Wide dropout ?
- Thread starter ebike11
- Start date
MadRhino
100 GW
There are some hardtail MTBs that are made wide, usually through axle, they are designed for slopestyle or freestyle acrobatics. I have a Chameleon that is 148mm rr axle, and I have seen a Doberman that was 150mm. They are expansive, and not so easy to find on the used market. If you want wide and cheap, the fat bike market might be your only field of research. Alternatively, just spread the dropout width of a standard 135mm.
dogman dan
1 PW
You can spread a steel frame plenty.
Alu frame best not to spread much more than 5 mm more. More than 5 mm steel or alu, the dropout plates will start to not be parallel anymore. It will bolt up in a V shape, and the result will be the axle nuts don't stay tight anymore.
Steel frame, bend out the stays, then bend the dropouts back in, to parallel again.
Alu frame best not to spread much more than 5 mm more. More than 5 mm steel or alu, the dropout plates will start to not be parallel anymore. It will bolt up in a V shape, and the result will be the axle nuts don't stay tight anymore.
Steel frame, bend out the stays, then bend the dropouts back in, to parallel again.
MadRhino
100 GW
Alu grade and thickness is very different on various bike frames. Some of them you can cold shape, some of them you can heat and shape, some of them you can't do much with but welding. Heat treatment is complicated, making it difficult to restore alu grade properties after it's been re-worked. Best is to add custom dropout plates, bolted on existing material ideally, that will extend length and width at will to best fit your motor, wheel, brake, tire, to your bike frame. This requires to replicate existing brake and derailer mounts to the custom plates, and let you add other mounts that you may need (mud guard, rack, kick stand, trailer...). That is the way to make a perfect fit.
MadRhino said:
Thanks for your info
But if the motor is too wide to fit the narrow dropout width, then how can custom plates make the width wider?
Also
Is it ok to file off some of the area around the axle to make it narrower to fit properly? I think i seen someone on endless do that to their motor
Thanks
MadRhino
100 GW
Yep. The axle shoulder can be filed. It is common to cut the dropout width of a QS 205 to 146mm.
Custom dropout plates are not only making a wider seat for the axle, they are stretching the chain stay. Once the freewheel is behind the original dropout plates of the frame, the motor itself will fit in 135mm. Also, backing the motor a few inches, sometimes combined with a smaller diameter wheel, does make it possible to fit a 3 inch tire on frames that are not clearing it normally. Adding length to the wheelbase is also making the bike more stable, in acceleration especially.
Custom dropout plates are not only making a wider seat for the axle, they are stretching the chain stay. Once the freewheel is behind the original dropout plates of the frame, the motor itself will fit in 135mm. Also, backing the motor a few inches, sometimes combined with a smaller diameter wheel, does make it possible to fit a 3 inch tire on frames that are not clearing it normally. Adding length to the wheelbase is also making the bike more stable, in acceleration especially.
MadRhino
100 GW
There are no standards other than IS or POST brake mounts, and derailer hanger. You have to make them custom for your frame and motor. It does look much harder than it is really. Once you started making them, half the challenge is done and the rest is only patience. Some do them in 3 hours, other spend the week, but all of them are riding after all...
MadRhino
100 GW
Axles are steel. 2 minutes to cut with with a hacksaw, then maybe another 5 minutes filing them perfect. I never cut them shorter than 146mm, to avoid brake fitting problems. I use POST mount brakes, making it easier to tune the caliper spacing and alignment.
dogman dan
1 PW
Back to my last comment. You can flex out an alloy frame about 5 mm. from 135mm to 140 mm. At the very most, 3 mm each side. After that, your dropout plates start pointing out, and your nuts and washers will not be flat on the plate anymore. This will make your nuts loosen fast.
A custom plate is a good way to make a frame wider, but only if there is a lot of meat on the frame to bolt it to. The basic idea is that the plates go on the outside of the dropout, making the whole dropout as wide as the outside of your frame, vs the normal inside the frame width.
This works best on bikes that already have removable bolt on dropout plates.
If you run a single speed gear on the bike though, you will have some room on the gear side. Very easy to cut a new shoulder on an axle, with a simple hacksaw. Then you might be slim enough to fit inside that 5 mm more.
A custom plate is a good way to make a frame wider, but only if there is a lot of meat on the frame to bolt it to. The basic idea is that the plates go on the outside of the dropout, making the whole dropout as wide as the outside of your frame, vs the normal inside the frame width.
This works best on bikes that already have removable bolt on dropout plates.
If you run a single speed gear on the bike though, you will have some room on the gear side. Very easy to cut a new shoulder on an axle, with a simple hacksaw. Then you might be slim enough to fit inside that 5 mm more.
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