If you found this video useful, head to the website/amazon links to purchase some sweet Garage 31 products. Available in Canada and USA! Thanks! WEBSITE bikegarage31.ca/ AMAZON Canada www.amazon.ca/shops/garage31 AMAZON USA www.amazon.com/shops/garage31
I'm competent at brake bleeding, but your tips with the allen key, pad pre-load, and screwdriver lever technique for accurate pad-rotor alignment have elevated my servicing skills. Thank you.
I have been searching for this video for an hour in my yt history. It's the only brakes alignment instruction that shows you how to align the pistons with the caliper. So helpful! Thank you!
This is the best video, period. I've literally watched 20+ instruction videos, but yours is the most concise and complete there is. Thanks, my brakes don't suck anymore.
I was about to bin a rear Guide RE as the pistons on one side where so sticky I couldn’t align the calliper without it rubbing on the disk. The 4mm Allen key trick is absolutely genius and allowed me to push pistons out and get them moving with dot fluid. The brake now sits central in the rotor with zero rub. Fantastic.
The only right method video I could find on UA-cam and watching all the supposed pros shown were not helpful at all to align this system properly! Hats off to you 👍
took my bike to a shop to get my new brakes and rotors installed and when I got it back I realized the brakes were rubbing against the rotor and this video helped me align the rotor with the brake pads correctly, thank! Just wish they did that at the bike shop lol
after watching the sram videos and being a bit apprehensive, I went through both your videos (this and the bleeding) and it was so simple and my brakes feel really good. I'm ready to hit the trails in Santa Cruz tomorrow. Thank you!!!
This solved my problem, thank you so much!! I changed pads and one rotor and had so much rubbing on my first ride. When I took the pads back out, I realized that the inboard piston on both front and rear were very dry and kinda stuck, now working great!!
Well, I did both front and rear brakes today. I must say in all honesty, best feeling Sram Brakes I've ever felt. Comparable to my buddies Shimano brakes, you can really "feel" the brakes now. Thank You!
I just wanted to say thank you for posting this vid, it allowed me to completely remedy problems I’ve been having ever since migrating to a hydraulic braking system on my road bike. The SRAM Red AXS is performing off the charts now and I’ve learned something really valuable! All the best from a welshman 🤘🏻
This video is GREAT! I've never tried aligning based on sight only (I've always used the traditional method of having pads in place and pumping levers). Followed this and discovered my caliper was 3 mm off the middle which probably contributed to noise and vibrations. Thanks for making this video!
Thank you so much. My back brake (code r) was almost pulling to the bar. I tried bleeding it 3 times with different tutorials including yours. None seemed to make a difference. However once I bled according to your instructions, then immediately did this piston service (without removing the plunger from the lever). This made all the difference. Brakes no longer pull to the bar, while it doesn’t feel as good as the front you can’t have it all! Thanks.
I never used to service my brakes except for changing the brake pads (without opening the bleeding port). However, I had some issues with my Sram Maven brakes and got tired of going to the shop, especially since I have two pairs on two bikes. The information in this video helped me a lot! In addition, after almost 20 years of riding, I finally decided to learn how to bleed brakes so I could finally take care of my brakes myself.
I have spent literally hundreds of dollars on brake pads thinking I just need to find the right compound in order to get the maximum performance from my Code Rs. What a waste of money. The improvement gained by lubing the pistons and aligning caliper and pads to the rotor is incredible! My experience to date was SRAM brakes sucked, and this video changed that. Thank you thank you thank you!
Excellent video. I've been wanting to learn how to swap out my Sram brake pads but could never figure out how to push back the pistons until I watched your video. Most of my issue was not having the correct instruction and parts (i.e. DOT brake fluid, brake cleaner, etc.). Thank you for posting this. Super helpful. Keep up the good work. You're the man!
I've never been good with my hands so I usually take brake stuff to my LBS. After only a few months, my brakes began to suck. I thought I'd give this a try. Thanks so much for uploading this tutorial. My brakes are so much better and I managed to do it myself! Cheers!!
I know I'm late to the game finding this video, but man o' man thank you so much for creating this gem! It's saved to my favorites for bike maintenance and made me excited again for my SRAM CODE R brakes.
I was about to give up and buy a replacement set of disc brakes when struggling to tackle this issue. So much appreciated, this video was of great help to me.
