Bike Build 3 – Adding The Groupset

Part 3 of our bike build series deals with adding the groupset elements such as: crankset, front derailleur, rear derailleur and chain. It’s a critical element that needs to be done properly or you’ll end up with long term issues.

Our bike build is now at the stage where the groupset can be fitted and the whole thing begins to look like a bike that we can soon ride. Fitting the bottom bracket is critical and requires certain tools that bike shops such as Fulford have and also know how to use properly. An incorrectly fitted bottom bracket will cause untold issues and so it’s well worth having this aspect of your build done professionally.

Tools are not the only thing that the bike shop will know about. They’ll hopefully also use the right adhesive primer and retaining compound, stopping movement but also ensuring that you can remove things when the time comes for replacement. We used a standard Shimano PF30 bottom bracket, a widely used system with a 68mm shell width and 30mm axle. It really is critical to eliminate any slipping from here in order to avoid that common noise of poorly fitted units.

This is where using the right primer and retaining compound is key. Compound and primer in place, Rich from Fulford simply pressed the unit into the frame using the bearing cup press tool and his years of experience to know when it was securely in place. Thankfully, once the bottom bracket is secure, fitting the crank is usually simplicity itself and you can move on knowing that one of the trickiest issues is dealt with. With some cranks you may need an adapter, but we kept things simple on our build, with Shimano throughout. If however you’re cautious and worried about press fit issues, there are some excellent convereters on the market that simply screw together through the housing, made by Hope, Praxis and Wheels Manufacturing among others.

Fitting the Crankset

1. Before fitting the crankset, grease the spindle surface on the drive side crank arm and put it through the bb housing so that it protrudes out of the other side.

2. Next, apply grease or anti-seize to the threads of the left arm pinch bolts.

3. Position the drive side crank arm in the 6 o clock position and the left side crank arm in the 12 o clock position. Press the arm onto the spindle just using hand pressure and tighten , making sure that the stop plate is engaged over pinch bolt threads after the crank is installed.

4. You then need to apply some anti-seize to the threads of the crank cap before threading it into the spindle.

5. Tighten the pinch bolts on the cranks, alternating each half turn to tighten equally, making sure of the correct torque. Use the Feedback Sports Torque kit to help you out here and follow the Shimano torque settings. Check the crank arms for play and you’re all done.

Fitting the front & rear mech units

Time to move onto the front and rear mech units and once again, we’ve kept things to Shimano Ultegra components. Tools needed for this are:

1. Set of Allen keys

2. Phillips screwdriver

3. Chain Tool

4. Cable cutters and pliers

The Feedback Sports mechanic kit has these within it and they’re truly well-made tools that will last you a lifetime and worth the money. Never buy cheap tools; they’ll damage your components and cause you issues. Feedback Sports tools not only look great, but they truly are exceptionally well made and will love your bike like you do.

Our Shimano front mech uses a braze on mount, which features a small nub with an internal thread to which you put the mounting bolt. In lots of cases the mount will be fitted to the frame already and the derailleur will simply bolt on to it. However, we needed to fit a mount and in these instances you will need to make sure that you get the correct mount for your frame, as the band clamps do come in various sizes such as 34.9mm, 31.8mm and 28.6mm. With our mount fitted to the frame correctly it was a case of bolting on the derailleur.

Placing the front mech against the braze-on, fasten the bolt and hand tighten it so that you can move and adjust the derailleur as it is fitted. Set the correct height by looking at the mech from the side. You should get the outer case of the unit between 1 and 3 mm of the outer chainring, keeping it parallel with the outer chainring before tightening it all up. Don’tover tighten things though. Use the Feedback Sports Torque Kit and ensure that you read the instructns on the mech packaging for the right settings. To attach the cable, pull the cable through behind the bolt and clamp and pull it around the bolt until it is tight. Then tighten the crimp bolt, but not too much as you will need to make some adjustments as you set up the gearing. With the rear wheel fitted into the bike it’s time to fit rear mech and chain.

Before installing the new derailleur, make sure the derailleur hanger is fitted and not overtightened.  Make sure that the hanger is visibly straight, has no stress marks or nicks and that the threads are all okay. If the derailleur hanger is damaged, the new derailleur will not shift properly, so get it right at this point.

