Brake caliper question.

[alans27]

Guys, I actually have this question running in the post 1998 chat section but was hoping some of you in here could answer this one for me.

Question is, road caliper drop lengths. Can they vary between manufacturers? I mean can say a Tektro caliper rated at a 49mm drop turn out to be slightly longer than a shimano caliper with a 49mm drop?

See I attempted to change the calipers on my scott flat bar road bike today and install shimano 105 in place of the tektro it came with. Well on the tektro the pads are at the bottom of the caliper arms and they are aligned fine with the wheel. But on the shimano with the pads at the bottom they only just catch the tyre. I reckon another 2-3mm would have been enough to clear the tyre.

So it sounds like the Tektro calipers are a longer drop distance than the shimano. But whats's confusing me is to look at the two side by side I could swear they are the same length!! I mean ok if you look hard enough you might think the tektros are longer by about 1mm maybe, but certainly no noticable difference! So why are my 105 pads catching the tyre when the tektro ones do not? I mean I know you can get longer drop calipers than the 49mm shimano ones, but surely if you held the two side by side you would see the difference in lengths straight away? Confusing!!

 

[nammonk]

Do you mean that they have the same drop when wide open? Do the arms pivot in the same way? The amount of vertical movement of the brake blocks as the arms close depends on where the pivots are.
Nick

 

[alans27]

Actually, as we speak I think i've found the answer to my mystery. Looking on the tektro website they are rated as a 51mm drop, whilst the 105's are 49mm. So there's the little length i'm missing on the 105's! Just another couple of mm's and the 105's would have fitted but it was not to be.

 

[tonyf39]

Actually, as we speak I think i've found the answer to my mystery. Looking on the tektro website they are rated as a 51mm drop, whilst the 105's are 49mm. So there's the little length i'm missing on the 105's! Just another couple of mm's and the 105's would have fitted but it was not to be.

You can easily file out the extra 2mm, I've done it on shimano calipers and because the alloy is relatively soft isn't such a long job even with a cheap £1 packet of files from your local home bargains/pound shop

 

[alans27]

Crap never thought of that!! Lol. I've sent them back now too. Never mind I'll just use the cash towards a nice set of wheels instead. Thanks for your reply though.