Just did this to my Guide Ts that have always felt spongy and underpowered, now they feel like real brakes. The lever throw is now just a few milliliters long, and as soon as the pads bite the lever feels rock solid. Amazing video!
You sir are a legend! After bleeding my brakes i could not get rid of brake rub. No other bleed video showed these so simple techniques! I was ready to just buy a new set but thanks to you my brakes are silent but grab hold the second I need them to!
Thanks for this mate , just bought myself a Santa Cruz Bronson and was having nightmares with 2 pistons on one side of the calipers pertruding more than the other side. Had bought two sets of brake seals which I installed but didn't cure the issue. Did your trick with the screw driver and I now have brakes that feel like they are factory fresh ❤
Great video, not a lot of people know how to do this right. Secondly, my biggest upgrade was switching to MTX Red racing pads. They are super grippy and they never ever squeal. I have seen instances where people want to upgrade the rotors and calipers but instead tested these brake pads first And that was all that was needed.
You just saved my Saturday - thanks, man. I had lubricated the pistons, but they weren't running great, and I was going nuts trying to get things to center by pulling the lever, then finding that one side was way further out and I just kept dragging... screwdriver trick saved the day.
Just saved me $60. Thanks for the tip on moving the pistons out and into position after you get them back in. And centering the disc in the caliber first.
Thank you for this video. I just replaced my centerline rotors and metallic pads for HS2 rotors and MTX gold pads for more power. I could not get the pads to not rub until I saw this video. I can’t even list all the other things I tried first!
WOW! I have been less than satisfied with the Code RS brakes that came on my new specialized Stumpjemper Evo Comp. For "enduro and downhill brakes they were very underwheling and honestly the shimano mt200s on my other bike seemd far more powerful. I started with a full bleed and that helped a tiny bit, but i was still very unsatisfied. I then combined this video with a video about re-bedding your pads (light sanding of the pads and rotors followed with a bed in procedure) with this video and NOW they are stopping like Iwould expect. ZERO problem locking up the rear on a fast downhill on pavement. THANKS!!!!
My brakes are now working perfectly, thank you. The 4mm hex key trick is genius. Just a word of warning about using pliers to push the pistons - be careful if there are serrations as the piston material is quite easily chipped.
Hey Tom, glad to hear your brakes are working better. For sure the pliers can be risky, you can use a plastic tire lever for the same effect. The Snap On pliers i use are pretty forgiving. Luckily rebuild kits for these calipers are cheap and easy to install if the worst happens.
@@TheFullKanani That Park tool, made of metal, is intended to push the pistons back *with the brake pads in place*. i.e. the tool doesn't touch the pistons themselves. [If I'm thinking of the same tool.]
Nice tips here! Got a new bike on the way that comes with Sram G2 R and I'll be sure to use this as a guide to get them all setup. it will be interesting to see how they are brand new.
Very good explanation. Consider buying an inexpensive collapsible tripod. It's really helped me with my videos, in showing the things I couldn't before. If you're using your phone, I also found a cheap spring loaded phone holder with the standard camera thread in it at TJ Maxx. Keep putting out good content like this. I hope to try this process soon.
One thing I'd do differently: I am much more careful and gentle when pushing the pistons back in. I usually use a worn out pad to push against the piston, and I would never directly force the pistons with any sort of pliers. They can go off-center and really get damaged.
Brilliant idea 🥇 with 4mm to hold all pistons - Well done. One step up would be to keep 4mm (use robber band) inside caliper to hold on all pistons and slide/ squeeze flat screwdriver between 4mm and piston to push one piston back and/or reanimate one if stock. That way you protect the caliper body from damaging by plyers and popping pistons out. Its nice to see when brain is used. Great job men.
Thanks! I really don’t care about superficial issues especially when I’m going to crash into a tree or a rock on the next ride ha! But good idea to save the paint if your worried about it. Thanks Len
One of the best SRAM brake videos. If you could maybe get one of those tripods that can grip and hang over the parts that you're working on so we can see more of the action wills be GREAT! I'm a subscriber!
So, the part that really improves the brakes is centering them; all the rest is just to make it easier. Because "lubricating" the pistons seems not so important in the long term, as they are self-lubricated, the part of the piston outside the chamber eventually will dry after the first wash. Actually my front brakes are centered and though they do brake better than non-centerd rear, still, locking the front wheel is almost impossible on mine Guide R comparing to Shimano XT 2-piston where it is super easy. Maybe its good for safety, but not for situation when you need to "stop now" even with possibly losing balance.
