Flange Distance & Dish Measurements

IDK

Hi,

Shimano specify on their web site the Tiagra FH-4500 rear hub flange distance as 57.9mm and the dish as 8.4 (somethings or ratio?). It's probably obvious, but how do you calculate the centre to left and centre to right flange distance from these figures?

Cheers, IDK.

nick348

I assuming your thinking of having a wheel built up with this hub. I don' t think you should get too hung up on Shimanos figures. If you're looking to build up a wheel then the amount of dish will also be affected by your choice of rim etc.

During the build the dish would be checked by a dishing tool to ensure that the wheel will be correctly positioned in the frame.

IDK

Hi Nick,

Yes, I'm trying to calculate my spoke lengths for a given rim and hub. For the Tiagra FH-4400 Shimano specify the centre-left and centre-right flange distance, For the FH-4500 for some reason they specify a single flange distance and a dish figure. As you say, the amount of dish varies with rim, but to the precision of the data perhaps a single ball-park figure for dish is good enough for a "generalised" 700c rim? I don't know because I don't understand Shimano's FH-4500 data in the context of a rear hub (ie different L/R flange distances) and whether it can be related back to centre-left and centre-right flange measurements. Perhaps just using the FH-4400 data would be good enough for spoke length calculations.

If anyone has a FH-4500 they can measure that would be great!

Cheers, IDK

IDK

Okay, I'll answer my own questions.

Using my incredible powers of mathematical manipulation:

Centre-to-Right Flange = (flange distance / 2) - dish
Centre-to-Left Flange = (flange distance / 2) + dish

For the Tiagra FH-4500 this gives 20.55mm and 37.35mm respectively (which compares with 21.3mm and 38.7mm for the FH-4400 - so seems to make sense).

Cheers, IDK

nick348

I have had a look at the Sapim and DT Swiss sites and they dont mention your hubs, so I'm no further forward on that one.

Do you intend to buy the hubs and build the wheel yourself? If that is the case you will be able to measure the various dimensions from the hub to calculate the spoke lengths, sorry if I,m stating the obvious there.

Monty Dog

How do your numbers compare to the old Shimano 105 hubs? I think you'll find hub shells are identical - it's just the finish is different.