Front Chain Ring size?

[joker3366]

I have a Centurion Ironman Expert. The front chain rings are 52 and 42 and they are the Bio-pace Hp rings and a 7 speed rear. I feel the front chain ring sizes are too close to the same. I ride a lot of rolling trails and some hills. What would a good pair (sizes)?

[GeorgeET]

Nice Bike. The gearing spacing of 10T is common. You may consider a 38T chain ring to replace the 42. You do not say what the rear sizes are. The other way to go is get a larger cassette in rear if you do a lot of climbing and want to set up for that. Like a 14-32.

If you can try bikes with different gearings that may help you find a good set up for your roads.

[joker3366]

The rear rings are 11-28. I feel they are a good range.

[Bill]

Another bit of advice is to go to a LBS to test ride a model with the close gear range of your rear cassette and different ratios in the front. Or if you are part of a riding group (friends) who may have something similar.


Good luck with your findings,
Bill

[cyclerUK]

(05-02-2010, 09:08 PM)joker3366 Wrote:  I have a Centurion Ironman Expert. The front chain rings are 52 and 42 and they are the Bio-pace Hp rings and a 7 speed rear. I feel the front chain ring sizes are too close to the same. I ride a lot of rolling trails and some hills. What would a good pair (sizes)?

The latest fad is "compact" chainsets. - 50/34. These are in favour with "sportive" riders as there is usually stiff climbs involved in sportive events.
Something like that would give you a great variation of gears.
Your Bio-pace rings can be changed for normal rings if you didn't want to buy a new chainset complete.
I do have one bike with this setup but sometimes I find it hard to get just the right ratio for some conditions.
You end up with a large chain angle such as large chainring to large rear sprocket.