DUDE! thank you so much! You really simplified the process. You just gave this chic a lil confidence boost (as well as the boost from no more brake drag!). 😉😎
Could you make a more in-depth video just on the flat screw driver part where you push in one piston against the disc? This seems to be a crucial part and it doesn't get much time in this video. Many, many thanks though for this great tutorial!!!
This was the perfect instructional video. Wish they were all this clear and CONCISE! Just did this to my rear brake and it was surprisingly easy! Thanks!!!
A couple comments from my own experiences: 1) be careful when inserting the screwdriver, don't lever against the tab for the retention screw or it can break, 2) pre-clean your caliper and pistons with IPA or degreaser before going in with the brake fluid. Great tips, thank you!
Very informative video Len. Keep up the great work. Thanks for the allen key tip. Very useful. Always fearful of accidentally pushing out the seals too far
Gotta tell you bro, every once in a while I start shopping for XT or Maguras. Then I watch this video, go do the shit you say to do, then go ride and they are pimp again. Thanks!
Oiling the pistons has made a TON of difference!! But… I can’t mimic the flathead screwdriver trick like you did. With the rotor between the pads, how do you get the pad and pistons on the opposite side of your pushing to retract??
Insert the screw driver behind the brake pad that needs to come out more and then push everything, the two pads and the rotor, against the side that needs to be pushed in. This technique will push the piston(s) on one side into the caliper to provide the needed gap between the contacting pad and the rotor. You'll also have to pump the brakes to bring out the piston after you push everything to one side. Repeat the process, on either side, as needed to provide equal gaps on both sides. Trial and error and eventually experience will get it right.
If you found this video useful, head to the website/amazon links to purchase some sweet Garage 31 products. Available in Canada and USA! Thanks!
WEBSITE bikegarage31.ca/
AMAZON Canada www.amazon.ca/shops/garage31
AMAZON USA www.amazon.com/shops/garage31
I'm competent at brake bleeding, but your tips with the allen key, pad pre-load, and screwdriver lever technique for accurate pad-rotor alignment have elevated my servicing skills. Thank you.
Nice one Dave!
Truth in advertising - this truly made my SRAM brakes not suck. Well presented, concise, and super helpful. Thank you!
I’ve always found SRAM brakes a pain to bleed and get good lever feel. I just did this to my front brake after a bleed and it’s incredible! Cheers!
You are the best, this video is way underrated, the level of information contained here is off the charts... Thank you!
I have been searching for this video for an hour in my yt history.
It's the only brakes alignment instruction that shows you how to align the pistons with the caliper. So helpful! Thank you!
Screwdriver technique pushing the pads to align the pistons worked a treat, cheers mate!
This is the best video, period. I've literally watched 20+ instruction videos, but yours is the most concise and complete there is. Thanks, my brakes don't suck anymore.
I was about to bin a rear Guide RE as the pistons on one side where so sticky I couldn’t align the calliper without it rubbing on the disk. The 4mm Allen key trick is absolutely genius and allowed me to push pistons out and get them moving with dot fluid. The brake now sits central in the rotor with zero rub. Fantastic.
Awesome Tony!
The only right method video I could find on UA-cam and watching all the supposed pros shown were not helpful at all to align this system properly!
Hats off to you 👍
This is one of the best, if not the best, bike repair tutorials on You Tube. Thank you 🙏
took my bike to a shop to get my new brakes and rotors installed and when I got it back I realized the brakes were rubbing against the rotor and this video helped me align the rotor with the brake pads correctly, thank! Just wish they did that at the bike shop lol
after watching the sram videos and being a bit apprehensive, I went through both your videos (this and the bleeding) and it was so simple and my brakes feel really good. I'm ready to hit the trails in Santa Cruz tomorrow. Thank you!!!
This solved my problem, thank you so much!! I changed pads and one rotor and had so much rubbing on my first ride. When I took the pads back out, I realized that the inboard piston on both front and rear were very dry and kinda stuck, now working great!!
Just followed the video with great results. Rear brake is perfect now.
This took my RSC’s from great to phenomenal. Thanks so much!
Your 4mm hex key tip is brilliant!
