Dia Compe 900 Vs 1000 & Front & Rear Differences

[Orange777]

Chaps,

I apologise in advance, I cannot find if this exact question(s) has been asked but pretty sure its one that can be closed down very fast.

1. What is the major difference between 900 and 1000? I have an 85 GT PP that has 900's on it and I am building an 84 GT PP that requires 1000's? Main reason I want to know is that I have an 86 Skyway TA and it has both a 900 (Front) and 1000 (Rear). I want to get some 86 stamped callipers, but do not know which would be the better fit.

2. I cannot see any difference (other than bolts / hardware) on a Front & Rear 900 or 1000 calliper. Am I being a moron or is there none?

Many thanks and please forgive me for asking. I can imagine it may get on some people's Bristols.

Cheers. 

[That Swan Guy]

the 900 and the 1000 are the lengths of the caliper arms. If you put them side by side you will see that the reach is longer on the 1000. Numbers in the caliper name signify the arm length.

[Orange777]

Legend - thanks Nick!

Is there one deemed better than the other or is it just a case of personal choice?

Also did you know if front = rear?

T H A N K   Y O U

[factory pilot]

I always thought that the 900 was more of rear brake?.....I could be totally wrong here though?...there are far more people with lots more knowledge than me here on rad!

[Orange777]

Not heard that before but with the comment on length wonder if its true? Not come across mixed set up, but then what I know about things could be engraved on a Weinemann adjuster

At least I am in the right placer find out!!

[Jono]

its true lol exactly the same just reach on the arm 1000, 1cm longer, front and rear difference is length of spindal, thats it

[Orange777]

Thanks Jono

I am no engineer - what would be the advantage of a longer arm?

Is sounding like its a personal preference thing!

T H A N K    Y O U

[Funkyworm]

There's no advantage to a longer arm however on some frames a mx 900 simply won't reach the wheel rim due to the placing of the brake bridge  (this is usually an issue on the rear but it can affect the front as well). 

[That Swan Guy]

Thanks Jono

I am no engineer - what would be the advantage of a longer arm?

Is sounding like its a personal preference thing!

T H A N K    Y O U

Some frames don't have long enough drop outs to take a 1000. It's a combination of:

Drop out length.
Distance from brake bridge to wheel, which is dictated to by length of groove in drop out.
Wheel type run on bike.
Gearing run. Something as simple as one tooth difference on chain ring or freewheel will dictate wheel position which in turn dictates caliper arm length.
It's horrible when you spend mega bucks on a 1000 only to find it won't fit because it's too long for your set up.

[Orange777]

Proper light bulb moment there!! Never even thought of that being the solution where 900's could not reach.

YAY!

Officially enlightened

[That Swan Guy]

Proper light bulb moment there!! Never even thought of that being the solution where 900's could not reach.

YAY!

Officially enlightened

 

[factory pilot]

that makes two newly enlightened radsters Nick

It's all coming back to me now.........

[Spen69]

Ok I've been through this a few times before.

The number on any caliper is the reach from the centre of the spindle to the average position of the brake block in the slotted braket. Just knock off the last zero a d the number is the dimension in mm.

730 =73mm
890 = 89mm
900 = 90mm
1000 = 100mm
1020 = 102mm

You get the picture by now I think 

[Orange777]

I thought I may be asking a question that had done the rounds. Apologies - but also THANK YOU!

That is really helpful and never in a million years would I have made that connection!!

 

 

[Bfellows]

Ok I've been through this a few times before.

The number on any caliper is the reach from the centre of the spindle to the average position of the brake block in the slotted braket. Just knock off the last zero a d the number is the dimension in mm.

730 =73mm
890 = 89mm
900 = 90mm
1000 = 100mm
1020 = 102mm

You get the picture by now I think 

^^^^ this alone would have saved me around £450.00.........

[Spen69]

Yeah, MRD forks only fit 890's or 900's Bert..........

[griff]

and for a rear brake on a Ripper a 1000 just about reaches 

[Bfellows]

Yeah, MRD forks only fit 890's or 900's Bert..........

Yep, £300 of the £450 quids worth of brakes I have sat on a shelf in the man cave were all destined for the MRD at some point 

Someone should do a spread sheet or something with bikes in one column and brakes that fit in another........

[kungfunky]

and for a rear brake on a Ripper a 1000 just about reaches 

That's why I'd rather use 1020s

[Spen69]

Or that pair of 1080's my brother has sat up here waiting for you to collect Ash

[kungfunky]

Or that pair of 1080's my brother has sat up here waiting for you to collect Ash

The pair he had for me 5 years ago ? 

[Spen69]

Don't exaggerate Ash.

It was only 2 or 3 years ago. ........

Or the last time you made it north of Leicestershire

[fischflo]

There's no advantage to a longer arm however on some frames a mx 900 simply won't reach the wheel rim due to the placing of the brake bridge  (this is usually an issue on the rear but it can affect the front as well). 

....like Funk said, length can be an issue on front ..........f.ex if you want to use a gyro/Potts Mod:

You will not be able to Pots mod a 901 on the front and spin the bars on a DP.  Not sure about the TRM but my guess is the same hence why people use an 880 on the front

  ->http://www.radbmx.co.uk/forum/index.php/topic,167719.0.html

[Mikku]

Yeah, MRD forks only fit 890's or 900's Bert..........

Yep, £300 of the £450 quids worth of brakes I have sat on a shelf in the man cave were all destined for the MRD at some point 

Someone should do a spread sheet or something with bikes in one column and brakes that fit in another........

Anyone know what brakes fit an '83 Laserlite (with a flat brake bridge)? I think they came with MX1000s as standard but think I've also seen them with 890s, so I'm guessing that 900s would be ok as well. Thanks in advance.

[fischflo]

Yeah, MRD forks only fit 890's or 900's Bert..........

Yep, £300 of the £450 quids worth of brakes I have sat on a shelf in the man cave were all destined for the MRD at some point 

Someone should do a spread sheet or something with bikes in one column and brakes that fit in another........

Anyone know what brakes fit an '83 Laserlite (with a flat brake bridge)? I think they came with MX1000s as standard but think I've also seen them with 890s, so I'm guessing that 900s would be ok as well. Thanks in advance.

->http://bmxmuseum.com/bikes/kuwahara/53799           1983 Kuwahara Laserlite  running "Dia Compe MX 900 with DC Tech III lever and DC cable"
...can't see the brake bridge, but should be a flat one, as it doesn't have ARX forks, which one with round brake bridge would have .....so should work. Besides, if you've already seen 890s, how could 900s not work then?