Double check that the new derailleur has a thread locker on the threads. This will keep the threads from backing out and the derailleur coming loose from all the vibrations when riding. Using a small allen key, mount the  derailleur. Make sure you don’t over tighten. Connect the cables now to both the front and rear mech, ready to fit the chain and set the gears up.

With the cables connected and initially tightened, don’t yet snip and cap them, but leave a reasonble length whilst adjusting things. Set the front mech first of all, by setting it over the smallest (inner) chainring. With the rear mech, set it to the smallest sprocket also, but don’t worry about fine tuning, as this can be done once the chain is in place.

With the chain in hand, thread the new chain through the front derailleur cage. Next pull it across and loop it over the rear cassette and round the upper jockey wheel on the derailleur. Thread it through the cage, being careful to keep inside the divider between the plates, and then around the lower wheel. The new chain will need to be cut to size and it’scrucial to get this right. With the chain around the smallest sprocket and around the small chainring, pull the ends together so they meet below the chainstay. You will need to find the longest length that still generates tension on the rear derailleur, so that it won’t drag. Remember, you’ll need to join an internal link to an external one. The trick is to grab both free ends of the chain and pull them towards each other. With the chain in your left hand, pull a small amount of tension on the derailleur arm. To gauge the correct chain sizing, find the first available link while the derailleur is slightly tensioned in its lowest gear.

Remember which link needs to be removed and take a hold of the Feedback Sports chain breaker, fit the link into the breaker and push the pin all the way out of the chain removing the excess chain length. Thankfully Shimano now produce a quick link and it’s super simple to install; remembering that Shimano recommend that the open end of the broken chain faces backwards, simply place the quick link into the chain gap, align it all up and snap it together – this is usually done by applying some pressure through the cranks. Chain in place, it’s onto the dark arts of setting the gears. You may wish to seek the help of a Bike Shop Jedi Master for this 😉

Setting derailleur limits

The limit screws control the range of movement of a derailleur. If they’re not set properly, the chain may well drop from the cassette or chainrings into the spokes, which can be dangerous.  Locate the H & L screws on the rear mech and screw the Lower ‘L’ screw fully clockwise. Push on the derailleur to manually shift up to the highest gear possible — it probably won’t take you t the biggest sprocket,but don’t worry.

Now, while still manually pressing on the mech unit, slowly and gently turn the cranks and screw out the Low (L) stop screw until the cassette shifts to the biggest cog and isn’t jumping or clicking.

Next, locate and screw out the High (H) adjuster and allow the chain to move to the smallest sprocket of the cassette by pedalling gently. Wind in the High adjuster until the chain returns to the smallest ring/highest gear and runs smoothly without jumping or clicking. Your rear high and low limits should now be set.

Next adjust the jockey-wheel clearance by locating the screw on the top-rear of the rear mech unit. With the bike in the highest gear, the upper jockey wheel should run just clear of the cassette.  If you turn the screw gently clockwise, this  will increase the gap and turning it anti-clockwise will close it. Adjust until there is approximately  2mm of clearance.

With the front gears on the smallest ring and the back gears to the largest cog. Fully wind in the front derailleurs low limit (L) adjust screw, completing this procedure with a slack gear cable, so you can be sure that cable tension isn’t overriding your low limit setting. Hence we didn’t cut it too short and cap it yet. To do this, release the cable retention bolt on the derailleur. Slowly turn the pedals and wind out the screw until the chain returns to the small ring and runs smoothly, without rubbing on the mech unit cage.

Pull the slack from the cable and re-tighten the retention bolt, not so tightly that you fray the cable. Wind in the high limit (H) stop screw. Shift the rear gears to the smallest cog. Pull on the gear cable manually, not with the shifter. You can use a tyre lever to pull on the cable, so that it doesn’t dig into your hand.

While you keep the  pressure on the cable, wind out the screw a half turn at a time until the chain jumps to the biggest ring. After this, quarter turns will allow you to adjust the derailleur so it doesn’t rub the chain. Fine tuning the gears is an art form and  we reccomend at this stage to pop along to the local bike shop and ask them to set things finally and check it over for you. It’ll cost a few shillings but it’s definitely worth it, unless of course you’re a gear guru yourself.

Next time we’ll be wrapping the bars with tape and setting up the hydraulic brakes. Then, with a little bit of fine tuning and size adjustments, it’ll be time to ride 🙂