Well, I did both front and rear brakes today. I must say in all honesty, best feeling Sram Brakes I've ever felt. Comparable to my buddies Shimano brakes, you can really "feel" the brakes now. Thank You!
I just wanted to say thank you for posting this vid, it allowed me to completely remedy problems I’ve been having ever since migrating to a hydraulic braking system on my road bike. The SRAM Red AXS is performing off the charts now and I’ve learned something really valuable!
All the best from a welshman 🤘🏻
Nice one Len 👌🏻
This video is GREAT! I've never tried aligning based on sight only (I've always used the traditional method of having pads in place and pumping levers). Followed this and discovered my caliper was 3 mm off the middle which probably contributed to noise and vibrations. Thanks for making this video!
Thank you so much. My back brake (code r) was almost pulling to the bar. I tried bleeding it 3 times with different tutorials including yours. None seemed to make a difference. However once I bled according to your instructions, then immediately did this piston service (without removing the plunger from the lever). This made all the difference. Brakes no longer pull to the bar, while it doesn’t feel as good as the front you can’t have it all! Thanks.
I never used to service my brakes except for changing the brake pads (without opening the bleeding port). However, I had some issues with my Sram Maven brakes and got tired of going to the shop, especially since I have two pairs on two bikes. The information in this video helped me a lot! In addition, after almost 20 years of riding, I finally decided to learn how to bleed brakes so I could finally take care of my brakes myself.
The pads meeting the rotor unevenly was driving me mad thank you so much for that tip
I have spent literally hundreds of dollars on brake pads thinking I just need to find the right compound in order to get the maximum performance from my Code Rs. What a waste of money. The improvement gained by lubing the pistons and aligning caliper and pads to the rotor is incredible! My experience to date was SRAM brakes sucked, and this video changed that. Thank you thank you thank you!
Excellent video. I've been wanting to learn how to swap out my Sram brake pads but could never figure out how to push back the pistons until I watched your video. Most of my issue was not having the correct instruction and parts (i.e. DOT brake fluid, brake cleaner, etc.). Thank you for posting this. Super helpful. Keep up the good work. You're the man!
I've never been good with my hands so I usually take brake stuff to my LBS. After only a few months, my brakes began to suck. I thought I'd give this a try. Thanks so much for uploading this tutorial. My brakes are so much better and I managed to do it myself! Cheers!!
I know I'm late to the game finding this video, but man o' man thank you so much for creating this gem! It's saved to my favorites for bike maintenance and made me excited again for my SRAM CODE R brakes.
Thank you for being the one video on here that showed how to center those.
I was about to give up and buy a replacement set of disc brakes when struggling to tackle this issue. So much appreciated, this video was of great help to me.
I was always disappointed with my code R's. I ran through your tutorial, they now work awesome. thanks heaps!
I'm impressed with how well you managed to set them up, thank you.
Thank you from the UK, really helpful. Rubbing discs was putting me off cycling. Rim brakes are just so much easier to sort.
Just did this to my Guide Ts that have always felt spongy and underpowered, now they feel like real brakes. The lever throw is now just a few milliliters long, and as soon as the pads bite the lever feels rock solid.
Amazing video!
You sir are a legend! After bleeding my brakes i could not get rid of brake rub. No other bleed video showed these so simple techniques! I was ready to just buy a new set but thanks to you my brakes are silent but grab hold the second I need them to!
Wow, this was finally what removed all the free play in my levers of my G2 RS brakes! Thanks so much!
Solid tip with the 4mm Allen key!
This works amazing.... Thanks!
Rather than a q-tip, i used a small paint brush to clean the pistons. Got in there much better than a q-tip.
Many say to just change them out. It's an option, but I want to save my coin where I can. This flat-out worked for me.
Thanks for this video. I just did this on my brakes and they have never felt better!
best brake pad install video for sram Ive found. Thank you!
Thanks for this mate , just bought myself a Santa Cruz Bronson and was having nightmares with 2 pistons on one side of the calipers pertruding more than the other side. Had bought two sets of brake seals which I installed but didn't cure the issue.
Did your trick with the screw driver and I now have brakes that feel like they are factory fresh ❤
Great video, not a lot of people know how to do this right. Secondly, my biggest upgrade was switching to MTX Red racing pads. They are super grippy and they never ever squeal. I have seen instances where people want to upgrade the rotors and calipers but instead tested these brake pads first And that was all that was needed.
