bike I would leave it alone. Seriously, how often does one stand over their bike like that. Typically we have one foot on the pedal and have our bike at an angle when standing over them. I see the benefit on a bike you are taking off road and if you were racing and needed to come to a sudden stop and but both feet down but in over 40 years of riding I have never had a time when I have had to stand over my bike quickly. I would be way more focused on correct stem length and saddle position. Congrats on the purchase go enjoy the ride!