Tri bike fit - err big, or err small

Triathlon Forum
1

I’m slowly shopping for a new frame to replace my currently too big tri bike.

When buying a frame, if I don’t have a chance to try it, would it be better to err on the side of slightly too big, or slightly too small?

2

I’m no expert here, but in my experience, err on the side of small.

3

I would go with the smaller size. Also in picking a tri or time trial bike, the top tube length is main concern. The listed size is usually by seat tube so you need to refer to the specs.

4

Thanks.

I have been looking at top tube sizes, and there is a pretty wide range for particular sizes.

My current frame is an old Tequilo, with a 53.3cm top tube.

52 might be small enough, but I guess I’ll be safe and go with a 51.

5

I have always erred on the small side, as in one size or a half size down from your standard road bike size. It is often easier to make a slightly smaller bike fit and get power out of it than it is to make a slightly larger bike fit.

6

Check the top tube & seat tube length’s of both 51’s and 52’s compared to your QR before you settle on one. All manufaturers do not size their bikes the same so the labeled “size” is often not an apples to apples comparison!