Bro unreal stuff, I did my rear one and now feels incredible!! Thank you soo much 🙏🏻🙏🏻🙏🏻
Glad to hear!!
You just saved my Saturday - thanks, man. I had lubricated the pistons, but they weren't running great, and I was going nuts trying to get things to center by pulling the lever, then finding that one side was way further out and I just kept dragging... screwdriver trick saved the day.
Just saved me $60. Thanks for the tip on moving the pistons out and into position after you get them back in. And centering the disc in the caliber first.
Thank you for this video. I just replaced my centerline rotors and metallic pads for HS2 rotors and MTX gold pads for more power. I could not get the pads to not rub until I saw this video. I can’t even list all the other things I tried first!
Superb! Many Thanks had trouble resetting my Guide R piston, wasted a lot of time then saw a your video and problem solved!
WOW! I have been less than satisfied with the Code RS brakes that came on my new specialized Stumpjemper Evo Comp. For "enduro and downhill brakes they were very underwheling and honestly the shimano mt200s on my other bike seemd far more powerful. I started with a full bleed and that helped a tiny bit, but i was still very unsatisfied. I then combined this video with a video about re-bedding your pads (light sanding of the pads and rotors followed with a bed in procedure) with this video and NOW they are stopping like Iwould expect. ZERO problem locking up the rear on a fast downhill on pavement. THANKS!!!!
Never thought SRAM brakes could feel this good 🤩 Thanks a lot for making this video 👏
it's unbelievable how much this helped my brakes, epic video :)
years of peace just added to my life , thanks
Thanks brakes work so much better now , haven't seen this tip on any other channel .
Great tutorial. I’m new to SRAM, as I have always had shimano. Your video took the frustration right out of fixing my pistons and alignment. CHEERS!!!
This was the best tutorial! Was thinking I need to scrap the rear guide rsc and this worked! Thank you!!
SRAM should have this on their channel. Great work!
Best sram brake video EVER! Thank you!!!!!!
You are great, man! Simple and clear...best way to teach anything! Really really appreciate the knowledge!
Thanks for your kind comment!
Dude, thank you so much for this! I owe you big time!!
My brakes are now working perfectly, thank you. The 4mm hex key trick is genius. Just a word of warning about using pliers to push the pistons - be careful if there are serrations as the piston material is quite easily chipped.
Hey Tom, glad to hear your brakes are working better. For sure the pliers can be risky, you can use a plastic tire lever for the same effect. The Snap On pliers i use are pretty forgiving. Luckily rebuild kits for these calipers are cheap and easy to install if the worst happens.
There’s also a specific Park Tool tool to push back the pistons. About $20 bucks on Amazon.
@@TheFullKanani That Park tool, made of metal, is intended to push the pistons back *with the brake pads in place*. i.e. the tool doesn't touch the pistons themselves. [If I'm thinking of the same tool.]
@@phorest yes that makes sense!
I’m so glad I found this video, was honestly about to buy new brakes altogether but you helped me sort out my code rs 😊 can’t thank you enough
very useful that allen key trick.
Nice tips here! Got a new bike on the way that comes with Sram G2 R and I'll be sure to use this as a guide to get them all setup. it will be interesting to see how they are brand new.
Thanks for this video. I've found my next service project.
Great advice. I had a lot of lever play and did this, then strapped my lever to the bar overnight and it advanced my pads to the best position.
Very good explanation. Consider buying an inexpensive collapsible tripod. It's really helped me with my videos, in showing the things I couldn't before. If you're using your phone, I also found a cheap spring loaded phone holder with the standard camera thread in it at TJ Maxx. Keep putting out good content like this. I hope to try this process soon.
huge help, brought my g2 rsc back to life!
Dude you are the GOAT. Wow, my code rsc are rock solid now.
This is a very good vid! The 4mm allen key trip is money! Thanks!
Thank you for the pro tips on Code R's!
After following your advice, my brakes are finally quiet!
Thanks!
One thing I'd do differently: I am much more careful and gentle when pushing the pistons back in. I usually use a worn out pad to push against the piston, and I would never directly force the pistons with any sort of pliers. They can go off-center and really get damaged.
Wow. This really works. Thank you very much. I will be purchasing some of your products.
This is a awesome video just bought new codes and this made one hell of a difference
I just adjusted my Sram brakes with a lot of effort. Too bad I didn't see this video before, finally not the usual advice!
Awesome sauce. Best brake set up tip ever. Thank you
Awesome job. Definitely going to do this.
This is a great video. I have a new bike coming and I might do the caliper / piston alignment he shows before the first ride.
Brilliant idea 🥇 with 4mm to hold all pistons - Well done. One step up would be to keep 4mm (use robber band) inside caliper to hold on all pistons and slide/ squeeze flat screwdriver between 4mm and piston to push one piston back and/or reanimate one if stock. That way you protect the caliper body from damaging by plyers and popping pistons out.
Its nice to see when brain is used. Great job men.
Thanks! I really don’t care about superficial issues especially when I’m going to crash into a tree or a rock on the next ride ha! But good idea to save the paint if your worried about it. Thanks Len
Next level, I'm off to the garage to do this right now
Awesome! It makes such a difference
Thank you, my red brake pads are sticking on one side, I’m going to try your methods tomorrow
One of the best SRAM brake videos. If you could maybe get one of those tripods that can grip and hang over the parts that you're working on so we can see more of the action wills be GREAT! I'm a subscriber!
Thanks Paul! I had a tripod but it broke, trying to find a better alternative than just using my phone.
Holy cow dude! Great tips! I don’t subscribe to much, but you’re an exception!
THANK YOU!!!! This is exactly what I was looking for, this is very very helpful!!
So, the part that really improves the brakes is centering them; all the rest is just to make it easier. Because "lubricating" the pistons seems not so important in the long term, as they are self-lubricated, the part of the piston outside the chamber eventually will dry after the first wash.
Actually my front brakes are centered and though they do brake better than non-centerd rear, still, locking the front wheel is almost impossible on mine Guide R comparing to Shimano XT 2-piston where it is super easy. Maybe its good for safety, but not for situation when you need to "stop now" even with possibly losing balance.
DUDE! thank you so much! You really simplified the process. You just gave this chic a lil confidence boost (as well as the boost from no more brake drag!). 😉😎
Used the allen key trick, my piston jumped right off the caliper, there are few thing I hate more than SRAM brakes
You just made my day, I was so stuck!! Haha thanks for that awesome video
Could you make a more in-depth video just on the flat screw driver part where you push in one piston against the disc? This seems to be a crucial part and it doesn't get much time in this video. Many, many thanks though for this great tutorial!!!
Sram manual states to not lube pistons. This will keep proper grip with the seal and keeps retracting properly.
Excellent video. Sram Tech should watch
This was the perfect instructional video. Wish they were all this clear and CONCISE! Just did this to my rear brake and it was surprisingly easy! Thanks!!!
Great video! Can't wait to do this service. Do I have to do it at the same time as a bleed or can I just do the caliper service on its own? Cheers!
Preloading the pad spring is something iv never thought of doing….
It makes a big difference especially on the code's, Thanks Len
A couple comments from my own experiences: 1) be careful when inserting the screwdriver, don't lever against the tab for the retention screw or it can break, 2) pre-clean your caliper and pistons with IPA or degreaser before going in with the brake fluid. Great tips, thank you!
Very informative video Len. Keep up the great work. Thanks for the allen key tip. Very useful. Always fearful of accidentally pushing out the seals too far
Awesome Video. Helped me out a lot. Thank you
Super helpful little video. Thx for this🤘
Gotta tell you bro, every once in a while I start shopping for XT or Maguras. Then I watch this video, go do the shit you say to do, then go ride and they are pimp again. Thanks!
Awesome video! I have wondered for years how to do this the best. Your technique looks really promising.
Oiling the pistons has made a TON of difference!! But… I can’t mimic the flathead screwdriver trick like you did. With the rotor between the pads, how do you get the pad and pistons on the opposite side of your pushing to retract??
Insert the screw driver behind the brake pad that needs to come out more and then push everything, the two pads and the rotor, against the side that needs to be pushed in. This technique will push the piston(s) on one side into the caliper to provide the needed gap between the contacting pad and the rotor. You'll also have to pump the brakes to bring out the piston after you push everything to one side. Repeat the process, on either side, as needed to provide equal gaps on both sides. Trial and error and eventually experience will get it right.